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Author Topic:   Air Pressure
Rookieracer76
Dirt Maniac

Total posts: 182
posted June 05, 2002 08:15 PM
I have a 76 monte. The car wieghs about 3400 pounds. i'm racing on a 5/8 mile with low banking. the track is usally tacky. my question is what tire pressures should i run?? Below are the pressures i run now but the car seems to be a litle tight at the end of a 12 lap feature.In practice the car is good.The tires are all street DOT approved.

Rf- 265/60/15= 28psi
Rr- 225/70/15= 24psi
Lf- 205/60/15= 22psi
LR- 215/70/15= 22psi

What is the normal increasement of each tire ?

uforacing51
Dirt Freak

Total posts: 349
posted June 06, 2002 05:54 PM
I wonder if you could run them all about 6 lbs lower and see what that does at first and after a long run, I always run my pressures lower than that, about 10 lbs lower on DOT tires.

Rookieracer76
Dirt Maniac

Total posts: 182
posted June 06, 2002 09:12 PM
Thanks for the reply. I just have one question for you. Are u running tubes ? I always tryed to stay above 20 because i was afraid of rolling the tires off.

ryan
Dirt Freak

Total posts: 430
posted June 07, 2002 12:18 AM
I usually run anywhere from 17-23 psi on dot rubber with tubes and lots of baby powder.

uforacing51
Dirt Freak

Total posts: 349
posted June 07, 2002 11:48 PM
I have run the right side tires with and without tubes, with mixed results. I have rolled the tires off. without, but never have with. Some say the tire weighs more, and it does. If you have went to alot of trouble to make less rotating mass on the wheels then don't run the tubes, if you havn't then you may be better off with the tubes. Plus, what kind of track do you race on most of the time? if its tackey then may you could get away with not using the tubes, but if its dry slick then maybe you should. Alot of this just comes down to personal preference and experience. I have just gotten to where I use the tubes in the right side and not in the left. Hey Good luck.

hobby39
Dirt Roller

Total posts: 14
posted June 08, 2002 07:55 PM
I always run tubes everytime i've ran a tire without one it rolls off the rim. I run anywhere from 14# to 19# and was running 12 last year but due to track rules we can no longer change a flat in the main so just to be sure the lowest i run is 14#.
I have a question what does the baby powder do? I have a tire sponsor and they never use baby powder and i've never had a problem.

dreamcatcher
Dirt Maniac

Total posts: 128
posted June 08, 2002 10:34 PM UIN: 14464409
the baby powder is to keep the tube from sticking to the tire, if it sets for any peroid of time, the tire mounting compound will dry up and get sticky. it will let your tube flex with the tire. it is an old racers trick. i like to weld a bead in the in side of the rim and run no tube. sence i started doing this i havent had a flat due to tire roll off.


dreamcatcher
Dirt Maniac

Total posts: 128
posted June 08, 2002 10:38 PM UIN: 14464409
i run stock spring from a big m/c, air presure lf 12 rf 18 rr18 lr15, and if the track gets rough, i go to 22 on right side , 18 lr. if the track is sloppy wet or dryslick i go down to 13 rf 14 rr 12 lf 12 lr.


YAZ
Dirt Forum Racer

Total posts: 77
posted June 12, 2002 10:59 PM
WHEN YOU RUN TUBES, DO YOU USE IMPLAMENT
TUBES. I HAVE TRIED RADIAL TUBES BUT I
KEEP GETTING PIN HOLES IN THEM. SOME OF
THE MODS AT MY TRACK SAY THEY USE IMPLAMENT
TUBES BECAUSE THEY HAVE THICKER RUBER.

ryan
Dirt Freak

Total posts: 430
posted June 13, 2002 01:57 PM
quote:
Originally posted by YAZ:
WHEN YOU RUN TUBES, DO YOU USE IMPLAMENT
TUBES. I HAVE TRIED RADIAL TUBES BUT I
KEEP GETTING PIN HOLES IN THEM. SOME OF
THE MODS AT MY TRACK SAY THEY USE IMPLAMENT
TUBES BECAUSE THEY HAVE THICKER RUBER.


Yaz is right I also run tubes from the local Co-op they are better tubes than from automotive places


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