3.45:1 Diff

[rb25_vl]

probley been done 100,000 times before but the serch didnt come through

ok i dont need to ko now where or how hard it will be to find one just info.

ok i have a vl with a rb25de it used to run the 3L (rb30e) auto but its now dead. i have obtained a auto box to suit the 25 and was wondering, what the 3.45:1 diff ratio will do

should i get a 4.11:1 diff as i wanna up date to disc and lsd anyways or will i see not a lot of diffrece in spedo readings or will it be more anoying and have no take off and all top end or will it be opposite?

any help would be good....thanks

[SteveL]

3.45 is quite tall for an RB25DE. 4.1 or 4.4 is the diff ratio for that engine (4.4 for the auto ??). Anyway 4.1 diff from a Pintara is probably the way to go, and that will give you discs as well, but mounts might be slightly different and I'm not sure about track. Your speedo will be out, but it might be possible to change the speedo drive at the trans for the Pintara type. The car will be quicker off the line, but rev harder at any given speed.

[rb25_vl]

3.45 is quite tall for an RB25DE.  4.1 or 4.4 is the diff ratio for that engine (4.4 for the auto ??).  Anyway 4.1 diff from a Pintara is probably the way to go, and that will give you discs as well, but mounts might be slightly different and I'm not sure about track.  Your speedo will be out, but it might be possible to change the speedo drive at the trans for the Pintara type.  The car will be quicker off the line, but rev harder at any given speed.

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so a pintara diff and spedo drive maybe? what year pintara and does it have to ba manuel

i can get hold of a 1987 (r31 looking one) but its manuel

[SteveL]

so a pintara diff and spedo drive maybe?  what year pintara and does it have to ba manuel

i can get hold of a 1987 (r31 looking one) but its manuel

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R31 Pintara is the one (87-90), not the later U12 type. As to how much work is required to make things fit I can't say, but the diff model is the same in VL Commodore and R31 Pintara/Skyline (ie BW model 78). Someone else here might, but I'm sure it will have been discussed on the Commodore forums.

[Rolls]

Theres lots of talk on r31skylineclub.com about those diffs, also I've heard the pintara diff is not as strong.

[SteveL]

... also I've heard the pintara diff is not as strong.

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It's not. R31 Pintara uses a twin spider gear centre, but R31 Skyline has 4. Pintara also has 25 spline axles to the Skyline's 28. But for an RB25DE the Pintara diff/axles will be plenty strong enough. An RB25DET would be another matter.

[rb25_vl]

It's not.  R31 Pintara uses a twin spider gear centre, but R31 Skyline has 4.  Pintara also has 25 spline axles to the Skyline's 28.    But for an RB25DE the Pintara diff/axles will be plenty strong enough.    An RB25DET would be another matter.

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but i do wanna go rb25det soonish but being a non turbo motor i was thinking of a rb20 turbo running low boost but this is a diff section, i was also thinking of just getting a set of gears to suit my diff

[Pantera999]

Hey bud, on r31skylineclub.com, heaps of info for you there. Go LSD, from an r31 silo or vl turbo (exact same anyway). My silo lsd has 3.89:1 gearing. As for fitting pinny gears into an lsd diff, not hard if you know what your doing or have a Gregories in front of you, 2 hour job.