Jspell, your buddies that say more pressure will get you more traction are right depending on rim width, and what pressure you are starting out with. And your other buddies that say less pressure are right also depending on what pressure you are starting with, like going from 8-9 lbs to 7lbs may get you more traction because the high pressure makes the tire too rounded. Also street tires get you more traction when lowered. But you have a FED with slicks.
I have been racing a JrFueler for 12-13 years, running 31x12x15 Goodyears. We started out using 10" rims, which is good for tire growth, then I built another set on 11" rims to run when the sun went down at Bakersfield [ Finals], when the track gets loose. Then as I found more power we needed more bite, so then I built a set with 12" rims for night time Bakersfield, all with D2585's. Yes the 12" rims ened up with less tire growth, but with more power we were going 186 to 189 mph with 4.71 or 4.88 gears. We run 5 3/4 to 6 1/4 lbs of pressure. I have a RacePak computer so I can see our driveshaft speed and curve. But one good indication of what is happening with my tires is using my infra-red temp gun, the one I use to check head temps before staging the car, and read the temps across the tires right after the run. When running lower pressures to get/ keep the tires spining abit to keep from pulling the motor down out of the RPM range it wants to run with-in, it will be hotter toward the edges, because the tires will concave abit with lower pressure. Like 2400 drive shaft speed about .400 into the run. And 6 lbs will lower the driveshaft/ tire speed.
This last week-end we raced a Div 7 race in Sonoma, with the goal of just experimenting, 1'st run was a 7.10 @186 on the D2585's, but the next 4 runs were with MT 33x10.5wx15, 1'st run at 7 1/4 lbs then kept lowering the pressure, to 7#'s then 6 3/4 on the last run, after going to a tighter converter, and lowering the launch from our normal 6500 to 5400, and added another 15 lbs on the nose. We ran a 1.01 sixty foot, and a 7.17. So I will try more weight on the nose, raise the the wheelie bar even higher like 5" and a liitle tighter converter, like 8500 rpm stall. I have been trying to not hit the wheelie bar and unload the slicks, and get a much better driveshaft curve, but we need to get the balance better [ ie enough weight on the nose].
I know some JrFuelers running less power than us running 7-7 1/2 lbs with 2585's, so they are getting more tire speed with the higher pressures, and benefit is your reaction times will go down because the tires will react quicker, but if you are having a red-lighting problem go with the lower pressures, it takes a little more time for the tire to windup.
I hope this helps.
Jon
