Legacy SS Drivetrain Strength/Durability

suby25 · Post by **suby25** » Sun Apr 16, 2006 6:57 pm

I'm in the research phase for my track build this summer. The car will be used solely for racing - track days, auto-x, and rally-x. My current setup is:
-1995 Impreza L chassis
-1994 EJ22T motor
-TD04
-WRX intercooler
-unorthodox lightweight crank pulley
-3" Rallispec TBE to Megan Racing muffler\
-competely gutted interior

The car is running the stock L trans and its in rough shape, not liking the ~200-220hp it sees. I'm pretty sure the clutch is not stock, as it is much stiffer than my 00 RS clutch. I have alot of issues to address and choices to make, but I'm in need of a new drivetrain, and I've been giving some consideration to running the Legacy SS drivetrain for its stronger transmission and rear LSD. Can anyone comment on the durability and torque limitation of this trans, especially compaired to other USDM drivetrains? My other choice is to source a JDM drivetrain from a V1-4 car.

I'm most likely going to use the EJ22T shortblock and swap most everything over from a USDM EJ205. I'm looking to make 250-300 whp, so most likely an upgraded turbo/IC will be in order as well as engine management of some sort. I did a few searches and didn't see the info I was looking for, so I apologize if this is a frequently asked topic. Thanks alot!

Cheers

greg donovan · Post by **greg donovan** » Sun Apr 16, 2006 7:06 pm

it is pretty strong but also pretty expensive to fix if you break it.

if you have the money look into doing something like what BAC5.2 is doing w/his dogbox transmission.

i believe you can put the dogbox gearset into the L case.

Kelly · Post by **Kelly** » Sun Apr 16, 2006 7:13 pm

So far, we've had better luck with the NA transmissions. Ive got Two older turbo boxes on my floor right now, one is a V4, the other is a T Leg. Both blew the imput shafts. I cant count how many USDM WRX trannys We've done. They just cant handle 300whp a good clutch, and a good driver.

I still have yet to rebuild any NA gearboxes. Granted none of the NA cars put down the power, but I know of a couple putting it down. Brydons 2.5 GT32 400whp+ CG is running the NA box, and it seems to be holding together for quite a while now. Same with Matt Pecks 300whp+ nitrous bastard. Theres a couple more WRX swaps Ive done as well, still running the NA box.

There cheaper to replace than turbo boxes. Clutches are cheaper. Gears are cheaper. And theres many more of them floating around.

My $.02

Splinter · Post by **Splinter** » Sun Apr 16, 2006 7:13 pm

from what I've read, a WRX case with STi-RA gearset should take that kind of power without sweating, as long as you're not dumping it at WOT

Thats what Im planning on putting in for my build

suby25 · Post by **suby25** » Sun Apr 16, 2006 8:00 pm

I haven't ruled out reusing the L case and running straightcut/dog box. That may turn out to be a good way to go. I was thinking about running straight cut 1/2 and stock 3-5 since the L gears are very short and great for acceleration. I'll have to read up on gears and see what I find.

The other issues is running a rear LSD, I believe the L is a 3.9 final drive so I could use a stock WRX without much trouble. I've got a lot of research to do.... Thanks for replies everyone, you've been helpful as always.

rallysam · Post by **rallysam** » Mon Apr 17, 2006 1:12 am

Everybody I know with an SS has broken their trannies. I highly recommend a PPG gearset from http://www.gearboxtech.com (the shop BAC5.2 works at). You can get a synchro'd set instead of dog so it is not terribly expensive. PPG will be way stronger than a WRX or an STI-RA set.

A stronger tranny is a little more expensive than a weak tranny up front, but not a lot. And, in the long run a weaker tranny is much more expensive if you catch my drift

Splinter · Post by **Splinter** » Mon Apr 17, 2006 1:20 am

hate to be a highjacker, but Im sure this information would be useful for the original poster.

If I were to pick up a WRX tranny, and have gearboxtech make me up a set of PPG gears and all, could I assemble it myself, relatively easily?

Or have them ship me the gears and me take it to a local shop?

Or would it be best for them to ship me the assembled unit?

What kind of cost is gonna be associated with this?

Im relatively far away. Im looking for something that can support 300-350whp with some relatively hard launches

BAC5.2 · Post by **BAC5.2** » Mon Apr 17, 2006 4:00 am

Not something you could build yourself and have it last.

Local shops would proably charge you more.

Best bet, send us a WRX case (with a gearset in it), we'll rebuild it with PPG gears, and send it back.

Easiest, and 9 times out of 10 the cheapest.

RA gears are the biggest waste of money ever. Period.

I'm running a PPG straight cut synchro box, RWD for the moment, and it's nice. Handles hard shifts very well, and I can break them loose on a 3-4 shift.

Kelly · Post by **Kelly** » Mon Apr 17, 2006 4:34 pm

BAC5.2 wrote:
RA gears are the biggest waste of money ever. Period.

.

Yup. I dont even offer them as a rebuild option anymore.

greg donovan · Post by **greg donovan** » Mon Apr 17, 2006 4:42 pm

BAC5.2 wrote:
RA gears are the biggest waste of money ever. Period.

why?

is it because they arent any stronger than stock wrx gears?

BAC5.2 · Post by **BAC5.2** » Mon Apr 17, 2006 7:06 pm

That's 1 reason.

The other reason, is that they ARE stock WRX gears.

Another reason, is that the 03.5+ gears are the same width as the RA gears, just different ratio's.

Plus, it'll cost you ~$3,000 to build an RA gearbox. It'll cost you more to do it right with a PPG gearbox. But what will almost definately happen, is that you'll blow the RA gearset, and have to drop another 3k to replace it (and then worry about blowing it again). You've now surpassed the price of doing it correctly the first time.

No one has ever broken one of the PPG synchro boxes we've built.

greg donovan · Post by **greg donovan** » Mon Apr 17, 2006 9:18 pm

so the only benefit of the RA set is the ratios?

if you can share costs in an open forum what are the prices of the PPG boxes assembled and ready to go?

BAC5.2 · Post by **BAC5.2** » Mon Apr 17, 2006 11:43 pm

The only benefit is the ratios... if you are N/A. Turbo cars do better with longer gears, for quarter mile that is. I guess the short ratios might be cool for auto-X, but frankly, a long 1st gear means you can stay IN 1st gear in an auto-X.

Prices?

Sure.

Note: Prices subject to change based on exchange rate and production costs. Prices can change daily.

1-2 straight cut or helical synchro gearset. $2000 for the gears.

The 1-4 set (helical or straight cut) is $3500.

Often times, all of the synchros will be replaced (it's a good idea to do it). That's about $250 to $270.

There's about $100 in transmission install parts (shims, gasket, misc other stuff).

Then there is shipping.

Frankly, the best idea is to find a known good stock WRX unit. Then we won't have to worry about the front diff being blown or anything.

That's about the cost right there.

Various other charges can occur, and every tranny is subject to circumstantial charges. Sometimes more, sometimes less.

That about covers it I think.

Splinter · Post by **Splinter** » Mon Apr 17, 2006 11:54 pm

If we sent YOU some cash, could you get a WRX tranny from a local jy for us, to save on shipping one from here?

greg donovan · Post by **greg donovan** » Tue Apr 18, 2006 12:56 am

BAC5.2 wrote:The only benefit is the ratios... if you are N/A. Turbo cars do better with longer gears, for quarter mile that is. I guess the short ratios might be cool for auto-X, but frankly, a long 1st gear means you can stay IN 1st gear in an auto-X.

i think part of the reason for the short close gearing is because rally speeds are typically lower and most of the time is spent in 2nd 3rd and 4th w/very little time in 5th or 1st.

BAC5.2 · Post by **BAC5.2** » Tue Apr 18, 2006 2:50 am

Don't the rally cars run 4.11 or 4.44 final drives? I agree that's what it's for. But such close ratios doesn't pair well with boostedmobiles. Very hard to have enough of a load on the engine to build significant boost when you can't stay in gear for more than 20mph.

Far as me finding a junkyard tranny, I can look at the yard. We'd need a 99+ hydro-pull-type tranny to install the gears in (unless you want to convert to push type or cable). Best idea, look for a blown tranny in/around the Mid Atlantic region and have them ship it to either my house or to the shop directly. That'd probably be the cheapest thing to do.

greg donovan · Post by **greg donovan** » Tue Apr 18, 2006 3:05 am

BAC5.2 wrote:Don't the rally cars run 4.11 or 4.44 final drives? I agree that's what it's for. But such close ratios doesn't pair well with boostedmobiles. Very hard to have enough of a load on the engine to build significant boost when you can't stay in gear for more than 20mph.

Far as me finding a junkyard tranny, I can look at the yard. We'd need a 99+ hydro-pull-type tranny to install the gears in (unless you want to convert to push type or cable). Best idea, look for a blown tranny in/around the Mid Atlantic region and have them ship it to either my house or to the shop directly. That'd probably be the cheapest thing to do.

most open class run the 4.44 unles they are running 30 psi like Doug Havir's yellow STi. he runs the 4.11 and it is plenty fast. that thing does 0-60 in something like 3.5 on gravel.

i must confess that i dont know enough about the exact ratios used. there are others that know more than me i am sure.

as far as i know they want a tall 1st and short 2-4 w/as short a final as the car will support and not top out too much on the straight sections.

georryan · Post by **georryan** » Tue Apr 18, 2006 5:47 pm

BAC5.2 wrote:Don't the rally cars run 4.11 or 4.44 final drives? I agree that's what it's for. But such close ratios doesn't pair well with boostedmobiles. Very hard to have enough of a load on the engine to build significant boost when you can't stay in gear for more than 20mph.

That's probably why so many of them are trying to get fast spooling turbos. Most of the ralley people I've heard of are trying to get as much bang out of their TD04s as they can, or going with a twin scroll setup.

rallysam · Post by **rallysam** » Tue Apr 18, 2006 11:44 pm

Hmmm...

Also I would guess that rally cars are typically in each gear longer than you're thinking because they don't get as much traction/accelration. So that means more time to get on boost. And I bet he's right that they get fast-spooling, low-flowing turbos because they have flow restrictors anyway. On top of that, there's the anti-lag and and left foot braking to keep her spooled.

Come to think of it, what percentage of a rally stage is long extended periods of acceleration? 25% maybe? You spend just as much time braking, or sliding side to side without shifting - squirting throttle here and there.

They don't get to very high speeds (relatively) anyway. I mean, if you ran higher gear ratios you might as well toss the top gear or two cause you wouldn't hit 'em

I'm not claiming to be an expert though. All I do is rallycross. For that you only need a 1-speed gearbox

BAC5.2 · Post by **BAC5.2** » Wed Apr 19, 2006 3:46 pm

I'm not saying that a low final drive is a bad thing for rally, don't get me wrong....

I'm saying for 1/4 mile runs, or any kind of highly spirited, high duration on-boost driving, a higher final drive isn't a bad thing.

Rally or Auto-X where binary throttle is more important that building lots of boost before shifting, a shorter final drive is awesome.

No, for rally you want a shorter final drive. For 1/4 mile (or for higher output goals, with large turbos and such), a higher final drive (3.90) is a great setup. The helical dogbox with a 3.90 final drive is really really kickass for 1/4 mile racing. Really kick ass.

legacy92ej22t · Post by **legacy92ej22t** » Wed Apr 19, 2006 4:42 pm

For the original question: Not strong enough. I've already blown up one, working on another.

I'm waiting to either win the lottery or for Phil to get Andrew to sponsor me. Hmmm, about the same odds either way! HAHAHAHAHA.

rallysam · Post by **rallysam** » Wed Apr 19, 2006 6:52 pm

BAC5.2 wrote:I'm not saying that a low final drive is a bad thing for rally, don't get me wrong....

Yeah man, I gotcha. I'm not sure if you were talking to me, but I'm wasn't disagreeing with you either. I'm just hypothesizing about why stage rally guys do what they do, I don't even know the answer to that for sure

suby25 · Post by **suby25** » Wed Apr 19, 2006 7:36 pm

Holy off topic discussion.

Hey Phil, want to sponser me for this summer?

Perfect zero to hero L build.

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Legacy SS Drivetrain Strength/Durability

Legacy SS Drivetrain Strength/Durability