I have undertaken to delete my posts of any content here since the Management here has made this an unfriendly place for me and the club I founded and am President of, the S2000 Club of America, Inc. and they have claimed that my words have somehow become THEIR property and I think that's pretty uncool. If you would like to read whatever post, please contact me at greg@s2kca.com. Thanks

 

When you say hard load do you mean hard acceleration load or hard lateral load (i.e. cornering)? What mods do you have in the area of suspension?

 

What RPM range seems to aggravate it, I assume you meant engine load rather than cornering load?

is it a high frequency or low frequency vibration?


Is there any other type of noise with it, like metal grinding?

A major mechanical problem should be repeatable, like if gears/bearings/shafts/clutch were messed up.

Quite possibly your exaust has taken up a resonance w/ the engine and rubs or something? Maybe 'spirited' driving has worked something loose? A mounting bolt/flange?

 

I have undertaken to delete my posts of any content here since the Management here has made this an unfriendly place for me and the club I founded and am President of, the S2000 Club of America, Inc. and they have claimed that my words have somehow become THEIR property and I think that's pretty uncool. If you would like to read whatever post, please contact me at greg@s2kca.com. Thanks

 

[QUOTE]Originally posted by gregstevens
[B]The problem with all of this is that it isn't consistent.

 

Using my old rule, "Always check the last thing you fixed", I have two thoughts. One, tire balance or some other tire installation thing. Two, if these Kuhmo's are really as heavy as some say, you may have slightly changed the rpm point of engine bog. Just a thought...

 

Greg,
You describe the 'vibration' to be coming from the rear (1/2?) of the car, but I wouldn't discount the intake as some sounds can be deceiving. Is it more or less noticeable with the top up? And what kind of intensity is it, can you feel it? A low frequency vibration that you can feel in the seat could be attributed to the engine stumbling, maybe a side effect of the mods - I hate to be like a dealer and point to the mods first though. I always try to get straight to the problem, if a mod gets in the way it does and if it doesn't, well, it doesn't.

It may be possible that the ECU (Its not OEM is it?) is producing a "racing" type of map for fuel and spark or even causing an erratic timing retard after sensing knock. Timing changes that don't have a slow recovery (maybe on purpose) could cause a stumble symptom if its not too bad, and then a hesitation when worse.

If this is happening below 2kRPM and in to high of a gear thats of course normal for a low torque engine, but I know you are one of the more experienced and qualified drivers on the board , so its gotta be something else that sounds similar.
I dont think tires would change a bog characteristic in an engine just because of the gearing and clutch the power is transferred through.

 

It is not as though the engine is bogging and the only thing the heavier Kuhmo's would do is slow the car down. It is a vibration that can be felt through the entire car. It is not the Mugen ECU either. I have been in a few other S2000's with the ECU and nothing felt like this. The only other thing I could think of is an engine or tranny mount that may be going.

Greg, keep us posted!

Brian.

 

Well I just got a vibration. Though I think I figured it out.

I just installed Mingsters CAI though it didn't start right after that.(interesting enough) It only happens at high speeds in the higher RPM range. Usually 2nd and 3rd.(in VTEC) I said ok something has changed!!!! I checked over the rear tires looking for those weights they put on.......At least one is missing!

Well I guess I will live with it for another month or 2 till winter sets in and I put on my snowies(most likely!).

So to Greg and others check your wheel weights for missing ones.