[racerx69]

I bracket race and index race this car with a 28X10.5s tire 3450lbs with driver automatic trans.

My question is about the number of runs I would get with the standard tire was close to 200 but with these stiffs I have about half the passes and seem to be spinning more than it should.

The old tires I ran were 28X9 with no tubes on an 8 inch rim while the new tires are 28X10.5s on a 10 inch rim with no tubes.

The 10.5s worked very well in the beginning but seem to have fallen off performance wise compared the standard tires with similar runs.

I see the 10.5 guys change tires pretty regularly so is it the tire design or do I need to run a tube with these?

Bill

 

[MIKE FROM SM]

How fast is the car? When I switched from the regular side wall to the stiff sidewall, I had to hit the tire harder for them to work. I run high 8's with a 3500lb car.

 

[racerx69]

Car is a 69 Camaro that runs 10.50s at 127 mph, set up is caltrac bars with split mono leafs, rancho shocks in rear, BBC 427 alum heads, glass hood the rest is all steel. Drag springs in the front with 90/10 non-adjustable shocks.

I did set the rear shocks about as tight as they go the last race but only made a couple of passes 1 was great the other I spun the tires. This was the first time at this track so I don't have any good data on the last adjustment.


Bill

 

[Jason Moulton]

You should certainly get the same or more runs from the stiff sidewall tires. Tubes won't hurt, but rotating then as often as you can will help.

Any other changes to the car???

Thanks,

Jason Moulton

 

[racerx69]

Jason,
The car is a little faster now than it was when I ran the 28X9s by about a half second.

I ran a set of hoosiers 28X10s before these 28X10.5s MTs and the car would not hook very well at all, so I bought the rear shocks and that helped dial in the hoosiers.

The car worked very good on the MTs at first but seemed to be falling off now, the weather is very hot down here in Houston so that could be part of the problem. I can't check track temperature so I don't have those numbers to help with the set up.

Thanks