Bead Lok Tire Pressure (part 2)

I have a 265" Spitzer sliptube car with a blown 428" Brodix small block, running through a glide and 3.89 gears, 1490 Goodyear tires on Bead-Loks. I've run the air from 5.75 to 7 lbs. and have gone from shaking the crap outta the car to launching sideways spinning. Kinda wondering about 4.5 to 4.75 air psi. would do. Also confused about what to do with the slips. Last advice I had was lock the chassis down, start with 5lbs. air and work down to 4.5 to see if it helps. (going up didn't help) It seems like a car with this power (7.33 @ 190 in Denver) could take a wide open launch. Right now we bring it up to about 4000 rpm with an air controller, and when the car launches the computer says about 5500 to 5800 flash. Sure would like to clack the blades open quicker. Best 60' so far is 1.12. Anything faster and "Hang On" I've even toyed with the idea of taking some timing outta the car while on the converter. Hate to go try MT tires when these are brand new, but there must be a reason you TAD guy's quit running Goodyears.

Thanks

 

Lars, one of the cars I work on is a 289" Spitzer slip tube car with a root blown hemi and a converter (Lencodrive). We run the 34.5 Goodyears on beadlocks at around 5.4 to 6.0 pounds of air pressure.
Thing I might look into:
The speed that the throttle contoller opens the throttle plates. Too fast will definitly knock the tire loose. I know this from experience.

Timing control. I sometimes take as much as 6 degrees out at the hit. If it shakes at the hit put some timing in, if it spins too much at the hit, take some out.

I would not lock the slip joints. It is designed to work that way. This car has run 5.80s with .940 sixty foots on match race tracks. In my opinion locking the sliders will not solve your problem.

Good luck.
Tom

 

Thanks, Tom. I guess I'll just have to sneek up on it little by little. I figured if I had a REAL car built, a guy could just clack open the blades and go. I definantly have a new found respect for the Alcohol cars. I guess once you have this kind of power and no clutch to slip alittle, you just get it as close as you can. I'm going to let the rear upper slips about a 1/2" loose and maybe an 1/8" on the ones in front of the foot box and see what happens with 5.5 lbs of air. I go about a 1/4 turn on the air valve at a time to speed up the blades. I damn sure ought to get some 1.0's in the heat of the day @ Bandimere. It's not that bad of a day track, and the mph is telling me there's more, but if I can't get off the line there's no since in leaning on it more..

Thanks again, Lars......

 

Thanks Mike, I've been toying around with that idea also. What do you suppose a guy would use for a soleniod/valve? Do you think an NOS fuel soleniod would hold under that kind of fuel preassure? I could just control it with a delay box....

Thanks again, Lars..

 

Lars,
Use one of the .110-.120 orifice nitrous solenoids with a teflon piston to do what you want.

Have a safe race
Dave Koehler
www.koehlerinjection.com