17x8.25 front with STI LCA caster arms?

[redfogo]

I am looking at ordering wheels for my 818c I'm not sure if they have made any changed yet with the small front tire sizing or not. I am looking at the following

17x8.25 35mm front & rear

or

17x7 35mm front & 17x8.25 35mm rear

or

run the top two front possibilities with a 18x8.75 33mm in the rear

[Bob_n_Cincy]

I am looking at ordering wheels for my 818c I'm not sure if they have made any changed yet with the small front tire sizing or not. I am looking at the following
17x8.25 35mm front & rear
or
17x7 35mm front & 17x8.25 35mm rear
or
run the top two front possibilities with a 18x8.75 33mm in the rear

I ran my stock Impreza wheels first. 6.5"x16"x53mm with Toyo 225/45R16.
Then I measured all my clearances before selecting wheel and tires.
I suggest you do the same before spending $$$ on wheels and tires.

I select bigger tires than recommended as I also made other suspension modification to make them fit.
Bob

[redfogo]

I ran my stock Impreza wheels first. 6.5"x16"x53mm with Toyo 225/45R16.
Then I measured all my clearances before selecting wheel and tires.
I suggest you do the same before spending $$$ on wheels and tires.

I select bigger tires than recommended as I also made other suspension modification to make them fit.
Bob

I am not using a donor so not to much to base things off of. I may just need to stick with recommended sizes then. Also with all the holidays sales soon to come up I figure now was the best time to grab the wheels and get tires closer to completion.

[Mechie3]

Bob, did you detail your changes on here?

[Bob_n_Cincy]

Bob, did you detail your changes on here?

Craig,
I don't think I shared all my changes and settings on here. They were so far outside the box, I want to be sure they all worked well.
An overview of changes from recommendations were:

Front track width
Front roll center
front static camber setting
Front wheel offset
front rim and tire size
front camber gain
front shock length
front shock bump stop
different upper ball joint
different upper "a" arm tube
added one steering rack spacer

Rear roll center
rear wheel offset
rear rim and tire size
rear camber gain
rear static camber setting
rear shock length
rear shock bump stop
rear upper lateral link tube
Rear spring rating
moved body to match wheel center.

I need to get more experienced drivers to take my car out on a track and give me feedback.
Bob

[Tamra]

You'll be fine with either of the 17" options. Our wheels for the street are Enkei PFO1 17x8, et 45, and clear just fine. We have the aluminum STI arms in the front.

We have 215's up front (touch at full lock but no major rubbing) and 255's in the back. The back will rub slightly on the lower arm from tire deflection under hard cornering, just enough to scuff the paint, so wouldn't want to go any closer back there.

[redfogo]

Went with 17x7 up front and 18x8.75 rear. I figured I may like 17x7 up front more for autox.

[Lumpyguy]

I am curious the handling difference between the 17x7 and 17x8.25 wheels up front? I am going to run the 18x8.75 on the back. I like the looks of the bigger wheels

[redfogo]

I am curious the handling difference between the 17x7 and 17x8.25 wheels up front? I am going to run the 18x8.75 on the back. I like the looks of the bigger wheels

I can't talk about the 818 yet as mine isn't done yet, but having gone from a "narrow tire up front/wider back" to a wider tire all around on my old mr2 I found that it under steered a lot more. I much rather be tail happy versus having an under steer problem. That's part of why I went with this set up. A lot of lotus guys are also using narrow front wide back and seem to like it a bit more. To each there own though!

[xxguitarist]

Red, Pushing the limits in autox, a loose tail will ruin a run, where a slightly pushy front end will just put you a few feet from where you intended to be.

To add to what Tamra said, it's the 215/40/17 up front. Not much room there!

We went to 15" fronts to fit more tire width up front for autox. 245s fit on 15x8"s of the right offset without any custom work as long as they clear your brakes.

[redfogo]

Red, Pushing the limits in autox, a loose tail will ruin a run, where a slightly pushy front end will just put you a few feet from where you intended to be.

To add to what Tamra said, it's the 215/40/17 up front. Not much room there!

We went to 15" fronts to fit more tire width up front for autox. 245s fit on 15x8"s of the right offset without any custom work as long as they clear your brakes.

Just don't loose it :D and your fine haha. For me I find it easier to drive an autox course with more oversteer then understeer. But I have owned an mr2 since I was 15 so the snap oversteer just feels natural. My plan is to adjust as needed though with the 818. I can only speak from what I have encountered I am by no means an expert driver just my opinion! Xxguitarist I'm sure has far better knowledge on this subject.

[Tamra]

Just to clarify... typically if you put more tire up front, the car will push less (more grip due to more tire). Less tire up front and the car will push more.

That is assuming you haven't gone so large in the front so as to not be able to get enough heat in them (which would require really big so likely not what happened). Or, if you are doing large burnouts which cause your rears to heat up significantly faster and start gripping sooner than the fronts. In that instance the front will push regardless of front tire size just due to unequal heat in the tires. The hotter tires (unless they are too hot) will grip better and cause the other end to let loose.

I'm guessing when you went to wider tires all around that you weren't heating up the fronts as quickly as the rears which resulted in them not gripping as well, followed by understeering more. It's all a balance based on the car and the driving style.

The width of the wheels will determine how supported the tires are. Slightly stretched set up (tire slightly narrower than the wheel) will result in a really fast turn in, but you probably aren't getting as much ultimate grip due to simply running less tire. Pinched set up (tire wider than the wheel) will have more squirm and less sharp responses, but more ultimate grip from having more tire on the ground.

For me I'd rather drive a car that's balanced and doesn't have any significant oversteer or understeer characteristics... a car that just "works" :) But if I had to pick one, I know from experience that understeer bias is less punishing, resulting in more consistent, faster times.