VHR + FD Gear Ratio upgrades - 3.9 and 4.08

Originally Posted by Z eliminator

I changed the diif on my 7 AT to a 4.08 gear set up. The rev matching in city driving takes some getting use to. It uses to turn 2100 at 100 km. Now it turns 2750 at 100.
Fuel consumption went from 7.8 up to 8.7 L / 100 km. I took it to the track and it ran a best of 13.201. Average pass was 13.32 to 13.43. The colder the moter the faster it goes.Going down the track i shifted at 7400 and the RPM only drops to 6300. I have to put in 5th. On the 13.201 pass i hit the limiter in 4th as i tried to make the pass in 3th
It ran at 102.8 mph in that pass. Mt best trap was a 107.9.
The only mod is a stillen G3 intake. Base line was 266 and 286 RWHP after the intake.
The next Z drag day is in Septmeber and it will have a stillen CBE. Berk cats, Stillen headers and the underdrive pully. It should run 12.8 on the 19 inch wheels. Its hard to hook the bridgestones. Best 60 ft 2.01 to 2.09.