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I understand the ratios in the GTS4 are shorter and suitable for putting in a GTR. However my question is what is the best way do do this. Scrounge around for a wrecked 4 (Of which I cant imagine there are many), buy new crown wheel and pinion or is there an aftermarket option or different donor vehicle?

The rear GTR diff I have has a Nismo LSD in it so obviously I want that to transfer accross.

Ah ok. Was a bit doubtful about the wisdom of finding a 20 year old diff and then trying to track it. Guessing it is drug money for a new version from Nissan?

By the way did it give you a good gain? I am sick of getting hosed by Emos out of tight hairpins etc on hillclimbs and the like.

Yeah I didn't look into the new price from Nissan; after all you are only reusing 2 gear wheels not the centres.

As for the gains; I did the change years ago so I can't really confirm back to back any more...I do know that I can hose those pesky Emos and WRXs off the line these days (it launches like a champ). More importantly in my case, because I have to run nasty 80's bush bearing turbos, lower gearing definitely helps get them come on earlier. The only place where I came close to having an issue was Phillip Island, and even there I was only doing about 6000 in 5th on the straight.

GTR gearing is pretty tall. So you tend to find that on tight hillclimbs and supersprint courses, even certain corners on certain circuits) there are times where you are stuck between gears (eg 2nd too tall and first is too much fapping about) or the thing is off boost (say exiting a 3rd gear chicane). Shortening it up can help mean it gets on boost quicker or it is less compromised when you have to pluck a taller gear anyway. If I could be stuffed I would do a engine torque cascade graph where you multiply the torque by the gear & diff ratio and plot it againt road speed. It tells you how much powahs the car delivers.

yep, essentially. 10% shorter gears are effectively 10% more torque at any given speed, with a trade off against top speed (which has never been an issue for me on any track I've been to).

particularly useful for me because I have to run nasty, laggy r32 n1 turbos.

Hey mate I'll try and get back to you tonight; and re cages the guy I would have recommended is no longer in business....they were good and cheap but too late now.

Any decent welder can do a decent cage like my car has, if you want something a bit special they generally get very expensive. Probably easiest way is to get a pre bent hoop from Bond cages and get someone to do the rest custom

  • 2 weeks later...

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