i have got a 409ci vortec setup t700 3.08,,etc,,,,,,,the engine is great,so is the gearbox and possi,,,,real good setup,,,,,,,,,off the line the car is suffering from severe wheel hop or axle tramp,,,,the wheels are hopping in wheelspin,severe,,,,,the new rear springs were just replaced and uprated 25% more firm ,, the shocks are brand new gabrial sports type,, the car has 235,65,,15 rears on stock z/28 rims,,,,,,,the car has stock height,,,,,,,,,the car didn,t do this before, with the old metric 3 speed auto,,and the 2.78 rearend,now i have a few more bits like a full 1 3/4 header setup and full 3 inch exhaust system and a K&N cold air setup,,,,,,,,the engine is strong,,,,,,,,,the shocks have already damaged ther floor,, and i cant race this thing due to not being able to control the car in low ,,,or ripping the floor out of the car,,,,,,,,,,,please advise me ,,i dont want to fit bigger tyres,,,,,,,or lower the car,,,,that will solve nothing

 

You need LCA lowering brackets. That's the magic bullet for wheel hop in these cars.

Aftermarket (tubular) control arms will also help, but will usually not cure it by themselves.

Lowering the car aggravates the problem; which is defective design in the control arm geometry. If you look at one of these cars just sitting still at stock ride height, the front (frame) end of the rear control arms is lower than their rear (the rear end end). As we all know, the car will transfer weight to the rear under acceleration, and "squat", which makes the front end of the LCAs even lower. Now think about what happens..... imagine looking at the car from the left side, such that it's moving from right to left.... you dump the clutch or release the brake or whatever, the tires bite (you hope), the rear axle begins to push the car to the left, and the car presses down on the rear springs, such that the rear of the body is now lower than the front. But, the LCA is now angled from bottom left (the frame) to top right (the rear end mount point); so when the rear end pushes on it stratight to the left, it tries to rotate upwards. So, the tires bite, the rear pushes the car, the rear rotates up, that unloads the tires, the tires spin, the bite goes away, the tendency of the rear to rotate upwards goes away, the rear springs push the rear end back down, eventually the tires bite again, the rear begins pushing the car again, the rear tries to rotate upwards, the tires unload, they spin, ..... about 7 - 10 times a second. Bam-bam-bam-bam-bam. If you do it on dry pavement, you can see your tire marks look like a string of dashes. Like - - - - - -

The brackets lower the mount point of the LCA, so that the rear tries to rotate downwards when it bites, which improves traction and reduces squat; instead of the factory design, which impedes traction and creates squat. Under virtually all other conditions, they have no effect. They don't make the car ride hard, corner worse, brake worse, or otherwise compromise the car's performance (as long as they're not lowered excessively). They merely repair the faulty design from the factory, and make up for the dynamic loading conditions imposed by launching the car at the strip.

The LCAs themselves help by being more rigid (you can flex the stock ones with your hands or at least I could mine), which in turn prevents them from storing energy and releasing it and storing more and releasing it and so forth. Again, when properly chosen, they create no offsetting penalty to anything. No other property of the car is compromised.

The upper mount point for the rear shock is very weak in these cars. Weld a couple of big washers in there, they help the shock do its job by controlling sheet metal flex. But repair the suspension design, so that as little stress as possible is transmitted to that point.

 

It may be the tires.
My car is lowered with LCA brackets and LCA's and I get wheel hop with my new Nitto 555RII tires when they are cold. once they heat up the wheel hop goes away.
All the other street compound tires I ran had no wheel hop with the above mods.