tranny swapping for gearing ?

[superu]

Has anyone swapped a tranny and rear diff with different gearing from their stock gearing in a new gen Suby?

 

If so what performance changes have you noticed??

 

Here's the scenario. . .

 

I'm toying with swapping out the 5-speed 3.9 (final drive) geared tranny (and rear diff) from my 95 legacy to a 4.44-geared 5-speed from say and forester or later outback. I have done a strut swap and larger tires (plus some other stuff), and the car is a bit sluggish when compared to stock vehicles..

Yes, the 2.2 does not have the power of the 2.5, but the 2.2 is a strong motor and moves the car around well, and engine swaps are out of the question...

 

The BF Goodrich website has a cool "off road tire size" tool(http://www.bfgoodrichtires.com/bfg/productIdSubmit.do) that tells you about ground clearance, acceleration, highway performance, speedometer and how to regain performance when going with oversize tires. From this it looks like a taller-geared tranny would help my car run "more like stock"...

 

Expereinces, ideas, comments.?

[Numbchux]

From this it looks like a taller-geared tranny would help my car run "more like stock"...

 

future reference....'Taller' gears implies lower #. as in swapping 4.444 -> 3.90 would be swapping for taller gears. you need 'shorter' gears to conteract the bigger tires

 

 

but I know what you mean. and yes, I know a couple people have done it. with stock sized (stock impreza anyway) tires, you loose alot of freeway legs and end up running high rpms. BUT, with your oversized tires, that'll be counteracted. as long as the 1-5 gears are comparable (not like the EA82 3.9 trannies compared to the 3.7 turbo ones), the lower gears will be perfect.

[johnceggleston]

i'm not 100% sure but i think most 5 speed trannys from the 90s were either 3.9 or 4.11. i haven't heard of a 4.44 5 speed. but regardless, the 4.11 with your larger tires would put you on back on track.

 

2.2L legacys came with higher geared final drives and smaller tires. 2.5L legacys/outbacks came with lower geared final drives and larger tires. generally the difference in final drives matches the difference in tire size (% wise).

 

the exception was the GT 96 - 98. it came with the 2.5L engine, lower geared final drive like the outback and smaller tires like the legacy L. this tends to make it quicker? it also makes it a slightly stronger tow vechile. also slightly less economical.

[Numbchux]

i'm not 100% sure but i think most 5 speed trannys from the 90s were either 3.9 or 4.11. i haven't heard of a 4.44 5 speed

 

most of them are, but, like he said, foresters and (maybe...I'm not entirely sure) later outbacks got 4.444's

 

2.2L legacys came with higher geared final drives and smaller tires. 2.5L legacys/outbacks came with lower geared final drives and larger tires. generally the difference in final drives matches the difference in tire size (% wise).

 

not really. in first gen legacies, they all had the same tire size, and for the most part, they all had 4.111s and the turbo's got the 3.90s.

[Phizinza]

For around $800 you could get the Australian delivered Liberty (Legacy) dual range gearbox parts you need to make a 4.11 with 1.59 low range. You can't use the 4.44 though, as it gets in the way of the gears.

 

You'd just need to source the EA82 low range gearset, EJ center diff and rear casing, and the 4.11 pinion and crown wheel. All you need from Australia is the front gearbox casing minus front diff and pinion. You might even get away with not having the output gearset side if the ratios from australia are the same wit hthe US.

 

Just a thought.... Will have to find out how much shipping would be I guess.

[thatswhatshesaid]

That's interesting - I'd like to look into the shipping...