Discussion Forum - Northstar Chevelle Club

Jon H · 1K+ Club

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Derek69SS · Founding Member

Is it a specific RPM range drone, or do you want it quieter at all RPM?

Jon H · 1K+ Club

The drone is across the whole RPM range but only at a constant speed. Accelerating slow or fast is not an issue but when I get to a constant between 10-65 mph the drone kicks in. I am told there is not enough air flow at constant speed causing the drone, while under acceleration the air is being forced through the mufflers eliminating the drone. I am using a new Pypes Turbo Pro muffler. Pypes suggests going to a straight through muffler design. Oddly the big advertisinghype about the new muffler is that it is drone and resonance free.

Derek69SS · Founding Member

I used Pypes "Race Pro" straight through mufflers which I do not have any problem with drone.
At the time, they were advertised as their quietest muffler.

If it was a specific RPM range, I'd suggest a J-pipe, but that won't work for you if it's all across the RPM range.

Jon H · 1K+ Club

Thanks Derek. I went for a ride with Stan yesterday and he has Race Pros on his. Not a bad sound. The more exhaust companies I talk to the more I believe the straightt through is going to work better for me than a turbo. I have ridden with a number of club members that have turbo set ups that are very nice sounding but since this Pypes Turbo Pro is new to their line I am thinking they is my problem. Irritates me that I waited for three months for them to get off the boat and then have this result. Live and learn. Thinking I will be moving on to a straight through muffler come spring.

Lost in the 60s · President

I have Race Pros also on my Camaro and no drone.

I have Thrush chambered mufflers on my '38 and didn't have a drone, but the car is small and tinny which seemed to transfer the exhaust noise, so I wrapped the mufflers with header wrap and it did get quieter. Don't know if that would quiet the drone, but it's a fairly easy and cheap method to try.

My wife said it was still too loud for the trip to Gatlinburg a few years ago, so I wrapped the entire system and it was much quieter to me.

Pypes isn't willing to stand behind their claim of drone free and send you a pair of the Race Pros to try ?

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