Best Diff For Circuit Tuned Gt-r

[justinfox]

Hi guys,

So many questions, hoping to get some opinions on the best diff/s I can get for my circuit tuned R32 GT-R.

I had a standard torsen in the MX-5, loved it, getting the tail out was nice and predictable but it always snapped back in quite violently. My mates Cusco 1.5way in his MX-5 was a lot better all around.

I've heard I need to replace 2 of them in the GT-R. I'm just unsure of what to get. Any opinions and experiences would be greatly appreciated!

[Beer Baron]

my opinion. 1.5 way rear. 1 way front. as for brands, I think the cusco diffs are quite good and at around $1200 or so not bad price wise either. from memory the only difference between the MZ and RZ is one of them has springs to put preload against the clutches and the other type uses conical washer type things at each end of the stack to acheive the same end. difference in price is about $80 between them with the spring type more expensive.

[justinfox]

Will I see much difference with upgraded diffs Richard? IE: Are the stock ones really crap or quite good?

[Beer Baron]

well the stock front diff is nothing fancy. but the rear diff is a pretty good thing for track. it's already a 2 way mech. the only thing that varies is the condition it's in which will obviously affect it's performance.

cheap way out would be buy a front 1 way, and get the rear rebuilt, and re-shimmed with a little more preload on it, but I know mine is already quite tight and will spin up the inside wheel with tight, slow turns.

[djr81]

I was looking for a similar sort of thing.

With regard to the one way fronts there are actually four options (I think).

Type RS (low initial torque)

Type MZ (Initial torque created by the cone plates)

Now both of these come with either 35 or 45 degree cams.

So what does it all mean. Dunno. But I would think an RS would be preferable?

[justinfox]

I'm finding it hard to source more info. It seems many Jap. circuit tuners leave the front one stock but put a 1.5 at the rear (mostly ATS/Cusco). Not many use a 2 way. Hmmm.

[djr81]

Well that is fair enough. A two way will give you some push understeer on turn in. In a GT-R this is probably last to very last on the things you want to have. Hence the 1.5 way at the rear.

On the front I was of a mind that the more gentle in transition the better off you will be. Maybe I am wrong in that - they don't seem to torque steer, so maybe a more sudden cut in will be ok.

[JAGR33]

My original diff wore out, it was turning the inside tyre on the slow corners at corner exit.

I ended up putting in an ATS 2-way, then it became a drift machine.

Got the front transfer case modified and now it works great.

The only downside is when driving around at slow speed the rear end vibrates from the inside tyre turning at the same rate as the other, similar to a locker. Not that noticeable on street tyres...

Front diff is stock...

[justinfox]

2 way drift machine could be fun

Looks like I might stick to stockies until I know more (or develop a problem!).

[scathing]

Would anyone consider a Quaife front diff (torsen type) and a 1.5 way Cusco / ATS clutch-pack type in the rear? That way you can get the progressiveness of a torsen LSD in the steering end, with a positive clutch-style engagement in the rear?

Or would that just unbalance the car?

That is assuming that Quaife makes a front diff for the GT-R.....