24 replies to this topic

[3diamonds]

hey, just wondering if anyone has heard of the rear end from the gto or 3000gt (same car) rear diff set up being used in a 89-92 model vr4?

i have had a look and there rear diff and there rear shafts, they look like our 4 bolts but i haven't had a chance to measure up to see if there the similar. i think it wouldn't be to hard to run there diff/shafts as i'd assume they would be bigger and stronger as well. i doubt they are the same but i'm thinking of trying out there rear diff and driveshaft set up in my car.

i have no more spare 4 bolt sets left(been through 4 sets)and just recently smashed my rear diff and it was the biggest pain to have it fixed due to the diff being different to other vr4 rear diffs ratio. ended up having to get the shop to machine up new parts cause they couldn't source out parts to fix it.

anyway enough rambling, has anyone heard of this?

[to4garret]

What ratio are you running?

If you are smashing diffs and drive shafts change your clutch for something softer or modify your driving style.

4 bolts are plenty for 600hp, if you are concerned perhaps consider a move to billet shafts, but your diff should be fine.

[bazeng]

Yes you can buddy.
There is a guy in NZ who has done this.
He has photos etc showing its progress.

Everything basically bolts up (subframe) but it does protrude quite a bit. He is running R32 skyline rims on it and it sticks out quite a bit!

[3diamonds]

What ratio are you running?

If you are smashing diffs and drive shafts change your clutch for something softer or modify your driving style.

4 bolts are plenty for 600hp, if you are concerned perhaps consider a move to billet shafts, but your diff should be fine.

I'm running a direct clutch twin plate it's soft and not that agressive at all, but holds on when needed. i'm thinking about the billet shaft option but the 3000gt option is alot cheaper.
i know there good for 600hp atm. i've got that atw.

[to4garret]

ahhh, good ol'direct crutch. i've smashed many a gearbox, diff and transfer case with my old one. great crutches though

[brisvr4]

How are you launching the car? Loading up the drivetrain with the handbrake?
Seems strange that you keep breaking these things as there are guys in the US with a lot more power than you are putting out and they are staying in one piece.
Not a dig at you but there must be a reason for it.

[evopwr]

US power figures are optimistic compared to everywhere else in the world..

Barry have you got a link to the 3000gt rear end conversion?

[brisvr4]

US power figures are optimistic compared to everywhere else in the world..

Dyno figures may be but 1/4 mile times and MPH do not lie.

[3diamonds]

How are you launching the car? Loading up the drivetrain with the handbrake?
Seems strange that you keep breaking these things as there are guys in the US with a lot more power than you are putting out and they are staying in one piece.
Not a dig at you but there must be a reason for it.

yeah, i'm loading up the driveline. learnt how to be gentle after having a 3 bolt rear end.

i know the US guys are pushing power out of 4 bolt rear ends and not breaking but i've broken a few now and i'm getting sick of it. the rear has been done a few times now to make sure that everything is ok. because i thought there was problems for breaking all the time. but everything was fine.

so i'm looking at options. because the diff has been rebuilt and i'm thinking either sell it and try another driveline(which the 3000gt option is not so expensive) or get some billet shafts made. just weighing things up.

[3diamonds]

talked to that guy from NZ about his conversion. he actually only changed the hubs to suit off a 3000gt. he is still using the vr4 4 bolt diff and shafts.
think i'm just gonna go with getting some made up. here goes more $$$$

[bazeng]

Ah ok...

Do you think that it could simply be your driveshaft angles?

How low is your vr4?

Also what weight?

[3diamonds]

i'm running pedders shocks with KMAC springs. the front is 2 inches lowered and the rear is 1.5 inches lower with the stiffest spring rate they made.

about body weight, i don't know haven't weighed it. but i have only changed to jspec front and rear bars as far as any weight reductions goes and i'm not running any extra not needed weight(stereo sub box etc). the car body is basically stock beside motor and driveline mods.

[brisvr4]

It's not getting a litle bit of wheel hop on launch is it? That would kill axles faster than you could buy them.

[3diamonds]

na no hopping... major wheel spin though

[bazeng]

The car doesn't bind up at all does it?

Could it be possible that you have the incorrect transfer case installed? ie EvoIII?

[3diamonds]

na none of those problems. just breaks rear end parts

[bazeng]

What gearbox do you have?
Standard rs type box or built box?

Just seems strange that you keep breaking them. I would have thought that the gearbox / xfer case would have broken before the rear.

I know Rob Barac used to break gearboxes
He then strengthened it and started breaking transfercases
He then fixed that and started breaking the rear.

[3diamonds]

a rs box but got it rebuilt(standard) when i smashed it a while back. don't remember the numbers of what model it is.

[bazeng]

But you've converted the rs box to 3.5?
Or is your 4bolt 3.9?

Which part of the rear diff are you breaking?
The shafts only?

What rims do you have? something heavy?

[3diamonds]

still running the 3.9.

broken the shafts inside the diff. i've broken a shaft on the outside near the wheel hubs.

i'm running evo1 wheels same diamentions as the standard vr4 wheels i think on 205/60's.

last time i broke the diff, it was more of what didn't i break then what i did break.