Well my freind just got his 4.10 gears(with locker) and underdrive pulleys put on today and he has had his superchip in for about 2 weeks now. his truck did run 15.9 in the 1/4 mile (stock).. So we wanted to know how fast it was now after the changes.. Then we found one of his freinds with a 99 Z71, (his mods are hypertech PPIII,throttle body spacer,ram air,and flowmasters) They race often and it is 50/50 just depending on who gets the better jump. Anyways we went to the old highway were we always race and they lined up and took off, amazingly he lost everytime. ??? It is a 4.6, stick, he went from 3.73 to 4.10. we are all stumped, what happened???

 

4ord_man,

His driving technique has to change to account for the 4.10's. If he is spinning his tires he will have to get fatter tires.
Slipping the clutch can help but it is very hard on the clutch.
The 4.10's change where the next gear starts in the rpm range. With 3.73 gears shifting at 5000 rpm put you at 2800 rpm now with the 410's you are at 3000 rpm. You have lost 200 rpm of usable torque/hp. Try shifting at a lower rpm.

Regards

Jean Marc Chartier

------------------
00 F-150 XLT SC Flairside 4x4 4.6 w/5spd 3.55LSD
Warn XD9000i, skid plates, Draw tite class III,
Rancho RSX Reflex shocks,
BFG 285/75 R16 MTs,
Borla Cat Back, Headman Headers,
Modified Air Cleaner Outlet Tube
and air box, Ported Throttle body,
Shortened MAF sensor tower,
K&N air filter,
Superchips

 

I'll have to tell him that the next time i see him, Right now he is mad because he spent $800 for nothing.. I know the gears should drop some time off of his 1/4 mile because that is the first thing we do to our mustangs around here and that makes a lot of a difference..