I was woundering what the best final gear ratio would be for road course and highway. i was looking at 3.90 final 4.10 final and a 4.30 final. With the 3.90 final with stock transmission the top speed is 191mph @ 7500 rpm. The 4.10 final the top speed is 181 mph @ 7500 rpm and the 4.30 final top speed is 173mph @ 7500 rpm. which do you think would be the best for road course racing and highway.

 

I can just about guarantee you that the only thing that is an issue here is gas milage and revs per mile.

The car can't reach the top speed of a 3.9 and probably a 4.1 end gear. If you have a modded TII then you can probably reach rop speed in a 4.3 end gear but then you have to have purchased a 4.3 diff or be using the wearker N/a diff.

 

i dont have anything done to it yet but i was thinking about going with the gears first. i need better gears because the fastet i have been in my rx is 137mph and it was floored and i lost to a civic. I NEED MORE SPEED!!!

 

I'm assuming that was on a track, since only a brainless moron would actually be racing someone on a public road at that speed...

Without strapping a rocket to it, no NA is going to get anywhere near 173mph, let alone 181 or 191, so discussing gear ratios with regard to top speed is pointless. Spend your money in areas that will actually make a worthwhile difference.

 

If it's an NA you'll need at least a 4:88 for a track car. The 5:12 is actually the hot setup. Both are spendy.

 

4.88 5.12 damn I thought I was a maniac wanting 4.55 for my turbo vert. 5.12 gears would rock in a gutted NA. You would definalty hit 8k in 5th gear with those bad boys.

 

get some more power out of the motor and stop worrying about your gears right now

 

Maybe with a ported motor. Our ITS car only sees 120-130mph at most tracks. Road America with it's LONG straight is an exception. We usually see 6500-7000 in 5th (.756) with 225/50-15 Kumho V710s depending on the track.

Where did you find a 4.55 gear for the turbo housing?