How to reduce exhaust drone?

Robinhood · March 1, 2003

Recently replaced the stock muffler with a Borla and now have a love-hate relationship with this new muffler. Love the sound both at idle and at acceleration but hate the constant interior drone at cruising speed (approx 1500-1700 rpm). Anyone have any first hand results with soundproofing the interior cab and floor to reduce exhaust drone? How effective would this be if at all?

OneFastSilverado · March 1, 2003

I had this problem too. I had the muffler shop move the muffler back some so it's not directly under the cab. It should quiet the interior to tolerable levels. Give it a try or ponder other options.

Chris97K1500 · March 1, 2003

I haven't done any sound proofing in a truck before, but I've done it many times in old Big Block and High Performance SB's. My dad had a 65 Chevy II with a 327 that you couldn't hear yourself inside the car. We used a heat shield/noise deadening padding from JCWhitney. The part # was 25UV0705N. Go to their website and type the # in, it'll explain what features it has. It was quality stuff. One other thing, is this Borla on your Truck or Tahoe? When I've just replaced stock mufflers on trucks I like to put the muffler as far back from the cab as possible, totally under the bed if I can. That takes some of the cab noise away, that may not be possible in your case. What type of Borla muffler is it? I will be replacing the stock muffler on my truck in early April, when I get a chance. My Borla muffler is more of a Universal application, it was about $200. Just curious as to what you put in your truck. Chris

Robinhood · March 1, 2003

Chris97K1500,

Thanks for the product info from JCWhitney. I was thinking about an asphalt based sound dampening sheet like Dynamat or a lightweight vinyl sheet at www.partsexpress.com but your product is much cheaper.

My muffler is Borla's universal fit muffler also. We located it in the stock position near the rear axle, not closer to the extended cab on the truck. It was smaller than the stock muffler and just sleeved the pipe in both front and rear of the Borla. The rest of the exhaust system was left untouched using the same tail pipe and exit behind the rear wheel making sure the end of the pipe extended past the lower edge of the bed.

Chris97K1500 · March 2, 2003

Well, I hope mine doesn't resonate that bad. Usually mufflers have a "break in" period. Mine was actually on my Toyota for a month or so, then the engine blew. So mine might be a little worn in. I'm pretty sure we have the same muffler, it isn't as big as the stock one for sure. Plus, I don't know if it will make any difference that the stock exhaust is a dual in, where I think yours is a single in. I'll find out in April! Thanks, Chris