So while changing gears from 1st to 2nd today, i released the cluth way to fast. I expected the car to jolt a little bit, but for like a good 3 or 4 seconds the cars rpm was bouncing up and down like real hard. Any ideas wat happened? Did I mess something up?

 

Were you heavy on the gas? Loosing traction?

 

1) Your clutch was slipping.
2) You broke rear traction.

Most likely #1.

 

Sounds like axle tramp. I've had it happen on older V8 cars. Not sure if you can induce it on an S2000.

 

It happens on many cars under light throttle in 1st gear. I have never heard of it happening in 2nd.

I personally believe it is too much play in the driveline. I have had mine checked and been told it was within specs so I believe that Honda has specs that allow for too much play.

 

I used to have that condition in a Dune Buggy I had years ago (VW Beetle drivetrain & chassis) during heavy launches. I don't know the exact cause but I was told that I could get rid of the problem by stiffening up the transmission mounts. It worked, and I never had the problem again.

Check your motor, transmission and differential mounts. If they are not intact, this might cause enough play in your drivetrain to put your car in harmonic oscillation.

 

He's right in that harmonic oscillation is usually caused by excess movement in the driveline which brings us right back to the fact that I think Honda allows excess driveline lash.

 

Where did it seem like the shaking was stronger at? The rear?

 

It wasnt specifically teh rear that was shaking, the whole car was just thrusting back and forth, it was enough to get my head shakin. It happened because i let go of the clutch way to fast in my gear change into second. I drove the car today and everything seemed fine.

 

I had that happen to me before. Kinda like riding a bull or having hydraulics feeling It happened while gassing lightly... I quickly released the gas and left it in neutral for it to stop and then threw it back in gear to drive off... this happened a looong time ago..