wrogers55 Wayne I know rolling on and off the gas pedal is no fun but alot safer. The question I have, Is the alignment with rear toe and thrust angle setup right? I am going to assume that the weights of the car are setup with your weight in the drivers seat and you have a 50/50 front to rear and right to left side weight ratios. Tire pressure are another thing with causing cars to slide all over the road. Tire temps maybe cause the all over the road condition. They sell VHT that is used to soften tires and give better traction.
Going back to the alignment, Have rear toe pos about 1/8" in with your weight in the drivers seat and having the thrust angle at "0" the car should go in a straight line unless a suspension part has play or tires are at different pressures, temps, or road surface where you are running on an
oil centered road. dirty or sandy roads give the same problem. I hear the Avons are good road tires. One of the guys ran them a couple of years ago and won the R&G street class. I have run pilots for 9 years and looking at a new tire from Nitto The 05N has a 200 wear and top ratings for the rest. A can also get them in a 315 rear tire. Price is also pretty good compared to pilots. The last thing is get a video of the car doing the 2nd gear dance and a start from a stop. You want the rearend to swat about 1-2" to get max weight transfer to the rear tires. this will also stop the rearend sliding around when hard accel is done. The rear shocks may have adjustment for compression and need to be lightened up to increase rearend transfer. I don't know how many settings you have but drop the setting by 2 clicks to start and see if there is a differents. Good luck. Rick L. Ps I am running a real soft setting and the rear tires go about 2" into the rear fenders and get good weight transfer. Almost get the l/s front tire off the ground on 1/4 mile runs. I switch back for autocross and road race. Rick L.