Exhaust Drone?

[lowjack]

Drone and resonance can be made less noticable by adding resonators which do not hinder the airflow. The issue we found with the Z was not having enough room to weld them inline with system. (I have 6 smaller resonators rather than one/two large mufflers)

Some cars are very difficult to tune to get rid of that drone/resonance. It usually varies by engine type, with V8 hitting it in the 1500 to 1800 rpm range, V6s in the 2000-2500 rpm range. It has been a thorn in the side of Every Exhaust Mfg. for years. Every engine made has a natural resonant frequency. The reason original equipment mufflers are so large and restrictive is a result of manufacturers attempting to control sound levels at the resonant rpm, ussaly decreasing performance.

I would be willing to entertain a truly "Tunable" exhaust if by using it did not decrease performance in either HP or Torque, but will at the same time keep the dB level at a livable level. I believe it would be difficult to develop a system which would allow for both. It's a lot easier to control resonance with a very restrictive exhaust system. The trick is controlling ti with a free-flowing system

So to answer your question, Yes. As for the cost, that all depends on the amount of gain/loss a system would offer. The other issue I see it that you would have to change more than just the muffler persay.

I hear the new deal out there is a "stealth" system. Which allows the user to open a section of pipe that is before the "stock" muffler. It increases performance, noise, as well can go back to a closed state if you were popped by the noise patrol.

Take Care,

[speedminded]

Drone and resonance can be made less noticable by adding resonators which do not hinder the airflow. The issue we found with the Z was not having enough room to weld them inline with system. (I have 6 smaller resonators rather than one/two large mufflers)

Some cars are very difficult to tune to get rid of that drone/resonance. It usually varies by engine type, with V8 hitting it in the 1500 to 1800 rpm range, V6s in the 2000-2500 rpm range. It has been a thorn in the side of Every Exhaust Mfg. for years. Every engine made has a natural resonant frequency. The reason original equipment mufflers are so large and restrictive is a result of manufacturers attempting to control sound levels at the resonant rpm, ussaly decreasing performance.

I would be willing to entertain a truly "Tunable" exhaust if by using it did not decrease performance in either HP or Torque, but will at the same time keep the dB level at a livable level. I believe it would be difficult to develop a system which would allow for both. It's a lot easier to control resonance with a very restrictive exhaust system. The trick is controlling ti with a free-flowing system

So to answer your question, Yes. As for the cost, that all depends on the amount of gain/loss a system would offer. The other issue I see it that you would have to change more than just the muffler persay.

I hear the new deal out there is a "stealth" system. Which allows the user to open a section of pipe that is before the "stock" muffler. It increases performance, noise, as well can go back to a closed state if you were popped by the noise patrol.

Take Care,

resosance frequency's are crazy....running with an M3 on a mountain run at a certain rpm's we would match frequencies per say (b18c5 stock cat, high flow stainless resonator) Whatever that speed/rpm was it would make your head feel like it was going to implode

On my old Z32 300zx, running stock cats with straight pipes i think it was 1,800 rpms that would set off car alarms (it's been so long i can't remember exact rpm)....could cruise at 5 mph through a parking lot or deck and get them going all over, go 500 rpm's higher and it wouldn't do it. Sounded good at WOT through the tunnels downtown though

Maybe they've come up with a white noise generator to cancel out the resonance

[MDPsJcars]

My roommate has one of those apexi tunable mufflers and it still drones inside the car even with it restricted down. (b16a with high flow cat, header, 2.5 inch custom cat back) So i really dont see the point. If someone came up with something that had a lot of adjustability in sound and really worked well it would be great and probably sell. But even still there isnt too much of point in my opinion, considering that changing other parts of the exhaust system make a huge difference in sound as well.

[coolZero]

The 3200 rpm drone in my PT drove me crazy for years and yes my spouse hated it because you could not have a "talk" (I think that what she calls them lol) in the car. I dyno matted the whole car and put down 2 layers by the exchaust area and it just did not kill the drone (also had a resonator). Now I was running a Flow Master Delta 90 (it is a load exhaust).

I went to Paul's Custom Exhaust in Snellville and he got it corrected and my cars sounds deeper and better than before and I'm running true duals. This included the cat too so that was about half of the 600. So the exhaust part was like 325 give or take.

So if I were able to pay for a tunable muffler that could actually remove the drone and I could get for 100+ even it was still worth it to me. Oh and sound bites would be cool.