Gearbox Ratio Change

[Haysey]

Im sick of 3000rpm at 100kmh..... in 5th gear...

has anyone changed their ratios in the box? or anything else that will solve the high revving problem.....

at the moment the car uses more petrol on the highway then in the city.... lucky to get 200km from half a tank!!!!!!!!

soooooooo sick of it!

Ed

[Tommyk]

change your diff ?

Otherwise try stay off boost while in 5th

I easily get between 450-500kms while highway driving

[Cubes]

lol..

Imagine the poor souls with their R32's running a RB30DET's.

I'm always reaching for 6th.

The tacho is actually a little wrong, the pfc h/c states ~2800rpm for 100km/h. It is still too high though.

I will be dropping a S13 3.9:1 diff in mine, there is also available a S13 ~3.7:1. Really depends what you want, I want to keep the 'sports' feel so 3.9:1 is the highest ratio I will go.

The VLT has a longer 5th gear, throw a vlt g/box in to the r32.

Edited October 18, 2005 by Cubes

[GKTECH]

I was also wandering this. I hate sitting on boost in 5th gear at 100km/h

Greg

[inissane]

u guys are lucky mines even shorter, rb20 with s13 ca auto diff must be like 4.3:1 im looking at 4000rpm in fifth

gotta get a 3.9:1 too by the sounds

[Cubes]

The R32's diff is 4.363:1.

[inissane]

is the ratio in autos from the factory higher than 4.363 cause they are 4 speed?

[Cubes]

No.

[SimonR32]

get a bigger turbo and you wont sit on boost in 5th gear at 100km/hr

haha

[Sydneykid]

100 kph is 2,750 rpm with a 4.363 diff (R32GTST) a 0.759 5th gear and 245/45/17 tyres.

100 kph is 2,600 rpm with a 4.1 diff (R32GTR) a 0.759 5th gear and 245/45/17 tyres.

100 kph is 2,500 rpm with a 3.9 diff (S13) a 0.759 5th gear and 245/45/17 tyres.

100 kph is 2,400 rpm with a 3.7 diff (S13) a 0.759 5th gear and 245/45/17 tyres.

As you can see there is not much difference, I suspect that you will improve the fuel economy far more by spending the money (that a dif change would cost) on some tuning.

cheers

[Beer Baron]

or you could buy an R34 GTR 6 speed box and adapt that if you are mega keen.

[Scooby]

or you could buy an R34 GTR 6 speed box and adapt that if you are mega keen.

<{POST_SNAPBACK}>

and change the diff ratio while you're at it as the gbox ratios are shorter - in GTR at least.

[paulr33]

check your 02 sensor as well, nuturious for angry fuel economy. if i do all highway driving i get over 400k's to a full tank and thats sitting on 100km's in 5th gear so it sounds like you arent going into closed loop mode or your sensor is dead

[Cubes]

I've just used my trusty gearcalc program.

@100km/h in 5th.

225 x 50 x 16" tyres.

4.36:1 Diff - 2782rpm

4.11:1 Diff - 2621rpm

3.9:1 Diff - 2487rpm

3.7:1 Diff - 2360rpm

So for myself running a 3.9:1 a drop of 300rpm, the diff needs replacing anyhow.

The biggest benifit will be picking up approx 9km/h in second gear and ~13km/h in third. Especially with the rb30det this will be handy.

Should I go the 3.7 that will be ~14km/h in second and ~20km/h in third I pick up.

[discopotato03]

I've just used my trusty gearcalc program.

@100km/h in 5th.

225 x 50 x 16" tyres.

4.36:1 Diff - 2782rpm

4.11:1 Diff - 2621rpm

3.9:1 Diff  - 2487rpm

3.7:1 Diff - 2360rpm

So for myself running a 3.9:1 a drop of 300rpm, the diff needs replacing anyhow.

The biggest benifit will be picking up approx 9km/h in second gear and ~13km/h in third. Especially with the rb30det this will be handy.

Should I go the 3.7 that will be ~14km/h in second and ~20km/h in third I pick up.

<{POST_SNAPBACK}>

Hi Cubes , how do the numbers run for the manual VLT ? I think the final drive was 3.45:1 but it used a 3.6 1st wide ratio box and 205/60/15 ? Also how does the weight stack up compared to a typical RB30DET R32 2wd ?

Cheers A .

[GTS20X]

Make sure you have a turbo box fitted, they have a taller 5th.

[inissane]

well im seriously at 3500rpm in fifth @100km/h maybe i have a non turbo box on the rb20det

[blind_elk]

My R30 runs nearly 4000 rpm at just over 100kph in 5th gear! Thank your lucky stars you've got a 32.

[Freeman]

*edit*

Edited October 20, 2005 by Lukeisbuyinga33