Ive hear alot about changing the gears in the S2k ive got an 04 and i was wondering what the advantages and dis advantages are on swapping gears. What is stock gear size and what should i change to? also does it drop the top speed of the S or increase it? Thanks!

 

first, enter your VIN in your profile when you get a few so it shows you as an owner and not an enthusiast.

second, search, brother, search. the questions are you are asking have been asked time and time again. instead of waiting to hear the same thing, find that search box and type in something like 4.77 or 4.57 or 4.44.

short answer ... stock is 4.10. it slows down the top speed marginally but why would you need to go over 150? and it adds acceleration by shortening the time it takes to hit VTEC and increasing the slope of your curve. but it adds no actual power. finally, it's prob the best performance gain for the buck.

 

It is my understanding that on an '04, due to the change in ratio of the secondary tranny output shaft, gears 1 through 4 is "like" having a 4.44 rear end on previous cars. They changed gear 5 and 6 so that the cruising rpm in those gears are similar to previous cars. So, if you put a new gear into the rear end of an '04, you will get even more mechanical advantage in 1 - 4 and lose the cruising characteristics that Honda meant 5 and 6 to keep. If you understand this and this is what you really want, then go for it.

 

Anway, I've been thinking about the same thing for the 2004.

So I took an app someone built and revamped it for use for 2004's (8200rpm redline, new drive shaft ratio, different 5th & 6th gear ratios and different sized rear tires).
http://www.revillusions.com/s2000/rearwhee..._calc_2004.html

Anyway, here's an idea between a stock 2004 w/4.1 final drive compared to 2004 w/4.57

65mph in 6th gear (tire deformation calculated)
4.10 - 3358 rpm's
4.57 - 3743 rmp's

Top Speed in each gear (8200rpm)

Gear -- 4.10 -- 4.57
1st -- 38.65 -- 34.67
2nd -- 59.21 -- 53.12
3rd -- 81.76 -- 73.35
4th -- 104.29 -- 93.57
5th -- 128.54 -- 115.32
6th -- 158.69 -- 142.37

I recently realized that redline is actually at 8000rpms. Not having driven a '04 to redline I'm not even sure if it goes past 8000 to 8200 before fuel cutsoff.

But, you can just use the above app to calculate again at 8000rpm.