I went racing last night and when I turn the car off my car will continue to run. Also, by the time I near the 1/4 mile, my car will die off at wide open throttle. It only dies when I am almost at the 1/4 mile mark. The RPMs will drop down and it feels like I just took my foot off the gas. Also, I think it is backfiring at the 1/4 mile. At the line, I got a huge backfire out of my carb then the car died... it started right back up. I lowered the fuel pressure to 8psi and the timing is advanced 10 degrees at 600RPM. I also put springs and bushings in my MSD distributor (will this cause it?). Anything will help.