Shiv,
Well, I find myself in the same boat as you. Last week at ATCO Raceway I killed the trans. I shifted from 1st to 2nd. Apon letting the clutch out I was greeted with a loud bang, and a busted tranny. I never, I mean never, powershifted or was extra hard on the tranny. It just wouldn't hold that hard 1st to 2nd shift. I believe it was a shifter fork, but we won't know for sure until we crack the case. The tranny was pulled on tuesday, and we will be cracking it soon.

I was wondering what you are doing as far as trannies go. Are you just going to rebuild yours? Have you located an STi unit? What about just replacing the gearset? How much do you think what your doing will cost?

If don't want to discuss this here, you can email me at xferralx@home.com .


TIA,

MattC

MattC-- I think we experienced different failures. My car is still driveable. Just no second gear. And the gear failed in the middle of the gear run, not between shifts. I doubt it's the shifter fork. It looks like I'll be trying out the same gearsets that are currently being used in the 10 sec Rigoli WRX. I'm quite certain that they'll work for my application. They will be coming from BPM.

I'd be suprised if the STi gearboxes are any stronger than the 2.5RS gearboxes. Those seem to be failing just as often and at the same torque levels. Still, the stock tranny lasted ~25k miles of 10+psi use. They can be picked up used at junkyards for $800 or so. It's almost like setting aside $400 each year for the tranny fund http://www.i-club.com/ubb-files/wink.gif

shiv

I hadn't heard what your exact failure was. I believe that mine was the same as AdamB's. My tranny will not go into any gear, at all.

Does BPM have a website, or phone number? Do you know how much these gearsets cost? Will you be able to use the ACT or will you have to go to a WRX style clutch? The only gearsets I have found are from Possume Borne Motorsports. They are hardened STi gearsets, used in most Group N cars. They go for over 2 grand. This was my other option, but we weren't sure if we would be able to use the ACT or stock flywheel.

Thanks for your help,

MattC

MattC,

I may be mistaken (as I often am http://www.i-club.com/ubb-files/wink.gif ) but I think Trey at Cobb tuning is selling hardened gearsets, amongst other transmission goodies. You may want to give him a call.

Aaron

If hardened STI gears are $2,000, then why are Trey Cobb's (now BPM's) $3,600?

Sean

Trey cobb's performance have yet to be seen.

My prediction is that it is near identical to suspension rule. There's going to be a BIG sacrifice of "confort" for "performance"

Uh, yeah. Why would harder gears ride rough? Might shift rough if the synchros are deleted and you can't double-clutch, or make some noise if they're straight cut...

The only thing uncomfortable is going to be your wallet.

Colin,
im not saying the RIDE quality of the car is going to be rough. Just the shifting.

I already talked to shiv about it, and he gave me a full tech explanation but I can't remember the techie stuff http://www.i-club.com/ubb-files/smile.gif

All I know is that shifting is going to be massively harder, that's my prediction.

This sucks. Why is there no clear transmission answer? I mean, look at what's happening. MattC, Shiv, Adam B, and a bunch of other folks are breaking their trannies.

Seems as though other car manufacturers have transmissions that don't break...why are Subaru's so damn weak??

By the way, has anyone busted their tranny with the stock clutch? AFAIK, everyone who breaks the transmission is running the ACT setup...am I right? Is there a possibility that there is something wrong with the ACT clutch? Or are our trannies really that weak?

Sean

The gears break, you get hardened gears, then the keys holding the gears break and you get hardened keys, then the shaft breaks and a hardened shaft, and finally the case breaks...what is wrong with this picture.
How about a nice auto w/ paddle shifter 6speed that can take the pressure? Due out at the end of summer http://www.i-club.com/ubb-files/wink.gif

Ravent-

Amen, brotha! Why not just use the Modena's tranny? :)

But seriously, why are Subaru trannies so weak? It just bugs me to watch my friends push a helluva lot of horsepower through Toyota, Honda, Nissan, Chevrolet, Ford, etc, trannies with no problems. Here we are pushing 300bhp and breaking them right and left. It SUCKS!

Sean

Maybe GM will give Subaru some of its transmission ideas. See GM buying into Subaru is a good thing.. http://www.i-club.com/ubb-files/smile.gif

Sean,

It is because of the huge amount of traction that AWD cars have - their biggest strength becomes their biggest weakness.

Ok, so since the center differential isn't blowing up, and the wheels aren't spinning on the 1-2 shift, and the clutch isn't slipping, that means all the force is being transfered to the gear? Makes sense. It really sucks, though.

I wonder what's better...a slipping clutch that is less hard on the transmission or a stiff clutch that will break your transmission. Both suck in my book :)

Am I the only one who sees this as a large issue? I mean, everyone who is going for big power is breaking their tranny. And the only options to fix this problem are either:

a) less comfortable and untested
b) expensive as hell and untested

I hope some tuner is taking note of this problem. As more and more people go with forced induction, there will be a growing market for trannies. And while Trey Cobb/BPM might have a solution, $3600+$850 (core exchange) is hard to swallow.

Sean

Or just build an Impreza with 1000 hp so you can spin the wheels!

All right...I'll get right on that :)

Shiv, can you please turn my boost up to 135psi and tune it with the TEC-II? Thanks. :)

Sean

rao has it right, something just has got to give. the transmission is simply not spec'ed from the factory to handle the torque we're asking of it. It is reasonable for us as enthusiasts to expect FHI to engineer a more robust MT, as the european and STi trims have the same problem.

GM is not immune to this, they just have a lot more scar tissue and experience. I've toasted several 'glides and TH400 trannies and they are damned tough. Every time they go it's on the line at a drag race-- if you have over 600HP, a pair of 31x10.5x15 slicks and a 9" Ford rearend something has got to give every now and then. Now have you ever seen a powerglide or turbo 400 compared to the puny 4EAT? How about a Super T10 compared to the Subaru 5 speed?

By now you're probably wondering what the hell I'm talking about. I'm talking about the fact we have a small transmission, a fair bit of torque relative to the size of the driveline--especially when modified, and a WHOLE LOT of traction.

Exactly - all that excess stress is being transferred away when you spin the tires - but when you have the amount of grip we do, it gets absorbed by the drivetrain instead of "harmlessly" spinning off as tire smoke..

Colinl - do you remember right when the Porsche C4 came out, and Road and Track got it as a test vehicle? They had to do a clutch replacement before 20k miles because it was slipping so badly.. hehe..

Basil

I was talking to a guy in Australia, he has a 2000 WRX. I asked what his shifting is like. He told me when he power shifts the Clutch Slips for half a second to a second when letting it out. He was telling me that this is a good thing as it makes for a softer shift, yet is not any slower if it were to be a hard gripping clutch. My STOCK car is very much like this, and sense I put my ITC and AFC in and tuned it I'm clearly making more HP because the amout of time it's slipping is more when I shift. It is quite nice to tell ya the truth. You shift hard as hell and let the clutch almost pop into gear and it slips just a bit making a smooth shift compared to if I were to do that same shift in my fiends Hopped up Mustang. I drove TMR's car with the ACT clutch and it was very much of a OFF/ON clutch, almost like a racing clutch. I believe it is the Street ACT one to. I am installing one of these with my turbo kit within a couple weeks but am scared of braking my tranny. I believe the clutch needs to be JUST RIGHT to where it can GIVE a little bit when shifting, yet doesn't slip under power. So, the big stinking question is WHO ELSE MAKES A DAMN CLUTCH for out car???????? I remember hearing someone talking about Exidy (sp?) making one. I would like more options than just the ACT clutch.

Kyle

Here's a crazy idea-- match the revs and don't powershift, and then you only need a firmer clutch if it slips while fully engaged. If it does, you *are* loosing power, period.

I agree with thepas...there HAS to be more than one aftermarket clutch choice for us. One that is a little less firm than the ACT setup.

Colin, rev matching and power shifting is fine, but we're all human and sometimes we mess up. Or at least, I do :) I don't want to be SO paranoid about breaking my tranny that my driving pleasure decreases, ya know?!

I always take it easy on shifts, but it sounds like some others are taking it easy as well...and STILL busting their tranny. Hell, Shiv broke 2nd gear in the MIDDLE OF THE GEAR!! :)

Once my turbo is tuned (oh God, let that happen next week...running 0psi of boost is really starting to piss me off :) ), I'll want to run a 1/4 mile at least once. Just to see what the car can do. Now, I'm having second thoughts about that because shifting fast is bad for the tranny.

Oh well...just venting at this point...so I'll stop :) I hope that BPM's gearset turns out to be the answer to my worries. Only time will tell.

Sean

We were the original importers of the "Sam gearboxes" which are what the Rigoli's have used in the 10 second WRX. All three stages are VERY proven and well developed.

BPM has since bought world-wide and exclusive rights to the pieces from Sam so we're waiting to hear back from BPM regarding our new prices.

Since this all happened, we've also decided to offer them as gearsets only instead of only as fully built boxes. Our original decision to only offer the units already built was for quality control. We didn't want a set sold and improperly installed and have people thinking the gears were bad.

Now that they're being sold under a worldwide brand name, and are openly known as tried and true units, we're happy to supply gearsets only or we'll still do installs on your own transmission or (if we have the right type in stock) and exchange.

If anyone has any questions about these boxes, feel free to ask. I hate to come off sounding egotistical but I did ALOT of research before offering them so I feel confident and handling any technical issues you might have.

As for why Subaru boxes are weak, it's partially to do with the material Subaru uses for the gears (both in the STi and non-WRX units) as well as how small the gears are. There's just not much room in there to put in gears of a necessary physical size to handle gobs of power unless you ditch the synchronizers to make some room and throw in some dog gears.

Cheers,
Trey
CobbTuning.com