Just wondering what would be the least amount of air you would run on the rear of a 72 Dart I'll say the weight is about 3200 lbs the tires are M/T Et drags 26x8.5-14

Minimum is going to be very different for each chassis/motor combination.

A low pressure one guy could get a way with will crush the tire for another.

Besides, it's not how low you can run, it's how high can you get it before it doesn't hook. Also remember that a lower pressure could 60' better but give up MPH out the back.

Higher pressures are more stable a speed as well.

IMHO, bump up in 1/2 # increments till the car/timeslip tells you you went to far and back down a tad.

I guess I'm looking at it one way and asking the question the other. I was running 16 lbs last saturday and was doing some spinning upon take off. being pretty new to the game. I wanted to take alittle bit more out but wasn't sure what the minium should be from a safety stand point. I do understand you want to run as much air pressure as you can and still hook up so you keep your resitance to a minium. The suspension is pretty much stock all the way around(for now)

M/T tires like air pressure but you can run to much. You should take the car out and start at your current tire pressure and make a pass and come back and take a pound out. Do this and keep track of your sixty foot times to see where it is the fastest. With those tires a think they would start to wod up at around 11psi. We run the 28*9 M/T tires on one of our cars and keep them at 13psi. With leaf springs and a small block at 3200lbs it runs 7.20's in the 1/8th and 60' very well and consistently. Hope this helps.

Thanks I will do some experimenting and try backing it off a bit more.

Mike,
Can you get someome to take photos of the rear tire at the launch? Or a video will be better.that way you make a pass and go back and look at the tire in slow motion and see what its doing. This was very helpful to me. I use MT 11.5-29.5 and always ran 9.5-10 lbs. When I saw pics, it showed me that I was just about crushing the rim into the track. I am now running approx 12 lbs, depending on track "sticky". If you don't have a camera, ask a buddy, or fellow racer to help.
Brian

Think I will carry the camera tomarrow and see if I can get someone to snap a few. Thanks

[quote Or a video will be better.that way you make a pass and go back and look at the tire in slow motion and see what its doing. This was very helpful to me. I use MT 11.5-29.5 and always ran 9.5-10 lbs. When I saw pics, it showed me that I was just about crushing the rim into the track. I am now running approx 12 lbs,

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i was running 9 psi at first but the video showed the same story. this also helped me to decide 10.5 -11 was optimum for my combo. i run my 32x14's at 7.5 psi & came to this pressure decission with the aid of the video too, that & tread wear.