fasterplease

I had a sweet track day this weekend at Fontana. Tons of fun, another good Speed Ventures day.

When I was running at the fastest parts of the track (> 120mph) I was getting ferocious wind buffeting in a number of places: the hood was flapping at the corners, the rear stock "wing" was flapping which is all to be expected. The thing that was actually holding me back from getting much past 130mph (there was more grip there) before turning into the oval was my head was shaking so bad from the wind I couldn't read the markers for turning in! Crazy!

Has anyone experienced this? And if so, any recommendations to tame the buffeting?

Thanks!

danzcool

The hood is well know for shuttering at high speed, The best you can do without hood pins is to adjust the rubber bumpers, screw in or out until the hood is solid on both sides and no to out of wack on aligning with the fenders. I've also heard that some self adhesive weatherstripping (from home depot or lowes) along the top of the radiator cover helps keep the hood from moving.
Are you sure it's all from wind? How long ago were your wheels last balanced?

UPRSharad

Yeah, I put UPR hood pins on my car because it had crazy flutter at speed!!

Didn't have any trouble with my head shaking with my helmet on at 130mph at Sebring. Not sure what that's about.

fasterplease

I know, it's weird right? I could reduce the amount of vibration by opening the visor on my helmet.

Also, I removed the back seats so the car is open through to the trunk. Any chance that'd do it?

UPRSharad

I wouldn't think so. The open track cars run with their windows down and no back seat. It's definitely a weird situation. I rep UPR on almost 20 forums and this is the first I've heard of this phenomenon.

427Roush

Assuming weather conditions were stable, I've only heard of wind buffeting from some Porsche drivers on track. Perhaps due to poor aerodynamics or even spoiled pansie owners.
I've experienced this only once with a closed face helmet and a neck brace that I borrowed from a fellow driver, as I left my open face helmet at home.
The only suggestion would be to try a rear seat delete or put the rear seats back. Although, if you've removed the seats and carpets for racing this would not apply.
I have hood pins and still see flutter but feel secure that my hood won't blow off into my windshield.
The weather stripping by danzcool sounds interesting but I would be concerned about heat soak with my blower.
Good luck.

Grant 302

I think that's the issue. I've run one session with the rear seats down...never again.

Norm Peterson

If this was the event that had a bunch of 5th gen Camaros out there running (including a crashed ZL1), nobody who chimed in over on Camaro5 mentioned any buffeting whatsoever, nor did any of the videos posted so far show any. I might inquire, though.

I'm inclined to agree with the rear seat situation being the problem - what you do aerodynamically behind an open driver's window still matters. I can get into a couple of unpleasant conditions in most sedans at normal driving speeds - a heavy throbbing if one rear window is open the right (wrong?) amount, or wind blowing right into my ear if I don't lower the rear window about half as much as I lowered my front seat window.


Norm

Norm Peterson

What I heard was that it was a little windy, which probably explains the buffeting not occurring over the entire course. But nobody who has responded so far was noticing buffeting anywhere, all the way up toward or slightly beyond 150. That rear seat thing is looking better all the time.


Norm

fasterplease

Thanks for checking that out and providing feedback. The seats will be going back in, which will certainly reduce my cred down at Adam's time attack!!! Although, I won't know for sure if it is cured after the next track day because I don't reach 120mph out at Buttonwillow!