5Speed swap part??

[kewilo]

Hi guys,

I'm about to purchase an SVX with a tranny that is off to join the many other Svx trannys in tranny heaven.

So i've found a mechanic to do a 5speed swap but i am not sure which parts would be best for the swap in terms of performance and compatibility.

Here is a list of parts the mechanic has put together:

4.11 gearbox from a 2000 Impreza RS
rear differential from a 99 RS
Clutch and pedals - New from Subaru
Clutch master cylinder - new
used slave cylinder
wiring
"Drive shaft will be extended"??

The mechanic expressed some concerns that the 2000 RS gearbox might not be strong enough to handle the SVX engine, and gave me the option to use a (not sure of year) 02WRX 3.54 gearbox for a little more $$.

Some of my facts and figures may be off but here is what i'd like to know.

Is the lower gearbox ratio of the wrx better?
Is there a different crossmember needed?
Are the parts listed correct?
Is there any parts missing from the list?

Thanks for any help offered.

[mbtoloczko]

Neither the RS gearbox nor the WRX gearbox will stand up to abuse (5000 rpm launches, speed shifting, and such). Not sure that the RS gearbox is really any stronger the the WRX gearbox.

-You'll need to get the front half of the driveshaft extended by 2.0".
-You will need to have a custom crossmember made up. There is an example in my locker in the custom exhaust folder. Subafreak has a nice one in his locker too.
-You didn't mention shifter linkage. You'll need that.
-Shifter boot and some way to secure it to the console.
-When you remove the steering wheel column, be careful to keep track of its orientation. If you spin the steering wheel while the column is out of the car and loose the orientation (including rotations) of the steering wheel relative to the column, the wiring for the airbags will get destroyed when you try to turn the steering wheel after the column is put back in the car.

[kewilo]

Originally posted by mbtoloczko
Neither the RS gearbox nor the WRX gearbox will stand up to abuse (5000 rpm launches, speed shifting, and such). Not sure that the RS gearbox is really any stronger the the WRX gearbox.

I've read other guys on this network were using tannys from pre 2000 legacys, Rs's, and wrx. Are those better to handle the power of the 3.3

In general, i figured that a new gearbox would be better. The trannys the machanic has are a 2000 Impreza RS and 2002WRX. What would be the proper tranny for the swap?

The final drive for the WRX is 3.54, how much of a difference is that to the RS's 4.11? I know most guys are using 4.11 or 4.44, not 3.54

Not sure what is best. I don't plan on bringing the car to the track. However, i will open her up at least once to and from wherever i'm going.

[wawazat??]

Originally posted by kewilo



I've read other guys on this network were using tannys from pre 2000 legacys, Rs's, and wrx. Are those better to handle the power of the 3.3

In general, i figured that a new gearbox would be better. The trannys the machanic has are a 2000 Impreza RS and 2002WRX. What would be the proper tranny for the swap?

The final drive for the WRX is 3.54, how much of a difference is that to the RS's 4.11? I know most guys are using 4.11 or 4.44, not 3.54

Not sure what is best. I don't plan on bringing the car to the track. However, i will open her up at least once to and from wherever i'm going.

A couple of points you need to fully understand here kewilo. First, the final drive ratio of the front differential MUST match the final drive ratio of the rear differential. The '02 and + USDM WRX is the only Subaru transmission that will allow you to keep your SVX rear differential. ALL OTHER 5 speeds will require a diff or ring/pinion gear swap to match ratios and avoid damaging the transmission.

That said, there is not a considerable difference in the strength of the gearbox itself bewteen the WRX and Legacy turbo transmissions and the RS/Outback/Legacy transmissions. Clutch mechanisms are different (which means cluthes are different). Some are hydraulicly actuated and some are mechanically (cable) actuated (good and bad with both of these in terms of installation and longevity).

Good luck with you swap.

Todd

[kewilo]

Thanks for the feedback guys.

I get the jist of it. Final drive ratio of the front must match the rear diff.
If i get a 4.11 then i must change the svx's rear diff to a 4.11 as well. However, if i use the WRX 3.54 then i wouldn't have to change the rear diff because the final drive on the svx is already 3.54.

Is the WRX ratio of 3.54 as good as a tranny with a 4.11 final drive? Which one would produce more torque off the line and high end?

[TomsSVX]

the 4.11 with put less stress on the transmission itself but in fact make the engine rev higher than the 3.54 gears. The 3.54 gears will be fine for anyone not looking to race their car as it will be better on gas mileage. It is all up to you to decide whether you want better mileage or better acceleration. Might be able to save money by not swapping the rears if you go with the WRX trans. I will be racing my 5mt so my 4.11 suits me fine but since i alsouse it to travel the gas mileage is effected slightly which is a down point. Either way, you still have a 5mt SVX which is cool in and of itself. Good luck and enjoy the shifting

[wawazat??]

Originally posted by kewilo
Thanks for the feedback guys.

I get the jist of it. Final drive ratio of the front must match the rear diff.
If i get a 4.11 then i must change the svx's rear diff to a 4.11 as well. However, if i use the WRX 3.54 then i wouldn't have to change the rear diff because the final drive on the svx is already 3.54.

Is the WRX ratio of 3.54 as good as a tranny with a 4.11 final drive? Which one would produce more torque off the line and high end?

Final drive of the USDM WRX works out to be 3.90:1 even though the rear diff is a 3.545:1. The transmission uses a 3.90:1 front diff ratio and a 1.1:1 output to the rear diff, which equals a 3.90:1 final drive ratio.

Todd

[TomsSVX]

Thats probly just gonna confuse him. Since he will not be doing the swap himself, it is unnesescary(spelling?) knowledge. Good to know for future problems though.

[wawazat??]

Originally posted by tomssvx
unnesescary(spelling?) knowledge

No such thing Tom. If this helps him to better understand the process it's good. If it helps him determine if the shop he is going to use really knows their stuff, it's good.

No downside in my book

Todd

[kewilo]

Originally posted by tomssvx
Thats probly just gonna confuse him. Since he will not be doing the swap himself, it is unnesescary(spelling?) knowledge. Good to know for future problems though.

Yeah, that did confuse me somewhat. However, it gives me something to look into.

At least now i'm sure that i know that i don't know.

Thanks for the info guys.

[TomsSVX]

very true Todd. I guess I try to keep it simple thats all.
Too much of a good thing can go bad.

But besides that. the plus side of the 4.11 gears is faster acceleration where as the plus side of the 3.54 gears is better gas mileage. It is simple to differentiate them when it is laid out plainly.

Another plus of the 3.54 gears is the ability to leave the rear diff without changing the gears out. Good luck with ur swap

[Earthworm]

Which will cost you more...the RS tranny+diff or the WRX tranny by itself. I'd strongly recommend the WRX tranny for the better gears. (IMO)

[kewilo]

The WRX would cost me an extra $450 however, i would need to replace the rear diff. The machanic didn't mention if that you reduce the price in turn. I'll have to bring it up.

I like the speed off the line with the 4.11 but am leaning towards the WRX.

I've been told the WRX gear box provides better high end.
Fact or Fiction?

[TomsSVX]

if you use the wrx transmission you don't need to change the diff. This might be cheaper than doing the 4.11. Make sure before u do it.

[wawazat??]

Originally posted by kewilo
I like the speed off the line with the 4.11 but am leaning towards the WRX.

I've been told the WRX gear box provides better high end.
Fact or Fiction?

The final drive of the WRX 5 speed is 3.90:1. Comparing this to a 4.11:1 ratio will give slightly less acceleration and slightly higher top end. Not enough to make a difference unless you were in competition, in my opinion.

Todd