How Exactly Does The Center Diff Work On A Gtr?

[Ramius83]

Hey guys. Short story here is I need to know how exactly the center diff works in the transfer case on a GTR Skyline. I know about the ATESSA crap, but I need to know mechanically how it works. Helping a buddy swap an R33 AWD GTR set-up into another chassis. We have no ATESSA stuff, but was wondering how "hydraulicly" the system works. Other than a difference of fluid pressure into the center diff to engage/disengage the clutch packs, are there any other electronic devices on the diff itself that are needed? We were thinking about a fluid based pressure regulator to control the pressure into the center diff front from the rear HICAS port on the power steering pump (which we have from an R32) which is driver controlled in the cock-pit.Thanks all....Please don't flame me as I am just the messenger.

[GTSBoy]

Oh, boy.

[doo doo]

try this thread for starters

http://www.skylinesaustralia.com/forums/topic/331724-center-clutch-gtr-r33-how-strong-how-to-do-the-torque-splitting/page__hl__centre+diff

[NoFigJamHere]

I admire your enthusiasm!!!! A GTR is actually 2WD until it hits a preset G figure or different wheel speeds front to rear... Then depending on the amount of Gs or difference in front to rear wheels speeds, a computer then controls how much hydraulic pressure gets applied to the rod at the back of your transfer case that activates a fork etc which in turns applies pressure to clamp the plates in the centre diff. It can only "feed" a maximum of 50% to the front wheels and is constantly variable. If can get a V-Spec set-up its actually 10 times faster in response times... ie: a non v-spec always spins rear wheels abit before engaging. Hope this helps mate.

[luke gtr]

I've seen manual controllers, that look similar to a handbrake mechanism, just set and forget.

Stays at the same torque split until you adjust it.

Try tracking one of these down.

Pretty sure the drag boys use them.

Don't know how common they really are though.

Probably the best bet for what your describing.

Good luck.

[NoFigJamHere]

What Luke is describing is mechanism Veilside developed once they found out No could make an electronic device like the HKS Split Torque controller for R34 GTRs when they first came out. It looks very similar to a Handbrake assy, problem was you had to totally remove the centre console to fit it! The Veilside item was full alloy (quite sexy) and had a pressure gauge so could actually see and record what the pressure you were using to determine if the car needed more or less split. I even actually have a Brand New never used Veilside assy i'll take a pic and post in here later 2nite so OP can look see. Wont mention what it cost but it was bort for a customer i had in Singapore who "had to have it" until when it arrived i explained the centre console would have to come out! Only realised ive still got it upstairs (workshop) when i read Lukes post!! Thanks mate

[luke gtr]

^^^cheers

[NoFigJamHere]

You actually have to push lever down to pump the pressure up to desired setting. Knew i'd find it you rekon i could sell it in here?

[NIS.26L]

i think the z tune runs one of these,if u look at the interior pics there is 2 hand brake levers so u may be able modify the standard center console

here is the pic hope the link works

http://www.powerplay....JPG&list=NISMO R34 GTR Z TUNE&page=1

if not check out the pics in powerplay imports gallery on the ztune

Edited January 18, 2012 by NIS.26L

[R31Nismoid]

  On 17/01/2012 at 3:33 AM, NoFigJamHere said:

I admire your enthusiasm!!!! A GTR is actually 2WD until it hits a preset G figure or different wheel speeds front to rear... Then depending on the amount of Gs or difference in front to rear wheels speeds, a computer then controls how much hydraulic pressure gets applied to the rod at the back of your transfer case that activates a fork etc which in turns applies pressure to clamp the plates in the centre diff. It can only "feed" a maximum of 50% to the front wheels and is constantly variable. If can get a V-Spec set-up its actually 10 times faster in response times... ie: a non v-spec always spins rear wheels abit before engaging. Hope this helps mate.

It also depends on the transfer case itself, that has an effect on the overall.

You can "rebuild" them and tighten them up better than factory, similar in fashion to a diff with shims/plates etc.

It doesn't upset the system at all, and lets me launch from 6500rpm easily on street rubber with hardly any wheelspin. Sends heaps to the front almost from the get-go. Better drive outta the corners as well.

[Kinks]

  On 16/01/2012 at 2:18 PM, Ramius83 said:

I know about the ATESSA crap, but I need to know mechanically how it works.

Magic..