Going fast has a LOT to do with your tires. If you do not have good traction, then it really doesn’t matter how powerful your engine or how low your suspension is set. The tires are the one thing on your car that make contact with the ground. Well, they’re supposed to be the only thing. So unless something went horribly wrong, they are the 1 and only thing in contact with the ground. You can autocross on street tires. There are many performance tires for the street that are good tires to use for a street tire class in autocross. However, even stock classes allow for R-Compound or race tires.
R-Compound tires are tires that have a really soft rubber compound to them that grip very well at the cost of shear. This means that you will not get many miles out of them. Most performance street tires have a tread wear rating of about 300. And most of the autocross R-Compound tires that I’ve looked at and/or used has a rating of about 20. That means that they will not last long at all in a daily driven scenario. They are street legal though. If you look closely at the picture below, you’ll see a couple grooves that run the circumference of the tire. These lines are what give the tire “tread” and to differentiate them from “slicks”.
Kumho V710 Impressions
Once you make the switch from street tires to r-comp’s, it is really tough to go back. The level of grip they give is incredible. It’s almost like you’re riding on rails. This allows you to push your car harder with the confidence that the tires won’t break traction as easy. They do break traction though. And when they do, you’re likely not ready for it the first time. since they have incredible grip, they will hold and hold and hold …. and then they won’t. There is a slight “give” period right before they completely slip, but it’s a really narrow window and you’ll need to feel it a few times to know it’s about to happen. I’ve been happy with these tires at events for many years.
They will last about 1 season of autocross and cost about $1k for a set of tires for 15″ wheels. I run 205/50/15 in the front and 225/50/15 in the rear. 225/45/15 would be more appropriate of a size, but that size is not available. So the extra height in the tire isn’t significant enough to cause me much stress. Some others may want to have it as close to stock proportions as possible though. So you may need to check sizes that suit your needs.