Exhaust drone

[Garand1]

I've got 1500 miles on my 95 since I brought it home last fall and I'm going to try to mitigate some of the exhaust drone that I have. My exhaust system is OEM cats, True duals with no x or h pipe, back to Flowmaster Super 10s, and out to std rectangle tips. It drones pretty good, though it doesn't bother my wife at all, after 3 or 4 hours in it, it starts to drive me bonkers. I've done a bunch of reading the past week and while I LOVE the sound of the Super 10s, I'm going to try to lessen the drone. I had read about the Blockit sound deadening kits. I decided to try to make something like that. Ive got some 1" foam board that's foil lined on both sides. I cut it up to fit the floor of the rear compartment and made pieces to fit behind the seats and took it for a test drive. I have say Im pretty impressed with the result. So, I'm going to put a bottom layer of corrugated plastic on the bottom foam board and want original type carpeting on the top. The average sound level on my phone before was, id say, an average of 86/87 decibels, With just the foam board installed, I was seeing 80 to 82. While there was still a drone, it was different, Id say the frequency was lower and less .............obnoxious , I would say it was improved by 50%, much easier to carry on a conversation, and music was able to be listened to at a slightly lower volume. I may try a couple of other things along with this, but its definitely a start.

 

[vintagevetter]

I've got 1500 miles on my 95 since I brought it home last fall and I'm going to try to mitigate some of the exhaust drone that I have. My exhaust system is OEM cats, True duals with no x or h pipe, back to Flowmaster Super 10s, and out to std rectangle tips. It drones pretty good, though it doesn't bother my wife at all, after 3 or 4 hours in it, it starts to drive me bonkers. I've done a bunch of reading the past week and while I LOVE the sound of the Super 10s, I'm going to try to lessen the drone. I had read about the Blockit sound deadening kits. I decided to try to make something like that. Ive got some 1" foam board that's foil lined on both sides. I cut it up to fit the floor of the rear compartment and made pieces to fit behind the seats and took it for a test drive. I have say Im pretty impressed with the result. So, I'm going to put a bottom layer of corrugated plastic on the bottom foam board and want original type carpeting on the top. The average sound level on my phone before was, id say, an average of 86/87 decibels, With just the foam board installed, I was seeing 80 to 82. While there was still a drone, it was different, Id say the frequency was lower and less .............obnoxious , I would say it was improved by 50%, much easier to carry on a conversation, and music was able to be listened to at a slightly lower volume. I may try a couple of other things along with this, but its definitely a start.

When I bought my 94, coupe back in 2003, it had a set of Flowmasters on it. They should of called them "Drone Masters" The drone was the worst right at cruising speed 70 MPH in 6th gear. Droning exhaust seems to be the most noticeable on coupes, as they seem to act like a sounding board. Not nearly the problem with convertibles with the soft top up. So I went to Corvette Central, and order a set of chambered-exhaust, which are designed similar to the C2 side pipe mufflers. That system got rid of the drone completely, and still produced a good exhaust tone, without being obnoxiously loud. Check into it.

 

[GWinter]

I have a 90 convertible that I built my own cat back system on . I went to three in OD stainless pipe and built the mufflers using turbo mufflers as a pattern . I ended up with some drone but not real bad. I did a lot of reading on exhaust systems and the larger pipes can cause drone. I wonder if an exhaust wrap would help cut it.

 

[Toms007]

When I bought my 94, back in 2004, I wanted to upgrade the exhaust. I did a tremendous amount of research before deciding that Corsa was the only one that didn't have some amount of drone. I installed it, never wished for anything different. The sound was awesome and ZERO drone at any speed or RPM.