The car is a 12 GS.

Installed B&B Fusion, got a little drone@1500 with valves open, but tolerable. With valves closed, nice quiet ride.

Just installed ARH 1 3/4 with catted X pipe, got terrible drone@1500. Tried the following:

1. Put silencers after the cat - no drone reduction.
2. Wrap the mid pipes - 5% drone reduction.
3. Welded SS plates between pipes at the front and back - 50% drone reduction.

Thought I share the experience.

Continue searching other methods like auger exhaust baffle.

New ideas are welcome, but don't tell me to change axle back.

Cell phone photo:

 

If you have headers and mufflers you are going to get drone and nothing will make it go away*.

* - well this is a bit of a lie. If you built some massive custom resonator box that you don't have room for that was build to cancel out the frequency custom to your needs then yes you could get rid of it.

........which is why I plan to stay OEM mufflers and do headers with cutouts so I can pick when to be loud.

 

Drone and B&B seem to be interchangeable words. I had B&B 3" cat backs on my "96" CE and when my ears stopped bleeding I sold the car! Now I have Corsa Sports and couldn't be happier.

 

Did the exhaust pipe wrap help with heat? If so, what kind of wrap is it?

 

I recommend you remove the wrap if you only got a slight improvement. It can shorten the life of your mid pipe. I don't blame you for trying to find a solution. Last car I owned had it, and it is obnoxious.

 

A performance exhaust with headers. Will have some drone. You knew this beforehand. Many members complain of drone when they change their exhaust systems. I think it's hilarious. What most people call drone is music to my ears. A performance exhaust should sound like performance! Maybe put the stock system back on. IMO of course.

 

I have been a muscle car guy and gearhead for ~40 years and the dreaded exhaust drone has been my BIGGEST annoyance. If you have an exhaust drone, then you need to reconfigure the exhaust system itself. The drone will penetrate any soundproofing. Believe me, I've tried EVERYTHING. I spent oodles of money trying to get rid of drones in different cars. My last muscle car was a '68 Camaro with 550hp big-block. I went through 5 different sets of mufflers, and 3 sets of pipes before I found a sound that I could live with.

A few years ago, I had detailed conversations with some of the major aftermarket producers (Flowmaster, Corsa and others). They were all very nice and gave me simplified science lessons about how the sound waves bounce around from the engine all the way through the exhaust. Basically, whenever you change out any exhaust component(s), you run a risk of introducing drone.

Good luck with your car. Bottom line - you're now in the 'trial and error' zone, where you just need to keep swapping parts until you find that Goldilocks exhaust note.

My '08 Coupe has the NPP and it is one of the best-sounding exhausts I have ever had. It's dead quiet at cruise, but barks when you hammer the throttle.

 

the "only" reason I didn't go this route with my combo is this said bark is not loud enough for me.

 

Since the wrap did not reduce the drone, so I took it off today. You can clearly where I welded two SS plates.

I also started thinking maybe it is time to change B&B Fusion to some other brands such as Corsa Sport. I looked at Corsa web page and have questions:

1. I have ARH 1 3/4 with 3 x 2.5 catted X pipe, and I want the polished 4" axle back tips. Corsa Sport does not seem to have 2.5" axle back with polished 4" tips?

2. Corsa claims that there is no drone at cruising speed. What at non-cruising speeds?

 

I have corsa with longtubes and no cats, no drone. Ever. At any speed.

There is only one true solution to drone. A Helmholtz Resonator (quarter wave resonator). It will stop drone. It is a section of pipe welded in at a 90* angle before the mufflers. The pipe is capped at the end. You have to find the Hz of the drone and tune the length of pipe to match that frequency.

Do some googling. Lots of information on it. That's your fix.

 

I agree. helped my 840 hp Camaro lose the drone

 

I think the 50% reduction with the plates is great. That would be a huge improvement.

 

what type of plates you talking about I am a little confused I don't see any .

 

Circled in red.

 

They don't know what Drone" means...

 

Drone is caused by vibration, you were able to reduce it by 50% with your plates. I think if you were to tie the over axle pipes together with some cross bracing you would achieve you goal.

 

All noise is vibration. Therefore, drone is technically vibration. But not in the definition you are using. More plates won't help.

And there is also a difference between "drone" and "noise". Noise from a performance exhaust is expected and normal. Drone is a certain frequency caused by exhaust design and air velocity through the pipes.

Drone isn't music. It is a dull, low roar that overcomes the ears and causes headaches. My "performance exhaust with headers" has lots of wonderful noise, and NO DRONE.

 

I did some research - Helmholtz Resonator aka J pipe aka 1/4 resonance pipe. Frequency@1500 needs 33.75" of J pipe to cancel the drone. I will talk to my mechanic to draw up a plan to weld the J pipes.

J pipe looks like:

 

Same here,with ar's & stingers=No Drone in the cockpit.Just a great sound.

 

I personally loved the short burst of drone I got between 1500 and 2000 RPMs in my 1998 Z28 427 with SLP longtubes, high flow cats, and SLP Loudmouth. I REALLY loved driving it through parking garages and setting off car alarms with a blip of the throttle. I've never heard a louder car, especially with the cam thumping and loping. My current Corvette has the Corsa extremes and I don't get any harmonic vibration (drone). What most of you think is "drone" is the sound of the exhaust or you're keeping your car in the harmonic vibration sweet spot, and need to shift gears.

Most people either don't know what drone is or don't know what a muscle car should sound like. Those of you wanting dead quiet cruising and noise on demand really should just go back to stock, NPP, or a Lincoln Continental.