I run 13-14 and check before each run, you might want to run a little more until you get used to the feeling of a boat ride
ran mine at 15 psi with the 6.55 motor. I would suggest starting at 15. I ran my 7.70 motor at 11 and it was very inconsistant, ended up running 13. You go to low and you start to float the rear of the car down the track (chasing it to keep in a straight line)and it will help contribute to being very inconsistant.....plus it was not all that fun at 130 mph. this is assuming you are running tubeless.
I agree with John. There is no reason to drop tire preesure unless you are not hooking up. I run mine on the Maverick at 14-15. Previously I had a low 10 second, 130 mph Mustang that I ran at 11-1/2 psi. It was a real handful on the top end if I dropped below that, even a 1/2 lb. Also, try pushing the car by hand at 15 psi, and then again at 10 or 11. You will feel the difference. It costs HP to run a lower tire pressure than necessary.
10 psi might work for your car....only T&T will tell. But 15 is a good starting point and work from there. You can probably go in 1 psi interval at first. Remembering that even 1 psi + or - on a 15 psi setting is a substantial move. Also try to check your pressures after the tires cool off. For fun you can set them and then after a pass get out and check again, see how much pressure you build during and pass. But you will want to check them after a cool down period to get as accurate (consistant) reading as possible. *FYI, the main reason I ran my 6.50 motor at 15 psi is (1) it hooked good at that setting (2) went straight down the track, very easy to drive (3) when I ran the pressures down any lower, I was getting real inconsistant reaction times. The determination was that with real low pressure, at the initial hit of the throttle, the tires where "wadding up", then the car would launch almost (for lack of better example) catapulting the car. If you could see some really good super slow-mow videos of fast cars launching with the camera focused on the rear tires, you will see that they are almost always spinning the tires faster than the car is moving at the start. The faster you go the smaller the window.
. i get my best 60 ft times and et with mine at 15 also. another thing m/t recomends little or no burn out ... i used to do the long smoky burnouts cause they looked kool and all i was doing was wasteing my tires and spending money, haze em good , dont hit 2 or 3 times before ya get to line, its a waste also . just pull up to line and race. anyways thats my humble opinion and what works best for me.
Not really tire pressure info, but also count in your head the amount of time your doing your burnout and keep it consistent. If your not heating your tires up the same way everytime, you can chase your tail while adjusting tire PSI.
what size tires? Is your car a typical iron headed small block car? Just giving an idea what your rear weight is....it makes a difference. Light cars=less PSI. Heavy cars=more psi. Also the horsepower level will make a difference. A car that has a ton of power and a low starting line ratio (think lots of power + 3 speed transmission or a manual shift car + 5.xx rear gear), you can get away with more psi. I used to run 28x9-15's on my mild Maverick. Found they were most consistent around 15 psi. Also ran 28x10.5's for a good while and ran those at 13-14 psi until I put the 351 in it-then it had to go down a little on the pressure because of more front end weight and less rear weight. Now we run Hoosier 18327's and run them at 9-11 psi on a good track and a sorry track (hot) I can't run more than 8 or 9. I seem to get about 250 passes out of them before they're done. That's why I like them. They hook until the cords are showing and they still hook just not quite as consistent. And they hold air. I'll park the car in the trailer at 9 psi and come back a month or so later and it's still 8.5-9 psi (air temp makes a difference). Never could get Mickeys to hold air unless I dawn'd them. Little trick-use some dawn dish soap on the inside of the tire. Smear it all over especially on the insides of the sidewalls. I mean you really gotta get this stuff in there...I use a whole 10 oz (or whatever the normal size is) container full in each tire (like on 28x9's...2 in each on my Hoosiers). Smear it. Wipe out the excess. Let it dry overnight. Do it again the next day and let it dry. They'll leak a lot less that way. Sometimes we even do it at work on lawn tractor tires and wheel barrow tires as lots of those leak through the sidewalls as well--but the Dawn prevents it.
mavman,they are 28x9-15 and my mav is a mild built 302 so i will start at 15psi.and yes its a iron headed small block weight is about 2900 with me in it.thanks for all the good input john
Mine are at 13 before each run. Have a little more in them than you need when you go up to the lanes. Check them there. If you sit for a clean up or something and the weather cools, the pressure will drop and you don't have any way to add. If you know it's going to get warmer, you're okay, as you can always let a little out.
don i was running them at 14 psi and still didnt get them to hook so i will try 13 and see what happens.i know when i get them to hook im going to be in for a hell of a surprize.
