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View Full Version : Rear gears...Someone shed some light

Zacho
01-04-2010, 10:34 PM
My car was originally automatic, and has a mystery LSD from J-land in the pumpkin. The gears seem to be extremely short. Examples:

120 km/h (gps confirm, speedos off) = 3400-3600 rpm ISH 5th gear
I did some speed runs and made it to about 200 ish running out of gear.

I got a pumpkin for free from an R32 gtr (customer's pinion bearing was destroyed, request I kept it haha) and took the ring/pinion off it and I'm thinking these might be my ticket. I still need to open mine and find out what is in there though.

Baisically - can anyone recall their RPM at 100 or 120 km/h?

As well, will I be able to calculate the ratio of what is in there with only pulling off the cover plate and not have to remove the entire pumpkin?
mcfly
01-04-2010, 10:46 PM
what transmission do you have and what size rear tires. We will work backwards and calculate your diff ratio from there

the gtr has a 4.111, chances are you have something similar already.
Rapier46
01-04-2010, 10:51 PM
I recall being at about 3000 at 115? I've taken my gtr to 260 km/h , still more room to go.
Aaron
01-04-2010, 11:11 PM
In my gts-t I was around 3100rpm at 110kph. If I remeber right...
archaeic_bloke
01-05-2010, 01:19 AM
ya second that.. 120 = 3,100 rpm for me roughly, and ya.. gone up near 260 and had lots more room in 5th to go.
DrMango
01-05-2010, 10:09 AM
In my gts-t I was around 3100rpm at 110kph. If I remeber right...

My GTSt is about the same. GTRs must be a bit different gearing. Ive hit around 250 or a little less but thats the reading my AVC-R gave me, not my speedo. AVC-R takes my speed reading from my ECU. I didn't have much more to go as I was basically at as much RPMs as I felt safe doing with my little RB20

Kyle
Zacho
01-05-2010, 11:34 AM
At the time it was an RB20 transmission.

My rear tire diameter (according to manufacturers site) is 25 of what I assume to be inches. I wasn't really out of gear at 200...just not a fan of burying my tach for long periods of time. Could maybe make 240 ish.

I found this on HardTuned

4.363 - R34 RB25DE 4WD, R34 RB25DE Manual, R34 RB20E, R33 RB25DE 4WD, R33 RB25DET Auto, R33 RB25DE, R32 RB20E, C35 Laurel RB25DE 4WD Auto, C34 Laurel RB25DE 4WD Auto, C34 Laurel RB25DE Auto, C33 Laurel RB20DE Manual
A31 Cerfiro RB20DET, A31 Cerfiro RB20DE Manual, S13 CA18DET, S13 CA18DE, C23 Serena SR20DE 2WD, C23 Serena CD20T 2WD


Thanks guys!