Launching @ 4Krpm problem .... need tips

[Loren]

Better shocks should help. Specifically, more rebound damping in front and more compression damping in the rear to resist the rapid transfer of weight to the rear on launch. Stiffer rear springs would probably help, as well, for the same reason.

Grippier tires will actually make wheel hop worse unless they don't spin at all. Less-grippy tires will just spin and not grab and hop. Add grip and the tire tries to hang on, but can't quite do it. Every time they grab, you get a jolt of rearward weight transfer (rear goes down, front goes up -- hence the suggestion for rear compression damping and front rebound damping) and when they spin, you get a little less of a jolt in the opposite direction.

In the extreme, you dump the clutch, you have enough grip to start a launch, but all the weight immediately transfers HARD to the rear, leaving the front tires light... the front tires spin, the acceleration ceases, the weight transfers back to the front, the tires hook up again... and the same thing happens again several times.

Keeping the suspension movement more controlled (not STIFF, just controlled) will help minimize hop.

There is much you can do to try to address the problem, but probably the biggest thing is to just launch smoother. Slip the clutch a little, maybe launch at 3500 instead of 4000? Try to keep the front tires hooked up so that they don't hop.

Toyota Starlet... you can't compare. It's RWD. When you launch a RWD car, the weight transfer to the rear HELPS the car to hook up.

Simplest/cheapest thing you can do is fit a set of adjustable shocks. For hard launches, set the front shocks somewhere in the middle and the rear shocks full stiff. Then adjust your technique to fit the car. Not every car is going to launch well at 4000 rpm!