I know its been beat to death, but has anyone gone from a 3.5 to 3.7 final drive? I'm just about to order one, but want to make sure no-ones had a "waste of time" experience with a 3.7 from a 3.5 already. I'd go 3.9, but they're more expensive and might be a bit over the top for the little highway driving I do.

I was going to swap some shorter rear wheels on the car to mimic what the 3.7 will drive like, but my cars put away for the winter and i'm impatient.

Any experiances or help appreciated.

 

Well the 3.9 on the highway is not really over the top. As i have one in the car, i think the difference in RPM is like 500 or so nothing to major. You will notice it in the city if you do alot of that driving. I put the 3.9 in the same time i did my TT setup so i did not really get to see the difference when i was N/A. I say go big or go home.

Sylvan and myself tried it out one day as he has 3.3 and mine is 3.9 and i think the difference was only 750 to 1000rpm. Just to give you a idea.

 

Thanks Dustin, that does help. I like the idea of the performance gains of the 3.9, just not a 4000rpm 130kph cruise.

Is your coupe a 6mt? What's your 6th gear rpm at 120?

 

Thanks Dustin, that does help. I like the idea of the performance gains of the 3.9, just not a 4000rpm 130kph cruise.

Is your coupe a 6mt? What's your 6th gear rpm at 120?

 

my increase from a 3.35 to 3.53 was almost exactly 200 rpms.

from the 3.53 to 3.69 you increase is going to be a little smaller than that.

from a 3.53 to 3.9 FD you can expect a jump of about 400 rpms.

 

Yeah mine is a 6 speed. As the car has been parked for a while I can not remember the RPM exactly but I want to say 3000-3200 ish I think at highway speed. Does that sound right? Or like mentioned just add 400-500 RPM from what u have now if you were driving it.

 

Very good info. Thank you Willey and Red.

 

Keith, hurry up and DO IT! Reason? What reason? No reason....

 

Any idea who might want my 3.5 Wayne? If only I could find a recipient...

Maybe the 3.9 is the way to go. Dustin, expect a pm.

 

^ yaya canadians!, too bad you guys are gonna lose tonight to the nucks.

anyhow, how can the FD make that big of an acceleration difference if the rpm's only differ in terms of 400-1000 rpm,

isn't that how shorter gears in the FDs work?