I will be the **** and disagree with some of the advice here
Personally I have only gone slower when I messed around with tire pressure. Maybe drop a couple of pounds if you like but going to 20psi or less is too low, IMO. At that point you just start buckling the tires and get LESS tread area. My best 60' times were in the 1.6 range on stock MXX3's at 29psi. I could consistently get below 2.0, even on a crappy track or even on the street. Just gotta be judicious with the clutch. Launch at 2800-3000RPM and use the clutch to modulate wheelspin (to where you get almost none). If the car bogs at *all* you just lost a tenth or two - should be ZERO bog - none, zip, nada.
You gotta shift FAST. On a 95 degree, super humid day in July I could run 116mph trap speeds. Usually around 119-119.5, and on a cool day I could get into the 120's, with a best of 121.0mph. The car was pretty much stock - smooth tubes and home-made rear-muffler delete and nothing more. Dynoed at 414RWHP. The trick to the MPH is to SHIFT QUICKLY. You're shifting too slow, which kills your MPH. If you shift slowly, you're going to lose 2-3mph without question. You need to clutch in-shift-clutch out in LESS than 1/4 second, quicker if possible. People standing trackside should not hear a shift, just a constant revving sound. If you can hear the shift, you're shifting too slow.
I also say rev the thing higher than 5600. I would rev right to 6000 before I shifted. And always, always, always, ALWAYS go into 4th. You will only slow down if you don't.
I could hit the 11's consistently on a decently prepped track, and my MPH never was below 116-117, even in bad weather. On a cool night, it was always above 120mph. My best ET was 11.68 and best mph was 121... an "average" run would be
12.0-12.1@119-120 or so. ANY Viper, on a 70-degree day, low humidity, sea-level or at least less than 1000' DA, will run a
12.0@119mph.
