Just looking to see which is "better" or should a combination be used. My s2k is a daily driver and usually I cruise on the highway at 160 kms and travel for an hour at a time at that speed. Now the car is also tracked every so often and I would like to possibly do one of the suggested or if not both.

in switching to a 4.4 or any other fd will make the car accelerate faster than stock (if I am not mistaken), will the same apply for the 4.77 diff? What would the rpm range be with a 4.4 at 160 kms?

Now what about the same senario with a 4.77 diff and stock fd? how much different would accleration be?

same scenario with a 4.4 fd and 4.77 diff?

 

FD as in "final drive" is the exact same thing as the diff gearing. You change the fd, you change the diff. It's like trying to have two different 1st gears.

Regarding which is better, 4.4 or 4.77, I don't have much opinion on that sorry.

 

I think 4.56 are probabl the best compromise. Im not sure if ricks is still selling thoes. Its up to you are you willing to get worse gas milage to aheive better performance.

 

OEM final drive ratio is 1 : 4.10

Maybe ^AnDre^ is mixing reinforced diff with final drive?

There is a combination possible :
An OEM diff with non-OEM FD gears
A reinforced diff with OEM FD gears
A reinforced diff with non-OEM FD gears.

The reinforced diff alone does nothing to the FD as it is a reinforced diff
The reinforced parts are the bearing caps and the bolts that tighten the bearing caps.

Most aftermarket ratio's are:
1 : 4.44
1 : 4.57
1 : 4.77

Yes, a higher ratio FD will make the car accelerate faster (believe me ) but you also run out of gear faster and the revs go up at the same speed.
Its easy to figure out the difference in revs once you know the OEM FD ratio
The 1 : 4.57 ratio is considered by many (and me now I got them) to be the ratio the car should have been build with.
I have not driven any other S2000 with another FD, so my opinion is bias.
(apart from my own with the OEM gears)
Others will disagree without a doubt