THE Wheel & Tire Thread

[Xusia]

There has been a lot of discussion on wheels & tires, as well as a couple other threads. In the hopes this makes it as a sticky, I'm going to reference the other threads here:

New Tire Options (High Performance Tires) (http://thefactoryfiveforum.com/showthread.php?10069-New-Tire-Options-(High-Performance-Tires))

Budget Lightweight Wheels Thread (http://thefactoryfiveforum.com/showthread.php?9945-Budget-Lightweight-Wheels-Thread)

What I'm attempting to do is gather all the known info we have into a single thread so you don't have to glean it all from other threads like I just did for hours last night! The wheels & tires on my donor are toast, so I'm now in the market. Hence the reason wheel & tire info is now important to me.

I'm going to update this a bit later, but for now, you all might find this document interesting. I put together a list of wheel & tire combinations with various specs so I could get a better idea what route I wanted to go:

Wheel & Tire Combinations (https://docs.google.com/spreadsheet/ccc?key=0AhG99PnZiZFHdGZJVFhJVm5hanp0QkxONTAwNXQwd 3c&usp=sharing)

The blue highlighting indicates the - in my opinion - 2 best choices for 17" wheel & tire combinations on the street (The race track types will likely have a completely different plan of attack). The orange highlighting indicates the same for 18" wheels. For both, I've taken into account tire fitment, spacing/offsets (to make sure they will fit and not rub - given the best info we have at the moment), and overall circumference (to minimize speedo error).

UPDATE 2013-05-26
I've updated the document with specific wheel info, and specific tire info. I've gleaned the data from the previously referenced threads, as well as my own research (THANKS Google!). The document now has 3 tabs:

Sizes - provides estimated fitment for both specific tires onto specific wheels, and for specific wheels onto the 818. I used this site for the measurement estimates: http://www.rimsntires.com/specs.jsp
Wheels - A list of specific wheels, including available sizes (5x100 ONLY), available offsets, weights (where known), and prices. I can add links also if people care to provide them.
Tires - A list of specific tires, including available sizes, weights (none yet, but when we learn them...), and prices. Again, I can add links also if people care to provide them.



I will continue to update as I come across or see relevant information, but at this point I would appreciate any input you brilliant folks can provide!

[Xusia]

Place holder #1.

[Xusia]

Place holder #2.

[shinn497]

sticky?

[Xusia]

I've done more work on the spreadsheet and added 2 new tabs for a total of 3 tabs. See updated first post.

[Frank818]

In the hopes this makes it as a sticky,

Well it hasn't. :( Yet. I was about to start one I thought I'd call "THE Wheel and Tire thread". Then I looked carefully through the pages and bam I hit on yours. loll

Let's reference another thread: http://thefactoryfiveforum.com/showthread.php?10647-Wheel-discussion-%28From-818-Open-House-Pics-Thread%29

There are various options on the wheel sizes and tire sizes.

What are you guys going to fit?
And how do you think it will be in terms of ride comfort, ease of steering, grip, clearance front vs rear (if you have too small tires up front vs rear, maybe you'll have too much clearance tire/fender up front and it will look ugly vs rear? Or you'll have to lower the front much more so the rear end will look jacked up, like those big Muscle cars you could see the rear differential bigger than anything else loll), etc.

I do not know if 215 or 225 are better up front. 40 or 45 series? 17" or 18"?
Back in the rear, 255s for me, 18". But 35 or 40 series? I cannot make the difference, I don't know if I could feel the difference on the road.

How about you?

Now I am not talking about rim sizes yet, but 18x9.5 rear seems the choice for me.

[Canadian818]

I'm just waiting to see what the first few guys run, and base my decision on theirs. I want as wide and as tall a tire as possible. If I can squeeze in 235/265 combo then I will.

[Xusia]

I'm waiting to see what FFR offers. I have a strong preference to run 17" wheel all around (to better protect the wheels on the street), ideally 8.5" in the rear, and 7.5" up front. If I can't find the widths & offsets I want to make this work, I'll just get 8.5" all around.

My tire plan is to run 245/40 in the rear. Not IDEAL for traction, I know, but I'll have the RLTC system, so it will hook up as well as physics allow. If the front wheels are 8.5", I'll run the same as the front. If they are 7.5", I'll run 225/45.

[bnr32jason]

Being a mid-engine RWD setup (MR) you may want to reconsider running equal tire sizes front and rear. Snap oversteer is already a common problem with MR cars and running big tires on the front is only going to make this problem even more prevalent mid-corner. Even if you do run the same size wheel all around, I would still suggest different tire sizes front and rear.

[wleehendrick]

Snap oversteer is already a common problem with MR cars and running big tires on the front is only going to make this problem even more prevalent mid-corner. Even if you do run the same size wheel all around, I would still suggest different tire sizes front and rear.

I agree, and think a staggered wheel & tire set-up is ideal for handling balance as well as aesthetics.

I hope that snap oversteer (my biggest concern with the 818) has largely been mitigated by FFR with a solid and balanced chassis and suspension set-up. The quote from the Road and Track article:

"the 818's a true sweetheart, pushing the front predictably before uncorking its tail in a lazy slide"

seems to imply that they got it right, and that it won't be a tail-happy nightmare.

[Frank818]

As far as I have read everywhere, they spent a lot of time designing the chassis but also those guys at KONI spent a lot of time tweaking the suspension. My guess is they did build something not too hard to drive and possible to drive fast without requiring Sebastian Vettel's skills.

[metalmaker12]

Well it hasn't. :( Yet. I was about to start one I thought I'd call "THE Wheel and Tire thread". Then I looked carefully through the pages and bam I hit on yours. loll

Let's reference another thread: http://thefactoryfiveforum.com/showthread.php?10647-Wheel-discussion-%28From-818-Open-House-Pics-Thread%29

There are various options on the wheel sizes and tire sizes.

What are you guys going to fit?
And how do you think it will be in terms of ride comfort, ease of steering, grip, clearance front vs rear (if you have too small tires up front vs rear, maybe you'll have too much clearance tire/fender up front and it will look ugly vs rear? Or you'll have to lower the front much more so the rear end will look jacked up, like those big Muscle cars you could see the rear differential bigger than anything else loll), etc.

I do not know if 215 or 225 are better up front. 40 or 45 series? 17" or 18"?
Back in the rear, 255s for me, 18". But 35 or 40 series? I cannot make the difference, I don't know if I could feel the difference on the road.

How about you?

Now I am not talking about rim sizes yet, but 18x9.5 rear seems the choice for me.

I am running 17x7.5 Sti bbs with 235/45's all around for all most driving, but I will have a set of 17x8.5 225/40-45 front with 18x9.5-9.75 255-275 35's rear for shows and all highway smooth roads etc. I like Rays wheels and will prob get a set soon after I get her legit and on the road. I don't want to put to much on my car so I potentially get taxed more for those parts at inspection.

[Frank818]

It seems so far no one is thinking of going as small as 215s. Everybody is talking about 225, 235 and even 245s up front.
I thought of 215s to make it easier on the steering, but maybe it would be less good through corners.

Looking at the 2013 458 Italia (which I want to beat in all performance aspects lollll), front are 235/35/20 and rear 295/35/20.
So I guess 225s front on the 818 isn't that bad. 458 weighs a bit more than 1400kgs (over 3200lbs).

For me so far I have 225/45/17 (OEM) front and 255/35/18 rear. Though I wish I could fit larger tires, I love large rear tires (GTM on 305s or 335s is awesome looking). But the 818 is there for agility, quickness, precision, lightness! Large tires are all but that.

[metalmaker12]

With some modification someday I might fit some wider stuff

[Xusia]

I don't think I'm likely to be pushing it hard enough to worry about end swapping. Plus I'll have traction control.

[Silvertop]

It seems so far no one is thinking of going as small as 215s. Everybody is talking about 225, 235 and even 245s up front.
I thought of 215s to make it easier on the steering, but maybe it would be less good through corners.

Looking at the 2013 458 Italia (which I want to beat in all performance aspects lollll), front are 235/35/20 and rear 295/35/20.
So I guess 225s front on the 818 isn't that bad. 458 weighs a bit more than 1400kgs (over 3200lbs).

For me so far I have 225/45/17 (OEM) front and 255/35/18 rear. Though I wish I could fit larger tires, I love large rear tires (GTM on 305s or 335s is awesome looking). But the 818 is there for agility, quickness, precision, lightness! Large tires are all but that.

There ARE a few of us planning on using narrower tires. I'm planning on using 205/55-16's up front and 225/50-16's on the rear (on stock WRX wheels), and I know of at least one other forum member who is planning the same setup. And I expect that it will go around corners just fine -- probably well enough to handle any corner at twice the recommended speed. As has been noted elsewhere in this forum, the Lotus Elise, which is similar in design, size, and power, uses this same tire combination, at least in stock street form.

Of course, I'm not planning on putting down great bucketfuls of horsepower. I'll be running a moderately tweaked NA engine, generating maybe 200-210 flywheel horsepower. I'm also going to run a Quaife LSD to help distribute that power as evenly as possible to those (relatively) narrower tires.

[bnr32jason]

I don't think I'm likely to be pushing it hard enough to worry about end swapping. Plus I'll have traction control.

The traction control system from Race Logic will do absolutely nothing to prevent snap oversteer.

You think you won't push it hard enough, until you are out on your favorite backroad (maybe the same one in your avatar) and decide you want to push just a little harder than last time, let off the throttle a little mid-corner because you went in to hot, and then all of the sudden your facing the wrong way.

[bnr32jason]

As far as I have read everywhere, they spent a lot of time designing the chassis but also those guys at KONI spent a lot of time tweaking the suspension. My guess is they did build something not too hard to drive and possible to drive fast without requiring Sebastian Vettel's skills.

They built the suspension to work best with a specific setup, namely staggered front and rear tires. You start messing with that critical part of the formula and you just thew off the whole suspension function.

[DodgyTim]

I am keen to try the BFG g-Force Rival, lots of good reviews, but their sizes are limited.
My 818R will be more track than street and the weather is warm to hot all year.
The best size for the rears is 275/35 R18.
These have a section width of 10.9" measured on a 9.5 rim, and do 814 rev/mile.
From Jim Schenck's post the blue 818R runs 255 hoosiers, from the photos they appear to be 255/35 R18's, that have a section width of 10.8"
At this size they have a slight rub on the outside with 35mm offset.
I'd be trying a 40 mm offset to account for the extra width and to avoid the rub.

Because the sizes are limited the fronts would have to be 215/45 R17, which do 844 rev/mile.

The problem I have is I want to try and run the factory ABS, which will see the front tyres turning faster than the rears, and potentially start bumping the rears thinking they are partially sliding..

I'd appreciate some feedback on how far you can go in diameter difference before it the ABS kicks in.

[bnr32jason]

Personally I'll be running Volk CE28N wheels 17x7.5 +50 front and 18x9 +40 rear. For tires, I'm not 100% decided on brand yet, but size will be 215/45/17 or 225/40/17 front and 255/40/18 on the rear. Brand and compound depend on if the 818 ends up being my daily driver or not. If I'm going to DD it I'm going have to get a tire that lasts more than 10k miles, maybe something like the Yokohama S-Drive, if not, I'll be going with the Yokohama AD08 probably. Not concerned with the speedo being off since I'll be running a GPS speedo anyways.

I won't be messing with ABS or any of that stuff, but I am considering that RaceLogic traction control system.

[Frank818]

There ARE a few of us planning on using narrower tires. I'm planning on using 205/55-16's up front and 225/50-16's on the rear (on stock WRX wheels), and I know of at least one other forum member who is planning the same setup. And I expect that it will go around corners just fine -- probably well enough to handle any corner at twice the recommended speed. As has been noted elsewhere in this forum, the Lotus Elise, which is similar in design, size, and power, uses this same tire combination, at least in stock street form.

Of course, I'm not planning on putting down great bucketfuls of horsepower. I'll be running a moderately tweaked NA engine, generating maybe 200-210 flywheel horsepower. I'm also going to run a Quaife LSD to help distribute that power as evenly as possible to those (relatively) narrower tires.

You are right, I believe power/tq output will also drive the size of the tires, that's true.
If you were to run a Toyota Prius engine, I doubt you'd stick 265s in. lolll

[Frank818]

At this size they have a slight rub on the outside with 35mm offset.
I'd be trying a 40 mm offset to account for the extra width and to avoid the rub.

Careful with that, as apparently the clearance on the inner side was very minimal. If you increase offset, you push the tire further onto the spring (suspension).

[Frank818]

I'll be running a GPS speedo anyways.

What will you change? The cluster completely? Just the gauges?
How will fit the new speedo?

I am currently looking at options to change the cluster or gauges, I'm having a hard time figuring out what can be done.

[narkosys]

Frank,

Check out SpeedHut. You can customize your gauges. I plan on getting a Speedo, Tach and a Quad Gauge to replace what is in the cluster.

P

[wleehendrick]

The traction control system from Race Logic will do absolutely nothing to prevent snap oversteer.

I made that point in another thread... to mitigate that condition, you'd need stability control which adds sensors for steering angle, yaw rate etc... and has the ability to brake one wheel individually. I don't know of any aftermarket stability control systems, although it's a mandatory feature on all new cars sold in the US.


You think you won't push it hard enough, until you are out on your favorite backroad (maybe the same one in your avatar) and decide you want to push just a little harder than last time, let off the throttle a little mid-corner because you went in to hot, and then all of the sudden your facing the wrong way.

I agree completely... unexpected things happen on the street, and human nature is to lift. In the wrong situation, this can lead to bad things in a MR car. I'm used to powerful RWD cars, but never driven mid-engine much. This is why I'm happy to hear Wayne's comments and the external perspective from R&T on the handling balance.

Although there's fun to be had sliding around with a limited coefficient of friction (hence why the BRZ and FR-S are fitted with Prius rubber!). I don't think it's a good idea on mid-engined 818 with high power to weight ratio. A staggered set-up (larger rear tires) will reduce the tendency towards over-steer and good sticky tires will provide an extra margin for error and I will be fitting something like a BFG Rival, Toyo R888, etc...

[Frank818]

Frank,

Check out SpeedHut. You can customize your gauges. I plan on getting a Speedo, Tach and a Quad Gauge to replace what is in the cluster.

P

Yes I've seen that last week, it's VERY interesting, but I am unable to know if the gauges will fit in the cluster or not. It seems the OEM gauges plug in the cluster in a plug or something, according to the youtube videos I've seen. But will those SpeedHut gauges have that same plug or what, that's the part I am totally confused about...

[Frank818]

I will be fitting something like a BFG Rival, Toyo R888, etc...

If other people come across this thread and look for tires, you got 2 options here, I am adding my option to that:

Yokohama ADVAN Neovo AD08 (not the R). They are absolutely amazing! They are smoother and quieter than one would expect, much more than the older Bridgestone S-02s I had. They stick superb, extremely predictable and easy to control when you slide. That is on a FWD car, but since they are not expensive and seem to last long enough, they are no doubt my next buy again, they will be on my 818.

[Xusia]

The traction control system from Race Logic will do absolutely nothing to prevent snap oversteer.

You think you won't push it hard enough, until you are out on your favorite backroad (maybe the same one in your avatar) and decide you want to push just a little harder than last time, let off the throttle a little mid-corner because you went in to hot, and then all of the sudden your facing the wrong way.


A narrower tire up front isn't going to solve that problem, and a wider tire up front isn't going to cause it
Both Wayne's comments and the R&T article would tend to indicate the car provides a bit more communication before all hell breaks loose
If I'm going in hot enough to cause a spin under breaking, then I'm probably going off the road no matter what (otherwise I could just steer through the corner, right?)
You don't know my nature when it comes to driving - I don't suffer ego and am just not likely to find myself pushing it harder if the previous speed was fun

[Xusia]

<rant>
I think a lot of people are also forgetting the FFR designed this car to use the donor wheels & tires. Those are a LOT smaller & narrower than being discussed here, so I don't really think it's the "OMG, you are going to kill yourself if you don't run really wide staggered tires" problem it's being made out to be. My nature is more cautious, and as such I'm planning to run both the RLTC system and the factory ABS (assuming I can).

Speaking of staggered wheels, the larger diameter of the rear wheel in a staggered setup doesn't increase the contact patch of the tire, and therefore doesn't affect grip appreciably. In another thread, articles were posted where they tested tires of the same width, but different diameters, and found very little difference - Stuff that would matter only when racing. I do not believe that running a 17" rear tire of the same width as an 18" tire is going to make my car more prone to snap oversteer. Sorry, but you aren't going to convince me of that. If the rear tire was narrower, that would make some sense because of the decreased contact patch.

Unless something drastic happens, I'm GOING to run 17" wheel all around! And I will be fine!! The only variable is whether or not I can get narrower front wheels and therefore run slightly narrower front tires.
</rant>

There. Now I have that off my chest. Back to normal! :)

[Frank818]

Well, to answer your question, 225/45/17 rear and 205/55/16 front. Both OEM sizes, both same diameter, slightly narrower up front.

[Silvertop]

<rant>
I think a lot of people are also forgetting the FFR designed this car to use the donor wheels & tires. Those are a LOT smaller & narrower than being discussed here, so I don't really think it's the "OMG, you are going to kill yourself if you don't run really wide staggered tires" problem it's being made out to be. My nature is more cautious, and as such I'm planning to run both the RLTC system and the factory ABS (assuming I can).

Speaking of staggered wheels, the larger diameter of the rear wheel in a staggered setup doesn't increase the contact patch of the tire, and therefore doesn't affect grip appreciably. In another thread, articles were posted where they tested tires of the same width, but different diameters, and found very little difference - Stuff that would matter only when racing. I do not believe that running a 17" rear tire of the same width as an 18" tire is going to make my car more prone to snap oversteer. Sorry, but you aren't going to convince me of that. If the rear tire was narrower, that would make some sense because of the decreased contact patch.

Unless something drastic happens, I'm GOING to run 17" wheel all around! And I will be fine!! The only variable is whether or not I can get narrower front wheels and therefore run slightly narrower front tires.
</rant>

There. Now I have that off my chest. Back to normal! :)

If I was going to run anything other than the stock 16" WRX wheels, I personally wouldn't choose to go any larger diameter than 17" either. Part of that is just because I don't care for the look of extremely low profile tires. I don't want to date myself, but in my generation, a 60-Series tire was considered low profile. Not so anymore. But the ultra low profile stuff still just doesn't look right to me.

Also, for ride purposes, I just think a taller sidewall is going to be more comfortable to ride on, as well as providing a little more protection for the wheels. But there are really no right or wrong answers here. It depends on the goals and preferences of the builder.

[Frank818]

Exactly, depends what you are doing with the car and what you want in terms of comfort.
The right answer will only come from you. :) I mean not "you" you, but from each of everyone for himself. :) Herself too. :)

[wleehendrick]

FYI... by staggered I was referring to wider rims/tires in the rear rather than larger diameter rims (a staggered set-up in the general sense just means different size front/rear). I agree, that there's no necessity to go to large (>17") diameter rims, or have different diameter rims front/rear. However, to properly fit wider rear tires, wider rims are obviously ideal.

As a point of reference, my current car has ~10lb/hp and ~50:50 weight distribution. I was not happy with the balance until I went to a more aggressively staggered set-up (245f, 275r). Intuitively, I think the 818 (with better power to weight ratio and more rearward bias) will be a bit unbalanced with the same width tires front/back.

[bnr32jason]

Xusia you are taking this way too personally, try not get so upset about some simple comments.

1) I never mentioned braking, not sure where that came from. I'm simply talking about weight transfer, lifting off the throttle will cause a weight shift forward, with equal tire sizes that means now the front will have more grip than the rear due to the increased load on the front. More grip in the front than rear = oversteer.

2) Contact patch is dynamic, not static.

3) If you truly believe you are never going to push the 818, maybe same size tires front and rear will be fine. I just find it hard to fathom why someone would buy a car like this if they weren't going to take it to a HPDE or push it a little on twisty roads from time to time.

4) Running 17's front and rear is fine, no one is saying you have to run 18's on the rear like the R, or like the unveiled S model from the open house. This specific discussion is about tires, not wheels.

In the end the decision is up to you of course, I'm just trying to get you to understand that an 818 with wider tires on the rear is going to feel much more comfortable when even approaching 70% of the limit. MR cars were designed to have wider tires in the rear, messing with that formula is going to yield undesirable results. If you choose to run same size front and rear, just know that you are choosing a path that is not technically correct.

[PhyrraM]

.....
I think a lot of people are also forgetting the FFR designed this car to use the donor wheels & tires. ........

While I sincerely hope this is true, I don't think it is. From every post and picture that I have seen (I could have missed some) all testing was done with the larger wheel and tire setups that we have seen since prototype #1.

[bnr32jason]

While I sincerely hope this is true, I don't think it is. From every post and picture that I have seen (I could have missed some) all testing was done with the larger wheel and tire setups that we have seen since prototype #1.

Exactly. From what I can see, all the way back to the go-kart stage, the 818 has not been developed using stock wheels and tires. This means all testing, development, etc was done on wider rear tires and more narrow front tires. There is a reason for that. The 818 was *absolutely not* designed to use the stock wheels and tires, the test mules prove that.

Just because you CAN use the stock wheels and tires doesn't mean you should. There are many things that I could do if I wanted, I could use a set of cheap eBay knockoff Bride seats and not wear a seatbelt while driving, but that doesn't mean that it's a good idea or an optimal choice.

[Silvertop]

While I sincerely hope this is true, I don't think it is. From every post and picture that I have seen (I could have missed some) all testing was done with the larger wheel and tire setups that we have seen since prototype #1.

I am certain that you are right about this. It does seem to me that the original "kart" was outfitted with stock WRX wheels and tires, at least at the beginning. But ever since then, the bodied prototypes have definitely been fitted with larger wheels and tires, and they have also been delivering significantly more horsepower than stock WRX's.

Nonetheless, I believe that the car will function just fine as a streeter with less dramatic tire/wheel combinations, particularly if horsepower delivery does not get too wild. And I also believe that forum chatter notwithstanding, many builders will ultimately choose milder power configurations, particularly those who are trying to complete their builds on the cheap.

[PhyrraM]

......MR cars were designed to have wider tires in the rear, .......

Not always true. Cars that are mid engined are primarily that way to reduce the polar moment - to make them turn easier. If the forward/rearward weight transfer cannot be sufficiently controlled with other design parameters, then larger contact patches can help control snap oversteer. An MR car can be designed with equal weight distribution if desired.

FFR could have developed for any tire sizes/stagger they wanted to. They chose a size/stagger that they thought most customers would be happy with, as any company looking to maximize sales would do. FFR chose to slightly reduce "maximum performance" because they knew that smaller wheels are not currently popular, styling wise.

[bnr32jason]

I don't believe there has been a modern MR car produced that has the same size tires front and rear.

Could one be made to work with that setup? Sure, but it would still be less than optimal.

I know quite a few guys in the MR2 community run a "square" setup because it's more "fun." The Road and Track article about the 818 mentioned the smooth transition into a lazy slide, and that was because of the tire sizes and suspension setup. You take away those wider rear tires and suddenly that lazy slide turns into a snap into oversteer. For some this could be great fun, especially if you are into the drifting stuff. But you are sacrificing overall performance for that extra bit of fun and fear.

But you better be sure that you learn the car well and have quick reactions because when the car does transition from neutral steering or mild understeer into no-notice snap oversteer, things can go from "fun" to "holy crap I'm gonna die" really quickly.

I setup my FD2 Type R Civic to have lift off oversteer by running 245's in the front and 225's in the rear. This made for a great gymkhana car, but I had to be VERY careful when driving on the local touges.

[Xusia]

Quick clarification, just in case there was any misunderstanding: I'm not talking about going narrower in the rear, so for the purposes of this discussion, rear tire width is the same and my intent is to go as wide as I reasonably can - to maximize grip. Also, I'm not taking it personally. My rant was more a humorous jab at the seemingly illogical over-concern about this issue. :)

I understand what you are saying, but I still don't think it makes sense, so please help me understand. You are saying wider tires (in front) would have more grip, so that when weight transfers to the front, the front would stay planted, potentially causing a spin. Assuming I have that right, what doesn't make sense to me is how having narrower tires on the front solves the problem? It seems to me that would only result in a front end slide. Perhaps a bit less problematic, but could still easily put me off the road or into a head on collision.

It also seems to me that if I'm at the point where the little bit of weight transfer caused by simply letting off the throttle is enough to cause the rear end to break loose, I am AWFULLY close to the limit. Mine will be a daily driver, and the street is no place to be driving that close to the limit. I do hope to take it to the track, but that will be fun based, and I'm very certain I can both have a ton of fun AND blow away a lot of other cars while not getting that close to the limit.

As to why anyone would buy a car like this and not drive it at the absolute limit, there are several reasons:

No other car is even CLOSE to the performance for the price. BRZ, 370Z, etc. all fall far short. I want more. I may not need or use ALL the "more" this car delivers, but that's OK. Really!
I find it comforting to know the car has capability in reserve that I don't plan on using. Knowing it's unlikely I'll come close to the limit provides peace of mind. If I get into a situation, I can have confidence the car can handle it.
It's about fun, not outright speed or craziness. I can have a ton of fun without ever finding the limits of this car.
It's my project; my car. If I want to build a 1000hp monster and drive it only to church on Sundays, that should be OK. :)
Still on the "my project" thing, it's about doing it myself. Knowing I can. Having something to bring my son and I close together. But more to the previous point, my reasons should really matter to anyone else!

[bnr32jason]

It's about a fine balance.

Let's take two examples:

1) 225 front, 255 rear when you approach the limit of traction, the front gently washes away so you instinctively let off the throttle and the extra grip provided by the bigger rear tires mitigates the "snap" oversteer. Instead the rear transitions smoothly into an easy to control slide.

2) 225 front, 225 rear the front gently washes away so you instinctively lift off the throttle which then throws the car into a "snap" oversteer situation since the fronts are now loaded with extra weight (more grip) and the rears have the weight shifted forward off of them which causes a spin unless you are a VERY experienced track driver and can handle it. Even then it's tough for the experts to catch too.

It's all fairly simple physics and vehicle dynamics. Having the engine sit over the rear axles has many benefits, but it also introduces a few handling quirks such as this. Most people haven't ever driven a MR car so they don't yet understand.

[Xusia]

What about 245 front & rear? That's far more likely (for me) than 225.

[bnr32jason]

You might want to check some other builds before you commit to a 245 front, it might not fit.

But the same thing will still occur, it's about the balance between front and rear grip.

[Xusia]

I get the idea of balance, but the outright amount of grip also applies. A 245 should provide more grip than a 225, raising the point at which the problem could occur. If the front also has a 245, then as long as we aren't exceeding rear grip, the car tracks, right?

[bnr32jason]

What you say has validity, but remember that grip is dynamic term. The transition from understeer or neutral steering to oversteer is still going to be much more violent when you do reach that limit. Or when you get nervous and lift off the throttle suddenly. We all like to say we would never do that and would keep our cool, but in emergency situations fight or flight takes over and we may or may not make the correct decision, even professional drivers are capable of doing it.

[C.Plavan]

Guys, guys, guys.... You all are over-thinking everything. Lets wait to people start really building/ driving the car to actually see what works.

[bnr32jason]

Well some testing has already been done by Road & Track. They confirmed that the development Factory Five did and the setup that was on the 818R for testing works very well. The transition into a "lazy slide" is a very good thing for amateurs like myself who want to visit the track and backroads for some fun. So we know what works already.

[C.Plavan]

Well some testing has already been done by Road & Track. They confirmed that the development Factory Five did and the setup that was on the 818R for testing works very well. The transition into a "lazy slide" is a very good thing for amateurs like myself who want to visit the track and backroads for some fun. So we know what works already.

So you plan on using Hoosier R6's on your car like they did in the article????

[Frank818]

Wow there's a lot of discussions going on here. lolll Maybe in the end it will make it as a sticky loll


Guys, guys, guys.... You all are over-thinking everything. Lets wait to people start really building/ driving the car to actually see what works.

And who crashes theirs lolll

[C.Plavan]

Wow there's a lot of discussions going on here. lolll Maybe in the end it will make it as a sticky loll
And who crashes theirs lolll

That's the truth, but the nut behind the wheel will be the biggest factor.

[Xusia]

We all like to say we would never do that and would keep our cool, but in emergency situations fight or flight takes over and we may or may not make the correct decision, even professional drivers are capable of doing it.

I ride a motorcycle with a scant 3.7 pounds per rear wheel hp (that's with me on it), and you are right. We do indeed like to think we would react correctly, but that's not always what happens. I know this from first hand experience, and can honestly say I'm lucky to be alive (for the record, I am a VERY well trained rider). knowing what can happen, and that despite good training you can react incorrectly, is why I don't drive, ride, ski, etc. near the limit. It's easier to prevent the situation, than to react appropriate to it...

[Wayne Presley]

bnr32jason, I drive lots of mid engine cars and none really "snap oversteer". You will spin any car that is set up mid corner neutral by lifting the throttle and not countersteering and getting back to neutral throttle. The Elise I drive at the track runs 205/225 tires and a 35/65 weight bias. The set up in the car is neutral mid corner and can be rotated by lifting the throttle when you are at the cornering limit. You give it just a little throttle and the tail comes right back in line. The 818R was run with 225/255 tires and a 42/58 weight bias. The set up in it was mechanically grip neutral, slightly aero tight and the car would come right back in line just by getting back to neutral throttle. Same on corner exit if you gave it too much gas, pull back on the gas a little, slight counter steer and the tail would come right back in line.

[Frank818]

I ride a motorcycle with a scant 3.7 pounds per rear wheel hp (that's with me on it)

I couldn't resist that one, but Xusia, 3.6 pounds of that 3.7 is you. lolllllll
Sorry dude I had to say it. :)

[Frank818]

The set up in it was mechanically grip neutral, slightly aero tight and the car would come right back in line just by getting back to neutral throttle. Same on corner exit if you gave it too much gas, pull back on the gas a little, slight counter steer and the tail would come right back in line.

That is AWESOMELY fun to drive!!

[wleehendrick]

bnr32jason, I drive lots of mid engine cars and none really "snap oversteer". You will spin any car that is set up mid corner neutral by lifting the throttle and not countersteering and getting back to neutral throttle. The Elise I drive at the track runs 205/225 tires and a 35/65 weight bias. The set up in the car is neutral mid corner and can be rotated by lifting the throttle when you are at the cornering limit. You give it just a little throttle and the tail comes right back in line. The 818R was run with 225/255 tires and a 42/58 weight bias. The set up in it was mechanically grip neutral, slightly aero tight and the car would come right back in line just by getting back to neutral throttle. Same on corner exit if you gave it too much gas, pull back on the gas a little, slight counter steer and the tail would come right back in line.

Thanks for chiming in Wayne... you're one of the few who can really contribute anything beyond pure speculation at this point.

By 'slightly aero tight', I assume you mean that the rear generates more downforce than the front, so that at speed the aero tend to shift the balance towards understeer?

One takeaway from your comment is that since the 818 is set-up to be neutral with a staggered set-up, this implies that with the same size tires all around, the handling bias will shift towards oversteer. Is the same applicable to the S? was is set up neutral with staggered tires? Or was a bit more understeer dialed in for 'safety'?

My only concern is that there are some rear/mid-engined vehicle with a known reputation for swapping ends (early 911s, 2nd gen MR2...). It sounds like the 818's suspension geometry and tuning is sorted well enough that this is not an issue, and the only oversteer characteristics are those which are unavoidable due to the laws of physics, as you describe!

[Xusia]

I couldn't resist that one, but Xusia, 3.6 pounds of that 3.7 is you. lolllllll
Sorry dude I had to say it. :)

LOL - I'm a lanky dude. 6'1" and 165 pounds. :)

[bnr32jason]

bnr32jason, I drive lots of mid engine cars and none really "snap oversteer". You will spin any car that is set up mid corner neutral by lifting the throttle and not countersteering and getting back to neutral throttle. The Elise I drive at the track runs 205/225 tires and a 35/65 weight bias. The set up in the car is neutral mid corner and can be rotated by lifting the throttle when you are at the cornering limit. You give it just a little throttle and the tail comes right back in line. The 818R was run with 225/255 tires and a 42/58 weight bias. The set up in it was mechanically grip neutral, slightly aero tight and the car would come right back in line just by getting back to neutral throttle. Same on corner exit if you gave it too much gas, pull back on the gas a little, slight counter steer and the tail would come right back in line.

Thanks for the input, from what you have written it has completely verified my suspicions that running the same size tires front and rear will cause problems due to the way the car is setup from Factory Five.

My experience on the track is mostly from when I was ages 7-19, starting in karts, then moving to Formula Ford, and ending in Formula Continental. I do have some experience tracking a Ferrari 308 and a mid 90's MR2. Both of these would easily go into a "snap oversteer" situation if you weren't careful, so that's what I'm basing my judgements on. The 308 was a car that was too expensive to mess with suspension tuning, so the cheapest way to change the handling characteristics was changing wheel and tire sizes. We went from the stock setup 205 front and rear to a 225 rear and the car became so much easier to drive it was ridiculous. The MR2 I had a little more freedom with and with an adjustable sway bar setup along with spring changes and tire changes I was able to get the car to handle very neutrally.

I haven't been fortunate enough to drive a modern mid-engine car like the Elise or a modern Ferrari sports car, but my experience with the old stuff is that mid-engine + same tire size F/R = disaster in amateur hands.

[Evan78]

To anyone that says that will not approach the limits of the car while driving on the street: skill, driving responsibly, looking ahead, and experience will help keep you out of trouble, but remember that you are operating in an uncontrolled environment. Are you comfortable with the setup of your car in the event that you need to jump on the brakes while coming around a corner or some other emergency avoidance maneuver?

[Xusia]

Hi Evan,

You say "To anyone" but I've been pretty vocal about that, so that comment seems directed at least partially at me. What you say is true, but what piques my curiosity is why you felt the need to say it in the first place. Have I somehow come across as immature, naive, or overconfident? I'd really like to know if I've somehow given off an incorrect impression.

[bnr32jason]

I don't think it's about coming off as immature, naive, or overconfident.

For me it's just hard to believe that someone would spend ~$20k building a Factory Five 818 but then say they aren't going to drive it like it's been designed to be driven. I'm not saying to push it to 95% of the limit on the street, or even on the track either. Something just isn't adding up, you've got a picture in your avatar of you on a ZX-6/10 pushing it decently hard through a corner on a public street, but you say you won't do the same thing in a car. It's just not adding up.

Think about it in motorcycle terms, in your avatar if you had come up to a disabled car stopped in the middle of the road mid-corner your first instinct is to let off the throttle which pushes you wide. Or you just go in a little too hot, an experienced rider stays on the throttle and leans in more, but our first reaction is to let off the throttle as well, which again pushes us wide. In 818 terms, especially one with equal size tires front and rear, pushing it the same amount through the corner as you are your avatar (around 65-70%) you end up spinning if you abruptly let off the throttle or even brake in an emergency situation because now the front tires have tons more grip than the rear which have been unloaded. So even though you weren't pushing it hard, an emergency situation still proves to be challenging.

But you said you were going to try to run wider tires on the rear if you could anyways, which is going to be the safest setup for handling these emergency situations.

[Xusia]

Ahh. I see the disconnect. You are associating my statements about limits and getting a preconceived notion of how I will drive. You don't really know me, so I think your impression is likely inaccurate. Not pushing the limits doesn't mean a Sunday stroll! LOL. It just means keeping a margin of safety (i.e. for the uncontrolled environment and such), which is below the car's limits and within my own personal limits (This is how I ride motorcycles too). I do plan to drive it aggressively on back roads and such, just with an appropriate margin of safety.

As far as my avatar goes, I had to laugh a bit when I read your comments. :) Bragging isn't my style, so I don't ramble on about how good I am or what my experience is, etc. As a result, you seem to have formulated an incorrect assumption as well as underestimated my riding skill (not surprising since we only know each other through this NON-motorcycle forum!): I'm not even close to pushing it in that pic (that was only at about 65 and I take that corner at 85 when I decide to ride closer to the limit). Seriously, I could taken a hand off the handlebar, turned my body completely around, waved to the guy behind me, and taken a sip of tea (if that were possible with a helmet on). I'm not even leaned over far enough to get my knee down. The only reason I'm even leaning off the bike is because it's fun. The photographer was a friend who wanted some action shots in his portfolio, so I thought I'd have a bit of fun while we were out and was just screwing around as I took various runs through the corner. That one just turned out to be a really good pic, so I use it as my avatar.

Not really related, but I thought I'd clarify something you stated incorrectly. I don't mean or want to offend you; I only want to ensure accurate information is presented in case there are other motorcycle riders reading this: Letting off the throttle doesn't push you wide. The front fork compression caused by using the front brake changes the bike's geometry and results in the bike wanting to "stand up" (the more forceful the braking, the more pronounced the effect). If you LET it stand up, THAT can cause you to go wide. If you maintain lean, however, you actually drop into the corner more, tightening your line. This can be dangerous, however, because braking while actively maintaining (or increasing) lean consumes additional front traction. And you don't want to exceed your finite amount of traction! That puts you on the ground and ends your fun.

Letting off the throttle causes engine braking which primarily affects the rear tire and shock. The front forks and overall geometry are not appreciably affected. So as long as the engine braking isn't enough to compromise rear traction, letting off the throttle causes you to drop into the corner more, tightening your line with minimal impact on traction.

Lastly, leaning more AND using the throttle is a bad idea in an emergency avoidance maneuver because it has a much greater likelihood of overcoming available traction than other options. Leaning/steering and accelerating both consume traction, so if you do more of them, you are in effect consuming more of your precious, finite traction (both front and rear). If you encounter an emergency situation and you need to tighten your line, the best response is to let off the throttle (but avoid excessive engine braking) and push on the inside bar until the you have achieved the necessary tighter line. This consumes the least amount of additional traction.

The following was taken from Sport Rider Magazine (link (http://www.sportrider.com/tips/146_0904_controlling_cornering_arc_with_throttle/)):


Your bike's trajectory or curved path through a corner is primarily determined by two factors: your speed and your lean angle. Increasing lean angle quite obviously tightens your cornering line while increasing your speed has the opposite effect. In other words, once you've set your lean angle you can tighten your line by simply reducing your speed or widen your cornering arc by increasing it; without ever changing your lean angle. Keeping your engine rpm between 60 and 80 percent of redline also enhances its throttle response, though the higher rpm also demands greater smoothness.

While I'm not as experienced with high performance driving as I am with riding, I am a sharp guy and quick study. And based on what Wayne said, the car is well mannered when being driven at less than the limit. So, I think I got this! :)

[blueoval_bowtie_guy]

When I build mine, I'm going to use the same size tires FactoryFive used. This is what the suspension was 'dialed in' with.

[bnr32jason]

While I'm not as experienced with high performance driving as I am with riding, I am a sharp guy and quick study. And based on what Wayne said, the car is well mannered when being driven at less than the limit. So, I think I got this! :)

I understand, and I didn't mean for this to become a war of words. It's just a simple fact that the car will handle differently and be more prone to oversteer if you decide to run the same size tires front and rear. Wayne's comments about the 818 throughout this forum apply only to the setups he has driven and track tested. If you take an 818 and start messing with the setup, everything goes out the window. It's simple enough to turn an 818 into a handling mess if things aren't approached the right way. Running equal size tires front and rear is step one towards making it a mess.

[DodgyTim]

The analogy with the sportbike and a 818 is a good one, they are both going to be too fast to have genuine fun with on public roads. Too many cops and distracted drivers for me. For $120 I can go to the track and pretend to be Valentino or Sebastan for the day!

[longislandwrx]

http://www.1010tires.com/Tools/Wheel-Offset-Calculator

Is a great tool for testing fitment.

[Frank818]

When I build mine, I'm going to use the same size tires FactoryFive used. This is what the suspension was 'dialed in' with.

You mean from the Open House?

[wleehendrick]

And you don't want to exceed your finite amount of traction! That puts you on the ground and ends your fun.

Been there, done that, front wheel washed out... four broken vertabrae.

I have no memory of several minutes before/after my accident, but looking at the scene afterwards, it was clear that I exceeded the traction limit of the front tire and I low-sided. I slid for a while, which would have been fine since I was in full gear, but then there's the guardrail. I always try to leave a significant safety margin on the street, but having no memory, I can't say what was responsible... did I come in too hot? possible. There was gravel in the corner that I may not have seen. I just don't know.

That experience is why I want my 818 to be as well balanced with as predictable handling as possible.

[Xusia]

...I always try to leave a significant safety margin on the street...
That experience is why I want my 818 to be as well balanced with as predictable handling as possible.

I hear ya and agree. I'm sorry to hear that happened to you. I had a similar experience in the past that has also shaped my thinking and behaviors. I wasn't injured, but the distinct potential of death was undeniable (had things gone another way, which they easily could have).

I think it's been forgotten, but my intent IS to run as wide a tire as possible on the rear, AND a narrower tire on the front. I understand that's the desired set up and what is best for handling. I would only run wider fronts IF I HAVE TO. Hopefully, I won't have to.

[wleehendrick]

I hear ya and agree. I'm sorry to hear that happened to you. I had a similar experience in the past that has also shaped my thinking and behaviors. I wasn't injured, but the distinct potential of death was undeniable (had things gone another way, which they easily could have).

Thanks... I'm fine now, but it does change your perspective.


my intent IS to run as wide a tire as possible on the rear, AND a narrower tire on the front.

That's my thought as well... just don't take it to an extreme, or you end up with this:

19243

http://www.caranddriver.com/features/dissected-nissan-powered-deltawing-race-car-feature

[Frank818]

Ok, so if we try to make this simple, can someone plz complete the following line?

The bigger the width difference (real surface contact) between front and rear tires, the ________________________________.

[wleehendrick]

less oversteer.

(although it's a bit more complicated than that)

[bnr32jason]

It's tough to simplify it THAT much, but to entertain your question:

"...the more the handling characteristics will shift towards neutral and eventually understeer"

But even that statement isn't wholly correct because there are so many different factors in play.

Track tested 818 with 225 from and 255 rear seems to be quite neutral. Make that a 225 front and 285 rear and then characteristics will shift more towards understeer.

[Evan78]

Hi Evan,

You say "To anyone" but I've been pretty vocal about that, so that comment seems directed at least partially at me. What you say is true, but what piques my curiosity is why you felt the need to say it in the first place. Have I somehow come across as immature, naive, or overconfident? I'd really like to know if I've somehow given off an incorrect impression.No, you don't come across as any of those things. I just felt it would be beneficial if you had not considered all scenarios that you may want to. I agree with you that there's no issue with equal size tires if you never approach the limit of any of the tires and I don't have any trouble believing you when you say that you will not be driving "ten/tenths" at any time. If everything goes to plan, you'll be fine, but I feel that the plan neglects the unforeseen or you are simply okay with that compromise. We all make compromises, but I figured it wouldn't hurt to bring up this one in case you had not already considered it.

When BNR32Jason mentioned that traction control will not do anything to help with off-throttle oversteer, your reply was "A narrower tire up front isn't going to solve that problem, and a wider tire up front isn't going to cause it." I disagree with your statement. Even if you don't have enough traction to stop without running into something, would you rather go in whatever direction you're steering or would you rather have the back end come around and potentially take you off the road/mountain, onto the sidewalk where pedestrians are, into opposing traffic, etc?

You've recently clarified or reminded us that you intend to run wider tires in the front than the back, if feasible. Even with the same size wheels, you should be able to get at least 20mm difference in section width between them, perhaps more depending on how tall your sidewall is.

[bromikl]

Thanks for the input, from what you have written it has completely verified my suspicions that running the same size tires front and rear will cause problems due to the way the car is setup from Factory Five.
...We went from the stock setup 205 front and rear to a 225 rear and the car became so much easier to drive it was ridiculous...
I haven't been fortunate enough to drive a modern mid-engine car like the Elise or a modern Ferrari sports car, but my experience with the old stuff is that mid-engine + same tire size F/R = disaster in amateur hands.

Given this, I'm surprised FFR hasn't recommended running larger tires in the rear. Maybe they will.

The 818 will drive with the stock setup. But to drive aggressively (and stay on the road), we will need RaceLogic and wider rear tires. Anything else?

[Wayne Presley]

Given this, I'm surprised FFR hasn't recommended running larger tires in the rear. Maybe they will.

The 818 will drive with the stock setup. But to drive aggressively (and stay on the road), we will need RaceLogic and wider rear tires. Anything else?

FFR already uses a 30mm split between front and rear tires... 215/245 S or 225/255 R

If you use the recommended tire sizes and alignment specs, you will have a well balanced and fun driving 818. I've driven the car a lot and it is gentle when the tail comes out. The references to other cars that snap oversteer are just that, references to other cars and not the 818.

Do you need the traction control? No, would it be nice to have? Yes.

[Frank818]

FFR already uses a 30mm split between front and rear tires... 215/245 S or 225/255 R

If you use the recommended tire sizes and alignment specs, you will have a well balanced and fun driving 818. I've driven the car a lot and it is gentle when the tail comes out. The references to other cars that snap oversteer are just that, references to other cars and not the 818.

Do you need the traction control? No, would it be nice to have? Yes.

30mm split, ok great.

So a 40mm split would "theoretically" make it a little harder to oversteer?

[bnr32jason]

Yes, a 225/265 or 215/255 setup would be more towards neutral/understeer.

[Frank818]

Yes, a 225/265 or 215/255 setup would be more towards neutral/understeer.

Would you really feel the difference on public roads under spirited driving? I am not talking about race driving on public roads, just spirited driving.

[Wayne Presley]

Would you really feel the difference on public roads under spirited driving? I am not talking about race driving on public roads, just spirited driving.

Nope, not with the 818...

[Frank818]

Tnx Wayne.

[Frank818]

Just thought about something.

I am onto FWD cars, so in the event I take a curve to the limit, if the rear end starts to slide I just counter-steer a little and give it a little gas to trsf weight to the back. Since the power goes to front wheels and they are in the direction I want to go, that technique works perfectly to give grip back to the back.

What would you do with an MR?

If you are at the limit and the rear slides, if you lift off weight will trsf to front, making the rear slide even more.
If you give it gas, it will probably make the rear wheels spin, making the rear end slide more.

So what's the technique here?

[Wayne Presley]

On a street car you would not set up the suspension to have the rear slide in the first place. It would have a push and when the car reached it's cornering limits the front would slide first causing an increase in its turn radius. You get out of the throttle and the weight shifts to the front tires allowing the turn radius to decrease.

[Frank818]

Makes sense. I guess that's what those Koni guys did.

[philly15]

ok so i traded a guy a while a go for some 17x9 RPF1's, +35 offset i believe. does anyone have a set of 17x8's and wanna trade 2 wheels? if so get a hold of me i wouldnt mind swapping and running a staggered setup.

[Wayne Presley]

What bolt circle are the 17x9's?
I can get the RPF1's 17x8's for $960/set plus shipping if anyone wants to split philly's set

[philly15]

5x100

[Xusia]

What color and what condition?

[philly15]

Silver and fairly new I traded a guy in Texas for my 17x8's a while back. He needed 8's for STX and I wanted the 9's for SM. I never ended up running them though I think he only ran em for a couple thousand miles

[Grintch]

5x100

According to the Enkei website, they don't make a 17x9 RFP1 in a 5x100, only in 5x114.

For a different direction, what is the smallest diameter wheel that will fit over the stock WRX 02-06, and 07-08 brakes? Rumour has it that 15" is popular with people rally crossing the earlier cars, and using a dedicated set of small diameter wheels & tires for the track would result in less weight, shorter gearing, and a lower ride height that can very quickly be undone for the ride to/from the track.

[Wayne Presley]

According to the Enkei website, they don't make a 17x9 RFP1 in a 5x100, only in 5x114.

And that is exactly why I asked and the price above was for brand new Enkei wheels as I am a dealer for them.

[philly15]

And that is exactly why I asked and the price above was for brand new Enkei wheels as I am a dealer for them.

they were special order on nasioc for a while in those group buys. thats where the guy got em in 5x100, now if you order from tire rack and go under the BRZ, they have a 17x9 in 5x100...

[Zodiac]

I was searching around and couldn't really find what I was looking for. So what are the recommended tire and wheel sizes? I found a few posts saying 17's front 18's back. 40 offset here and 48 offset there. 215/245. I'm just curious as to what's the recommended so if I find a good deal I can go ahead and get them instead of worrying if it's the right choice. I really do like the Raijin model and trying to go for that as well.

[Wayne Presley]

I'm running a 17x8 with 40 offset in front and 18x9.5 with 40 offset in back. To run that wide of a back rim I had to come up with trailing arms, spacers and lateral links. I will be selling that kit as soon as I do the final prove out on the pieces. What size tires do you want to run? You could do a 16/17, 17/17, 17/18 or 18/18. The Raijins are only available in 18's so let me know when you are ready to order.

[Samiam1017]

Wayne I pm ya awhile back on wheels. Can I get I idea on the cost of the kit too when you get around to it.

[Wayne Presley]

Wayne I pm ya awhile back on wheels. Can I get I idea on the cost of the kit too when you get around to it.

PM sent

[longislandwrx]

I'm running a 17x8 with 40 offset in front and 18x9.5 with 40 offset in back. To run that wide of a back rim I had to come up with trailing arms, spacers and lateral links. I will be selling that kit as soon as I do the final prove out on the pieces. What size tires do you want to run? You could do a 16/17, 17/17, 17/18 or 18/18. The Raijins are only available in 18's so let me know when you are ready to order.

How tight is everything? I originally thought you said a +45 wheel Were those custom? Or are you running a 5mm spacer?

[Wayne Presley]

How tight is everything? I originally thought you said a +45 wheel Were those custom?

I have the suspension done but have not put it on the ground, fitted the body and aligned it yet so I do not know. The wheels on my car are 40, FFR had other offset wheels on their prototype cars. At least 4 sets that I know of.

[longislandwrx]

Awesome. I'm glad it will be possible. 18x9.5 +40 has been my plan from the beginning. BRZ fitment offers tons of choices on new wheels. Lots of companies are selling staggered setups without needing to special order sets. perfect.

Cant wait to see exactly what its going to take.

[Frank818]

As long as you stay in 5x100.
There are that many choices of 18x9.5 +40 in 5x100?

[Twinspool]

Just thought about something.

I am onto FWD cars, so in the event I take a curve to the limit, if the rear end starts to slide I just counter-steer a little and give it a little gas to trsf weight to the back. Since the power goes to front wheels and they are in the direction I want to go, that technique works perfectly to give grip back to the back.

What would you do with an MR?

If you are at the limit and the rear slides, if you lift off weight will trsf to front, making the rear slide even more.
If you give it gas, it will probably make the rear wheels spin, making the rear end slide more.

So what's the technique here?

Drive a 911 and then a Corvette on a twisty track, the answer is somewhere in between those.

[Zodiac]

I was thinking 18x8 for the 5x100 pattern with 245/35 for the back. I found a great deal on the rims but i think those tires are too wide and i dont see the 5x100 offered in 18x9.5 without almost doubling the price of the rims. so I think I have to get 18x8 with something more like 205 or 215 :(. I've only seen them offered in 45 and 35 offset. I want to basically get them installed without having to get any extra stuff as I'm already going a little over budget as it is. Is that a good match? And I'm assuming it's best to have the front wheels a little smaller than the rear so any ideas on what size I should be looking at for the fronts?

[C.Plavan]

911 example. :) Just train your foot and brain to ignore each other..... click HD if your connection and computer can handle it.

http://www.youtube.com/watch?v=hw9Erbboqrk&feature=youtu.be

[longislandwrx]

As long as you stay in 5x100.
There are that many choices of 18x9.5 +40 in 5x100?

yes. go to any online wheel store and look for brz/frs wheels.

[Frank818]

I was thinking 18x8 for the 5x100 pattern with 245/35 for the back. I found a great deal on the rims but i think those tires are too wide and i dont see the 5x100 offered in 18x9.5 without almost doubling the price of the rims. so I think I have to get 18x8 with something more like 205 or 215 :(.

Well I see 2 tires in that size on Tirerack.com and taking one I see that the recommended rim width is 8-9.5. So 18x8 with 245/35 should be ok.

[Zodiac]

Well I see 2 tires in that size on Tirerack.com and taking one I see that the recommended rim width is 8-9.5. So 18x8 with 245/35 should be ok.

oh really? cool yea i was under the impression it would be too big for the rim. if that's the case I may still be going with that setup. now to chose a size for the front cause don't i need smaller ones?

[Mechie3]

I ran a 255 starspec on a 17x8 once. It fit, but you could feel the sidewall flex during initial turn in which killed my confidence.

[Frank818]

oh really? cool yea i was under the impression it would be too big for the rim. if that's the case I may still be going with that setup. now to chose a size for the front cause don't i need smaller ones?

Yup, but only 2 choices on TireRack, so if it's a rare spec you may have to live with the available tires.

Oh wait!! No, a bunch more than 2!! Sorry my search was bad, but take a look for yourself:

http://www.tirerack.com/tires/TireSearchResults.jsp?width=245%2F&ratio=35&diameter=18

[Zodiac]

Yup, but only 2 choices on TireRack, so if it's a rare spec you may have to live with the available tires.

Oh wait!! No, a bunch more than 2!! Sorry my search was bad, but take a look for yourself:

http://www.tirerack.com/tires/TireSearchResults.jsp?width=245%2F&ratio=35&diameter=18

Cool thanks. Yea been searching around and tirerack and discounttire seem to usually be the best. onlinetires.com has some good deals as well ($153 for hankook v12 evo) as well as on raijin rims. Just gotta check reviews first before i go through them since I haven't heard from them. Bridgestone would be ideal but the price jumps up quit a bit lol

[Grintch]

yes. go to any online wheel store and look for brz/frs wheels.

Yes, but our hardware is Impreza based. The BRZ seems to tend to a slightly lower offset, and allow a little wider fitment.

Typical GD Imprezza offset is 42 - 53mm, and a 9.5" wheel with appropriate size tires would require fender mods. Has anyone got the body & suspension complete enough to get a real feel for the size and configuration of the 818 fender wells? Seen a specific wheel & tire size recommendation from FFR?

As a reminder for track use, NASA TT/ST rules give a pretty good weight/point break to cars running a 245mm size tire or less. And a reduced one to cars running a 275mm tire or less.

[C.Plavan]

Yes, but our hardware is Impreza based. The BRZ seems to tend to a slightly lower offset, and allow a little wider fitment.

Typical GD Imprezza offset is 42 - 53mm, and a 9.5" wheel with appropriate size tires would require fender mods. Has anyone got the body & suspension complete enough to get a real feel for the size and configuration of the 818 fender wells? Seen a specific wheel & tire size recommendation from FFR?

As a reminder for track use, NASA TT/ST rules give a pretty good weight/point break to cars running a 245mm size tire or less. And a reduced one to cars running a 275mm tire or less.

Thanks for the info on the NASA rules. Do we even know where the 818R will fit yet in NASA?

[Grintch]

The FFR Cobra & Daytona are allowed in TT1 - TT3 (time trial) & ST1 - ST3 (racing) with a slight weight penalty, which sub class depends on the power to weight you are at. I expect the 818 will get classed there as well once a few pave the road.

So don't drive too fast, you guys that are first getting your car done, or the rule makers will stick us in higher classes (STR) or stick us with a bigger weight penalty.

[C.Plavan]

The FFR Cobra & Daytona are allowed in TT1 - TT3 (time trial) & ST1 - ST3 (racing) with a slight weight penalty, which sub class depends on the power to weight you are at. I expect the 818 will get classed there as well once a few pave the road.

So don't drive too fast, you guys that are first getting your car done, or the rule makers will stick us in higher classes (STR) or stick us with a bigger weight penalty.

I only know how to drive FLAT OUT.....lol

Good ideas..... I like to sandbag.

[JeromeS13]

I only know how to drive FLAT OUT.....lol

Do you need to be moved to the fastest run group?

[EricScottZehnder]

I just ran through this thread and it seems that most people will go with 30mm split front to rear. What I've also heard people talk about is getting to the upper limit of wheel diameter with a small sidewall. What I'm wondering is why.

As far as I know, you want a small wheel, not massive sidewall, and not overly massive overall tire diameter. Wheels weigh a lot more than rubber. Also, the taller the wheel the smaller the contact patch. I was reading an article recently talking about how people that go from, say, 16" wheels with 215mm rubber to 18" wheels and 235mm rubber are actually getting less grip because the taller tire means smaller overall contact patch. Note: These aren't the exact sizes, just an example.

Would it not be advisable to go for something like 14-16" lightweight wheels with the widest rubber that the car can accommodate and warm up?

Example: Check this F1 car's wheel size vs. rubber. (http://thenerdinsurance.us/wp-content/uploads/2010/11/3316d20dpirelli_1.jpg)

[C.Plavan]

I just ran through this thread and it seems that most people will go with 30mm split front to rear. What I've also heard people talk about is getting to the upper limit of wheel diameter with a small sidewall. What I'm wondering is why.

As far as I know, you want a small wheel, not massive sidewall, and not overly massive overall tire diameter. Wheels weigh a lot more than rubber. Also, the taller the wheel the smaller the contact patch. I was reading an article recently talking about how people that go from, say, 16" wheels with 215mm rubber to 18" wheels and 235mm rubber are actually getting less grip because the taller tire means smaller overall contact patch. Note: These aren't the exact sizes, just an example.

Would it not be advisable to go for something like 14-16" lightweight wheels with the widest rubber that the car can accommodate and warm up?

Example: Check this F1 car's wheel size vs. rubber. (http://thenerdinsurance.us/wp-content/uploads/2010/11/3316d20dpirelli_1.jpg)

A taller tire with same width will always have a bigger contact patch. Hypothetically, picture a tall 32inch off road tire, then picture a regular 16" car tire- both the same width. Which one will have a larger contact patch? The off road tire because of it's physical size/diameter. So regardless of the wheel size, the taller the tire, the bigger the contact patch. (Width being constant)

[Xusia]

Also, a smaller sidewall reduces tire flex under cornering. I don't personally think there will really be too much difference for those intending to use it mostly on the street, but it is a concern for some.

[Bob_n_Cincy]

Putting on my engineering hat I look at a racing car that has no tire size restrictions.
Sébastien Loeb decimated all at pikes peak this year running 31/71-18 Michelin Tires.
I believe that translate to a 315mm wide 710mm (28") tall 18" tire.
So there for (28 - 18) /2 = 5" tall sidewalls.
If I scale down the diameters by 10% I get a 25" tire on 16" rims with 4.5" sidewalls.
The Toyo Proxes R888 245/45ZR16 with 8" wide rims are close to the numbers for the rears.
I'm running autocross now 225/45ZR16 all the way around. I will use these on the fronts of the 818

What to you think of my idea?
Bob

21594

[wallace18]

Putting on my engineering hat I look at a racing car that has no tire size restrictions.
Sébastien Loeb decimated all at pikes peak this year running 31/71-18 Michelin Tires.
I believe that translate to a 315mm wide 710mm (28") tall 18" tire.
So there for (28 - 18) /2 = 5" tall sidewalls.
If I scale down the diameters by 10% I get a 25" tire on 16" rims with 4.5" sidewalls.
The Toyo Proxes R888 245/45ZR16 with 8" wide rims are close to the numbers for the rears.
I'm running autocross now 225/45ZR16 all the way around. I will use these on the fronts of the 818

What to you think of my idea?
Bob

21594

Bob it is going to hit the frame. See the did you notice The how little thread in the suspension area. Jim the engineer tells how 25" will hit. I think you need 1/2 to 3/4" less dia. JMO.

[Bob_n_Cincy]

Bob it is going to hit the frame. See the did you notice The how little thread in the suspension area. Jim the engineer tells how 25" will hit. I think you need 1/2 to 3/4" less dia. JMO.

My clearance seems to be fine. I'm within 3/8" of the ball joint. I am running stock rims with 55 offset, so my turning center is closer to the middle of the tire.
I'm going to mount all my autocross tires tonight and do a rough alignment.
I'll double check clearance.
Bob

[EricScottZehnder]

A taller tire with same width will always have a bigger contact patch. Hypothetically, picture a tall 32inch off road tire, then picture a regular 16" car tire- both the same width. Which one will have a larger contact patch? The off road tire because of it's physical size/diameter. So regardless of the wheel size, the taller the tire, the bigger the contact patch. (Width being constant)

I found a good calculator here: http://bndtechsource.ucoz.com/index/tire_data_calculator/0-20

It looks like this theory holds true but the difference is minimal. What makes a much bigger difference is overall width. Certainly, you're going to want to fill up your wheel wells (within reason) but if the trade is between a tire that is overall taller or overall wider, you're going to want wider. More than any of that, though, is making sure your rubber is of the best compound and set to a tire pressure that, along with the size and construction of the sidewall, gives you good grip and feedback.

Also, non-slick tires have varying tread patterns. Some have large gaps between contact patches which is bad for overall contact patch but good for allowing them to heat up and cool down when necessary.

No wonder games have a hard time simulating this stuff.

[Frank818]

No wonder games have a hard time simulating this stuff.

LolllllllllllllllllLL!!!!!!! That's a good one. :)

[Bob_n_Cincy]

Bob it is going to hit the frame. See the did you notice The how little thread in the suspension area. Jim the engineer tells how 25" will hit. I think you need 1/2 to 3/4" less dia. JMO.

I put my tires back on tonight to check clearance.
As I stated in post #118 my fronts are going to be Toyo Proxes R888 225/45ZR16 55 offset rims. They are 23.8 inflated diameter. They are at 41 psi right now.
I have about 1.25-1.5" on the right and 1.0 to 1.25 on the left.
see attached pictures.
21612
now the left side
21613
the 245 front tires Michael wants to use sitting next to a stock impreza tire
21609
Sébastien Loeb tires
2161021611

[wallace18]

I put my tires back on tonight to check clearance.
As I stated in post #118 my fronts are going to be Toyo Proxes R888 225/45ZR16 55 offset rims. They are 23.8 inflated diameter. They are at 41 psi right now.
I have about 1.25-1.5" on the right and 1.0 to 1.25 on the left.
see attached pictures.
21612
now the left side
21613
the 245 front tires Michael wants to use sitting next to a stock impreza tire
21609
Sébastien Loeb tires
2161021611

I stand corrected! LOL.

[EricScottZehnder]

Am I right in thinking that you need to add more positive offset for the larger tires because the tire needs to sit deeper to the center of the car body to not protrude out the side of the fenders? If so, how large of a rear tire can you use? There has to be some absolute limit like 315, 335 or something (even though I would never consider such wide wheels on a car this light).

[Bob_n_Cincy]

Am I right in thinking that you need to add more positive offset for the larger tires because the tire needs to sit deeper to the center of the car body to not protrude out the side of the fenders? If so, how large of a rear tire can you use? There has to be some absolute limit like 315, 335 or something (even though I would never consider such wide wheels on a car this light).

The back wheels are limited inside by the upper and lower trailing arms. FFR is saying 255 max with 40 offset rims.

[EricScottZehnder]

Bob - If 255 is the max rear than aren't you worried about having an oversteery mess with 245 fronts? It sounds like Wayne believes 30mm split would be best which is 225 fronts.

[Bob_n_Cincy]

Bob - If 255 is the max rear than aren't you worried about having an oversteery mess with 245 fronts? It sounds like Wayne believes 30mm split would be best which is 225 fronts.

Sorry if I was confusing.
Only my son wants to run 245 on the front. He is 16 and also wants 800 HP.
I plan to run 245/45ZR16 for the rears and 225/45ZR16 on the fronts.

As a side note: I have a 400 lbs battery pack I could put in the same box as the master cylinder giving the car a 50/50 weight. If I do this, I may run a square set of tires.
Bob

[WRX Dave]

Using the shorter wagon rear control arms, would it work to run a 30 offset and open up more clearance for a wider rear wheel?

[Bob_n_Cincy]

Using the shorter wagon rear control arms, would it work to run a 30 offset and open up more clearance for a wider rear wheel?

Hi Dave
I started out running my shorter wagon arms with my stock 55 offset wagon 6 1/2" wheels.
Only have 1/2" clearance between upper and lower trailing links and tire.( I am running 9" wide 225 tires on 6 1/2 rims)
If i went to 30 offset it would move the wheel out 25mm (1") so you could go to 11" 275 tires.
Note ( my side walls don't bow out because of narrow rim. If you put 275 tires on and wide rims, your overall tire width will be greater than 11" and might rub)
I think Wayne is doing some extra curved trailing arms to help with this.

I don't want to go to real wide tires but I do want them flush to the side of the car. So I put in adj. lateral links and set them to sedan width and then some. I'll set my rear quarter panels in place this week to see how the look.

Another note: I like the big offsets (55) because it keeps the bearing in the center of the tire.

Bob

[WRX Dave]

I wouldn't be worried about the rear wheel bearings on this car. They haven't worn out after 150k miles on my '03 WRX, and that includes about 25 hours of track time and six years of rallycross abuse. Given the weight of the 818 we should be able to run any offset that fits under the fender without bearing issues. The fronts are a little more of an issue. I had to replace both fronts on mine before 75k miles, and my friend who tracks his '05 on R-comps has gone through five front wheel bearings in the last two years. The more serious Subie guys I know keep a spare set of assembled front uprights in their race trailers.


I'm not planning on anything that crazy with rear wheels. Probably just a 17x9 or 18x9.5. There seem to be a lot more wide wheel options at 30 than 40 offset, so my plan would be to run 30 offset with wagon arms in the back with 245 tires, then use 17x8 wheels in the 40-48 offset range up front on sedan control arms with 215 tires.

[Mechie3]

Posted these in my build thread too.

225/40/r18 on an 18x8 et 48 wheel. Random wheel/tire I had lying around to make a table out of. Maybe 1/8" of clearance at the firewall. Plenty of clearance at the strut and upper ball joint. Math says diameter is 25.09". Tire was a Bridgestone RE 760 sport.


http://i.imgur.com/girLCWn.jpg?1

225/45/r17 on a 17x7 et 42 wheel. These are my WRX winter wheels. It only cleared the firewall because a groove in the tread lined up perfectly. A slick at this size would rub slightly at full lock. Math says diameter is 24.97. Tires were Blizzak WS-60
http://i.imgur.com/e35h0Y2.jpg?1

[mrprgrmr]

Reading this thread, I am trying to decide if there is any tire configuration that would be safe for use with my stock wheels (16 x 6.5"). For the moment, lets assume there is someone out there (me?) who would rather not spend $1200 on wheels at the start and would prefer to run on stock rims. Tires wear out and the wheels could be upgraded later.

The goals would be:
1) adequate traction for typical street conditions - spirited but not insane driving
2) Minimize the chances of oversteer & spinning the car due to inexperience and MR design
3) Ignore aesthetics for the moment
4) Ignore "ideal" and think about "adequate"

Assumptions:
1) The maximum width tire on a 6.5" wheel is 225 (yes, it would be a bit bulgy)
2) The minimum width tire on a 6.5" wheel is 190
3) The "ideal" configuration suggested by FFR for an 818S is 215 front and 255 rear (it's in the assembly manual)
4) 818S with a stock WRX power plant (round down to 225HP - it's an old engine)
5) FFR designed the 818 to handle more than stock HP (perhaps 300 HP?)

#4 is the only one I have absolutely no evidence for - it just seems to make sense. If you were to downsize the front tires to 190 and plus size the rear tires to 225, you would have 35mm difference between the two. Perhaps a little less because of non-ideal rim size for the 225's. I think you would have roughly 12% (25mm) less contact area in the front and 12% less contact area in the back compared to FFR's stated ideal 215/255 combo, with 25% less power (225 vs 300 HP design assumption). It might be butt ugly but this seems like a reasonable combo to attempt from a performance/safety standpoint. I would tend to think you could improve the appearance a little playing with the sidewall sizes.

Is my logic seriously flawed or should I just resign myself to the implausibility of building this car with stock wheels.

[Xusia]

Like you, I spent a lot of time worrying about these issues, along with fitment. I was in a slightly different position, as the wheels on my donor were for, all intents and purposes, destroyed in the crash that made it a donor. I had to buy wheels, whereas you don't.

You stated you want to use the stock wheels, but that seems mostly based on the perceived price of new wheels. After doing all my research I think using the stock wheel is going to be a compromise, and new wheels can be had for less than you might think. Specifically, I would suggest looking into the XXR line of wheels. They are very affordable, are not bad in regards to weight, and allow fitment of tires much more suited to your intended use. I bought a set of the XXR 530 (17x7 ET+35 front, 18x8.75 ET+33 rear) for less than $500. And that included shipping.

Bottom line is it's both an easier and better solution. Yes, you'll spend some additional money up front, BUT:
1. Think of it as insurance (better traction means less chance of an accident)
2. You'll spend less time thinking/worrying/dealing with this

[mrprgrmr]

Xusia - Thanks for setting me straight. You found the one assumption that I didn't explicitly state as such (and was wrong). Somewhere in here, I was seeing posts listing $300 each as reasonably priced wheels so I assumed roughly $1200 unless I went with steel wheels (not necessarily a bad idea if I could find them). Obviously, we all have different expectations and I don't see $300 each as unreasonable for good quality wheels but it is more than I wanted to spend considering I basically like the Subie wheels.

For $500, I agree that it is not worth taking chances with an untested and inferior combination. Sooner or later, the Subaru wheels may go on eBay or craigslist so I can recoup some of what I spend on new wheels.

XXR FTW!

[Xusia]

Did I mention Wayne is an XXR dealer? :)

[SixStar]

Remember that "fit" is a relative term.

I run a 17x9 on my WRX with a 275/40-17. Rolled rear quarters and the front liners need replacing frequently, but that's the price to pay for a Solo championship.

Here's a 18x10.5 with 295s (closer to 305, silly Hoosier) on the 818R.

24363

[bnr32jason]

Not trying to spam this, but I just lowered the prices on my wheels for sale (by A LOT):

http://thefactoryfiveforum.com/showthread.php?12134-(2)-Sets-of-Volk-CE28-(17x7-5-amp-18x8-5-and-17x7-5-amp-18x9)-Wheels-(818-Fitment)

Not building my 818 as hoped, so need to get these sold so I can start my other project.

[Scargo]

I've been saving up a lot of thoughts for this moment (having read all this in one sitting). Probably can't remember them all.
It would be nice to see any notation of wheel clearance and setup in the spreadsheet. Some might run a different rear spring diameter, for instance.

I can see that a lot of people will not be wanting to see how big they can go. The Prius tire size example reminded me of how I would not have been able to drift my Prius had the tires been bigger. Also, and especially with a light car, hydroplaning can be a real problem when the tires are too big.

I don't think a Pike's Peak dirt tire and it's profile is applicable to a hard pavement race tire.

My 275x35x18 BFG's are 25.5" tall. They are the equivalent of a 285 Hoosier. Am I correct in my impression that in the rear, they are too tall and will rub up top and in front?
255x40x18's with 40ET are being run on the rear of the FFR car. What rim width and offset? What about a 45 or 48 offset wheel in 10-10.5 width? Has anyone tried either?

Some 17" wheels will not work with a 282 mm BBK and some BBKs fit more easily than others. I'm still puzzling over how big a BBK to go with on the front and how it might affect my wheel choices.

[Xusia]

I don't have my body on yet, but I think you are going to have a hard time fitting anything that is 285mm wide (I don't understand why they would label it a 275 if it has a 285 section width, but that's another matter). With the right wheels & trailing arms you can get a 265 in the rear. You might also check Erik Treve's thread. I know he is running some wide tires.

In the front, good luck. Lots of issues. If you don't want it rub, tire sizes are limited.

All that said, general wisdom says wider is better, but on the other hand, FFR's 818R is putting down blazing lap times, and getting awesome corning and braking forces. All on smaller tires. Just sayin... :)

[Scargo]

No, your points are well taken. With the FFR racer, that was with around 300 WHP or about 7:1. I am building for ST1 or 5.5:1. As an aside, I've been told STR is being eliminated and I don't know how they ran the car in STR-3, which has a 9:1 power to weight limit.
My intentions are to build a completely unique front suspension so all the mounting points may change. The wheel center point may move forward and out, especially if I lengthen the LCA. I'm just speculating since I have no dimensions and no kit. No kit means I am on here, spouting off more.:o

[Santiago]

I'm pretty sure that they first ran the Blue R-car in STR-3 with a different turbo on the car. Put differently, I think they were legal then, but didn't bother to remove the class designation for other events in which that class wasn't being run. I think now they would be in ST1 with the same 300-320whp. You've seen my calcs on the classing. I think with most of the weight targets folks will have, we're looking at similar power levels if we also run slicks like the R-car does.

I'm also planning something different for the front - not quite a "unique" front suspension, but working with what we've got within reason (although I'm not sure others would share my standard of reason). I'm not so much interested in fitting wider tires as much as getting wider track. Dave Smith is fond of saying "weight is the enemy" and he's right...but I think it's more helpful to think in terms of saying "weight transfer is the enemy." A necessary evil (like weight), but an evil all the same. I think I'm going to start using that as my tag line...

Anyway, if you're going to revamp the front suspension, do what you can to increase track (and plan on being able to do similar in the rear). Bottom line: we're flaring those fenders buddy! They got to go.

Oh, on the BBK concerns, some of the more track-oriented vendors will work with you using templates to confirm wheel fitment. So if you've got a BBK in mind, see if you can find a wheel vendor who's willing to use it before you buy. I know of some who've done this for me in the past, but they're not on these forums so contact me direct. I wouldn't be surprised at all if Wayne would check a template for you if you're looking at some of the wheels he sells.

Best,
-j

[Scargo]

Traction! We need to generate more traction! My new byline...

"We're flaring those fenders buddy! They got to go."
I'm on board! She needs to have more of a "big butt" look! We're dealing with raw bodywork. Slap a curved piece of material on there and start laying up against it! No biggie.:p

[bompus]

Can you add these tires to your shared Google spreadsheet?

Sumitomo HTR Z III
- Cost 146 , Weight 26 lbs , Rim Size 18 , Rim Widths 8.5 - 10 , Tire Size 255/35 , Section Width 257mm

Sumitomo HTR Z II
- Cost 76 , Weight 20 lbs, Rim Size 17, Rim Widths 7 - 8.5 , Tire Size 215/40, Section Width 216mm

Now a wheel question... I'm planning XXR 530 18x8.75 +33 rear with 255/35 , 17x7 +35 front with 215/40 - does anybody see any issues with this and the stock setup?

[Wayne Presley]

Can you add these tires to your shared Google spreadsheet?

Sumitomo HTR Z III
- Cost 146 , Weight 26 lbs , Rim Size 18 , Rim Widths 8.5 - 10 , Tire Size 255/35 , Section Width 257mm

Sumitomo HTR Z II
- Cost 76 , Weight 20 lbs, Rim Size 17, Rim Widths 7 - 8.5 , Tire Size 215/40, Section Width 216mm

Now a wheel question... I'm planning XXR 530 18x8.75 +33 rear with 255/35 , 17x7 +35 front with 215/40 - does anybody see any issues with this and the stock setup?


Wheels will work well but you may want a stickier tire than those on such a light car.

[Xusia]

EDIT: Spreadsheet updated.

As for fitment, you shouldn't have any issues with those sizes. I have the XXR 530s in those same sizes, and I'm running the same tire sizes (different brand; more on that in a sec). They are good match for the car.

As for the tires, I have no experience with the HTR, but you might want to consider the Federal 595 RS-R. It's [supposedly] very sticky, and a bit cheaper for a set. They do tend to run wider than their indicated size, but they still fit those rims very well and have no clearance issues.

Here are 2 views the fitment of the tire to the wheel:
25927

25928

I don't have any pics of the back wheel & tire, but fitment is idential.

[bompus]

I like the Federal 595 RS-R .. they do seem harder to find, but not impossible. I was somewhat concerned in using a soft tire because of how hot it gets in Tucson, AZ ( hot! ) that the softer tires wouldn't last very long. I guess I can always give them a shot and see how they perform. Thanks for the quick responses guys.

[C.Plavan]

Bringing this thread back to life- I'm getting ready to pull the trigger on some race tires for the 818R. I need some opinions. Please note: I have 5mm and 3mm spacers to adjust fitment.

Hoosier R6's

Front- 225/40 R17 on a 17x8 inch rim +38 (23.8 diameter, overall width 9.8, tread width 8.9) Spec measurements were on a 7.5" rim
Rear- 255/45 R7 on 17x9 inch rim +40 (26.2 diameter, overall width 10.8, tread width 9.8) Spec measurements were on a 9" rim

Toyo RR (new race tire)

Front-235/40 R17 on the 17x8 +38 rim (24.4 diameter, overall width 9.5 -no tread width listed :( ) Spec measurements were on a 8.5" wheel
Rear- 275/40 R17 on th 17x9 +40 rim (25.7 diameter, overall width 10.9- no tread width listed) Spec measurements were on a 9.5" wheel

Optional Rear- 255/40 R17 (25.00, 10.2) Spec measurements on a 9.0" rim

So there it is. My dilemma- I don't want to buy $ tires and say $&*^. What does the 818 "Think Tank" think?

[Santiago]

Not sure what sort of "thinks" from the tank you were interested in, so I'll just try a stab at some random thoughts.

Fitment: looks like all o.d.'s should fit fine, so you're clear there.

Tire options: I'd lean towards R6's just because I'm familiar with the tire (it's my choice for the first "test tire"). I thought (don't quote me on this) that the RR was a step down from the R6 in terms of overall grip. If so, another reason to opt for the R6, unless longevity is high on your priority list.

Height Differences: obviously the R6 combo you spec'd out has greater fr/rr size difference. You're looking at a noticeably taller sidewall in back, but honestly I don't know what to tell you about that for our application. In theory you might expect the front to have a crisper response than the rear, so maybe you would end up looking at working to tune that difference out if it surfaces in a nasty lag between the time it takes for the front and rear to take a set. I dunno though...shooting from the hip here...

Stagger: I have to say I kind of like the idea of a 40mm split. I know Wayne has spoken fondly of the 30mm split that the Blue R-car ran, but I think that was with the front sway bar in play. I'd like to take that thing off and work with springs/tires/track to balance the car out. So removing the front bar might make your "wide" rears a sensible route to get the rear to come up to par with the increased front grip.

All in theory of course. :)
You're just one of the lucky chums who gets to do the concept validations.

Best,
-j

[Wayne Presley]

the 818R that I drove didn't have a front bar

[Rasmus]

I'm getting ready to pull the trigger on some race tires for the 818R. I need some opinions. What's your primary use going to be? AutoX? Track Day? Drag Race? Time Trial? Hill Climb? 24 hr endurance? Rally? MotoGP?

[Santiago]

the 818R that I drove didn't have a front bar

Wayne, did you drive it with the Hoosier R6's or the Yokohama Advan A005 slicks? Just curious.

What I'd really like to know is what their tire temps looked like... =) I have this worry (probably unfounded) that we might have trouble getting a larger tire up to temp in the 818 (and just as a heads up, fender flares are a given for me, so when I think "larger" I'm not constrained by that for how large).

Chad, along the lines of Rasmus' question, are you planning to compete in a class that you can fit into with 275s? Are the 255s going to permit you more legal power for your class? I guess, I'm asking if we should also be contemplating the trade offs between tire size and legal power?

Best,
-j

[C.Plavan]

Wayne, did you drive it with the Hoosier R6's or the Yokohama Advan A005 slicks? Just curious.

What I'd really like to know is what their tire temps looked like... =) I have this worry (probably unfounded) that we might have trouble getting a larger tire up to temp in the 818 (and just as a heads up, fender flares are a given for me, so when I think "larger" I'm not constrained by that for how large).

Chad, along the lines of Rasmus' question, are you planning to compete in a class that you can fit into with 275s? Are the 255s going to permit you more legal power for your class? I guess, I'm asking if we should also be contemplating the trade offs between tire size and legal power?

Best,
-j

Strickly road racing- I am familiar with the R6's also- But the new Toyo's are cheaper (test tire), and stick/last longer than the Hoosier. Plus the Toyo's have a better contingency program.

I will be racing with NASA, At first I am not worried about the classing/tire size. I just want to make sure the car is reliable and work the gremlins out. Then I will worry about what class I will fall into.

I'm really interested in the Toyo's and want to test them out. I would hate to flat spot the pricer Hoosier adjusting the brake bias the first time out! :)

I just wanted to see if the sizes listed above are even doable. Keep in mind the Hoosiers are much wider than other tires of the same size.

[Santiago]

Keep in mind the Hoosiers are much wider than other tires of the same size.

No! Hoosier wouldn't do that...:rolleyes:

Ok, so the RR's sound like they make sense for your gremlin runs. Are you flaring fenders? If not, you may be on the wide side. In front, Erik T. tried 235s but I think they were of a much larger outside diameter.

For the back, things might get dicey. The Road & Track article featured the Blue R at Gingerman wearing Hoosier R6s (if I'm not mistaken). I'm not sure exactly what size they were, but maybe Wayne knows. Here's a look at them:

27285

Looks like that sets your limit on what will fit, unless something like Wayne's trailing arms would allow you to tuck this in further than what you see here. I also don't have any specs on what wheels were on the Blue R for this pic.

Best,
-j

[Rasmus]

Strickly road racing
American Racing makes several nice all-stickys (http://www.americanraceronline.com/racing-tires/asphalt.html).
http://www.americanraceronline.com/Images/Treads/trtead-s-Lg.jpg
Look at that tread pattern! That's the "I-mean-business-super-cereal" pattern. They even make them 16 different grades of softness/stickiness:

User review on the GRM forums. (http://grassrootsmotorsports.com/forum/grm/new-tire-found/50100/page1/)

Largest wheel diameter they make tires for is 15". I'm looking at their 23.5-10-R15's for AutoX which in metric is about a 275/40R15. Sticky steam rollers.

A metric 275/40R17 in an old-skool imperial size 15" would be about a 25.5-10-R15 or a 26.0-10-R15

[Scargo]

Per Jim Schenck (http://thefactoryfiveforum.com/member.php?2215-Jim-Schenck), "wheels on the R are Rota Torque, the rear are 18x9.5 with a 35mm offset and they do rub slightly with the 255 hoosiers although those tires have a section width more like a 275 than a 255". He also said, "The tires rubbed on the outside, but there were two other factors that kind of cancle each other out a little. The R sits about an inch lower which hurts clearance but we ran more static camber which helps it. A slightly narrower tire like the 255 Toyo, and 5mm more offset is what we have on the white car and it is a nice fit. Maybe a 275 could be made to fit with some specific brand and just the right offset but I think it would probably require a bit more camber than you would usually run on the street, so we are saying 255 is max for what we know will work without problems."

As to tires, I was pleased with the traction, life and price of the Goodrich R1-S. I made this switch kinda late in the season, when things were cooling down on the track. I've gotten good life out of them. They say they are not as well suited for extremely hot days.
This was after running 888's and just previous to the BFG's, Hoosier R6's.
A 17" 255-40 R1-S (10.3"TW/10.2"SW 24.8"D) will run you $265 from Phil's, while a R6 255-45(9.7"TW/10.8"SW/26.2"D) will run $288 and a .010" shy of 4/32" tread depth Toyo RR is 10.2"overall width and 25"D for $232 (the cheapest). The BFG and Toyo look interesting if for nothing more than the footprint, sidewall width and smaller diameter. Did not see Toyo listing tread width.

[07FIREBLADE]

What are the fronts for the 818R, i know the rears are rota torque 18x9.5, just need to figure out the front size.

[Wayne Presley]

Wayne, did you drive it with the Hoosier R6's or the Yokohama Advan A005 slicks?
Best,
-j
I drove it with the R6's


27285

Looks like that sets your limit on what will fit, unless something like Wayne's trailing arms would allow you to tuck this in further than what you see here. I also don't have any specs on what wheels were on the Blue R for this pic.

Best,
-j[/QUOTE]

The arms do allow you to tuck more tire under the body

[wleehendrick]

I've been debating what wheel/tire size to run on my 818S. To avoid rubbing issues in front, a OD (overall diameter) of less than the Subaru stock 25" seems to be recommended. The issue is, with a 17" wheel, this really limits tire choices wider than 205mm. There is very limited choices in a 215/40-17, but almost nothing >225mm.

So, what about a 16" rim in front? I'm really not up on what will fit, but this occurred to me when I noticed that the donut (space saver spare) from my donor is 16". I've got 2006 WRX brakes, and the knew that stock alloys were 17", so I had only really been considering >17" wheels and tires. But since the spare is 16", 16x7 or 16x8 rims should clear the brakes in front... Is this a correct assumption?

I'm not hung up on big rims... and this opens up a lot more choices for sticky rubber in the front in 225/45-16. I'm thinking a 255/40-17 in the rear which would provide a nice staggered set-up. The 30mm width difference seems to be recommended for balance, and aesthetically, I think the same sidewall height with a 1" larger rear wheel will look best.

Thoughts?

[Bob_n_Cincy]

I'm not hung up on big rims... and this opens up a lot more choices for sticky rubber in the front in 225/45-16. I'm thinking a 255/40-17 in the rear which would provide a nice staggered set-up. The 30mm width difference seems to be recommended for balance, and aesthetically, I think the same sidewall height with a 1" larger rear wheel will look best.

Thoughts?

These are 225/45-16 R888 on 16x6.5 55 offset stock rims (Last years G-Stock autocross wheels)

27316

27317

[wleehendrick]

These are 225/45-16 R888 on 16x6.5 55 offset stock rims (Last years G-Stock autocross wheels)


R888's are what I'm thinking of, that size in front. On a 17" front rim, R888's would require dropping to 205's, or possibly rubbing with a 215-225/45-17. I see you have th 02-05 brakes. My donut is 16" and Tirerack shows 16" ('-1') wheel fitment for the 06 WRX, so I'm hoping there's no clearance issues with the 4-pots, just want to hear from someone that's tried it.

[Bob_n_Cincy]

R888's are what I'm thinking of, that size in front. On a 17" front rim, R888's would require dropping to 205's, or possibly rubbing with a 215-225/45-17. I see you have th 02-05 brakes. My donut is 16" and Tirerack shows 16" ('-1') wheel fitment for the 06 WRX, so I'm hoping there's no clearance issues with the 4-pots, just want to hear from someone that's tried it.

The brakes and wheels in that picture are off an 06 NA wagon 277mm front rotors.
My second donor is an 04 FXT with larger front rotors 294mm but still only 16" wheels.
06 wrx has 294 mm rotors
06 sti has 326mm rotors.

I think you can conclude the 294mm rotors will fit in 16" wheels because of my FXT.
Bob

[wleehendrick]

Thanks for the info... 16" should fit in front, but now the issue is wheel choice. I can't find anything that's available in a 16x7.5(+/-0.5) and 17x9.0(+/-0.5) with a 5x100 pattern. I may just go with 17x7 & 18x8.75 XXR's, with 215s in front, like GRM did (http://grassrootsmotorsports.com/project-cars/2013-factory-five-818/hot-wheels-818/).

[Xusia]

...I'm thinking a 255/40-17 in the rear which would provide a nice staggered set-up. The 30mm width difference seems to be recommended for balance, and aesthetically, I think the same sidewall height with a 1" larger rear wheel will look best.

Thoughts?

I don't know for sure, but I wonder if the additional sidewall height (vs. a 215/40-17) would negate the additional 10mm of width.


...I may just go with 17x7 & 18x8.75 XXR's, with 215s in front, like GRM did (http://grassrootsmotorsports.com/project-cars/2013-factory-five-818/hot-wheels-818/).

I have the XXR 530's in those sizes, and I put Federal 595 RS-R tires on them: 215/40-17 in front, and 255/35-18 in back. They fit very well. And since the sidewall height is nearly identical (89mm & 91mm, respectively), It's hard to even notice the size difference. It's a really good looking and well fitting combination. :)

[wleehendrick]

I don't know for sure, but I wonder if the additional sidewall height (vs. a 215/40-17) would negate the additional 10mm of width.

Any of the 225/45-16 tires I'd want (R888 for example) have stiff enough sidewalls, I don't think it's an issue.


I have the XXR 530's in those sizes, and I put Federal 595 RS-R tires on them: 215/40-17 in front, and 255/35-18 in back. They fit very well. And since the sidewall height is nearly identical (89mm & 91mm, respectively), It's hard to even notice the size difference. It's a really good looking and well fitting combination. :)

I've been thinking about that exact combo (chromium black rims) for a while, so if I end up with it, I hope you don't think I'm copying you!

Thanks for the info,

Lee

[Xusia]

Hahaha! Not at all. I hope my experience is helpful.

[JeromeS13]

Here's my setup:

17x8 +45 (using 10mm spacers, making the effective offset +35)
235/40/17 Federal 595 RS-R

18x9.5 +45 (using 13 mm spacers, making the effective offset +32)
265/35/18 Federal 595 RS-R

VCP Trailing Arms

4.5" ride height

"Free caster mod" on the front. This is basically adding 10mm aluminum spacers between the front lower control arm aft mount and the arm itself.

I only have minimal tire rub from the front end, on the aft section of the inboard aluminum.

http://i157.photobucket.com/albums/t43/JeromeS13/Project%20818/20140330_183452_zpspcr2x2en.jpg (http://s157.photobucket.com/user/JeromeS13/media/Project%20818/20140330_183452_zpspcr2x2en.jpg.html)
http://i157.photobucket.com/albums/t43/JeromeS13/Project%20818/20140330_183503_zpseukm9pvb.jpg (http://s157.photobucket.com/user/JeromeS13/media/Project%20818/20140330_183503_zpseukm9pvb.jpg.html)
http://i157.photobucket.com/albums/t43/JeromeS13/Project%20818/20140330_183520_zpseak0ekrj.jpg (http://s157.photobucket.com/user/JeromeS13/media/Project%20818/20140330_183520_zpseak0ekrj.jpg.html)
http://i157.photobucket.com/albums/t43/JeromeS13/Project%20818/20140330_183530_zpsmxi3lgmk.jpg (http://s157.photobucket.com/user/JeromeS13/media/Project%20818/20140330_183530_zpsmxi3lgmk.jpg.html)
http://i157.photobucket.com/albums/t43/JeromeS13/Project%20818/20140330_183542_zps06peif2e.jpg (http://s157.photobucket.com/user/JeromeS13/media/Project%20818/20140330_183542_zps06peif2e.jpg.html)
http://i157.photobucket.com/albums/t43/JeromeS13/Project%20818/20140330_183555_zpstrfffzin.jpg (http://s157.photobucket.com/user/JeromeS13/media/Project%20818/20140330_183555_zpstrfffzin.jpg.html)
http://i157.photobucket.com/albums/t43/JeromeS13/Project%20818/20140330_183614_zpsxlk0w9zy.jpg (http://s157.photobucket.com/user/JeromeS13/media/Project%20818/20140330_183614_zpsxlk0w9zy.jpg.html)


Not my picture, but this clarifies the "free caster mod":

27440

[metalmaker12]

You have a honda fit also, lol

Jdm engine, honda fit, 818 small world, looking good, did you get a price on a new front bumper, I am wondering what they cost, cause at some point I am going to trash mine as well. I get my tags weds, I would have had them Friday, but I had to get the title person to issue it and they were not back till weds.

[JeromeS13]

You have a honda fit also, lol

Jdm engine, honda fit, 818 small world, looking good, did you get a price on a new front bumper, I am wondering what they cost, cause at some point I am going to trash mine as well. I get my tags weds, I would have had them Friday, but I had to get the title person to issue it and they were not back till weds.

Not yet, I haven't even sent an email yet. I'll probably send one tomorrow. It's toward the bottom of the list right now. I'm trying to tidy up and finish a lot of other things.

[07FIREBLADE]

Do you need to do this caster mod to essential run a +35? Or it's ideal because of adjustability?

[JeromeS13]

Do you need to do this caster mod to essential run a +35? Or it's ideal because of adjustability?

It allows you to run a slightly wider tire up front.

[C.Plavan]

It allows you to run a slightly wider tire up front.

Jerome- You are giving me hope on running a 235/40 R17 Toyo RR race tire. Do you think by adding more camber (2.5+), and using the R height that will help the inside rubbing or hurt?

[JeromeS13]

Oops. I forgot to mention, I'm running 2.5' negative camber up front and 2.0' in the rear.

[C.Plavan]

I ordered up the "Pirate" Tires- Toyo RR's- 235/40 R17 and 255/40 R17, wish me luck.

[FFRSpec72]

I ordered up the "Pirate" Tires- Toyo RR's- 235/40 R17 and 255/40 R17, wish me luck.

Bad boy, I can see re treads coming your way from old RA-1s

[Kalstar]

Since I have 100% decided my 818 will be black. I have been getting ready to order wheels. All three of these wheels are 3 piece and are from a company name Niche. This go around there will be no budget, but I do not want to make a costly mistake.

Opinions on which wheel will look best??

[Wayne Presley]

I like 1&3 best. Can you get different colors rims on #3?

[C.Plavan]

I have a roller!
http://i.imgur.com/oOXlInol.jpg
http://i.imgur.com/p2WNVqIl.jpg (http://imgur.com/p2WNVqI)
http://i.imgur.com/Lt3Mjsql.jpg (http://imgur.com/Lt3Mjsq)

Front 235/40 R17 Toyo RR (17x8 +38 with 3mm spacer for now)
Rear 255/40 R17 Toyo RR (17x9 +40 with 5mm spacer- Clears regular WRX trailing arm fine- but car still need alignment)

[Kalstar]

I like 1&3 best. Can you get different colors rims on #3?

Yes, I can get any color I want.

[metalmaker12]

Yes, I can get any color I want.

You bold man, that looks killer man

[Xusia]

I'm with Wayne. I like #1 & #3. I have a slight preference for #3.

[Wayne Presley]

Yes, I can get any color I want.


then #3 for sure!

[TahoeTim]

be different - go with #3, add small bronze accents/stripes and do a BROWN interior. I am waiting for someone to do a brown interior.

[Scargo]

Although I'm looking at racing and will do something much like C.Plavan's wheels (which I like a lot), I like #2, the Niche Geneva H520. What about red or lime green rims? I wonder how much they weigh? The car begs for light wheels and tires.

Now that I know 235's work in the front, one of the first things I will do is see how my 18x10.5" Enkei RPF-01's (38ET) with BFG 275/35's (off the STi) will fit the rear.

[GUNS]

Anyone see any issues running a front setup of 17 x 8 + 35 offset w/ 225/45 & a rear of 18 x 9.5 +40 offset w/ 255/35's?

[Wayne Presley]

Anyone see any issues running a front setup of 17 x 8 + 35 offset w/ 225/45 & a rear of 18 x 9.5 +40 offset w/ 255/35's?

Yes, fronts are going to be too large in diameter

[GUNS]

Yes, fronts are going to be too large in diameter

So I would probably need to go with a 215/45 up front with that offset?

[wleehendrick]

So I would probably need to go with a 215/45 up front with that offset?

It's the diameter that's the issue; others have posted rubbing issues with stock Subie diameter (25") tires. 215 vs 225 tread width does't really address the issue, you need a thinner sidewall. I'll be going with 215/40-17 (around 24" OD). Same size as the GRM car:

http://grassrootsmotorsports.com/project-cars/2013-factory-five-818/hot-wheels-818/

[thall818]

I have been doing a lot of web searches trying to skin this cat. I set a challenge for myself, and think I finally solved it. Here's what I wanted:

1) Widest tires possible without rubbing.

2) Fill the wheel well. Don't stick out.

3) Be able to use Federal 595 tires.

4) Bolt on. No spacers or adapters. I'm sorry, I think these burn money that can be used elsewhere more effectively.

Here's the only set I've found so far. PLEASE, correct me if I'm wrong!

Drag DR-31 wheels Front: 17x8 35mm offset 215/40-17 tires. Rear 18x9 38mm offset 255/35-18 or 245/35-18 tires. I prefer the 255, but the 245s would give me an extra .2" of clearance on the inside if I need it.

The only thing I don't like about these wheels is that they are a little heavy. 21# & 24# respectively. About $600 delivered but lots of money saved on spacers.

Thoughts?

[C.Plavan]

I have been doing a lot of web searches trying to skin this cat. I set a challenge for myself, and think I finally solved it. Here's what I wanted:

1) Widest tires possible without rubbing.

2) Fill the wheel well. Don't stick out.

3) Be able to use Federal 595 tires.

4) Bolt on. No spacers or adapters. I'm sorry, I think these burn money that can be used elsewhere more effectively.

Here's the only set I've found so far. PLEASE, correct me if I'm wrong!

Drag DR-31 wheels Front: 17x8 35mm offset 215/40-17 tires. Rear 18x9 38mm offset 255/35-18 or 245/35-18 tires. I prefer the 255, but the 245s would give me an extra .2" of clearance on the inside if I need it.

The only thing I don't like about these wheels is that they are a little heavy. 21# & 24# respectively. About $600 delivered but lots of money saved on spacers.

Thoughts?


I do not know where you are buying your spacers, but they are cheap.... And cheap insurance to getting a wheel to fit right, or fit at all for that matter.

[Scargo]

Personal preference perhaps, but I do everything I can do to avoid using spacers. If you race you probably want ARP (or equivalent) longer studs with spacers. That adds weight and cost. Spacers add weight and cost. Both are unsprung weight.
Spacers add one more thing to possibly add eccentricity and mess with balance. I've had racers tell me to avoid using them. I know they are somewhat common, but on race cars? Also, cheap = more potential for poor quality.
Has everyone seen the lightweight wheel list (http://genesisforums.org/hyundai-genesis-wheels-tires/2820-light-weight-wheel-list.html#post12019)? There may be others or this may be a version of a better one. I have an extensive spreadsheet at home, but it is not available to me right now.

[C.Plavan]

All I'm saying a 5mm or 3mm spacer is nothing on a 1800 pound car. I challenge anyone to see if they notice the additional few ounces of unsprung weight. Also note the hub/bearing capacity is more than twice that of the 818 weight. The minimal load of a 5mm spacer in negligible.

I would rather error on the side of needing a spacer and being able to use the wheel, than not to need a spacer and the wheel does not fit and you cant use it at all.

Also keep in mind that tire measurements are not exact either... So there is not a perfect world until you test fit the tire and wheel combo.

Spacers=cheap insurance.

[thall818]

On the high end, ISC sells their wheel spacers for $150/pr. On the low end, I can get thin ones for $5 ea. After buying longer ARP studs, it can be done for as little as $75.00. I'm not trying to knock anyone for a $75 purchase. All I'm saying is that if I can solve the puzzle and save $75, it's worth it to me. Not to mention that I love a challenge.

I think just finding a wheel that is offered in both 17x8 and 18x9 is hard enough.

Don't forget, I'm also the cheap guy that is starting off with the low cost Federal tires and making sure I buy a rims that can use them.

[Jaime]

I can't see spacers adding weight, since low offset wheel simply have less metal removed. Some wheels will have deeper dishes if they are designed around that offset, but not usually.

I look at spacer cost the other way around. Spacers free me up to have five times as many wheels to choose from. The odds of finding a bargain that makes up for the $75 is pretty high. Also, with the 818 being new, it's safer to get too much offset and space to fit since you can buy the wheels, measure, then order the right spacers. If you have a no-spacer plan, the wheels better fit. The worst case scenario is that your low-offset wheels need to move in.

[C.Plavan]

I can't see spacers adding weight, since low offset wheel simply have less metal removed. Some wheels will have deeper dishes if they are designed around that offset, but not usually.

I look at spacer cost the other way around. Spacers free me up to have five times as many wheels to choose from. The odds of finding a bargain that makes up for the $75 is pretty high. Also, with the 818 being new, it's safer to get too much offset and space to fit since you can buy the wheels, measure, then order the right spacers. If you have a no-spacer plan, the wheels better fit. The worst case scenario is that your low-offset wheels need to move in.

That is another great way to look at it.

[ssssly]

The issue with spacers and racing is balance. Particularly on a hub centric setup.

If the spacers aren't machined perfect, your wheels will be out of balance.

How noticeable that will be, depends on how far from perfect the spacers are.

Unbalanced wheels at high RPM induce handling instability and put undue wear on bearings.

Again depending on how well or poorly they are machined. And as thin as the spacers being discussed are, how evenly they are torqued (unless they are made out of a harder metal than the wheel).

But in all likelihood, unless they are way off, decent spacers will likely be pretty negligible for this application.

[DMC7492]

Hi guys I noticed Advi.1 has quite a few wheels in the sizes we need and 35 mm offset.
Has anybody heard anything good or bad about these?
http://www.wheelplususa.com/wheels/Adv1/

[Hindsight]

Forged wheels. Not sure about the reputation but for $1600 a corner, you could go with a set of Ray's which have a legendary reputation. http://www.rayswheels.co.jp/

[Scargo]

What he^ said! That's a lot of dough. They appear to be two-piece. They would need to be light AND strong for that money.

[bompus]

Alright guys. I'm looking at getting the following wheels and wanted opinions if there would be any fitment issues:

Front - XXR 522 17x8.0 Flat Black 5-100/5-114.3 [+48mm] - Part # 52278102 ( 24.5 lb )
Rear - XXR 522 18x8.5 Flat Black 5-100/5-114.3 [+48mm] - Part # 52288102 ( 21.6 lb )

I'd wrap them with Federal 595 RS-R 215/40/17 front and 255/35/18 rear.

My question is.. is the +48mm offset alright or would I need to get 3mm - 8mm spacers for some reason? I can get all 4 shipped for $502 so it would be great if these will work out.

[Hindsight]

You will prob need spacers but they are cheap. You want a 35 to 40 offset roughly.

[wleehendrick]

I got XXR 530's; very nice for the price. I got the same size as the GRM car that I linked to here (http://thefactoryfiveforum.com/showthread.php?10156-THE-Wheel-amp-Tire-Thread&p=150119&viewfull=1#post150119). You probably will want the thicker spacers with those offsets.

FYI, I'm looking for 595's as well, but the 215/40-17's have been out of stock everywhere for a while.

[bompus]

Hrm.. I was originally going to go with the XXR 530's of those same sizes, but was worried about the +35mm offset being too much. Everybody I heard kept saying 40-45 no matter what. If the +35mm worked fine for you and GRM, I may just go with the XXR 530 or 535 then.

OnlineTires shows the 595 215/40/17 for $83 right now and 255/35/18 for $118. They don't say they are out of stock that I can see. Shipping is around $50 for all 4. If they do have them, I think that is a good deal for those tires.

[wleehendrick]

Hrm.. I was originally going to go with the XXR 530's of those same sizes, but was worried about the +35mm offset being too much. Everybody I heard kept saying 40-45 no matter what. If the +35mm worked fine for you and GRM, I may just go with the XXR 530 or 535 then.

Well my chassis is still up on jackstands so I can't personally verify fitment, but Wayne said they'll work, the GRM's using them, as well as a few others here. The offset is a bit 'aggressive', but I think it looks good on the 818. OEM wheels are way too inset.


OnlineTires shows the 595 215/40/17 for $83 right now and 255/35/18 for $118. They don't say they are out of stock that I can see. Shipping is around $50 for all 4. If they do have them, I think that is a good deal for those tires.

I recently placed on order with Onlinetires for the 595's but got a call back saying the fronts are out of stock eveyrwhere. I'm on a wait list with them. If the Feds don't come in by the time I need them, I may try the Maxxis MA-Z1 as a bargain option, since the Yokos GRM used are pricey.

[Hindsight]

I can't verify fitment either - I'm a long way from there. My comments were based on everything I have read here (which is a lot over the past year or so).

[Harley818]

I called them and they may have a new batch of 595's in December......

[wleehendrick]

I called them and they may have a new batch of 595's in December......

Onlinetires never returned two calls of mine inquiring about the 595's. I tried ordering a set of Maxxis from them, but a couple days later they sent an email saying those were out of stock also. From my experience with them (no realistic indication of inventory when ordering and poor communication) I'd prefer to give my business elsewhere. I sold my donor's wheels and am about ready to get my chassis to a roller and bring it home, so I didn't want to wait any longer. So I went to good old TireRack and got a set of Kumho Ecsta LE Sport in the recommended sizes (215/40-17, 255/35-18) for a bit more $. I had a set of Kumho Ecsta SPT on my Z in the past which were OK; these should be a step up in grip (280 treadwear), certainly plenty for a street tire. Got them mounted this past weekend on my XXR's:

http://thefactoryfiveforum.com/attachment.php?attachmentid=36032&d=1417021071

36032

[bompus]

Looks good. I'm having Nexen N'Fera SU1 ( ordered from local dealer ) in the same sizes mounted on XXR 530's this weekend. I'll post pics.

[bbjones121]

Anyone with 19s in back with 18s up front? Federal 225/35 18(24.1in dia) with 265/30 19(25.4)?

[Harley818]

I just finished ordering my wheels and tire package.
I called the ph number on the website for Onlinetires (also known as americaswheels.com) and they checked right then for stock on the Federals. Not till Dec.
So I called back a couple days later, and bought some XXR530's (17 x 8.25 and 18 x 8.75) with Maaxis 215 and 255's. They again checked stock and let me know that they were going to have to bring in the 255's. They ship next week, so I guess I don't know till then if i am getting the truth...... or a story. Good price though, includes mounting, balancing, wheel nuts, locks and shipping is extra.

[Sgt.Gator]

From FastWRX.com:

SUBARU WRX AND STI WHEEL INFORMATION

2002-2005 WRX wheels:

Bolt pattern: 5x100
Centerbore: 56.5mm
Wheel size: 16 x 6.5"
Offset: 53mm
Stock tire: 205/55R16


2006-2008 WRX wheels:

Bolt pattern: 5x100
Centerbore: 56.5mm
Wheel size: 17 x 7.0"
Offset: 53mm
Stock tire: 205/50R17


2009-2010 WRX wheels:

Bolt pattern: 5x100
Centerbore: 56.1mm
Wheel size: 17 x 7.0"
Offset: 53mm
Stock tire: 215/50R17



2011-2014 WRX wheels:

Bolt pattern: 5x100
Centerbore: 56.1mm
Wheel size: 17x8.0"
Wheel offset: +53mm

2004 STi wheels:

Bolt pattern: 5x100
Centerbore: 56.1mm
Wheel size: 17 x 7.5"
Offset: +53mm
Tire: 225/45R17

2005-2007 STi wheels:

Bolt pattern: 5x114.3
Centerbore: 56.1mm
Wheel size: 17 x 8.0"
Offset: +53mm
Tire: 225/45R17

2008+ STI wheels:

Bolt pattern: 5x114.3
Centerbore: 56.1mm
Wheel size: 18 x 8.5"
Offset: +55mm
Tire: 245/40R18


2015+ WRX wheels:

Bolt pattern: 5x114.3
Centerbore: 56.1mm
Wheel size: 17 x 8"
Offset: +55mm
Tire: 235/45R17

[bbjones121]

Anyone with 19s in back with 18s up front? Federal 225/35 18(24.1in dia) with 265/30 19(25.4)?

Anyone?

[Harley818]

OK, running into problems with the XXR530 wheels I selected.
Apparently the 17's and 18's are painted in two different plants...... so slightly different colour.
It was enough that they called me to let me know. The pics do show a difference.
Wleehendrix - same wheels as you........ are yours different shades?

I have two options for the front:
1 - 235/40 -17 with +25 offset - another wheel offset they offer for the front that will match colour with the rear 18's Diameter calc says 24.40 in.
2 - 215/35 -18 with +33 offset - same paint shade Diameter calc says 23.93 in.

Will either of these rub? either of them better than the other?
Based on what I have read in this thread, you will tell me the +25 will rub.

Thanks for your help.

[Hindsight]

Everything I have read says over 24" up front will rub.

Consider painting or plastidipping the wheels? Adds expense of course but is an option. Thx for sharing about this though. Those wheels were on my short list.

[wleehendrick]

No, my staggered set up matches perfectly.

[wleehendrick]

No, my staggered set up matches perfectly.

Ok, so I had to go out to the garage check... The 17s are a slight shade darker than the 18s. Not enought to bother me and I wouldnt have noticed if I werent looking for it (I didn't notice til you mentioned it) YMMV though. The Chromium Black finish varies quite a bit in angle anyway. Im OK with it, as the difference in mine is less than one spirited drive's worth of brake dust!

[Harley818]

as I was writing my post I was hoping I wouldn't make someone unhappy. Sounds like yours are close in shade of colour, and I thought that with the chromium colour and the angle of the light that I might not notice, but here is a couple pictures of the difference.
The 18's definitely look more silver.
I bought them from americaswheels.com. They have been very good about calling back and answering questions.

3656336564

Now I'm trying to decide if I will really notice the difference or not, or If i should just go with the 18's on the front.

[Bob_n_Cincy]

Harley
Is this a picture the vendor sent you?
Look at the reflection on the floor. That wheel on the right is sitting in the reflection of an overhead light.
I think the vendor is trying not to break up sets.
Something shady is going on.
Bob


http://thefactoryfiveforum.com/attachment.php?attachmentid=36565&d=1418799680

[Harley818]

Hi Bob,
Yes the vendor sent the pictures.
And you are right, but even in the other picture it looks slightly more silver.... again could be light.
i'm tempted to just get them.... the difference will hardly be noticable. I don't really wan to go for 18's on the front with lower profile tires..
Do you know if the +25 offset will cause rubbing on the fender?


Hindsight...... I just re-read the thread and the general consensus is that you can't go over 25 in Diameter or it will rub.

[Bob_n_Cincy]

Hi Bob,
Yes the vendor sent the pictures.
And you are right, but even in the other picture it looks slightly more silver.... again could be light.
i'm tempted to just get them.... the difference will hardly be noticable. I don't really wan to go for 18's on the front with lower profile tires..
Do you know if the +25 offset will cause rubbing on the fender?
Hindsight...... I just re-read the thread and the general consensus is that you can't go over 25 in Diameter or it will rub.

Harley,
I don't want to tell you what will work or not. I have not tried that size first hand.
Right now I am running wheels with 55 offset. 225/45-16.
With the high offset the wheel rotates (steering) more on it's center line. I have 3/4" to 1" clearance between the tire and the fire wall.
My suspension is -2.5* camber 2.5* castor and 0 toe. All set with harbor freight digital angle gauge and string.

Your 215/35 -18 are the same diameter as mine but with 33 offset. That means they will poke out the side of the car about 1" further than mine. When your tire is turned to a 45*. Your tire will be .707 closer to the fire wall.

Talk to Erik T about 18" tires. He did it, but I don't think it was easy.
Bob

[wleehendrick]

Bob, I don't think the vendor is trying to steer Harley away from them; it sounds like they want to avoid a unhappy customer or product return. There does appear to be a difference, but it's slight and less than the effect of lighting and angle given the reflectivity characteristics of the 'Chromium Black' finish. It took me a while to be convinced last night under the overhead florescent light in my garage. The photo above definitely accentuates the difference because of lighting, as you pointed out.

I hesitate to recommend you just go for them, because everyone's tolerance is different, but I'd rather have the ideal size. It's raining pretty hard now, but if it would help you Harley, I'd be happy to take some photos of mine in natural light when I can.

(P.S. remember, they'll be 95" apart on the 818)

[Bob_n_Cincy]

Bob, I don't think the vendor is trying to steer Harley away from them; it sounds like they want to avoid a unhappy customer or product return.

I may be a little biased about Onlinetires as they caused me pain last year. I order tires for an upcoming autox event. Two weeks later, when it got down to crunch time. I call to find out why I hadn't received them, only to fine out they were not in stock or even ordered from the manufacturer yet.
Bob

[wleehendrick]

I may be a little biased about Onlinetires as they caused me pain last year. I order tires for an upcoming autox event. Two weeks later, when it got down to crunch time. I call to find out why I hadn't received them, only to fine out they were not in stock or even ordered from the manufacturer yet.
Bob

I agree regarding Onlinetires... I cancelled two orders with them and went to TireRack, got them the next day! However, Harley ordered his wheels from americaswheels.com

[bompus]

I got my xxr 530s from tirecrazy. Great price, no issues, and I don't see a noticeable difference in color between the sizes.

[Harley818]

Thanks for the advice, and the offer for pictures (wleehendrick)
I decided to play it a bit conservative. I decided to go with the sizes that have been proven.
I didn't want to gamble with the +25 offset on top of my 235 front width.
I went with the wheels in hand......I'm thinking that like someone said......its all lighting and reflection and probably not even noticable. (i hope)

Called and told them to go ahead this morning...... hope I don't get any more stories....... americaswheels apparently is a sister company to onlinetires.

I had it all set up to pick them up in Washington state on my way home from Portland this weekend........
If I visit the USA for more than 48 hrs, I can bring back $800 per person duty free.......

When they were out of stock on the tires I wanted.... it totally messed with that concept.

[Harley818]

Santa came early.
americaswheels.com came through...... and I received my tires/wheels.

The colour difference is slight, and I'm glad I went for them.
367943679536796

They look awesome!!!!
3679736798
Merry Christmas & Happy New Year to all.

I'll take pics of the clearances, but they fit great.
235/40 - 17 in front
255/35 - 18 in rear
About 1/4 to 3/8 in at full lock on the front, and 1/8 in to the trailing link in the rear.

[Harley818]

As promised, here is the pics of the clearances:

Fronts: lots of clearance all around, with 1/4 clearance to the front firewall at full lock.
3691036911
369123691336914

Rears: about an 1/8 of an inch to the trailing link (ebay purchase). I was hoping they would be enough!
3691536916

36917

[Hindsight]

Thx for the info and pics. Canyou please poat final wheel widths with offsets? I see a few posts talking abt 25 offset but not what you ultimately went with front and rear.

[Harley818]

Hindsight..... sorry. I should have indicated offsets I ended up with.
I didn't want to go with the +25 so ended up with the following:

235/40 - 17 in front
255/35 - 18 in rear

53078102N-XXR 530 17x8.25 5x100/5x114.3 +35et Chromium Black
MA-Z1 VICTRA 235/40/17

53088102N-XXR 530 18x8.75 5x100/5x114.3 +33et Chromium Black
MA-Z1 VICTRA 255/35-18 94W

Included free mounting, balancing, chrome valve stems, wheel lugs & locks.
$828 all in plus shipping

[Hindsight]

No apology necessary! Appreciate all the info.

[flynntuna]

I noticed that FFR is offering a free set of wheels with your 818 order during their winter sale.

[Pearldrummer7]

Great thread so far. I was hoping I could add my limited experience with wheels/tires so far and also ask a question.

I tried my 2012 WRX wheels (Sparco RTT 524 17x8 + 48mm) and the wheels hit the forward link in the rear, and the 235/45/R17 Direzza Z2's on them rub frame. Just to confirm that that sizing definitely won't work :lol:


I ordered RPF1's (should be here in a day or two) in 17x8 +35 and 18x9.5 +35 rear. Tough to find in 5x100 but Oakos had them (http://oakos.com/Merchant2/merchant.mvc?), with a good price (even better if you order over the phone and ask for a discount! and free shipping).

For tires, I was thinking of running Direzza Z2 Star Specs, in 235/40/17 and 275/35/18. What do you guys think about this? Any help is way appreciated!

[Hindsight]

That sounds like a great setup Pearldrummer. The RPF1s are on my short-short list (along with PF01). They are high quality, light, and available in the right size and offset. I personally think the looks are just ok, but I can't find a wheel I'm in love with at the given size/offset needed for the 818. The Star Specs are great and I'm going to run the same thing, though in a 215/255. I'll be very interested in seeing if your 235/275 fits and if it does, I'll be unashamed to copy you.

[Bob_n_Cincy]

Great thread so far. I was hoping I could add my limited experience with wheels/tires so far and also ask a question.

I tried my 2012 WRX wheels (Sparco RTT 524 17x8 + 48mm) and the wheels hit the forward link in the rear, and the 235/45/R17 Direzza Z2's on them rub frame. Just to confirm that that sizing definitely won't work :lol:


I ordered RPF1's (should be here in a day or two) in 17x8 +35 and 18x9.5 +35 rear. Tough to find in 5x100 but Oakos had them (http://oakos.com/Merchant2/merchant.mvc?), with a good price (even better if you order over the phone and ask for a discount! and free shipping).

For tires, I was thinking of running Direzza Z2 Star Specs, in 235/40/17 and 275/35/18. What do you guys think about this? Any help is way appreciated!

I'm a little confused about your rim size.
You said 17x8 +48 rub on of the trailing arms.
You ordered 18x9.5 +35 rims.
The new rims are 1.5" wider or 38mm (19 on inside and 19 on outside)
Your offset went from 48mm to 35mm which is a change of 13mm.
I figure that the new rims will hit 6mm more than the original ones you tested.
Am I not understanding something?
Bob

[C.Plavan]

FYI- My Front 235/40 R17 Toyo RR (17x8 +38) front with a hit the inside chassis pretty good. Then on long sweepers with bumps the outside tire rubs a tad on the fender (smokes). I'm going 225/40 in front now because of it. You could get away with 235 on a race car since you rarely go lock to lock (no need to), for a street car no way. You could not make a u turn to save your life. Stick with the recommendations from FFR.

I have 255's on the rear (17x9 +40 with 5mm spacer) 275's would of rubbed for sure.

[Pearldrummer7]

That sounds like a great setup Pearldrummer. The RPF1s are on my short-short list (along with PF01). They are high quality, light, and available in the right size and offset. I personally think the looks are just ok, but I can't find a wheel I'm in love with at the given size/offset needed for the 818. The Star Specs are great and I'm going to run the same thing, though in a 215/255. I'll be very interested in seeing if your 235/275 fits and if it does, I'll be unashamed to copy you.
Well, we'll certainly find out, won't we! :)



I'm a little confused about your rim size.
You said 17x8 +48 rub on of the trailing arms.
You ordered 18x9.5 +35 rims.
The new rims are 1.5" wider or 38mm (19 on inside and 19 on outside)
Your offset went from 48mm to 35mm which is a change of 13mm.
I figure that the new rims will hit 6mm more than the original ones you tested.
Am I not understanding something?
Bob

Bob, crap. I messed up twice in my original post. First, I should've mentioned that I'm doing Brandon's mod of moving the fwd link in by putting both spacers on the outside(giving me a little more room), and more importantly I meant the tires rubbed, not the wheels. I'm hoping that I can fit the new wheel, despite the larger inside width. I'll certainly find out soon. I'm not opposed to a spacer in the rear for this reason.



FYI- My Front 235/40 R17 Toyo RR (17x8 +38) front with a hit the inside bar pretty good. Then on long sweepers with bumps the outside tire rubs a tad on the fender. I'm going 225/40 in front now because of it. You could get away with 235 on a race car since you rarely go lock to lock (no need to), for a street car no way. You could not make a u turn to save your life. Stick with the recommendations from FFR.

I have 255's on the rear (17x9 +40 with 5mm spacer) 275's would of rubbed for sure.

Maybe I'll be doing 225 and 265 or something instead. I'm gonna of course see how the new wheels fit "naked" first. Good point regarding going full lock vs. rub.

Don't RR's run pretty wide?

[Pearldrummer7]

I might mention that on page 4 of this thread, Jerome says he is running:

18x9.5 +45 (using 13 mm spacers, making the effective offset +32)
265/35/18 Federal 595 RS-R

Which gives me hope that a small spacer might be able to make this size work

*crosses fingers*

[C.Plavan]

I'm going back to Hoosier crack. I'm going with the new R7's this time 225/40; 245/40 R17's (If I run a 245 tire I get less of a penalty in the ST classes).

It was the first time I had run the Toyo RR's- Not that impressed with them, I did like the audible feedback they provided at the limit though. IDK if they are considered wide. I'll know more once I mount the R7's on my identical 2nd set of race wheels (Team Dynamics). We all know Hoosiers are wide for their sizes.

[Scargo]

"Oh boy", is all I can say. No, I can say more; trust me.
Pearldrummer7, I can't find your build thread so I have no idea what you are doing or trying to accomplish. I have read some of your posts, but I still don't know the critical aspects of your build and I'm not going to do all the digging/research to know.

Tire specs are everywhere. Phil's Tire Service (https://philstireservice.com/)has lists of all the major players. I cut and pasted into Word all the ones of interest to me so I can refer to them instantly.
I think the wheels you've ordered are a good choice for the price, quality, availability, etc. I do not care for the thin ring. I have PF01s on my STi. However, for saving a couple of pounds per wheel, my Wedssports are (appx.) twice the money and may not come in 5 X 100. I went with 17's in the rear, as well as the front.
Why buy wheels that likely won't work and then have to spend the money for spacers? Why haven't you settled on tires?
225/245 seems to be the norm for the track and ST2. I squeezed 275's on the rear of mine (in a test fit) but mine is far from a stock FFR rear suspension. I will start with 225/245 slicks.
Why do you want such big tires? On the track you have to heat the rubber and they might be too big for a fast warm-up and might never get up to proper operating temps.
Perhaps I'm missing something, but I feel like you've got a lot of 'splainin' to do.

[Pearldrummer7]

"Oh boy", is all I can say. No, I can say more; trust me.
Pearldrummer7, I can't find your build thread so I have no idea what you are doing or trying to accomplish. I have read some of your posts, but I still don't know the critical aspects of your build and I'm not going to do all the digging/research to know.

Tire specs are everywhere. Phil's Tire Service (https://philstireservice.com/)has lists of all the major players. I cut and pasted into Word all the ones of interest to me so I can refer to them instantly.
I think the wheels you've ordered are a good choice for the price, quality, availability, etc. I do not care for the thin ring. I have PF01s on my STi. However, for saving a couple of pounds per wheel, my Wedssports are (appx.) twice the money and may not come in 5 X 100. I went with 17's in the rear, as well as the front.
Why buy wheels that likely won't work and then have to spend the money for spacers? Why haven't you settled on tires?
225/245 seems to be the norm for the track and ST2. I squeezed 275's on the rear of mine (in a test fit) but mine is far from a stock FFR rear suspension. I will start with 225/245 slicks.
Why do you want such big tires? On the track you have to heat the rubber and they might be too big for a fast warm-up and might never get up to proper operating temps.
Perhaps I'm missing something, but I feel like you've got a lot of 'splainin' to do.

http://thefactoryfiveforum.com/showthread.php?13414-Frank-s-818R-build

Build thread^ definitely messed up the whole name thing on that part. My mistake. It's an R for dual use (track/street eventually) with a 257/205 hybrid motor with forged internals. It was a car that belonged to a friend and was cheap for me by the end of the donor experience.


Whew. Alrighty then. I guess I have a lot of returning/research to potentially do. I got a fantastic deal on them, and figured they were the "correct" sized wheel for my application. I'm starting to feel that I may have oversized the rear. Which is *okay*, as I can always do it again (perhaps at a small cost burden).

I'm settled on tire, just not size. I am getting the wheels from somewhere that doesn't sell tires, so I didn't have the immediate incentive to decide on what size my tires are. I definitely feel as though I've messed up at this point. I've never had a RWD car, a track car, track tires, or anything mid/rear engine. I'm quite far removed from knowing what exactly I need for wheel and tire specs, and decided to go with an "aggressive" sizing based on what I've heard from seemingly less knowledgeable people than I thought. Hopefully I can sell or return the rears and keep the fronts. Luckily RPF1's are available everywhere and I can find a 17x9 to fit my application.


tl;dr- I'm a complete noob and messed up. Don't follow my lead on this one.

[Hindsight]

Dont panic. I see nothing wrong with your wheel sizes and offsets. I am pretty sure others are running similar sizes. You will need offset rear trailing arms (Wayne sells).

Tires.... If you put the FFR suggested sizes on the wheels you mentioned, you should be ok.

[Tamra]

I used one of the wheel/tire calculators online, and according to it your setup in the rear will be 3mm closer to the suspension than ours (17x8, et 45 Enkei PFO1's with 255/40/17 Direzza Z2 tires, OEM trailing arms). We don't have much clearance, but it does fit as is. I imagine with a small spacer you would be fine on the inside suspension. However, it does say it will stick out 17mm further, so I'm not sure about fender clearance. We don't have the body on yet, so can't comment on our fitment.

We also have 17x8, et 45 Enkei PFO1's with 235/40/17 Z2's on the front, with the aluminum control arms with the castor mod (4mm spacer). We rub slightly at full lock, but we have not limited the steering yet.

[Pearldrummer7]

Scargo- we all know you like saying "I told you so" ;)


The fronts fit great (17x8 +35)
https://farm8.staticflickr.com/7308/16438086322_2ef4f128c9_z.jpg (https://flic.kr/p/r3zunq)
https://farm8.staticflickr.com/7366/15818963613_fcf2325677_z.jpg (https://flic.kr/p/q6SjKX)

The rears... (18x9.5 +38) aren't even remotely close. I measured quickly and need at least an ~8mm spacer to comfortably clear I think. Which is too much I think. I'm sure Wayne's mod (which I intend to do either way) will help with that, but not that much I think.
https://farm8.staticflickr.com/7433/16253119557_8064323a30_z.jpg (https://flic.kr/p/qLeucg)
https://farm8.staticflickr.com/7304/16252772639_b3244c22c7_z.jpg (https://flic.kr/p/qLcH4V)


According to Rev F of the manual, I can run this size -_- That's what I get for listening to the manual!
https://farm9.staticflickr.com/8588/16256266987_4c030b7087_z.jpg (https://flic.kr/p/qLvBPi)

[Scargo]

Nice looking wheels. I had it in my head that you were getting NT03s, which have the ring I don't care for.
You need ARP studs anyway. Get them and buy the adapter or send the rear wheels back if you can. I'm not familiar with the Wayne fix for the trailing arm unless it is to move the front trailing arm mount as far inboard as you can.

[Pearldrummer7]

Nice looking wheels. I had it in my head that you were getting NT03s, which have the ring I don't care for.
You need ARP studs anyway. Get them and buy the adapter or send the rear wheels back if you can. I'm not familiar with the Wayne fix for the trailing arm unless it is to move the front trailing arm mount as far inboard as you can.

I like the wheels a lot. And at 15.6 and 18.6 lbs, they're pretty light. Wayne cuts and welds the trailing at the end that attaches to the spindle.

I'll be trying to send them back for 17x9 +35mm RPF1's. Cheaper tires, and lighter overall (wheel + tire). Might even fit ;)

Scargo- is it possible to install ARP studs in the rear without removing the wheel bearing? Maybe through the ABS slot or something?

[Wayne Presley]

Nice looking wheels. I had it in my head that you were getting NT03s, which have the ring I don't care for.
You need ARP studs anyway. Get them and buy the adapter or send the rear wheels back if you can. I'm not familiar with the Wayne fix for the trailing arm unless it is to move the front trailing arm mount as far inboard as you can.

He's talking about my wide wheel trailing arms.
http://www.verycoolparts.com/home-copy-3.shtml

[wleehendrick]

I'll be trying to send them back for 17x9 +35mm RPF1's. Cheaper tires, and lighter overall (wheel + tire). Might even fit ;)

Those will definitely fit. My rears are XXR 18x8.75" +35 (255/35 Kumhos mounted) and I have at least 15mm of clearance with OEM trailing arms.

[Wayne Presley]

The rears... (18x9.5 +38) aren't even remotely close. I measured quickly and need at least an ~8mm spacer to comfortably clear I think. Which is too much I think. I'm sure Wayne's mod (which I intend to do either way) will help with that, but not that much I think.
https://farm8.staticflickr.com/7433/16253119557_8064323a30_z.jpg (https://flic.kr/p/qLeucg)
https://farm8.staticflickr.com/7304/16252772639_b3244c22c7_z.jpg (https://flic.kr/p/qLcH4V)




Pearldrummer, I'm running 18x9.5 Enkei Kojins with +40 offset and clear my arms so your +38 RPF01 will have 2mm more clearance with my arms

[Scargo]

Sounds like Wayne may have the solution!
I have only done late-model (GR) and it can be challenging, but doable without pulling the hub out. In one case I just ground a small spot on the flange of the upright and was able to wiggle them past. Might have ben the front... You can use the ABS hole in the backing plate, too. Here's a how-to. (http://forums.nasioc.com/forums/showthread.php?t=1694965) Now, I AM NOT advocating grinding down the heads, but assuming you are not using ABS then just open up that hole. It can still be used but alignment of the sensor is trickier.
Studs don't have to be for a Subaru, either. In fact, if you haven't spent $500 for Ti lug-nuts then switch to 1.5 thread pitch studs. The 12x1.5 nuts are far more common, plentiful and a little cheaper. Just get studs with the .565" knurl. Look on Summit's site. You want a Mitsubishi Evo stud. (http://www.summitracing.com/parts/arp-100-7717/overview/) Amazon may be cheapest.

[Pearldrummer7]

Pearldrummer, I'm running 18x9.5 Enkei Kojins with +40 offset and clear my arms so your +38 RPF01 will have 2mm more clearance with my arms
Wayne, what size tires are on the 9.5?


Sounds like Wayne may have the solution!
I have only done late-model (GR) and it can be challenging, but doable without pulling the hub out. In one case I just ground a small spot on the flange of the upright and was able to wiggle them past. Might have ben the front... You can use the ABS hole in the backing plate, too. Here's a how-to. (http://forums.nasioc.com/forums/showthread.php?t=1694965) Now, I AM NOT advocating grinding down the heads, but assuming you are not using ABS then just open up that hole. It can still be used but alignment of the sensor is trickier.
Studs don't have to be for a Subaru, either. In fact, if you haven't spent $500 for Ti lug-nuts then switch to 1.5 thread pitch studs. The 12x1.5 nuts are far more common, plentiful and a little cheaper. Just get studs with the .565" knurl. Look on Summit's site. You want a Mitsubishi Evo stud. (http://www.summitracing.com/parts/arp-100-7717/overview/) Amazon may be cheapest.

My fear is not that they'll fit or not, it's much more that there's no reason for the size, cost, and weight if I'm only running 255 tires, which should fit nicely on a 9" wheel (perhaps even nicer than on a 9 than a 9.5).

[Scargo]

I understand. I did not say this before but the stock studs are prone to failing when highly stressed, as during track days+. They are not reliable. They snap off in an unpredictable fashion and they get chewed up. Sometimes, at the track, I am changing wheels three~four times a day. Constant re-torquing. Weight of longer studs in the center of the hub is insignificant. It does, incrementally increase un-sprung weight but it's still insignificant. Just do them...