Thread: Changing out gears

Maybe someone over here can tell me since the guys on the b15 forums dont seem to have a clue (copy/pasted):

Okay, so I looked and searched and did not find the complete answer, so I ask it here:

What all needs to be changed out to swap the final gear on a spec v 6 speed tranny?

I have an 02 tranny and wish to swap it out for a 04+ final so the gearing will look like this:

Spec-v 02_______MPH______RPM DROP AFTER SHIFT from 8000rpm.

1 : 3.417:1______38.8 _____1-2 4551
2 : 1.944:1______68.3______2-3 5176
3 : 1.258:1______105.6_____3-4 6022
4 : 0.947:1______140.3_____4-5 6530
5 : 0.773:1______171.8_____5-6 6520
6 : 0.630:1______210.9
Final drive : 4.133:1
2275rpm @ 60mph

205/50r15 Tires and MPH are at 8000rpm.

Any and all help would be very much appreciated. I know on the sr20 trannys we change out the main shaft and ring gear for gear swaps, but have no clue which needs to be done on a spec v. Thank you ahead of time!

+

Found an even better final I think. Can someone confirm the 02 maximas final was 3.812:1?

Spec-v 02_______MPH______RPM DROP AFTER SHIFT from 8000rpm.

1 : 3.417:1______42.2 _____1-2 4551
2 : 1.944:1______74.1______2-3 5176
3 : 1.258:1______114.5_____3-4 6022
4 : 0.947:1______152.2_____4-5 6530
5 : 0.773:1______186.4_____5-6 6520
6 : 0.630:1______228.7
Final drive : 3.812:1
2100rpm @ 60mph

205/50r15 Tires and MPH are at 8000rpm.


But the main question still remains: What all needs to be changed out for a final gear swap? Just the main shaft and ring gear?

What is it you are looking for, acceleration or top end? If you go with the 3.8 final you need a 1000hp min. to see 228.7 MPH

I got my anwsers from Trav. Thanks though. To anwser the question: all you need is the main shaft and ring gear to swap out finals on a spec V tranny, and yes the 6 speed Maxima finals can be swaped between the spec V easy useing only those two parts.

And I am looking for saving gas in 6th and having a good run on the rest of the gears. And yes, I have the power to do it. No, I am not trying for a 200mph+ car, though I wouldn't mind it, just not for the daily.

I always wondered why the 6th in my spec was so low. I found it dumb that being a 6th gear you would want the revs a bit lower for MPG. IIRC from 5th to 6th it only dropped a 1/4 - 1/3 rev which i thought was pointless. But this was also in a 02 Spec, and they changed the tranny after that since it was geared so low.
Now in my SER i want to find a taller 5th for MPG cause there is plenty of torque and you can always down shift.