Best for Traction New or Worn Tires?

[par1969]

Ran 13.35 @ 107.24 last week with a poor 2.25 60ft time on very worn stock tires. Next week when I go would I be better off using the new take off set of stock tires I have? Its been over a year since I've had new tires I don't remember if they hook up well. The worn one's seem slippery but I don't know if its just the cold weather or not. Any info would be appriciated.

[Harpo]

Street tires don't do much for you because their compound isn't that great for grip. Best thing to do is to get some purpose built tires for drag racing.

As for bald vs. new street tires, depending on what you buy, you should get better forward grip with new -- as the tread blocks are designeed to help. You should also lower your tire pressures to the mid 20's out back as well.

[TriflowM5+M3]

in terms of street tires, new will always perform better than old....

[par1969]

Thanks for the response guys. I very rarely go to the track and as a result want to better my time next weekend when I go because it may be a while before I get another chance. Sounds like I should install the new set of stock take offs I purchased a few months ago berfore heading to the track again. Hopefully they will help me get a new PB. Thanks again.

[Riddlefox]

Most of the high performance summer tires out there perform much better when worn. Many autox'ers will shave their new tires down to 4/32". Taller tread blocks means that there is more tread squirm. Lower, stiffer blocks mean less tread squirm. As long as it's dry out, most tires get grippier as they wear, until you're down to the cords.

In addition, taller tread blocks + more tread squirm = more heat. Sometimes you have to shave tires in order to avoid overheating them at road courses so that you don't chunk them and make them greasy.

In the wet, less worn tires will tend to do better because there's more channels to get water away from the rubber/road interface.

Of course, this assumes that the compound is consistent all the way through the tire.. some tires have stickier compounds near the bottom of the tread blocks, which wears faster, and harder compounds at the top of the tread blocks, which wears slower.. this allows them to make a tire that has a longer tread life (all the ST* classes in autox require a minimum of 140 treadwear), while allowing the hardcore racers to shave their tires down immediately to the good sticky stuff.

I have no idea how it works in relation to drag racing, though.