DragStuff

A tire question. My truck is trying like hell to hook up but not quite there yet (street use so far). I noticed the rear tires 31x16.5 nearly new ET streets on 12 inch wheels (actual tread width of 12.5") are rolling up the tread in the center but are smooth on the edges. About one inch on the inside and outside. Both of the tires look identical. My thinking is that there is too much air in them but they only have 11 psi in them right now. On the street it'll leave two black lines from the outside edge of the tire and a fairly solid black mark where the tread is rolled up. Higher air pressure and it just cooks them. It weighs 3820 and if I run it up against the converter it hooks better than at an idle or near an idle.

Basic specs are full size long bed chevy truck, 505, turbo 400, 10 inch converter stalling at about 4200, 4.88 gears. The picture is just from goosing it across my carport but they look pretty much like that after nailing it out of the hole. Only thing is the grain pattern on the tire is a little finer. Any opinions/advice/wisecracks welcome I haven't had a race car in a long time and am trying to sort this out before I go to the track. Getting put out in the first round is no fun. Thanks



Roger

Well any time you spin the tire it's going to look like that. Trying to make traction on the street is just about worthless in my book especially if your going to take it to the track . I would just take it to the track and work with it there because it will be totally different.

have you tried it with more air? maybe with more air you will get a bigger foot print?

505r10 wrote:My thinking is that there is too much air in them but they only have 11 psi in them right now.
Roger

Looks like too much air pressure to me too. Try dropping 1 psi at a time until you get even contact.

Craig W. wrote:

505r10 wrote:My thinking is that there is too much air in them but they only have 11 psi in them right now.
Roger

Looks like too much air pressure to me too. Try dropping 1 psi at a time until you get even contact.

I haven't run them lower than 11 psi. I didn't know if conventional wisdom applied to drag type tires or not. I'm going to start lowering the pressure 1/2lb at a time to see if it starts covering the whole tire. Thanks


Roger

I know its apple to oranges, but my 28x10.5w on a 12" rim like 9.25-9.5 on a greasy track. Usually bigger slicks like less pressure. Also do you run tubes?

427belair wrote:I know its apple to oranges, but my 28x10.5w on a 12" rim like 9.25-9.5 on a greasy track. Usually bigger slicks like less pressure. Also do you run tubes?

Sorry for the late reply. Yeah they've got tubes in them. I did let them down some and they're much worse. I'm going to try to get to the local track's test and tune next Thursday night. I'm sure it'll do much better at the track.


Roger