What's going on everyone? Was wondering what's the best gear ratio for 450whp. Sold my diff with 4.56 gears since I got rid of my supercharger and bought a turbo kit. Was wondering if 3.90s would be great to keep me in boost longer or if I should just stick with the oem 4.10s. Planning on having a diff stiffened up to hold the power without dropping 4 grand.

 

You cant go wrong with either. But 3.90 would probably be my choice, especially if your rev limit is limited to near 8k.

 

i personally just swapped from oem gears to 4.56 gears, car makes right around 400whp, went 12.0 at 115 with oem gears but it feels much more aggressive now with the shorter gears. I love how it feels now, but I rev mine to 9100 rpms, and if you drive it on the highway at all I would just stick with 4.10 oem gears. with 285 35 18 tires on the rear at 70mph I'm at 4300-4400 rpms now

 

285/35/18 is a tall tire. 285/30 would be the stock equivalent. So your actually running a bit closer to stock gear ratio then you might think. Have you done the break down on the Turn 0 calculator to see where your at?

 

Calculator says it should be 72 mph @ 4000 rpm with the 4.56, with stock 4.1 rear it's 80 mph.

 

is that ap2? because with my ap1 im around 72 @ 4000.

 

I autocross and would want the 3.9 to get more speed in 2nd.

 

what about the 4.77 gearing im looking into gears for a supercharged setup and want to make up for the lack of torque until the vtec kicks in around 4k ill have it set.

 

4.10s under 550hp IMO

 

Correct Joey!