Just out of curiousity, what RPM's are you hitting the traps at, and what are your trap speeds? If possiable can you compare them to the stock 3:23's?

 

An 3.23 A4 will go through the traps at around 4300-4400rpm.

An 3.73 A4 car will go through the traps at around 5000-5100rpm.

 

Rear tire height is also a “major” factor in this equation and the stall converter will have an affect on the trap RPM. I’m using M/T ET Streets that are only 26” tall to keep the car geared low. With my setup (3.73s, Vigilante 3200, 26” slicks) on the factory tachometer I’m at 5900+ RPM on the line. Also, F-Body factory tachs typically read 100 to 150 RPM high.

1997 Silver Z/28 LT1-Auto
w/ 30 th Anniversary navy blue stripes and Chrome ZR1 wheels
Kooks Long-Tubes w/ Off-Road Y-Pipe and Cut-Out (no Cats), LT4 Hot Cam, Valve Springs and Crane 1.6 Roller Rockers, GM Performance Roller Timing Chain, Holley 58mm TB, 160 degree thermo, Aeromotive Fuel Regulator, 3.73 Gears, Vigilante 9.5” 3200 stall, TCI Super 2nd Gear Servo, B&M Trans Cooler, MSD Coil and Plug Wires, K&N Air Intake, PCMforLess Performance Program, LT4 KM, Jegs H/B w/ Under-Drive, Aluminum Driveshaft, Aluminum LCAs w/ Relocation Brackets, Mickey Thompson ET slicks and a few undisclosed performance upgrades. (Best ¼ time; 12.44 @ 110.13 MPH, Nov 2005 (N/A, no NO2).

 

Idk the exact rpm but my car with 2.73s just shifts into 3rd right before i get to the finish line. So 2.73s are not optimum.

 

www.f-body.org/gears