There is a company I've read about on here. I'll try to find the link. Its expensive.

Why are you only running a 38mm EWG?

 

You only really NEED a 44mm at the 500+ mark. Since %99 of the time I'm on 93oct, the 38mm is plenty. Besides it's less expensive, easier to maintain & less bulky in the engine bay.

I'm one of those weirdos that thinks EWG's are sort of an ugly neccessity.

 

Look at PPG gearsets. What are you doing with the car that requires more than 160mph?

 

I believe that M-Factory has a new set coming out as well. Not sure if they have the new set for the 6 speed or not though.

 

Contact PPG. Expect to pay a very pretty penny to go 170+.

 

Thanks guys... It's looking like PPG is the way to go; but an EXPENSIVE way to go at just over $10 grand!

Someone was telling me that the Legacy Spec.B gears are actually longer than the STI gearing. Can anyone confirm this?

As far as why? I guess the answer is why not! It seems like a shame to have a 500whp car that tops out at 160... It's true that there are very few road courses that would give me enough of a straight away to go much faster than that, but it would be a nice compliment to the additional power, braking & suspension mods that I have already done.

besides, check out this link!
210mph scoobie!

 

I'm prolly gona get flamed for asking but why, for god sakes, do you want to go faster than 160, let alone the money you would have to put in the car to do it. Are you doing this on the track? I hope.

*** Edit***
Ignore me... you beat me to the punch.

 

I thought PPG gears were straight cut at least 1-4 am I wrong?
I personally wouldn't want to drive a daily car with straight cut gears.

 

Thats correct. Now whether or not it's tolerable is strictly a matter of opinion of course. I just can't wrap my head around spending $10-$15k on gears and a tranny rebuild for no other reason than "why not". To each their own.

 

I have contacted PPG to see if what I want is doable, and how much it will actually cost.

Ideally I would have all 6 gears cut semi-helical for strength & smoothness of engagement. They would have a comletely different gear ratio throughout to make the shifts "longer," more even, and ultimately provide a higher top speed.

I think at this point I'm just wet dreaming, but maybe after everything else is done to this car that CAN be done, I'd consider it. It's kind of like that one last piece to the puzzle that most people don't quite get to. I haven't seen too many STI's with modded gearing, and that's half the draw for me.

I have done a lot with my car that's unique, and have several "firsts" in my build. I have the first Alcon BBK to hit the US, the first P&L "silent series" quad tip exhaust, and a couple of other goodies that I'm not quite ready to talk about because the projects aren't completed yet.

Really it all comes down to having USEABLE power. It doesn't really help me that much to have a boatload of power if I can't harness its' strengths. I'm not really into drag racing, so it's ok if it takes me more than 9 seconds to get up to speed.

 

I'd like a longer gearset in my '05. If you find something useful, post it up. I'm not looking to do 170+ just looking to shift less between 1-4 and would like 6th to be longer.

 

you can get straight cut or the helical cut gears. im 99% sure on that

 

RalliSpec - Gearbox Parts

if you scroll down you can see STi 6MT Upgrade kits.

 

Yeah, I saw that... If I read it correctly, those are close ratio gearboxes meant for maximum acceleration. I was hoping for the opposite!

 

no there is also high speed gear ratios under the close speed for $1,200 and they have the PPG for $10,000

from there site:

RST-F145kit High Speed 2nd-6th Ratio Conversion $1214
(Ratios -- STD / 2.235 / 1.521 / 1.137 / 0.891 / 0.707)

High speed ratio conversion ideal for high speed track or drag use. Improves gear spacing over existing USDM ratios. Includes main shaft and 2nd-6th gears. Includes updated 2nd and 3rd synchros (required for pre-'06 models) and special keyways.

 

Where are you getting a top speed of 160 mph from? At 7000 rpm the stock gear ratios are good for 175 mph. If you raise your rev limit to 7500 rpm, which you may be able to do with your built engine, the theoretical top speed becomes 188 mph. The top speed gear set looks pretty cool, but you might want to consider whether you really need it or not. Also understand that the stock suspension and aerodynamics are not designed well for that kind of speed. Although you can improve them, the Sti is not built for a lot of top speed and you would be better off going with another ride if you are looking for a lot of top end. Either way, your set up sounds pretty sweet man, best of luck with it.

-Brett

 

Where are you getting a top speed of 160 mph from? At 7000 rpm the stock gear ratios are good for 175 mph. If you raise your rev limit to 7500 rpm, which you may be able to do with your built engine, the theoretical top speed becomes 188 mph. The top speed gear set looks pretty cool, but you might want to consider whether you really need it or not. Also understand that the stock suspension and aerodynamics are not designed well for that kind of speed. Although you can improve them, the Sti is not built for a lot of top speed and you would be better off going with another ride if you are looking for a lot of top end. Either way, your set up sounds pretty sweet man, best of luck with it.

-Brett

Brett - The 08+ STI actually has a slightly different transmission than you do. They changed around a few things including gear ratios and design of the cogs. Our 1-3 are actually a semi-helical design for strength, 4th gear is super long, 5th seems a bit short, and 6th gear @ 80 mph (highway crusing speed) I'm at 3500rpm.

It is true, about my redline being increased. As soon as I'm done with the break in period, my redline will actually be set at 8500rpm!

I wonder if my speed issue DOES have more to do with aero than the trans. Hmmmmm. I might have to try a few things to improve that before I jump on a $10k transmission. We'll see how it pans out.

Side note - does anyone know where I could get access to a wind tunnel in the Chicago area?

 

this is a nice thing to see, ive been searching for this for a while. Its one of the things i hate most about the STi. I just had my car at road america and being able to space out the gears a little would greatly help. Many of the corners on a high speed road coarse require being in too low a gear to exit with power. Not to mention it would help with fuel economy on the highway. Its not too bad a price either.

why subaru felt it was a good idea to use the shortest gearing on the planet i will never know. the motor makes plenty of low end torque and almost all highway driving is at 70 mph on the interstates and the short 6th kills econ. not to mention shifting every 2 seconds gets old.

 

Dumb question, but on a RWD car you can change out the diff gears to a different ratio. It wouldn't alleviate the close ratio, but it could space them out a little. Couldn't it? At the very least, I've played with that in Forza Motorsport

 

You'd have to swap both front and rear diffs. The rear is easy enough, but the front gets more involved... and more expensive.

 

Your a NutBall ... We just talked 5 days or so...and I said just go with a Dom3 XTR. and you complained to me about usable power. haha..and now you post that , that is your choice..I take credit for the choice..
your Pen Pal
Cory

 

Thanks Cory... I know, I AM a nut!

I talked to Ron at RAW Performance, and directly to the guys at Blouch before making up my mind.

It wasn't until I learned that I would have to lose the A/C by going with a rotated manifold setup that I even started looking deeply into the stock location big turbos. Then I also found out that the 2.5 Polka Pickle tops out around 440hp and the Dom 3.0 starts to spool at 2k and reaches full boost by 4200rpm. Also, with my built motor plans, the Polka Pickle wouldn't pull all the way to my new 8500rpm redline!

 

Brett - The 08+ STI actually has a slightly different transmission than you do. They changed around a few things including gear ratios and design of the cogs. Our 1-3 are actually a semi-helical design for strength, 4th gear is super long, 5th seems a bit short, and 6th gear @ 80 mph (highway crusing speed) I'm at 3500rpm.

It is true, about my redline being increased. As soon as I'm done with the break in period, my redline will actually be set at 8500rpm!

I wonder if my speed issue DOES have more to do with aero than the trans. Hmmmmm. I might have to try a few things to improve that before I jump on a $10k transmission. We'll see how it pans out.

Side note - does anyone know where I could get access to a wind tunnel in the Chicago area?

Here these links might help you out. I did consider that the 09 trannys are different, but the top speed at 7K is theoretically 182 mph (I said 175 because tires are never quite as big as they are calculated to be). The 6th gear ratio and final drive ratios have not changed at all for any USDM STI's thus far. The 09's have bigger tires so if anything you should have slightly more top end than previous years. Enjoy!

2009 Subaru Impreza

Top Speed Calculator

 

Hmmm... Theory is nice in an ideal environment. I wonder what the actual values will be post turbo / built motor installation. I can tell you one of the problems right now is that the stock turbo falls flat on its' face at 6000rpm.

These values are also not taking wind resistance into consideration. As posted earlier, I wonder how much it would help out my cause to change the aerodynamics of the vehicle.

 

What those values represent is the speed you would be at if you were to be at the rpm specified. IE if you are at 7000 rpm the car will be going 182 mph as long as your tires are inflated fully. Wind resistance does not affect gearing. You started this thread because you wanted to modify the transmission so you could achieve a higher top speed. What I'm telling you is that the stock gear ratios especially with a higher rev limit will allow for a much higher top speed than 160 mph. The only thing preventing you from getting that high is the aerodynamics and power of the car at higher rpms. If you want a top end monster get some power out of that new longblock and improve the cars aerodynamics. You don't need to touch the gears, save your money.

 

As I said... That's definitely food for thought. I am already having the longblock built, and a DOM 3.0 XTR is on order, so POWER = check! Now I need to figure out a way to make my little pig a bit more aero... That could prove to be a little more challenging.

Other than the usual front lip spoiler, side skirts, wind splitter, under tray, rear diffuser.... Is there anything else I could look at to improve the aerodynamics? This is a field where I really have NO experience whatsoever!

 

...Other than the usual front lip spoiler, side skirts, wind splitter, under tray, rear diffuser.... Is there anything else I could look at to improve the aerodynamics? This is a field where I really have NO experience whatsoever!

I know it's pointless to compare our aero and gearing, but bone stock aero and 433whp easily got me to 170mph (GPS verified) at about 6800-6900 rpms...still had a bit left and could have gotten to 7200 rpms, but I had to back off.

 

RalliSpec in NJ. They have been building Rally cars for over 10 years(US prorally cars). Dave, the head mechainic/ builder is also a head mechanic for a prorally team so expect a little wait to get in there but it will be the best thing you did having your tranny built by RalliSpec. They are THE #1 Subaru transmission experts in the country. Call and speak to them. Thay have a gear package for the STi that extends the mph ALOT 1-5th along with making them nearly unbeakable without going to a straight cut dog box. STiLOS has them and you can read up in his members journal in the GD section journals. There are quite a few options you can get if money allows. Cheaper than KAAZ and better for driveability in my opinion. KAAZ ststes unbreakable but I now of 3 people that have broken a KAAZ gear on the street. Dave at RalliSpec is the MAN when it comes to building our transmissions and uses genuine STi parts and custom pcs where needed to make it all function like a stock box, nice and quiet with excellent ****s but strong and LONG gears.
www.rallispec.com

I can't believe s h i f t s got *****

 

I know I'm opening a dead thread, but my question is proposed in here but not answered... Is it cheaper or easier to replace the diff gears than replacing the tranny gears? And if so, who makes them?