Differential Ratio

[Bugis]

Hi All,

I'm running rb25det box in my R32 GTR with GTR rear differential.

Feel like smooth respone. I'm looking more aggrasive at low end.

Which rear differential more suitable , GTR or RB25det

[RellikZephyr]

the gtr diff ratio is 4.11

and not sure but think the rb25 is 3.9

so gtr is shorter and will give better acceleration

but like i said not sure on rb25 ratio

RellikZephyr

[Bugis]

But I heard RB25det from Gts-t will be 4.33 ?

[RellikZephyr]

could be...like i said im not sure

but that does sound a bit short

RellikZephyr

[Gambit]

I know on the 33's an auto diff is 4.363:1 and the manual is 4.111:1

Believe the 32's are the same.

4.363 will give marginally better acceleration and a slightly lower top speed.

Edited December 28, 2006 by Gambit

[Abo Bob]

Not necessarily doubting you Mark but auto diffs are usually longer. In the R34 the auto is 4.089 and the manual is 4.111. I know that's close enough to be almost the same but you see whatI mean?

I thought the R33 auto diffs were 3.9xx but I've got nothing to back myself up there.

[Cubes]

From what I understand the auto R33 diff is a 4.3 and the r33 manual diff a 4.1.

The R32 Turbo's run the same diff ratio for both the auto and manual being a 4.3.

Abobob, The reason for the r34 ratio being different may be due to the gearbox ratio's. The R32/R33 auto's run quite a long first gear. If they were to run a 4.11 ratio behind the auto they would be looking at almost 70km/h out of first.

[Abo Bob]

Ah ok. I wonder if overdrive is longer to compensate and reduce fuel consumption. I would interested to see all the r33 auto ratios if anyone has them.

[wrxhoon]

Not necessarily doubting you Mark but auto diffs are usually longer. In the R34 the auto is 4.089 and the manual is 4.111. I know that's close enough to be almost the same but you see whatI mean?

I thought the R33 auto diffs were 3.9xx but I've got nothing to back myself up there.

In older cars when you had top gears with 1 to 1 in both manual and autos, autos always had lower ratio diffs ( lower number but actualy higher diff, longer legs). The reason for that, the torque converter in the auto slips so it makes easier to take off and because it slips lower high speed .

Most late model cars don't use a straight gear anymore and most autos have a very high top gear ( around .7-.8 to one, even lower) . Thats the reason you don't need a higher diff in autos now so it wouldn't surprise me if the auto was the same as a manual. These days most cars have a lock up converter in top gear ( even top 2 some of them with 5 or more ratios) .I have no idea what the skyline ratios are though.

Edited January 11, 2007 by wrxhoon

[blind_elk]

If you want to accelerate faster, you want the diffs (yes, plural - front AND rear) from the R32 GTS4. These are 4.375 ratio.

[Cubes]

On that note I have a rear diff ratio of 4.375 thats in good nick if any one wants it?

I bought a GTR diff that already had the swap done to it. Its in excellent condition but I'm keeping the centre and half shafts. I'm selling just the diff gears (pinion and crown) or the pumpkin if the individual wishes not to stuff around refitting the pinion to their pumpkin.

I was hoping for a set of 4.11's to go behind the rb30. Bugger.

[Abo Bob]

Thanks Jerry. I don't recall my old auto (R34) locking up in 2nd but it definitely did in 3rd and 4th.

[T04GTR]

INTERESTED CUBES!!!!!!! me wanty (4.375)

with the case if posible. and the spacers etc etc.