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reinforcing WRX tranny??

8K views 27 replies 15 participants last post by  03 CrazyTaxi 
#1 ·
ok so i know the tranny is super sensitive n weak n all that BS about not being able 2 take a lot of power like 300 horses or so. anyways...a clutch is definately on my list but what else do i need to do?? because i am always so paranoid about ruining my transmission or something. i am going to get engine n tranny mounts because i'm scared of breaking it when i launch or something but what else could i do like some stronger gears or whatever?? i have heard stuff before but can't really remember n draining the oil to swap in synthetic wont really do much huh?? thnx
 
#6 ·
another alternative to PPG's depending on the application are mFactory gears. I had 1-4 installed in mine and they are working well, at least that is what my tuner has said, I have not, and will not drive it for another two to three months. The total for gears and install was around 2200, for 1-4. They are close ratio gears, so they will feel totally different.

Another good way to ensure transmission longevity is to just take er' easy. I mean, do not try to launch often, unless you honestly know to do it(not doubting your driving finesse, for I know not of it). Also, change the transmission regularly, well, as regular as you think you would need, I do mine at 10k.

any other questions send me a pm or post them up. I have done a lot of research into these transmissions we love to lose!
 
#7 ·
A slight, and I do mean slight upgrade would be going to an 04-05 wrx gearset/trans.. the gears are 1mm thicker and can take more abuse, within reason... people still break them though.

PPGs are the best bet hands down imo... and you can get them cheaper buying direct from AU.
 
#11 ·
I think they are *pretty much* indestructible.... It would take a lot more abuse to break them. If you want a slight upgrade, some RA gears would help, but you can still break these fairly easy compared to PPGs.
 
#12 ·
Every gearset can be broken. It is directly linked to how much power you make but how you drive. The gears are broken by the shock of loads hitting them in a surge. Go easy with the launches and the gear changes and you can put a lot of power through the stock transmission. It is easier to shock break gears with more power but power does not break gears.
-Stick with the stock or a stock style clutch. It is better for it to slip than to fry your transmission.
-Helical gears are set at a slight angle from the axis of the center ring.
-Straight cut gears are straight. They are usually beefier but can be noisey.
 
#14 ·
I believe lil_shoaf has broke some stuff on his trans with his PPGs. Don't think his gears...but, shift linkage or something. I forget....speculation at this point. But, I'm sure PPGs can be broken, if your above stock power and tooling around.
 
#15 ·
I dont think its the PPGs, its the other things: i.e. axles, diff, other things you might not upgrade. You have to address all the stress points. If you take it from one area, it goes to another unless adressed. Its a point that make very apparent in my MOS (job in the army, sheetmetal mechanic on helicopters).
 
#16 ·
Straight Cut 1-4 dog'd PPGs can easily handle 1000whp. They're overkill. Just get the fully syncroed helixal cut. That's still a good 3x stronger than stock and your girl will still be able to drive it.
 
#17 ·
Thanks for clearing that up Mosc, I couldnt remember the numbers off my head. I know/knew its a ridiculous amount for a WRX/STI. Never seen one over 807AWHP in one of the import mags. And it wasnt street legal, so useless in my eyes.
 
#18 ·
I just ordered my ppg's this past week and Andrewtech will be installing them soon. The synchro set is rated @ a conservative 400awhp but Dan @ Andrewtech has seen them hold up to 630awhp with consistant dragstrip passes.

With the economy down, now is the time to buy. I picked my set up for a steal of a deal and would recomend buying now to anyone thinking about it.
 
#21 · (Edited by Moderator)
i was planning on changing clutch n flywheel but heard that's not good wit stock tranny is it true n why??
I've had an RPS clutch and Streetlite flywheel for over a year now without issues, and I drag race my car 2 weekends out of the month, on average. The lasting of your trans depends on your ability to drive just as much as the torque your engine makes. Also gear oil type makes a small difference.

However, there is much research to be done regarding a flywheel.. all are not created equal. Many aftermarket flywheels can cause CELs and random misfire codes at higher RPMs. A good and inexpensive upgrade for starters would be an STi clutch and flywheel. The STi flywheel weighs approx 18lbs vs the WRX ~ 29lbs. Both parts can be found in vendor/private classifieds, new or used for good prices. Something to consider. ;)

I just ordered my ppg's this past week and Andrewtech will be installing them soon. The synchro set is rated @ a conservative 400awhp but Dan @ Andrewtech has seen them hold up to 630awhp with consistant dragstrip passes..
That is a very conservative number.. I'm sure they do that for liability reasons. They can in actuality handle much more. I've seen RAs hold 400whp without issues. Good luck with yours !Thumbs Up
 
#26 ·
ok so i know the tranny is super sensitive n weak n all that BS about not being able 2 take a lot of power like 300 horses or so. anyways...a clutch is definately on my list but what else do i need to do?? because i am always so paranoid about ruining my transmission or something. i am going to get engine n tranny mounts because i'm scared of breaking it when i launch or something but what else could i do like some stronger gears or whatever?? i have heard stuff before but can't really remember n draining the oil to swap in synthetic wont really do much huh?? thnx
Stock gears, stock clutch. The OEM exedy is a very good clutch

DO NOT LAUNCH

And yes PPG's are strong gears, but you have to remember that the 5 speed case is not strong. And with ppg gears you will be replacing half shafts and drive shafts. I really would recommend a 6 speed swap. You get really tough gears, half shafts. Crawford is running sthe stock sti 6 speed in there 530awhp time attack car. So 6 speed FTW:sneaky:
 
#28 ·
With the 02, yes you have to be careful with 1st through 3rd. However, you do have a couple cheaper options than the PPGs or even the Mfactory gears.

#1. Find a late 03 transmission. The last two characters of the transmission code will be BA. This is Subarus fix for the issues that the 02 and early 03s have with the first few gears. Basically, they put RA gears in for 1st through 3rd. That's your cheapest option since it's a direct bolt in. The only thing I can think you might have to swap along with it is the rear drive shaft since the AA is 1/4" longer than the BA.

#2. Swap for the STi 6-speed. This is a bit more expensive. Because you have the 3.90 final drive, you don't have to worry about that. You will however need a DCCD controller if you want to be able to use that nifty little tool. Spider seems to be the recommended one.

Which way you go depends on a couple things. Money, car's purpose, and time. The quickest one is going to be the first option since all you really have to do is pull the AA out and slide the BA in.
 
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