It's been mentioned before that the clutch has been designed to be the "fuse" in the EVO driveline. This car was designed for fast sports car type driving, not drag racing.

Other brands of cars don't have as much problems with clutches because they can spin the tires and thereby take the strain off the clutch. Trying to spin the EVO's tires takes a lot of torque and the clutch tends to spin easier than the tires.

My theory is folks drag racing a nearly stock EVO would be better off with skinnier tires. Then you could launch by spinning the wheels and make it easier on the clutch. A certain amount of wheelspin might get the motor in the powerband faster. High horsepower EVO's are a different story - they probably need the traction.

The test of my theory would be racing with winter tires/wheels, maybe 16 x 195 with snow tread. Nobody makes these wheels to fit an EVO.

Any comments?

 

Although skinnier rubber would give you a better chance to light 'em up, it's because there would be reduced grip.

The Evo's main advantage is the fact that 4WD grip is insane. Putting enough power into the clutch dump to spin even thin tires is a bad idea.

Smaller tires would reduce drag, but you'd be better off sticking with the stock width and reducing the wheel diameter. Less wheel and more tire means less rolling mass, meaning faster acceleration.

You could experiment, but I don't suspect that you'll be able to gain more than a .10th just going to thinner contact patches.

 

I guess what I'm trying to say is that you could still maintain your ET while being easier on the car. In the stock car with the wide sticky tires the clutch becomes the item that slips. Make the tires do the slipping instead and the launch may be just as good but you saved the clutch.

A sort of rediculous test would be drag racing with 4 temporary spares. Less rotating mass, less traction. I don't know if they will take 100 mph. The lower gearing might mean an extra shift.

 

If you don't want to break stuff..dont drag race You could always just slip it at 3k rpms...but whats the point? Go faster not slower...

 

Why not buy a better clutch or some radials? It'd be alot simpler and u'd post better times.

 

There are those that may disagree with this but for those tracks like Atco Raceway who force you to go through the 'water box', go through it slowly. It'll get some water on the wheels for slippage.

Also, since reducing stress on the driveline is a concern for you, you may think about reducing your cars weight (especially rotational mass) considerably. Since less force would be needed to accelerate your car, less force would be shocking the driveline/transmission. Good luck!

 

I was thinking of the 4 spare tire run myself. I think i can get my hands on 13' spare tires.

What do you guys think?

My theory:

1) Less rotating mass.
2) Overall weight reduction. (Im running 15' rally tires right now)

I can get away with the cheapo, light spares since I dont need powerful tire traction - AWD will "compensate" for the traction loss of the tires.

Will still use the slip-clutch launch ...

What you think?

 

Try this instead, it's an old drag racing trick to help your mph. Pump up the front tire pressure to create a smaller contact patch on the pavement (47-50lbs). This in turn creates less rolling resistance and possibly allowing the tires to slip (a little). How about unbolting the front sway bar on the ends (keep it attached in the centers) to help weight transfer to the rear. This also allows the car to react slower, therefore, giving the clutch a little more time to grab before the entire weight of the car is upon it.

 

I think that the EVO clutch slip is to protect the drive train from those who think dumping the clutch is a good idea. Have heard of people who have nutted thier thier trans/transfer case from hard launches with low tire pressure etc.... Remember that the engineers who built the thing are not stupid and they know how to make the beast last better than we do!

 

Ohhh, So confused, to drag or not to drag????