aBrotze
07-23-2003, 04:50 PM
I am running a set of 10.5 X 15 X 28 ET drags. I usually run the tire pressure around 11 psi at the drag strip. Was wondering what other folks are running. What has been your experience with rasing and lowering tire pressure as far as MPH and sixty foot time?
I'm using ET Streets, not drags. Generally run 14.5 pounds. Up or down will depend on track conditions and temperature. The goal is to keep the maximum ampunt of air that will consistently hook. If you hook each time your sixty foots should be consistent.
A firmer tire will launch quicker and can impact your reaction time. It will also have less rolling resistance at the top end which may affect the mph, particularly in lower powered vehicles.
rskrause
07-24-2003, 10:14 AM
You have to experiment. I found that 12.5psi worked best with last year's setup (26x11.5x16" ET Streets).
Rich Krause
Pro Stock John
07-24-2003, 11:54 AM
Typically ran my 28x10.5x15 Hoosier slicks at 15psi cold, they would grow to 17psi after a run/burnout.
Here is a 1.48 pass off the footbrake on motor, keep in mind my car was 3550 lbs:
http://www.pbase.com/image/5269912
I ran some 28x9x15 ET Drags at 10-15 psi prior, and the car felt slushy and a bit squirrelly up top, I really disliked that but granted they were a thinner tire and I had them on 15x8's not my later 15x10's.
I also ran some 26x12.5x15 ET Streets on 15x10's at 15 psi and cut 1.50 as a best 50 ft.
rskrause
07-24-2003, 12:27 PM
Originally posted by Pro Stock John
Typically ran my 28x10.5x15 Hoosier slicks at 15psi cold, they would grow to 17psi after a run/burnout.
Here is a 1.48 pass off the footbrake on motor, keep in mind my car was 3550 lbs:
http://www.pbase.com/image/5269912
I ran some 28x9x15 ET Drags at 10-15 psi prior, and the car felt slushy and a bit squirrelly up top, I really disliked that but granted they were a thinner tire and I had them on 15x8's not my later 15x10's.
I also ran some 26x12.5x15 ET Streets on 15x10's at 15 psi and cut 1.50 as a best 50 ft.
Mine also did feel a little squirrley at the top, but the 60' were low 1.5's, best of 1.51sec which is not bad in a 4,100lb M6 car with a "road race" type suspension and a small tire. Higher pressure = more spin, at least for me. I tried it at 11.5psi once, and I wouldn't want to repeat that :eek: . I got out of it in 4th gear, it was pogo-ing around too much for me.
Rich Krause
Derrick Redd
07-24-2003, 04:43 PM
I run 15-16 psi cold. Best so far on a ok prepped track was 1.55.
I run 9" x 30" slicks on 10" rims. When I run bias ply slicks I run 14-15 psi and when I run radial slicks I run 18-22 psi. Sixty foot times are generally in the low to mid 1.4's. The radials are worth about 1 mph in the 1/8 th mile.
Daren