secrt0007agt

I am looking for some help from someone who has gone down the track a few times with these tires, either 1/8th or 1/4 mile.

I am running the following;

2011 Grand Sport, Roughly 650 rwhp, 2.9 WHIPPLE SUPERCHARGER, 6 SPEED PADDLE SHIFT AUTOMATIC, ALKY CONTROL METHANOL INJECTION SYSTEM, FORGED LS3 6.2, CUSTOM WISCO FORGED PISTONS, EAGLE H BEAM RODS, KOOKS 1 7/8 HEADERS WITH MODIFIED DUAL MODE EXHAUST, FORE INNOVATIONS LEVEL 2 DUAL PUMP RETURN FUEL SYSTEM, CIRCLE D TRIPLE DISK BILLET TORQUE 3200 STALL CONVERTER, DEWITTS DUAL CORE RADIATOR WITH DUAL SPAL FANS, 160 DEGREE SLP THERMOSTAT, HAYDEN TRANSMISSION and OIL COOLERS, 4-POINT ROLLBAR, not sure on the transmission, but I can't believe it is not built to some degree, gearing unknown, NITTO NT 555's on the front and MT ET STREET R's (305/45/17) on the rear.

My last run was a 6.65 sec. 107.77 1/8 mile. I had 20 psi in the MT's on all runs and wanted some advise on how low to go with the pressure.

BIGMAC

I run the MT's on my C5 at 18 psi. I have gone down to 16 psi but did not see any better results. BTW, I came close to buying your car in 2013 when it was titled to the owner of Stingray Chevrolet in Lakeland, FL. At that time the transmission was stock. I found that unusual given the level of other mods. I think the rear was the stock 2.73 gears as well. Good luck.

BIGMAC

C6David

I did 18psi in my 305/45/17 and worked perfect

secrt0007agt

I checked with MT Tech and with my setup they said I could run from 14-20 psi

Not sure if I want to do the low pressure number, things start to break.

Danny Richie

18 seemed to be the magic number for me.

Joe_G

General rule of thumb is you want the highest pressure you can get until it spins then go down. Lower pressure = higher rolling resistance and higher ET's.

If you aren't spinning at 20 then leave it alone or try going up a pound or two.

dogboy

I used to run them down to the low 20's. I wanted a little spin at the time on my stock 3:42 rear & A4 tranny to try & save it from destruction. 24-22 lbs. got me in the mid 1.60 60's
I used to drive them on 32 lbs. to the track. I had eventually destroyed my rear gears & also my torque tube joints with about 100 passes. I went ahead and upgraded to a 3:73 RPM rear & Tranny to handle 500 RWHP, also had torque tube rebuilt by NLP in Maitland (they did install also). Since than I went with Hoosier DR's as the MT's had hardened up from age & it developed wheel hop. The Hoosiers where also run in that pressure range. I had done about 30 passes on those & since retired from racing. I have the dr set up sitting in my garage now collecting dust. I may go back into it this year, debating??