Ok I got a pro allmotor car with a b20 vtec making close to 260hp and just over 200/lbs of torque I got a 4.5 final drive and it drops alot of rpm's in between gears and its got 24.5/8/13 tires
what final drive do u guys recomend?

 

Final drive does not affect RPM drop. If you're looking for a smaller RPM drop to keep you in the powerband, then you will need to change your gear ratios. Either by OEM gears, or a close gear set.

 

Final drive do affect rpms a bit, but not as much in the broad spectrum of things. The purpose is to keep the engine in the correct powerband a bit longer. If you're simply crusing, it shouldn't really matter. If attempting drive with more "spirit", then you would need to shift a bit faster to get the full affect. 4.5 is not bad at all really, its a matter of you getting adjusted to it. If you weren't sure why they are used, why did you purchase one?

 

Changing the final drive can help you accelerate quicker (less top speed), but your rpm drop will stay the same.
You could always swap in a 4.7 ITR final drive or raise your shift points so you fall in your "sweet spot".
If your still dropping too low after that,its time to open the tranny and do some gear swapping.
Or just get a whole ITR tranny!

 

I have this final drive because I purchased a dogbox off a friend of mine but in every gear drops almost 3000rpm and I'm reving it to 9500rpm
here are the gear ratios
1st - 3.18
2nd - 2.07
3rd 1.45
4th 1.09
4.5 final drive

 

Put shorter gears in if you're not happy with the RPM drop.

 

ok cool thanks

 

I ran a 4.7 in my coupe.