I have seen some good treads on gearing and accelleration. I have also seen that there are some final drive gear sets available for the S. So, I was wondering...

What would happen if you lowered the final drive a good bit and then raised 6th gear to make it a true overdrive? Is something like this possible? And would it harm drivability more than it would improve acceleration?

 

Yes it is possible to do what you are thinking, but depending on how much you change your ratios it may harm drivability more than you want. I don't know of anyone that makes different individual gears for the S2000 transmission( i.e. 6th). You could try and guess a different ratio for 6th but it would be very difficult to get it right the first time. The only thing that might happen that you might not like is that if you change your final drive from 4.1(i think) to say 4.5 or higher you will accelerate quicker in all gears, but if you "raised" 6th enough it might be like "hitting a brick wall when shifting into that gear. In other words there might be such a large gap between 5th and 6th that you would have to leave it in 5th longer until you are going the right speed for 6th. Thus almost defeating the purpose of getting the raised 6th. IIRC ATS makes a different final mission gear that sell for just under $2000. It will improve acceleration in all gears like you want, but it won't raise your 6th.

 

Any manufacturers reading, and that will get to it before me (within a couple years likely) Im looking for a .65:1 6th ratio which equates to about 2850 RPM in 6th at 60mph with a 4.44:1 final.

VTEC would hit 6th at ~127 MPH and that just happens to be right about 9000RPM in 5th at the original .97ratio

So if anything else maybe a 5th of .92:1 because that will leave you with a shift at 135 from 5th to 6th

and 4th is already shifting at 107 MPH and that leaves you at 7100rpm in 5th, a nice overlap.

Top speed would be around 190 assuming you have the power . . .

On second thought maybe a .70:1 6th and a .92 5th so the shift at 135 leaves you at 6880RPM in 6th and a top speed of 177 and about 3000 RPM @60 MPH in 6th

This is all at a 4.44:1 final