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I have been having this issue for awhile now. Car initially hooks then spins bad....I have had my double adj shocks all over with the adjustments and nothing seems to work at all. Have had 3 diff rear springs on it as well 150, 130, and now currently. 110s. Made no change. I run ladder bars. Im thinking I need a stiff sidewall tire. I run a 29.5x11.5 mt. Car runs mid to upper 1.3 s and 9.60s and weighs 3100. Should be in the high 1.2s. I feel with my alky injection. Any suggestions? Thanks for your time.



We want to spring the car as softly as possible without causing the spring to bow. The softer choice should provide the most consistent performance given multiple track conditions... If your car weights 3100 and is something like 55% front, 45% rear or so, The 110#'s should be ok, again as long as they aren't hitting the springs..

Ladder bar cars usually respond well to a fair amount of pinion angle. I have seen cars go from not trying to work with 2-3 degrees to hanging the front end with 5 degrees. Again, the front end has to work too. If it is dead, we may not get maximum performance out of the car. Also, we have to make sure we are bind free...




It was my understanding that Ladder bars only need 2-3 degrees of nose down pinion angle.
What's the benefit of 5 degrees?



More pinion angle can be a benefit up to a point..as the pinion climbs the ring, it creates downforce. We want those vector forces going directly to the tire contact patch. Two things occur as the pinion gets parallel to the drive shaft, that downforce decreases and moves away from the tire contact patch. I have had the benefit of working with many chassis builders that tell me when they get a chance to work on a car that is not hooking consistently, and they find out the car is lacking some pinion angle, they immediately know that they can help that customer.

Remember, as in most cases, too much of a good thing can be a bad thing. Our u-joints cannot stand excessive angle. The weld yoke will crash into the pinion yoke or slip yoke. Also, as the pinion climbs the ring, the drive shaft moves into the transmission under acceleration....As you let off on the big end, the pinion drops. It then pulls the driveshaft out of the trans. The length of the slip yoke is crutial here..We need enough engagement to cover total movement..Contact your driveline company here for specs..

I would strongly encourage testing of all systems in your car (vary tire pressure, fuel pressure, shock settings, rear suspension changes, front suspension changes). We never know what we leave on the table unless we try something different.

I have personal experience in dialing in more pinion angle. I broke a rear end on a car that was working very well. (Spun the center center section on the tubes at 3 cars in a 5 grand race and killed her on the tree. However, my pass ended about 15 feet out). Replaced the housing but didn't have the same amount of pinion angle. The car didn't work the same. I sent my converter off. I replaced springs. I swapped slicks with no real success. Finally, I made it back to the rear end and added more angle. The car was instantly better-back to where it was previously.