Has anyone experimented with gearing?

[turbomacncheese]

Seems like a car this light with all that power is screaming for taller gears. Maybe not for autocrossing, but on the street? Any experience?

[Frank818]

No experience yet but I already know I will change a couple of my gears, at least 1st-2nd.
When I did that on my Corrado (was all 6 gears back then) it made ALL the difference with the turbo. I can just imagine the same would apply on the 818, especially cuz it's lighter.

[jcpresto]

I have different 1-4 gears and a 25.5 rear tire size on my 818 C. I have had little street time since I'm now working on the body. I live in country so I did unwind it once or twice before starting in the body. I dyno'd 411 hp and 418 tq to the tires.

315/30-18 rear tire
1st 44 mph at 6700
2nd 75 mph at 6700
3rd 104 mph at 6700

I can't remember 4/5 without looking in my build file. So far seems to perform well, anxious to finish the body and put some real miles on it.

[Frank818]

I'm planning on the following (with over 400wtq/whp):

All at 7k in MPH
1st 56-60
2nd 88
3rd 109
4th 136
5th 173

I had the following on my Corrado at 7k

1st 53
2nd 80
3rd 100
4th 125
5th 150
6th 170

Both 5th-6th are theoritical speeds as I'm not sure with aerodynamics they are achieveable.

[turbomacncheese]

Oh man, don't know how I missed this. I am REALLY interested in what this would entail. On my turbo dodge, I had a taller final drive from newer cars popped into my older transmission and really put legs on all the gears. It was also a relatively light car (2500). Dodge never actually put a 2.5 in it because they thought it was TOO light. But that transmission alone cut .6 off my first 1/8 mile, and a little over a full second on the 1/4 mile drag. It also got me 27mpg driving to work.


How are you planning on changing the gearing? Are the gears easy enough to come by in production transmissions? Custom parts?

[Frank818]

How are you planning on changing the gearing? Are the gears easy enough to come by in production transmissions? Custom parts?

I believe this is for jcpresto?
I have a Porsche G50 gearbox so I don't know if it will be of any use to know my answers to the above questions. :)

[turbomacncheese]

Right. Something for the Subaru transmissions.

[Scargo]

My close-ratio six-speed with 24.85 dia. wheel at 7600 RPM is 171 MPH. I think... 135 in fifth.
My tranny specs are as below. I believe "T.R." (sometimes noted as T.G.) means transfer gear ratio. Most are "1.00". My tranny's 1.1 ratio is to have certain models have the rear diff gear ratio match with the front diff ratio. I'm thinking it doesn't figure into the calculations (because the front diff ratio must match the rear diff final ratio, which would make it a 3.9 ring and pinion front diff. Right?



1ST
2ND
3RD
4TH
5TH
6TH
REV.
T.R.
F.D.




3.636
2.375
1.761
1.346
1.062
0.842
3.545
1.100
3.900



With a 5MT you could have a 3.9 final drive and .738 fifth gear which would give you a laughable 195 MPH theoretical top speed. .95 fourth=151 MPH.
With the .825 fifth gear and 3.7 final drive ratio you would get 185 MPH. 1.151 fourth gear =132 MPH in fourth.
Source: http://www.rs25.com/forums/f8/t100042-learning-choose-your-gear-sets-ratios.html
For the track would you want to shift less or more, given the typical Subaru motor and limited RPM's? Most tracks I'm on are 1.5 mile on average and no really long, fast straights. I guess a big, wide torque band would help the five-speeds which would use second, third and fourth whereas I have used 2~5 and almost never sixth. With my new close-ratio box I think I will use more of a 3~5 gear range and rely on higher RPMs, from the de-stroker motor, for most tracks.

[Canadian818]

Here's a useful Gear calculator (http://www.apexgarage.com/tech/gear_ratios.shtml)

I have a RA 5mt, and my rear tires are 26" tall.

http://i1113.photobucket.com/albums/k519/pope83/3F8B97AE-7143-4777-ADBB-87E469D7800D.jpg (http://s1113.photobucket.com/user/pope83/media/3F8B97AE-7143-4777-ADBB-87E469D7800D.jpg.html)

[Scargo]

I have different 1-4 gears and a 25.5 rear tire size on my 818 C. I have had little street time since I'm now working on the body. I live in country so I did unwind it once or twice before starting in the body. I dyno'd 411 hp and 418 tq to the tires.

315/30-18 rear tire
1st 44 mph at 6700
2nd 75 mph at 6700
3rd 104 mph at 6700

I can't remember 4/5 without looking in my build file. So far seems to perform well, anxious to finish the body and put some real miles on it.
Is this what you have? 3.166 / 1.882 / 1.296 / 0.972 / 0.738 / ('08-current USDM WRX), but with 3.700 final drive ratio?

[Mitch Wright]

Here at NCM Motorsports Park using a 04 5 speed I use 3rd-5th (just get into 5th for short time on the front straight using my 260hp tune I haven't run the 285hp tune yet) with a top speed so far of 131mph. (still have work to do on the chassis and feel I can take out some rear wing)

[jcpresto]

Below is what I have:

http://www.rallispec.com/gea_syn_ppg-su5hs.html

http://mooreperformanceparts.com/products/blastplates/

60394

[Scargo]

jcpresto,
Holy crap! $5,000+ if you get all that... plus you are making it heavier which negates some of the benefit of the five-speed being lighter than a six. Frankly, I say "race car", meaning I have no issue with the six protruding out the rear and can deal with the weight difference (more weight on the rear wheels=less wing and less drag). I'm thinking a lot of areo can be accomplished on the front and the fuel cell will be forward. More power and balancing weight on the front? I've always been looking at ST2.

[STiPWRD]

jcpresto,
Holy crap! $5,000+ if you get all that...
Prices have really gone up for ppg gears, I bought mine (1st & 2nd straight, 3rd & 4th helical) in 2006 for $3200 shipped.

[jcpresto]

I purchased the transmission from Wayne ready to go. I went this route as I didn't want the close 6 speed with this lite of a car and was hoping the selection would help spin the tires less violently with as much power as I'm making. Since I have only go-karted it I don't have any great feedback.

[turbomacncheese]

I'll be driving this on the street more than the track, but there is a little bitty track not too far from me (can't be more than a mile, looks like less than that). Probably won't see more than 90 very often (if at all). A good cruising ratio for 5th would be nice. Are all the gears/final drives interchangeable between transmission, too?

[C.Plavan]

FYI- The car (818R) starts to struggle with the aero drag after 125mph. I would just run a Legacy GT trans, and not mess with gearing. It's not worth it on the track, and really not worth it for a street car.

[turbomacncheese]

haha, 125. I'm not sure I've got the stones to go that fast anymore. I did it a couple times on my motorcycle way back when. I was just looking for options here. I've seen a couple references to 1st gear being useless, and I'd rather not push 3000-3500 rpms cruising down the interstate. If it were as simple as "crack this trans open and take the gears" I'd still be interested. If it's "go buy this set for $2000+", well, not so much.

[Blwalker105]

Chad, is the Legacy GT transmission the same size as my '03 WRX 5-speed? My trans has 235,000 miles on it and I was going to put in new bearings, synchros, STI gears, a Quaife and a new cryo-treat ring and pinion. I already have the Quaife but the rest of that stuff will be $2400+ with me doing the installation. If the LGT was a viable option to live with 350 whp I may consider that option.

[GoDadGo]

Getting the gear ratio right in any build is crucial in order to truly enjoy the car once it is finished.
Making sure that your set up works within the operation range of you engine combination must be priority #1.

R.P.M. 2,500 (2,400-6,400 / Operation Range)
Gear Ratio 3.73
Tire Height 26.0
Displacement 383

Gear Ratio & MPH
1st / 2.68 / 19
2nd / 1.80 / 29
3rd / 1.29 / 40
4th / 1.00 / 52
5th / 0.75 / 69
6th / 0.49 / 106

While I know very little about the Subaru platform, other than the basics, I'd still love to build an 818 when the GoDadGo MK-4 is done.
I'm just am not sure if I'm up to tackling that car because finding Subarus, of any model, are tough to locate down here near N.O.L.A.

[C.Plavan]

Chad, is the Legacy GT transmission the same size as my '03 WRX 5-speed? My trans has 235,000 miles on it and I was going to put in new bearings, synchros, STI gears, a Quaife and a new cryo-treat ring and pinion. I already have the Quaife but the rest of that stuff will be $2400+ with me doing the installation. If the LGT was a viable option to live with 350 whp I may consider that option.

Essentially the same size and will bolt right in. There are some differences (speedo gear etc) that you would need to swap over to the Legacy GT trans if you change it. It may also have a different final drive ratio (4.11 IIRC). I bought 2 Legacy GT transmissions used. One had 78K miles, the other 90K miles. I threw the 78K mileage one in after installing a Modena TSB diff. I did not replace or change anything else. I never had any issues with it on the track. Also keep in mind I had a detuned race motor, but if tuned, the motor could easily make over 400HP.

When I say its not "Worth it" for gearing, I meant the cost. Gears are stupid expensive. Finding a better geared transmission, or Final Drive is far cheaper. I find the gobs of torque these motors put out, and the weight of the 818's, gearing is not all that important.

[Canadian818]

If a guy wants 350hp, I'm not sure the LGT is going to cut it for long. IMO the only options are 6 speed or ppg gears in the 5mt. It's true that a 6spd swap might be a little cheaper, but you're still starting with used transmission that has no doubt seen some abuse. And the added weight is in the worse location, behind the rear wheels.

5k might seem like a lot to have a bulletproof 5mt, but spend some time reading what the GTM guys are paying and you'll realize that it's a steal.

[Hindsight]

I thought I wanted to stick with a 5 speed but when it blows up, I will be going 6. 5 is great for the street but if you plan on tracking it, the closer gears really helps, even in a car as light as the 818. At the last track session I did, I had guys with bone-stock BRZs (except for Ohlin's coilovers) hang with me for a good ways on corner exits. If I took a corner in third, I didn't pass them until mid way through fourth gear.

[C.Plavan]

You also have to consider the weight of the 6 speed. Its alot heavier. Gearing and weight was not worth it for the track. Example of 3.9 FD
http://iharder.sourceforge.net/sti/WRX-STi-tx-ratios-transparent.gif

[Sgt.Gator]

LGT 5 speed trannys are cheap because a lot of LGT guys swap in the 6 speed, especially for drag racing. If you are doing hard launches you probably need a 6 speed in your 818 too, but if you are tracking/ road racing / street driving the 5 speed should be a better choice.
If you want a LGT 5 speed let me know and I'll watch for them on the LGT forum for you. I'm pretty active on the Legacy forum.
It's easy to add a tranny cooler to a 5 speed too, covered in another thread.
But note, they don't come stock with an LSD. Every once in a awhile one comes up for sale with an LSD already installed.

[turbomacncheese]

Getting the gear ratio right in any build is crucial in order to truly enjoy the car once it is finished.
Making sure that your set up works within the operation range of you engine combination must be priority #1.


This is what I'm talking about.


Gears are stupid expensive. Finding a better geared transmission, or Final Drive is far cheaper.

The very root of my inquiry.


I find the gobs of torque these motors put out, and the weight of the 818's, gearing is not all that important.

Interesting perspective, and something I'd like to learn more about. I found exactly the opposite in my other light-ish weight car. Big difference was the power band. It was strong at 2500 rpms, beastly at 3200 rpms, lunched at 5000.


LGT 5 speed trannys are cheap because a lot of LGT guys swap in the 6 speed

What have you seen them sell for?

[Blwalker105]

I won't be drag racing the car, but it might see some autocrosses and track days.

This looks interesting
http://www.ebay.com/itm/MY05-SUBARU-LEGACY-2-0GT-TURBO-MANUAL-AWD-TRANSMISSION-JDM-EJ20Y-4-11-TY757VBBAB/371604056136?_trksid=p2141725.c100338.m3726&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%2 6asc%3D20150313114020%26meid%3Dccf86e37020f4a2cac1 15663cfb9eaa6%26pid%3D100338%26rk%3D5%26rkt%3D18%2 6sd%3D232131986781

[Mitch Wright]

I agree with Chad, on track I am not finding the car between gears at least at NCM. The weight of the car and the amount of torque the engine has doesn't require a lot of gear changes to find speed. Plus as stated the additional 85lb is in the wrong place behind the axle.

[Canadian818]

And if you look real hard there are jdm 5mt's with RA gearing and a factory LSD.

[Scargo]

"And if you look real hard there are jdm 5mt's with RA gearing and a factory LSD."
And yet, don't you still have the weaknesses of the 5MT? I paid $3,084, delivered, for a like new JDM TY856WB7KA close-ratio box and it has the factory STi LSD. You can also buy fifth-sixth close-ratio gear sets for $500.
The added weight of the 6MT is distributed so it's not like all of it hangs off the back-end and you remove part of that anyway. I just think too much is made of the weight difference issue.

[turbomacncheese]

$700 doesn't seem bad at all. Change that 4.11 for a 3.9 and we might be in business.

[Canadian818]

"And if you look real hard there are jdm 5mt's with RA gearing and a factory LSD."
And yet, don't you still have the weaknesses of the 5MT? I paid $3,084, delivered, for a like new JDM TY856WB7KA close-ratio box and it has the factory STi LSD. You can also buy fifth-sixth close-ratio gear sets for $500.
The added weight of the 6MT is distributed so it's not like all of it hangs off the back-end and you remove part of that anyway. I just think too much is made of the weight difference issue.

Are we still limited to MY06-07 for 6mt's? I thought that those were the only years the FFR conversion adapter works with and possum stopped making theirs. Oh and I paid $800cad for my jdm STI 5mt with helical LSD and RA gears.

[Blwalker105]

I found and bought a JDM LGT trans with a 4.44 final drive for $700. Gonna swap that out for a cryo-treated 3.9.

[turbomacncheese]

Any idea when you'll have it back in the car and on the road? I'd love to hear some feedback on that setup. Exactly what I'm thinking.

[Pearldrummer7]

I have an 07 gearset with a (now hardened, after shredding the first one) 4.44 FD. I love my short gears. I don't top out 5th on the straights of the few tracks I've been to, and it's nice having the power everywhere. Maybe a 4.11 would be better, but either way I like having shorter than 3.90 gears.

[Blwalker105]

Yeah, it was kind of a tough call, but I liked how the speeds/gears chart numbers looked and I figured that was what my original '03 transmission would have had anyway.

I am sadly nowhere close to roadworthiness status. Probably another year.

[RM1SepEx]

I've found that for the street the stock 05 WRX gears are fine. First is a bit short, 2nd will approach 70 and aero should limit speed, not gearing. on the fun back roads all my driving is in 4th gear as the revs are too low in the powerband to have fun. The graphic is based on stock tire dia, my star specs should be a wee bit taller at 25 inches

61733

WRX MPH & RPM Calculator
Gear Ratios 1st 2nd 3rd 4th 5th Final
3.454 1.947 1.366 0.972 0.738 3.9

MPH Calculator
MPH 38.66 68.59 97.77 137.39 180.96
RPM 7000


Tire Diameter 25.00
Aspect Ratio 35
Section Width 255
Wheel Diameter 18

[Scargo]

I have no clue what you are talking about. Just too cryptic for me. Aero limits speed?
This fits the front of a stock built 818?
"Tire Diameter 25.00
Aspect Ratio 35
Section Width 255
Wheel Diameter 18 "

Didn't you sell your car in March with 17" wheels? You have another car?

[RM1SepEx]

Scargo, nope, no sale, I'll own J-Lo forever as a toy! :rolleyes: I'm running stock 16's now with tire dia 24.8 or so with 225-50-16 in the rear

the front's don't matter re gearing

for each ratio, top speed in each gear is listed with the stock 05 WRX gearing and a 3.9 diff 68 and change in 2nd, just short of 100 in 3rd, almost 140 in 4th

the car is not slippery enough for my engines HP (about 240 to the wheels) to pull 181 MPH at redline in 5th I'm guessing with the CD and cross section of my 818 155 -160 would be max speed

[turbomacncheese]

Any thoughts on that tire size? That's what I want to do, since I'm going to drive this a lot and I know that tire size isn't exactly rare.

[Bob_n_Cincy]

Scargo, nope, no sale, I'll own J-Lo forever as a toy! :rolleyes: I'm running stock 16's now with tire dia 24.8 or so with 225-50-16 in the rear the front's don't matter re gearing for each ratio, top speed in each gear is listed with the stock 05 WRX gearing and a 3.9 diff 68 and change in 2nd, just short of 100 in 3rd, almost 140 in 4th the car is not slippery enough for my engines HP (about 240 to the wheels) to pull 181 MPH at redline in 5th I'm guessing with the CD and cross section of my 818 155 -160 would be max speed

Speaking of coefficient of drag calculations.
Our car measured 195 whp on a conservative dyno.
At out last track day the data log shows we accelerated from 95 to 118mph in 5.25 seconds. I suspect our car to be near 2200 lbs with driver. I estimate tire rolling reistance at 0.015.
Does anyone know an online calculator that will take this info and spit out coefficient of drag ?
Bob

[NorCal Ray]

LGT 5 speed trannys are cheap because a lot of LGT guys swap in the 6 speed, especially for drag racing. If you are doing hard launches you probably need a 6 speed in your 818 too, but if you are tracking/ road racing / street driving the 5 speed should be a better choice.
If you want a LGT 5 speed let me know and I'll watch for them on the LGT forum for you. I'm pretty active on the Legacy forum.
It's easy to add a tranny cooler to a 5 speed too, covered in another thread.
But note, they don't come stock with an LSD. Every once in a awhile one comes up for sale with an LSD already installed.

Hey Sgt. Gator, just read your thread of 11/04/16 and am looking for a LGT 5 speed for my 818R. I am running a 07 5mt and want to have another trans. ready when this one bites the dust. I've read that the LGT is a stronger trans than 07 5mt, is this correct? I have'nt quite finished the car yet but am running 348 RWHP. If you could keep your eye out for one I'd greatly appreciate it . Thank you, NorCal Ray

[Scargo]

Just to revisit the history and stir the pot as Devil's Advocate... didn't FFR's car break its five speed early on with <300 WHP? Haven't others broken their stock 5-MT gears on the track? I know of one or more who have broken them doing hard launches with 300+ FPT. I estimate that an ST2 (8:1 P/WR) could make over 300 FPT.

What I don't know is how many trannys were stock LGT's . Also, what I don't know is who has had success with a stock case and aftermarket beefy gears. What happens to a stock LGT tranny when you add a LSD?

Was just looking at the Sadev transaxles. So expensive. Would be so much fun to have a sequential paddle shift car!

[Mitch Wright]

For ST 2 my R comes in at 260hp and around 2000lb

[taco20]

624686246962464624656246662467
Hey I just changed my 5th gear in my 5 speed. I noticed at the track above 120mph once I had to go to 5th the call quit pulling. On the big tracks we have in my area they have real long straights so need a car that will pull all the way down the straight away. With my tire size 265 in the rear and 4.11 in the trans it could run 170+ which I will never see. I changed the two gears at the back of the trans to a more track friendly .871 ration instead of the .74 the trans came with. Wasn't hard to change and I had the trans out waiting on my new motor anyway. I didn't even have to take the back cover off just removed the motor mount and back section of the trans. Only need like 3 sockets, a couple punches, and something to make a flame once you get to the gears. The bottom gear is pressed on but with some heat it slid right off. Anyway I put a picture of the stock Subaru part number for the gear set if anyone else wants to try. Cost me like $110 to my door.

[Innkeepr]

I bought an ej207 with a 5sp trans. According to the code book I have a TY754VB1BA .
Here is what I found ( link to info ) http://www.gearhack.com/myink/ViewPage.php?file=docs/Subaru%20Transmission%20Chart

Says mine is from a JDM Impreza WRX RA & RA Ltd. MY99-00 5sp Pull Clutch.
3.083 2.062 1.545 1.151 0.825 3.333(rev) 1.000(TR ?) 4.444(final) Center Diff type Viscous (4kgf) Front Diff type OPEN

Asking for advise on this. Planning on the 350+ WHP. Do I just get a Quaife lsd and leave the rest ? or should I at least get 1st/2nd PPG gears also.
Our nearest track is 2 hours away, so it may see the course some day. This is mainly for street, and I think the first 2 gears will take the most abuse.
Lastly,just skip this all together and find a LGT trans ?
Thanks for your input,
"E"

[Scargo]

... Only need like 3 sockets, a couple punches, and something to make a flame once you get to the gears. The bottom gear is pressed on but with some heat it slid right off...
Unless you consider the gear coming off as junk I suggest you do not heat the gear with a flame. How do you put the new gear on without a press? Some parts are combined by heating one component (evenly and slowly) and applying it to a cold shaft (like a VW oil pump drive gear) but I've never seen this recommended for a transmission gear assembly. These are hardened gears!

[taco20]

Unless you consider the gear coming off as junk I suggest you do not heat the gear with a flame. How do you put the new gear on without a press? Some parts are combined by heating one component (evenly and slowly) and applying it to a cold shaft (like a VW oil pump drive gear) but I've never seen this recommended for a transmission gear assembly. These are hardened gears!

Hey it wasn't that tight. I just tapped the gear on with a piece of wood. You could always just start the gear and use the nut to pull it into place. I tried to cut a grove in the original gear to crack it but had no luck so just heated it up, at that point the old gear was junk to me. Why would you want to put it back on in the first place?

[TouchStone]

What I don't know is how many trannys were stock LGT's . Also, what I don't know is who has had success with a stock case and aftermarket beefy gears. What happens to a stock LGT tranny when you add a LSD?

I'd like to know this as well since I plan to use the LGT tranny with a Torsen LSD and 3.7 FD at 322hp. The 3.7 FD will make 1-4 about 5-10mph taller.

[RetroRacing]

I bought an ej207 with a 5sp trans. According to the code book I have a TY754VB1BA .

We have two of those, and if I were you, I would keep it as is with the inclusion of an LSD. Now, ours is a race car, so we rebuild constantly, so we decided to go with a clutch type LSD, so that we can tune the thing, and, we want drive to at least one wheel just in case we get stopped on a curb (torsen type lsd's have no drive if one wheel is off the ground, so I've read). For a street/track day car, the Torsen type is a good choice.

We love the gear box, pulls to 7200rpm with 260ish WHP on our car and the rpm drop is perfect. Can't wait for our +60hp tune and lsd.....
https://www.youtube.com/watch?v=rWFHeF03KE4