Opinion on gears
 

i have a 99 z28 a4 looking to make it one hell of a quater mile car. got a set of 4.10s in my garage to put in it stock stall on a 27 inch slick. cars got bolt ons and a 100 hit anyone have experience with theese gears?

If you are planning on using slicks my advise would be to sell the 4.10 gear set and buy a 12 bolt or other type of aftermarket rear. The 7.5" ten bolt will not last long if you are going to be racing the car. Also the stock torque converter is going to really hurt your et. and could possibly break if you are going to be spraying the car..

yeah i know but what about the 4.10's even if im on a 27 slick or drag radial will this work

What exactly do you mean by "will this work"?

Sure you can install the gears and run a 27" slick if you want....

- Justin

Will it work, yes. Will it last, no.

The case on a 10bolt is weak and plenty of people have snapped them with stock gears on street tires. Some have gotten lucky and had them last a while, but lucky only lasts so long.

I think he wants to know is if he'll have enough gear to go through the traps without hitting the 6200rpm redline or going into OD.

We normally do not run 4.10's in auto street/strip cars.

for auto i wouldnt go much higher than 3.73's

but the question is not if it will break....its if the gears will let me get to the quater mile before red line....

Find a gear/tire calculator then?

http://www.f-body.org/gears/

- Justin

i already did that so in theory thatll work...but does anyone know if itll actually work....has anyone done it yet i know people have done it in mustangs but does it work in a fbody

Short answer, a stock car, No.

Any explination behind that answer....

Yes the 4.10s will work, but not the best with your setup. I met someone with 4.10s in an auto, and he said you get to 80 mph real fast, but then it starts to struggle. You will end up breaking too much **** running a 100 shot through the 4.10s in an auto. with your stock rear/stall consider 3.73s max. Since you seem to be looking for more speed than reliability, I think you should ditch the idea of gears and pickup a torque converter.

The car will be getting a stall soon enough....With the setup the car will be running it should have more than enough MPH to get through the traps before redline. If all else fails we can always go with a 28"....

If the car is trapping at 120, you will be fine with 4.10 gears.

his car would be more likely to trap about as fast as the tow truck can pull him down the track...your rear is gunna be in more pieces than you can count...i blew 4.10 and the stock 3.42 with street tires...believe me 3.73 is decently safe...but a 12 bolt is the way to go.