4.11 Too Tall For Rb30dett In R32 Gtr?

[James_03]

Hey guys,

Well I have been very happy with my rb30dett so far and I love it.

Problem I have is that 5th gear seems to run out of legs. Would this be caused by the diff ratio mismatch now? I am considering a 6spd getrag conversion, but maybe I can go to a 3.7 diff instead to resolve this? Not too mention it's cheaper.

Just seems like it wants that 6th gear now when your at the end of 5th.

Thoughts? Remember your talking to a diff/gearbox ratio n00b here.

[Deano 1]

Where are you toping out 5th gear???

[GTScotT]

If you are running this in a GTR I do not think you will find a 3.7s set in factory form. If it were RWD only you could get a crown and pinion from a 200sx.

The effect would be a 15% increase in gear length. 100kmh would become 115kmh at the same revs, so on and so forth. If you are topping out at 260 it will give you the ability to get very close to 300kmh.

However, last I remember R32 GTR's have stupendously long gears to begin with ?

[Beer Baron]

dude top of 5th gear is well over 260 km/h? where on earth are you topping out 5th gear? and what mismatch? you still presumably have the same diffs and same gearbox you did with the RB26? and the engine should pull about the same rpm? when you say running out of legs do you mean it's not pulling hard at the top of the rev range? if so it sounds like you've gone backwards?!

[Beer Baron]

BTW, 3.7 with a 32 box would give you an astronomical top speed. around 320km/h and you'd never get there. the car would feel so lazy. first gear would get you to about 80km/h, about 130km in 2nd gear.....

[Birds]

Also emphasis on diff/s. Change the rear and you'll need a new front one too