rear end gear
 

Has anyone ever put in a s4 2nd gen rear end into a 1st gen 12a car?

The car were building has the stock 3.90 rear end. We have an s4 rear end that is a 4.10

This car will be running a 13b FI S4 motor witht he 12a 5 speed trans. I was wanting to know if the rear end swap has been done before to give the car a slight more off the line. As for the top end the car will never reach 80-90 mph so that is not a factor. Also we are trying to get a ratio change as cheap as possible.
Any help would be nice.
Thanks

From everything that I have read it would be a no. 2 different types of rear. As for any difference in a 4:10 over a 3:90, I doubt that you will be able to tell it at all. I ripped the rearend out of my SE over a year ago and put in a 3:93 rearend from a GSL. No difference at all in time at the 1/8 mile track or in the butt dyno. I was looking into the Kia sportage swap myself. From what I have read the pumpkin is a direct swap with the SE or GSL with the bigger axles. Also the Miata rear is suppose to swap but I don't remember the years. The Kia is a 4:67 IIRC, and the Miata a 4:33 with LSD. Where the Kia is not LSD. Oh, the Kia is from the front differential only.

Good luck with your swap.