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Rb26 Conversion In S15 With Auto Diff

toy515

By toy515,
in Engines & Forced Induction

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toy515 Grand Master

toy515

Posted
Posted

hey guys i have a s15 with a 26 conversion but the diff is from a standard s15 auto i think the diff gears are 3.9 would this affect what power i make im looking to buy a gtr diff soon but just wondering would the auto diff affect the power output also im using a rb25 gearbo if that helps

cheers

KiwiRS4T Grand Master

KiwiRS4T

Posted
Posted
hey guys i have a s15 with a 26 conversion but the diff is from a standard s15 auto i think the diff gears are 3.9 would this affect what power i make im looking to buy a gtr diff soon but just wondering would the auto diff affect the power output also im using a rb25 gearbo if that helps

cheers

Final drive ratio makes no difference whatever to your power output. Are you happy with your present gearing or do you want lower for more acceleration or higher for quieter cruise and economy and maybe top speed? Those are the only reasons to change your diff (unless you want a LSD).
bubba Grand Master

bubba

Posted
Posted

3.9s might be a bit tall for teh 26, but the S15 is a pretty light car isn't it? All it's really going to affect is how fast it comes on boost (i.e. if you have a huge laggy turbo then tall ratios aren't for you).

I'm running 3.9s with my 3L but I've got the torque to deal with the taller ratio.

den001 Proficient

den001

Posted
Posted (edited)
3.9s might be a bit tall for teh 26, but the S15 is a pretty light car isn't it? All it's really going to affect is how fast it comes on boost (i.e. if you have a huge laggy turbo then tall ratios aren't for you).

I'm running 3.9s with my 3L but I've got the torque to deal with the taller ratio.

3.9 tall???

whats a gtr diff ?? as i also ahve a 26 in my s15, but i run a GTR diff and 25 box, i thought the gtr diff was 4.11:1 isnt this taller???? its the same gearing in a gtr isnt it?

Edited by den001
R31Nismoid Grand Master

R31Nismoid

Posted
Posted

GTR's are 4.11 or 3.9, it escapes me. R34's are 3.45 or so due to the different gearing in the 6 speed.

I think ive got 4.3's... i wish i had 4.11's or 3.9's.

VL/R31s factory are around the 3.45 if memory serves me correct... i wouldnt call 3.9 tall, its still fairly short in terms of a small step from factory

The above could be wrong :ermm:

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