I am thinking about putting some 4.10s in the rear end of my car. Right now I have stock 3.43s. The car made 381 rwhp and 375 rwtq. I know it should make it rev even quicker and feel more powerful. Right now, it's perfectly driveable with the stock gears, although I really can't use 6th gear much.

The problem is of course traction. Right now, first gear is almost useless at any speed. I broke the rear loose from a roll at 45 just mashing the gas. Would the 4.10s just be a "!traction" mod?

BRAD

 

Probably.

Do you have any plans of running a stickier tire? You need your peak hp rpm from your dyno and a trap speed from the track in order to pick the optimum gear assuming you'll have a sticky enough tire.

 

The peak horsepower occurred at 6100, but only drops a little from there to the 6400 redline. The peak torque came at about 4700. The torque stays above 300 ft-lbs from 2500 all the way to the redline at 6400. It's a really flat curve.

I would run stickier tires, but then I'd probably be springing for a 12 bolt rear end.

At the track, I'd think the car should trap around 110 at least given the power numbers. But then I'm an optimist and will probably be disappointed when I do run it.

BRAD

 

I think your car must be alot stronger than mine or your tires sucked. Mine never got loose until i began to really rev with my 3.42's like 5k plus. I now have the 3.90's and it will break them loose a little earlier. I kind of wish i would of gone 4.10's but i thought they would be too much gear. I think they would of been perfect.

 

why dont u put some real tires on there?
some 315 nittos should do the job
I cant really get lose in 1st with 4.11s It just pushes u back really hard hehee
Marcin

 

The tires do suck right now, so that may be part of it. I have worn out 275/40-17 Futuras on it right now until I pay off some of the money I spent on the engine. Since it's getting towards the time of year when it rains, I may just get the rain tires out early and try those. They are nearly new 245/50-16s BFG G-Force KDWS. Think that might help the traction issue, even though they are narrower tires?

BRAD

 

the traction will be worse because they are smaller rims too. They will be easier to spin than the 17inch rim. Buy some drag radials and the gears and rear end cover. Then save for a 12bolt

 

Most people feel the opposite, that more sidewall helps.

New tires, even non DR, could make a world of difference.

I trap 111.8 and you've got 40 hp on me, you should be trapping closer to 115 unless you've got a couple dead bodies in your trunk

assuming a 115 trap and 4.10s, that would put you at 6200 at the 1320, which is optimal for your setup.

Definitly get yourself some new tires

-brent