I just swapped out the 10 bolt for a 9inch Ford. Driving around i noticed i dont spin as much and its harder to chirp them into third. Is it possible to gain traction just through a different rear end? I actually went up in gears too(3.73 to a 3.89). All suspension is the same and same street tires. Whats the deal?

 

Maybe it has something to do with more weight beiing on the rear of the car. Or the fact that the 9 inch uses more horse power.

 

B.S. on the whole HP loss with a 9". I did an install on a 99 Z and the car droped 3 tenths 12.10's to 11-80's going from a 10 bolt with a 4.10 to a 9" with a 4.11, Go figure!

 

I was hoping the Hp loss was bs....with a mostly stock car i can use all the hp i got lol. I guess it might be the weight bc that thing is wayyy heavier than the 10bolt.

 

You should have taken the car down the track and then changed out the axle to see if it slowed the car down.