[speedbanditz]

Is a 3.90 differential better than a 3.54 turbo rear end? Which one is more better for drag?

 

[slownrusty]

3.90 is better for dragracingspeedbanditz wrote:
>
> Is a 3.90 differential better than a 3.54 turbo rear end?
> Which one is more better for drag?

 

[Lee Smith]

The 3.9 will spin the tires better, but I like the way they hook and you take off.

A 60 side wall may be about the same for draging and use a 75 for street use.
The best of both worlds and less $$$.

Jest my .02 thoughts, I havent checked the numbers.

Lee

 

[Unknown User]

the tire change is a good idea, especially if you drive the car other than at the track. you can go to a 50series even, probably the same as going to a 3.9 or 4.11. much easier to change back once the weekend of racing is over. and you only have to do the rear, the fronts make no difference. note however, that your speedo will be way off with 50 series tires.

 

[twinturbo240]

I use a 3.90 in my 260Z which i drag race with weekly. Worked great with a 280Z 5-speed, but when i tried it with a ZX turbo transmission first, and second were way low, and i actually lost .2 seconds consistantly. I only mention this because you say you have a turbo diff, if your tranny is from a turbo also you may wanna stick with the 3.54's.