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WRX or Legacy trans?

Posted: Fri Oct 03, 2003 2:25 am
by LaureltheQueen
When I do my swap, should I go all out, and get the wrx trans, or just swap it over to a manual legacy transmission.

Also, what are the advantages and disadvantages of the 4.11 and the 3.9 gear ratios, I know very little about drivetrain stuff

Posted: Fri Oct 03, 2003 2:35 am
by Yukonart
I'm far from an expert on this. . . but whatever better-mates up to the engine would be my first choice. . . . but if the Legacy tranny has the higher gear ratio, you're looking at more potential power reaching the wheels. . .

However, Ruby isn't much heavier than the WRX, so I can't say it should matter too much. :P

Posted: Fri Oct 03, 2003 2:49 am
by LaureltheQueen
all the transmissions mate up perfectly from what I've read on nasoic.

Posted: Fri Oct 03, 2003 3:29 am
by czo79
Well, my understanding is that a lot of people think the legacy turbo transmission, like many things on our cars, is overbuilt. Ie...better than the wrx tranny. I think the gears are shot peened, which isn't the case with the wrx. Also something about the bearing...bear with me, my tranny knowledge and vocab is limited...i think its the bearing on the input shaft (coming from the clutch) I think there are two, and the front one is maybe longer/wider...can't remember about the other bearing. But this gives more support to the shaft, preventing flex that people think is an issue/cause of the wrx trannies blowing gears, the shaft flexes and then gears don''t line up right.

Whats the story with NA vs turbo trannies. I'm wondering, in my 97 Legacy, could I put a turbo tranny in? it would meet up with the engine right? I suspect ratios might be a problem...but what about the push vs pull cltuch issue? how would I deal with that?
thanks
Micum

Posted: Fri Oct 03, 2003 4:09 am
by Brat4by4
Thread hijacking in process... :D .

Posted: Fri Oct 03, 2003 5:36 am
by vrg3
Laurel - A higher final drive ratio will just make all your effective gearing shorter.

So, put concisely, with a 4.11 instead of a 3.90 you'll accelerate faster but burn more fuel and have a lower top speed. (And vice versa if switching the other way.)

Posted: Sat Oct 04, 2003 1:31 am
by subafreak
I would just stick with a Turbo Legacy tranny, (unless your talking WRX STI) Another thing to consider is that US. WRX's use a 3.45 rearend (same as SVX but not any other Subaru in history) They have a wierd ratio converter in the center diff section, I have no idea why but it's only in the US WRX. I think the 4:11s are a little low for a car with good power, there great for my 90 wagon but seem like a waste for a Turbo car. You could also get 4:11s with a higher top gear for crewsin the hiway. My 91 Turbo has 3.90s and I had it up to 140mph with RPM's to spare, I now have the same tranny in my SVX and I have so far had it up to 145mph with lot's of RPM's to spare, I'm sure it's good for 150mph.

I'm not sure about the whole shot peaned hardned gears in the Turbo trannies, I think it might just be a myth. After all how the hell did I break 5th gear in mine?

Posted: Sat Oct 04, 2003 10:30 am
by LegacyT
I hear all subaru gearbags are weak, except for the 2nd and 3rd Legacy gen twin turbo tranny's and STi tranny's. I also remember hearing somewhere that the legacy turbo's final drive ratio (3.9) gives it more of a rear wheel drive car feeling, Whereas the WRX FDR makes it feel more like a FWD car. This is all I heared don't know whether its true or not, I still have heaps to learn in tranny's and such. Anyone care to comment?

Mark,

Posted: Sun Oct 05, 2003 4:45 am
by georryan
I used to own a rwd car. Our subarus feel nothing like it. I've driven several fwd cars, also, but in all honesty, I think our cars feel like an awd.

Posted: Sun Oct 05, 2003 11:36 pm
by Brat4by4
With the rear-end reduction on the WRX tranny, the numbers don't match up perfectly. The front gets the slightest smidgen more power, thus the comparison to front wheel drive. I believe people confuse suspension settings with powertrain bias. I know I could make my tail whip out all day with some AGX's and a huge roll bar in the back. From the factory they dial in understeer for safety sake. Unless you have something like a 90-10 or 10-90 split I don't think it should make the car behave differently. Except maybe with full power around a sharp, slippery turn in the first two gears.

Posted: Mon Oct 06, 2003 12:17 am
by subafreak
Hmm, I can get my 90 Wagon to slide out sideways comming up the hill where I work, ofcourse I can get the golf cart out sideways there too but, it's only RWD. :D

I'v heard some people say that the reduction in the WRX tranny was suppost to make it more like RWD? It seems like all it does it make it blow 2nd and 3rd gear easier, and make it a great canidate for an SVX swap. Except for the blowing of the gears part.

Posted: Tue Oct 07, 2003 7:44 am
by LaureltheQueen
Hmmmm... Okay. SO besides STi, what transmission would you folks recommend?

Posted: Tue Oct 07, 2003 8:52 pm
by entirelyturbo
The Legacy Turbo tranny would probably be the best. It was overengineered like most everything else on the car. Although the STi is definitely a strong tranny, I don't think it's really necessary for you application...

Posted: Tue Oct 07, 2003 9:36 pm
by Brat4by4
Everyone keeps dropping the "overengineered" phrase like there's no tomorrow. If they are so "overengineered" how come they still break? Just a pet peave. They are stronger, nuff said.

Posted: Wed Oct 08, 2003 6:16 am
by LaureltheQueen
My application will be WRX motor that will eventually be built up some. Still a good plan?

Posted: Wed Oct 08, 2003 10:55 am
by LegacyT
Legacy Twin Turbo tranny? their good for what, 280 stock hp or something

Mark,

Posted: Wed Oct 08, 2003 3:49 pm
by entirelyturbo
I would think you would almost have to buy a whole front clip in order to get a TT tranny... I've never seen em for sale separately...

Laurel, if you really want durability and $$$ is not too big of an issue, get a WRX STi gearbox from overseas, a version 5 perhaps, many 2.5RS-T owners have done just that.

Posted: Wed Oct 08, 2003 4:41 pm
by Brat4by4
You'd have to double check. Version 5 or 6 is when they actually had upgraded internals. The previous versions were just regular trannys.

Posted: Thu Oct 09, 2003 7:59 am
by LaureltheQueen
Money is sort of an issue. I've had problems with my motor for the last 15k miles or so,and I'd rather like to get it replaced asap.

Re: WRX or Legacy trans?

Posted: Fri Jun 06, 2014 7:02 pm
by Danteandsoob
11 year bump.

Anyone know if the SVX trannys bolt up to an N/A EJ22? And if they can, what the ratio on them is (higher than 3.90 if possible.) I'm wanting to replace my 4EAT (3.90, right?) with something that can let out a little more power (I know it will have to be a 5MT at that point.) I also read that some of the BC trannys had 4.11's, it that true, and will that work with a 3.90 rear diff?

Re: WRX or Legacy trans?

Posted: Fri Jun 06, 2014 7:39 pm
by mike-tracy
Svx tranny will work. They have a 3.54,final drive. Just get a matching 3.54fd diff from a manual 02-05 wrx. The svx has unequal length axles that don't fit your hubs. You'll need the Wrx rear axles or other Subaru axles that are male to female as you currently have male to male axles.

Re: WRX or Legacy trans?

Posted: Fri Jun 06, 2014 7:43 pm
by Danteandsoob
so is that a high acceleration, or top speed? and will the 3.90 diff match up.

Re: WRX or Legacy trans?

Posted: Fri Jun 06, 2014 7:44 pm
by mike-tracy
See my edit. Svx would be slower accelerating but higher top speed.

Re: WRX or Legacy trans?

Posted: Fri Jun 06, 2014 7:45 pm
by mike-tracy
No matter what, you have to match the rear diff final drive to the tranny. As mentioned the svx is 3.54.

Re: WRX or Legacy trans?

Posted: Fri Jun 06, 2014 7:45 pm
by Danteandsoob
Ah, okay. Well, don't really want that route; So how about if i swapped the 4EAT to a 5MT?