Wind Buffeting Modification Photos

[larry4pyro]

Just got back from the dealer where they did mods to the battery and side mirrors. There's been a number of posts on the battery enhancement so there isn't much to say except if you get it, the dealer tops off your gas tank, so you might want to keep that in mind.

The real mod I was interested in was the one to reduce wind buffeting. I live near the beach and like to drive the streets with the window down. My previous car was a roadster which I never drove with the top up, so driving around in a car with the windows up is a bit claustrophobic for me.

This modification consisted of two parts; a new "skull cap" over the mirrors and a different plastic piece at the A piller. Aero mods were made to both pieces to reduce the wind buffeting (see photos). There was no charge for this mod. Needless to say, these changes are made at the expense of aero efficiency, how much, I really won't know for some time. However, I'm happy to report that this modification greatly reduces the buffetting. I drove up to 55 mph with the driver's side window down without the buffeting noise. There was still, a tiny bit of pressure buffeting that was just barely noticable. I think this can be pretty much eliminated by cracking open other windows.

Both.jpgA Piller.jpgBoth2.jpg

[wishman]

Looks good, did they let you keep the old skull cap? Where did you get the blind side mirror? I always have to roll down two windows to offset the buffetting, even then i don't roll it down all the way.

[BAZINGA]

my biggest complaint with the Volt has been the horrible "air hammer" acoustic resonance a speeds over 40 MPH, yes you can configure the rear windows to cut it but it was really annoying to my ears.

I'll be stopping by my dealer tomorrow, is this another Customer Satisfaction enhancement?

I can't thank you enough for sharing this and GM for addressing this annoyance.

[larry4pyro]

Regarding the skull cap, the dealer had to keep it as part of the warranty action. I got the little convex mirrors at Pep Boys, they really don't work that well as you have to "refocus" on the mirrors for them to be useful, but they are better than nothing.

In regards to the question of is this a Customer Satisfaction enhancement? I believe the answer is yes, I was not charged for this change. I believe the information on the mod is in Service bullitin B6804 9090. The new mirror kit part number is 22778043. The dealer has to paint the skull cap to match the car.

[knorc]

The reason for the thumping is that having open windows really messes with the aerodynamics of the car. Much better to keep the windows up and the A/C on.

[wishman]

How does it look further away or maybe front of car view. I'm trying to see if the plastic on the A pillar is a bit aftermarket looking or if it blends in nicely.

[DonC]

Great information.

[dwl]

It's worth noting that the replacement skullcaps are less aerodynamic. Which is why they reduce the buffeting. Worth it for some people. But if it doesn't affect you, you're better off with the originals.

[larry4pyro]

It's worth noting that the replacement skullcaps are less aerodynamic. Which is why they reduce the buffeting. Worth it for some people. But if it doesn't affect you, you're better off with the originals.

I agree. I don't know what's worse, the mods or the fact that the windows are open, but aero efficiency is definitely reduced. On the other hand, you only live once, so if you enjoy driving with the fresh air blowing through the windows, than I say go for it.

[dwl]

Myself, I often drive with the front driver's side window all of the way down and the rear passenger's side window cracked maybe 2 inches. That completely elimiates any buffeting for me and I find it to be more than enough airflow. But I rarely drive with my windows down on the freeway. I try to keep my windows up once I hit about 50mph because that's about when drag really starts to affect efficiency. 45 and below, I enjoy the breeze and any minor losses that come with it. Maybe at 70mph it'd be a different story and I'd still experience noticable buffeting. I'll probably give it a shot next time I drive that fast.