Hello
I noticed my speedometer is wrong via GPS - and to my knowledge, the former owner had final drive installed at one point. First, I suspected the dif is still on the car (although he said it isn't anymore) and then I found this near the ECU / under the steering wheel.
Is this some sort of speedometer calibration tool?






Later edit: it's a blinker module. Found a serial and googled it.

 

How wrong is your speedo? Is the car on oem sized tires?

 

All tires are AP1 stock, 225 on the rears (but not bridgestone).
At 60 km/h on the GPS I have 50 km/h and 3000 rpm is 4th gear.
On the highway, I had 124km/h, and my friend with a stock FN2 on cruise control had 110 km/h. 6th gear @ 124 km/h = ~3800-4000 rpm.
Also, if I put it in neutral at like 60 km/h, it doesn't drop to 50 (well it does, eventually), but it seems to have no immediate effect.

I managed to go top down up to 264 km/h @ 8600 rpm and kept on going to 270 km/h and it was still going.
I have a CAI, Test pipe, catback, fidanza flywheel, bigger throttle body. But still, that's insane.
According to my calculations, I have the 5.1 final drive, the real speed would have been ~ 200 km/h.

I really think I have the 5.1 final drive...

 

If you statement is correct, you have 4.77s on your car.
Also 5.1 are pretty rare.

 

100% correct.
Speedometer shows 60 km/h and 3000 rpm is 4th gear.
GPS shows 50 km/h.

I used this: http://www.turnzero.com/technical_re...ear_calculator
If I enter honda s2000 00-03, Axle ratio 4.77, and Engine max speed (RPM) of 3000, the Maximum speed in 4th gear: 33.5 mph (53.9 km/h).
If I put axle ratio to 5.1, the max speed @ 3000 rpm in 4th gear is 31.3 mph (50.3 km/h)

4.77s? Don't know what the s is about, sorry.

 

He's just using the "s" to imply it's plural. I haven't looked at that gear calculator, but keep in mind the s2000 has a secondary reduction gear in addition to the standard gear ratios and final drive. If I remember correctly, a 4.44 is equivalent to a 5.1 without a secondary reduction gear.

 

Well... I guess I have to get a yellow box. Thanks for the replies.

 

thats pretty intesne if yur runnning 5.1 gears because i have 4.56 and my friend as 4.77's and both are revving pretty high on the freeway and well that little yellow box is to recalibrate your speeds, you can adjust it just look it up on the search they have a how to on this. i cant find it at the moment but just look for it.
its just if you disconnect that yellow box and dont run the wires right, your speedo will mark 0 the whole time and it ont add miles, it will show how much gas you had the very last time you pulled out the box and it'll make your car run a littl weird like bogging down.

 

I disconnected the box I had, and the speedo was indicating the speed. The one I have is a blinker module, it's just... yellow
I won't know for sure until I get the yellow box calibration, so far it's 4.77 (according to my calculations)