Tires, performance, tuning.....Yikes !!!

[Argess]

OK...not sure if this is the appropriate forum or not, but check out this video:

http://www.youtube.com/watch?v=qqkxu8TsJfw

Well, I don't think I can do what they are doing....well, I can, but not easily. Even with BFG T/As (which are supposedly not very good) I just accelerate faster and faster. I guess that's really a good thing.

So why is it I can't easily spin?

360 single plane manifold not conducive to low end torque

2x4 Holleys with progressive linakage, again not conducive to low end torque

mech only dist....not the optimim timing for part throttle

limited slip differential

I actually like my set-up...docile down low, but once over about 2000 rpm it comes alive. No shortage of higher rpm hp. In fact, a good 2nd gear run, shifting into third is with no more than 1/2 throttle and the steering is getting light with little weight on the front wheels.

So, if I keep the rpms up quite a bit, and ride the clutch I can spin. Is that typical?

ps: I have a 428 with RG 5-speed and a 3.07 differential. Crane did a computyer estimate and came up with 480 peak hp, however I think that's a bit optomistic as it assumes perfect ignition timing and fuel delivery.

EDIT: Let me clarify. In the linked video, many of the Cobra seem to have extremely "instant acceleration". Hard to hear if they are revving much before they let out the clutch, but it appears many arn't. Sort of wondering exactly what's going on.

[Dwight]

I'm the four Cobra in the video, the yellow one. I have BFG G-Force tires. Good on dry and wet pavement. Great tires for traction. I drop the clutch at 2,000 rpms and use about half the gas pedal in first, second I can go to 3/4 pedal, and after I'm in third I give it full pedal. I control my tire spin with the gas pedal. I don't slip the clutch.

I have a low rpm, high torque motor. At 2200 rpms I have 325 rear wheel torque. Remember this is a 302 small block. I know you big boys have more.

stroking gives you torque, torque spins the rubber.


Dwight

[Argess]

Thanks Dwight. I don't haqve a lot of power until I each about 2500 rpm, and even then, I'm sure not nearly the torque you have.

By "riding the clutch", I just meant momentarily, as once the wheels spin, it can be let out.....just need to do it to keep the revs up at the beginiing of my powerband.

I suspect it's just a product of what I've put together.

Certialy at higher rpms, I can feel when the tires are likely to slip, and keep the gas pedal at the appropriate amount.

Some of the cars in the video behave like mine, but I was impressed with the instant torque "just off idle" I saw with some. Guess mine is more "mistake friendly".....LOL.