Well it was getting to that time on my 07 STI to change out the stock clutch. I just rolled passed 85,000 km. The car went to stage 2 at 25,000 km, the following spring I upgraded the turbo to a top mount stage 3 at approximately 40,000 km, and last spring at 65,000 km I put in a front mount, and dyno'd out at 365 HP, and 350 tq. So all in all the stock clutch I think has done well, but under hard load in the lower gears I could tell she was grunting, and begging me to get off the gas.
So I started doing some research on what clutch to get. Lots of options out there, and in the passed I have always ran ACT's on my other cars with good luck(but not with this much power). I needed a clutch that not only could hold this power, but I plan to track the car so it also has to take some abuse. A visit to my friends at VEX, and Jimmy gave me two options. First being the Exedy clutch with similar characteristics to the stock clutch, or jump in both feet, and hands to the OS Giken. It is important that the clutch still be street usable so that pointed us in the direction of the Grand Touring Line with a twin plate, and hard shell. The clutch itself is good for the 600+ HP range. Went home did a bunch of research, and took the plunge as this is not a cheap clutch.
What do you get with this clutch? Everything including a new flywheel, and move alteration kit which is required on all pull type clutches as the OSG is a push type. Everything was packaged very well, and looked amazing. Of course I never took any pictures as I get too sidetracked chasing shiny things at VEX.
move alteration info ->
http://www.osgiken.net/techcenter.phpLets get into the actual results so far. This is very early in the review of this clutch as I have not put it through any race type situations. A few nice hard pulls, and shifts.
Car shifts extremely smooth, and accurate. The clutch pedal is not horribly hard to push, so those traffic days I will survive, and the clutch grab is very predictable of when it is engaging. This is true also in high RPM shifting, and I could tell the difference from stock to the OSG for crispness, and accuracy.
What I could tell right away was how much better it grips the engine to the gear. With the stock clutch I always felt it was leaving something behind, and it was. This OSG clutch holds the power! You notice it even just starting out for a regular drive as the engine power creates more traction than what I was used too in the passed. Under high load use you can also tell as you feel more in tune with the power the engine is creating to what is being put to the ground. I know that is saying a lot as we drive AWD cars, and traction is not an issue. However now the car is not leaving any power in the inadequate stock clutch(for the power I am creating), and it is being put where it should be. On the ground, and it is apparent, and a treat!
Only a few days into this review, but at this time this clutch gets two huge thumbs up, and the guys at VEX for the advice, and install. As I get more use on it, I will continue to expand what I have learnt on the performance abilities of this product!
OS Giken GT2CD ->
http://www.osgiken.net/products.php?Category2=subaru&SubCat2=&submit.x=7&submit.y=10&product=grandtouringVEX ->
http://www.vexperformance.com/Update May 25/2015 - Just an update as it has almost been one month on the OSG clutch. Continues to be accurate, and very driveable. I have got used to the twin plate engagement now, and lightened flywheel, so my low RPM shifts are much smoother than at first. You can hear the twin plates when the clutch is engaged, which might sound like something is wrong(sounds metal, to metal) however from reading this is very normal.
All in all so far the clutch has been great, and I would suggest this clutch to anyone needing a clutch that holds more power, or doesn't want a clutch that pre-maturely fails. Next update will be in 3 months, as that will give me a lot of driving time with it.
