FNBADAZ06

Something I had shared with a few others that gave me an idea of what gear ratio and transmission combo I wanted to use in my car.

A little background......

My car makes roughly estimated 585-600 RWHP (515-520 TQ), depending on the dyno .
Car weighs 2975 lbs in race trim, without driver.
Stock gearing and transmission, best ET of 10.40, best trap of 136, best 60' 1.49, best standing 1/2 mile of 164+ MPH at NFZ (166.1 per VBox at test track).

Swapped to MH3 ZR1 transmission, ran a VBox verified 204.4 MPH before running out of test track....roughly 1.5 mile run standing start.
I wanted to swap rear gear to a 3.90 to gain back some of my lost torque multiplication in 1st gear, have stronger acceleration in all gears, and still have the ability to attempt 190's in the mile and 200+ in 1 1/2 mile events.

Chart below shows the numbers, using a 325/30/19 rear tire and 7000 max RPM. Listed is overall rear axle multiplication factor and RPM drop for each upshift.

Reality may not equal out to what info I'm gathering, but hopefully it pans out and my powerband and peak power can make it happen.









For ***** and giggles, I compared a 3.90/ZR1 transmission car on 315/30/18 Hoosier drag radials to a car with 4.11/Z06 transmission on 275/60/15 bias ply slicks ......

FNBADAZ06

The 275/60/15 bias ply has a roughly 9% greater overall diameter than a 315/30/18 (or 315/35/17) , the 4.11 rear gear has roughly a 6 % multiplication factor over the 3.90.

Knowing that the bias ply tire can absorb a greater launch RPM and driveline shock on a dig start, but it's an interesting comparison none the less for those who roll race instead, knowing that a radial tire has less rolling resistance.

AzDave47

The bias ply tires would not be legal at Mojave, you may want to check the tire guide if Mojave is one of your goals.

The 3.90 with MH3 gears looks like a god combo for the Magnum, and 5th gear looks like it would be good for the 1/2 mile (right in the power peak).

FNBADAZ06

Dave,

A lot of drag racers and "roll racers" use a bias ply tire for their drag racing purposes, such as the "15 spindle" conversion kits that allow a 15" diameter tire/wheel combo to be run on the rear of a C6 Z06.

Any of my Mohave attempts would be on a proper radial tire

If I go back and run a 315/30/18 Hoosier radial tire for the calculator in the rear and configure the max RPM to 7300 RPM (7400 is what I run thru the trap in the 1/2 mile now with that tire), I get a good idea of a possible 1/2 mile trap speed....if I have the power to continue to pull 7300 thru the traps instead with the new gear/transmission combo...