WRX vs. RS Transmission

[GTDrifter]

I'm still thinking about a wrx engine swap. The swap is all figured out and now it's comes to the transmission. The following are rumors I've heard and am looking for more information stating which are true and which are false.

RS transmission is stronger than the 02-05 WRX transmission
RS transmission will hold up to 300 whp
RS transmission will be ok but will blow when launched/driven rough
RS transmission is not strong enough at all
Legacy GT transmissions are almost as strong or just as strong as an STI transmission

Any help will be greatly appreciated.

[mike-tracy]

Not sure where you heard all that. In late 03 they widened the teeth of the gears in the wrx tranny. The RS & GT (we're talking n/a here, right?) have the narrower gears until prob the same time.

There is some truth to the 4.11 gearsets being able to hold some power. Like any tranny (6mt included), you abuse it, you lose it. The 4.11 helps vs the 3.54, 3.7 or 3.9 turbo trannies in that the ring and pinions (not sure how to word this correctly) of lower gears (ie. higher final drive #) help relieve/transfer some stress from the gears.

You want a burly 5mt? Baja XT or Forester XT. 4.44 gearboxes. You'll be able to take a stock sti off the line. If you don't have a ton of money to spend, a Forester, 2.5GT or Rs 2.5 n/a tranny would fit the bill if you dont abuse it.

[GTDrifter]

I would like to autocross it after the swap but not if its gonna ruin my trans. Would my rs trans be ok? Basically get up to 40 mph and stay in 2nd gear is what the veteran autocrossers told me to run. This would cause some stretches where 7k rpm exists

[xoSubieLegacyxo]

I would like to autocross it after the swap but not if its gonna ruin my trans. Would my rs trans be ok? Basically get up to 40 mph and stay in 2nd gear is what the veteran autocrossers told me to run. This would cause some stretches where 7k rpm exists

Cause we know what happens when you throw your car into 3rd gear while AutoXing. HAHA I say find a forester XT or Baja XT trans.

[GTDrifter]

I would like to autocross it after the swap but not if its gonna ruin my trans. Would my rs trans be ok? Basically get up to 40 mph and stay in 2nd gear is what the veteran autocrossers told me to run. This would cause some stretches where 7k rpm exists

Cause we know what happens when you throw your car into 3rd gear while AutoXing. HAHA I say find a forester XT or Baja XT trans.
I'd have an easier time finding the Holy Grail

[xoSubieLegacyxo]

I would like to autocross it after the swap but not if its gonna ruin my trans. Would my rs trans be ok? Basically get up to 40 mph and stay in 2nd gear is what the veteran autocrossers told me to run. This would cause some stretches where 7k rpm exists

Cause we know what happens when you throw your car into 3rd gear while AutoXing. HAHA I say find a forester XT or Baja XT trans.
I'd have an easier time finding the Holy Grail

Does this mean we're going on a quest? I'll grab my coconuts! :smt005 :smt005

http://encycl.opentopia.com/enimages/thumb/20/19701/300px-HolyGrail036.jpg

[GTDrifter]

I would like to autocross it after the swap but not if its gonna ruin my trans. Would my rs trans be ok? Basically get up to 40 mph and stay in 2nd gear is what the veteran autocrossers told me to run. This would cause some stretches where 7k rpm exists

Cause we know what happens when you throw your car into 3rd gear while AutoXing. HAHA I say find a forester XT or Baja XT trans.
I'd have an easier time finding the Holy Grail

Does this mean we're going on a quest? I'll grab my coconuts! :smt005 :smt005

https://sl-i.net/FORUM/
Why don't you have a swallow carry them for you?

[nikolaus.conrad]

Trans swap

[nikolaus.conrad]

viewtopic.php?f=59&t=22635&p=280563#p280563 (http://www.sl-i.net/FORUM/viewtopic.php?f=59&t=22635&p=280563#p280563)

3rd page is a discussion about what sort of transmission to use for a turbo motor.

[GTDrifter]

That seems more like comparing the stock L trannys to wrx. I know it says all the 5 speeds are basically the same but idk. I might just go for a jdm tranny off an ej20k or something along those lines. A friend of mine has one running on his 20k pushing at least 250 hp so it'll do fine at least for now. Just wanna run stock hp.

[nikolaus.conrad]

I gotcha

[chuckthefuk]

I've gone through so many hybrid turbo builds and followed the thread down to the last page and the general consensus is that non-turbo 5MT have 2nd / 3rd gear issues when 200+ AWHP is achieved.

WRX and other 5MT turbo variations tend to hold up to 300 AWHP but when launched there is very little life left.

Now there are lots of reasons why 5MT's fail and to say that one is better then the other is almost impossible unless a full inspection / rebuild is performed.

You save your hard earned money and end up with a 6MT that has been launched 100's of times and end up with a worn gear set. Or a babied WRX 5MT that is factory fresh...

Its always a gamble with used parts.

I can say from experince that those JDM 4.44 shot gearing 5MT are surprisingly strong when abused.

Example: My friends GC had the 4.44 w/ EJ207 & GT30R / Hyrdra and Tuned @ 16 PSI / 325 AWHP . He would daily drive it and then red line drop at the track over and over again with no problems with driveline shock. Originaly the RSTi had a 4.44 open diff and that did not last but after a R180 swap he maintained 12.4 1/4 times through the season..

http://www.youtube.com/watch?v=-jE8Ct0yavw

In the end you just don't really know how strong a used transmission is going to be or the lifespan of it.

When people ask if a transmission can survive *** HP are they generalizing their goals or realistcly thinking about usable power at the wheels..
-Chuck

[GTDrifter]

that is a great point

[GTDrifter]

I think I'm just gonna run my RS trans cause I know its good. Not autocross it until I beef up the internals and just drive it easy.

[nikolaus.conrad]

How many miles are on your RS?

[GTDrifter]

163xxx

[GTDrifter]

all my questions have been answered. basically don't drive like a retard and the rs trans will hold up fine. if I want to upgrade a 2005 legacy gt trans will do the job really well and I could keep my clutch and rear diff.
http://www.rs25.com/forums/f8/131018-wrx-stock-tranny-2.html

[GTDrifter]

I was talking to one of the local subie guys yesterday and asked about swapping and keeping an rs trans. He said as long as I know how to drive it could handle all the power. He knows someone currently running a 300+ hp car on an rs trans and even autocrosses it with no issues. I'm gonna grab an extra trans/driveshaft/rear diff just in case and see what happens.

[grayguy]

I'm starting to believe I know some bad drivers, cause I have at least one friend who roasted 3 trannies in a stock motored RS autocrossing it, and our RS had blown up it's 3or 4th tranny when we bought it.

I think as long as our smart and don't have a stupid-aggressive clutch, the 5mt should hold. Plus you can pop a lot of 5mts before your up to the $3-4k mark for a 6mt swap...

[Bookem]

I'm starting to believe I know some bad drivers, cause I have at least one friend who roasted 3 trannies in a stock motored RS autocrossing it, and our RS had blown up it's 3or 4th tranny when we bought it.

I think as long as our smart and don't have a stupid-aggressive clutch, the 5mt should hold. Plus you can pop a lot of 5mts before your up to the $3-4k mark for a 6mt swap...

I'm wondering if it's more how the trans got "broke in" if they really do or maybe the fluid people use. I know some people curse at it but I used Uncle Scotty's cocktail mix in the original trans once my swap was done on my BD which has over 120k on it now and still ok (10k on swap with original trans) and I beat the crap out of it, launches at the dragstrip, autx, and getting on it to keep up in traffic. Last summer I switched trans with one from a 00 RS with redline heavy weight (I know, heard bad stuff on this lube as well, but this was a cheap trans to let me beat on and came with a good rear lsd diff) that was abused before me and definately abused now, now this trans is a lot worse than my original trans, but still holding up after 5k miles just fine. I'm talking 4-5k clutch drops at least once a month, anywhere from 10-20 runs at the quarter mile a year and four to five autox a year. I do have an Exedy stage 1 clutch, that holds very good and group n engine and trans mounts. I have let some of my drifter buddies do clutch kicks to get the tires breaking loose as well. I know some people cringe but this is my fun car so I have fun with it and so far nothing broken yet, but time will come. But yes I'll go through a few 5mt before even thinking about a 6mt swap.

[chuckthefuk]

Thats crazy talk.. "a few 5MT before even thinking about a 6MT swap"

The time it takes to source a 5MT and install it vs. saving just under $2500 and doing it once.. Just crazy talk... I tells ya!

[StatGSR]

Thats crazy talk.. "a few 5MT before even thinking about a 6MT swap"

The time it takes to source a 5MT and install it vs. saving just under $2500 and doing it once.. Just crazy talk... I tells ya!

not really, $200-$300 plus 6-8 hours of work is probably alot more obtainable then $2500-$3500 for the majority of the enthusiasts here on this site.

and there are the reasonable people like me that could never justify a transmission that is worth more than the rest of the car all together....

[chuckthefuk]

Then how can you justify a turbo motor swap + wiring when it comes out to more then the value of your legacy?

Its not about value vs worth it... its about wants & need.

And even still "a few 5MT's before a 6MT" that means after 4 trans you've eaten up 800-1200 + 24 hours of labor..

I am just trollin' here.. It doesn't make sense since I would have to ask my mechanic friends to help me swap.. I hate gear oil..

Anyways I am off :-D
-Chuck

[nikolaus.conrad]

Just don't launch like a Tool and you'll be fine :grin:

[Bookem]

Thats crazy talk.. "a few 5MT before even thinking about a 6MT swap"

The time it takes to source a 5MT and install it vs. saving just under $2500 and doing it once.. Just crazy talk... I tells ya!
I know some think it's crazy but I'd rather have a 5mt. My first trans swap I pulled my engine, swapped trans, installed Sti ignition coils, rewired to delete the ignitor and put back together in eight hours. Going to 6mt and getting another driveshaft/reardiff/axles/hubs is a lot more work I'm not ready to put into a fun car just yet. 5mt's are plentiful 6mt are a little bit more spendy over here in Minnesota as well, not many Sti part outs, and the 04's are getting harder to come by, I have four sets of rims that are 5x100 bolt pattern (three of those sets have brand new tires). Okay biggest reason, and don't tell my wife I said this (she drives my car every once in a while) but I don't think she could handle the thought process of one more gear!


Then how can you justify a turbo motor swap + wiring when it comes out to more then the value of your legacy?

Its not about value vs worth it... its about wants & need.

And even still "a few 5MT's before a 6MT" that means after 4 trans you've eaten up 800-1200 + 24 hours of labor..

I am just trollin' here.. It doesn't make sense since I would have to ask my mechanic friends to help me swap.. I hate gear oil..

Anyways I am off :-D
-Chuck
It makes a difference for guys that would do it themselves like me, but I'll slow the troll for now...........I do see your point just not my wants or needs, I do plan on keeping my BD for quite a while so maybe in the future, especially if I did sell I'd go 6mt.

[chuckthefuk]

I never said a full 6MT swap.. Just the transmission.

6MT w/ linkage & shifter + 6MT clutch fork + 4EAT legacy prop shaft = $2000 or less.

6MT center diff will run OPEN without the DCCD so not a big deal until you dish out for a controller.

Thats all you need.. I am working on a detailed writeup but you know.. life and such.

-Chuck

[StatGSR]

I never said a full 6MT swap.. Just the transmission.

6MT w/ linkage & shifter + 6MT clutch fork + 4EAT legacy prop shaft = $2000 or less.

6MT center diff will run OPEN without the DCCD so not a big deal until you dish out for a controller.

Thats all you need.. I am working on a detailed writeup but you know.. life and such.

-Chuck

I don't think the 2000 or less is a completely accurate statement, not saying it couldn't be done for that, but i don think that's the average market price. a quick check on ebay shows plenty for 3000...

Also, i have seen the tire wear that happens with running a 6mt without a controller (its far from even), the controller would quickly pay for itself.

you also still need a clutch and might need a matching rear diff depending on what you got to begin with. and also may need axle stubs or new axles if i remember correctly.


:smt024 :smt006 :grin:

[chuckthefuk]

1) eBay is not an accurate source for prices unless you are using the "completed listings"
--> I have purchased 6MT's for $2000 or less from local subaru members. Its possible..
2) You can re use a 5MT clutch & flywheel as long as you have a 6MT clutch fork
3) Yes you are correct.. a simple brighton/L/WRX 3.90 (assuming you are using a 04 6MT) R160 can be sourced for under $50 from a junk yard.
4) I agree with you about the controller but again.. it can be done and is not necessary to complete the swap.

Anyways.. if you would like to continue this please PM.. we have officially hi-jacked the topic.

-Chuck

[Bookem]

1) eBay is not an accurate source for prices unless you are using the "completed listings"
--> I have purchased 6MT's for $2000 or less from local subaru members. Its possible..
2) You can re use a 5MT clutch & flywheel as long as you have a 6MT clutch fork
3) Yes you are correct.. a simple brighton/L/WRX 3.90 (assuming you are using a 04 6MT) R160 can be sourced for under $50 from a junk yard.
4) I agree with you about the controller but again.. it can be done and is not necessary to complete the swap.

Anyways.. if you would like to continue this please PM.. we have officially hi-jacked the topic.

-Chuck
This is good info, I did not know about the 5mt clutch working with the 6mt, this is what the great round table of Sli discussion is all about!

[chuckthefuk]

:-D soon soon.. write ups and documentation

-Chuck

[GTDrifter]

I know someone in elizabethtown who has a swapped rs pushing I believe 300 hp and he blew his rs trans. Then he upgraded the internals and says it's running perfectly fine and that can be done for like 1600

[Garrison]

Cryo-treating and shot-peening. Yessir, 'tis indeed possible.

[rougeben83]

yeah but at that point the old argument is that youre approaching STI 6 speed territory.

Breaking trans more than once is fine if your subaru is just a toy you tinker around with, but if you're planning to be driving it for any length of time, doing it once and doing it right will always be more cost effective in the long run (whats your time worth to you every time you have to change out your 5mt? I'm not even going into paying someone to do the trans change each time because that's even less cost effective).

FWIW, my 05 STI trans was about 2400 shipped, everything added up if I didn't buy the lw fw and a couple of other things, it's a little under 3k.

Anyway, the basic structure of any subaru 5 speed as always been the same, WRX, RS, Legacy GT, etc. Its the same design for the past 20 something years. There have been marginal improvements in reliability with bracing, gears, etc but they always fall by the wayside; and I've seen more than one local guy break a newly rebuilt 5mt with PPG gears/cryo/etc.

The RS/outback trans are better paired with a 2.0l because the shorter FD's (4.11 and 4.44 respectively) and gets you into the sweet spot of the turbo quicker. There's also a theory of less gear strain with the shorter gearing. The late 03-05 WRX trans, FXT, baja turbo, 05+LGT trans are stronger due to changes in the gear widths, and the push/pull clutch accutation (I always get the two mixed up) is a little better at distributing the load over the clutch disc. All have threads of being blown up by "stage x engine" on any given subaru forum. The point being is, its all just marginal, relative improvements over the other, but all of them cannot take a certain amount of abuse from the driver, regardless of how much power you are putting down.

People that have asked me about transmissions for their engine swaps always get this reply: If your 5mt right now is in good shape, use it. Swapping for another 5mt from the get go will by no means guarantee drivetrain reliability so the upfront, additional cost of doing it is not worth it. Recover from the initial cost of doing the engine swap itself, then either start planning on getting a replacement if/when your current 5spd takes a dump, OR go straight to a 6 speed.

[Dead91silvia]

I would like to autocross it after the swap but not if its gonna ruin my trans. Would my rs trans be ok? Basically get up to 40 mph and stay in 2nd gear is what the veteran autocrossers told me to run. This would cause some stretches where 7k rpm exists

Cause we know what happens when you throw your car into 3rd gear while AutoXing. HAHA I say find a forester XT or Baja XT trans.
I'd have an easier time finding the Holy Grail

Found 12+ Forester XT 5 speeds $850-1350)

Found 7 Baja 5 speeds at $1000-1500

Found 2 04 STi 6 speeds for $2600-Call (build date from 9-1-03)

Found 8 04 STi 6 speeds for $2000-3700 (build date pre 8-31-03)

Found a butt load of WRX 5 speeds for $750-2300...

You just gotta know where to look... :smt023

[Dead91silvia]

Cryo-treating and shot-peening. Yessir, 'tis indeed possible.

Customer that I just finished a center and rear diff for has has a built trans like that. Built for 600+ whp, same as his motor, 2.5 hybrid... Motor has 290whp right now... 02 WRX...

[GTDrifter]

I would like to autocross it after the swap but not if its gonna ruin my trans. Would my rs trans be ok? Basically get up to 40 mph and stay in 2nd gear is what the veteran autocrossers told me to run. This would cause some stretches where 7k rpm exists

Cause we know what happens when you throw your car into 3rd gear while AutoXing. HAHA I say find a forester XT or Baja XT trans.
I'd have an easier time finding the Holy Grail

Found 12+ Forester XT 5 speeds $850-1350)

Found 7 Baja 5 speeds at $1000-1500

Found 2 04 STi 6 speeds for $2600-Call (build date from 9-1-03)

Found 8 04 STi 6 speeds for $2000-3700 (build date pre 8-31-03)

Found a butt load of WRX 5 speeds for $750-2300...

You just gotta know where to look... :smt023


Their all out of my budget right now