I just got my new engine in and have been playing around with the fuel pressure and timing trying to get it tuned so I can drive it till I get it dynoed. While tuning I have noticed a very loud and high pitched noise from the engine bay between 7300-7600 RPM. Sounds like a high frequency buzz that can be felt in the whole car. It doesnt last long, and the car continues to pull hard, it just makes a terrible sound. The noise didnt change with fuel pressure or timing. The bottom end was also balanced by Laskey racing so I dont think its and engine balance issue. Any ideas of what I should be looking for would be greatly appreciated.

 

Maybe some sheet metal resonating? Clutch maybe?

 

its not tuned.
that's one issue do you have a wideband installed to see if messing with fuel pressure is doing you any good?

 

Found it! Pretty much loose sheet metal as u said. Lost a nut from the driver side torque mount. Must have not tightened it enough. Oops... And no wideband yet, but I was thinking about getting one that data logs and use it instead of a dyno. Kinda like the idea of figuring it out. Thanks for the advise.

 

You need more data than just AFRs to tune. Get any wideband, choose your flavor of engine management (NepTune, Hondata, etc) and get to work.