[vertical-escape]

Can anyone tell me if adding the Helmholtz chambers to an existing aftermarket exhaust helps on the noticable awful blah sound that comes from the Fuel management sytem when it kicks on and off? I have a Pypes cat back and hate it when the FMS shuts down four cylinders, sounds terrible.

 

[RJT-SS]

Yes, it will help. See Solo's J-pipes as an example.

 

[BigRed585Lbs]

Ah, yes. Here's some I made up WAY back in '09 for my G8 Pontiac (a noted droner).



For anyone interested in how the length is determined:

There's a formula for figuring out the particular length required for a particular drone frequency. Simply put, it's:

1100 feet per second (the speed of sound)
divided by the drone frequency.
Divide this result by 4 to give a quarter wavelength.
Multiply the quarter wavelength number by 12 to give the required chamber length.

These chambers are pipes cut and welded into the tailpipes and capped off on the other end, creating a closed "echo chamber" to reflect back the drone frequency 180 degrees out-of-phase, thus cancelling it out.

It works. Try it and enjoy your exhaust.

 

[MidlifeSS]

I have the solo axel back with j pipes and a l99.The only way your going to get rid of that sound is to either have it stop going to four cylinders buy having it tuned out or use the range unit that can be installed by you and taken off when you want it to go to four cylinders.Last option go back to stock.The four cylinder thing is only good for around 2 miles a gallon.I went from 24 to 22 on trips,but no more nasty sound.J pipes are good for drone when cruising on the interstate with a upgraded exhaust.

 

[BigRed585Lbs]

Check out the Solo Performance website and see who they give some of the credit to for the development of their j-pipe systems for the G8 Pontiac and Camaro.

http://www.g8board.com/forums/showpost.php?p=426635&postcount=1126

 

[patriotpa]

Ah, yes. Here's some I made up WAY back in '09 for my G8 Pontiac (a noted droner).

For anyone interested in how the length is determined:

There's a formula for figuring out the particular length required for a particular drone frequency. Simply put, it's:

1100 feet per second (the speed of sound)
divided by the drone frequency.
Divide this result by 4 to give a quarter wavelength.
Multiply the quarter wavelength number by 12 to give the required chamber length.

These chambers are pipes cut and welded into the tailpipes and capped off on the other end, creating a closed "echo chamber" to reflect back the drone frequency 180 degrees out-of-phase, thus cancelling it out.

It works. Try it and enjoy your exhaust.

Nice, sound audio theory. Great post!:thumbsup:

 

[83Hokie]

Nice, sound audio theory. Great post!:thumbsup:

Can I get the Greek translation? J/K it will still be Greek to me. I'm just glad someone understands it.

 

[BigRed585Lbs]

You don't mind the medicine if you want the cure bad enough.

And it's free for the taking.

 

[JWD621]

I had the same problem and fixed it very quick and easy with out re programming or cutting on pipes. I bought and installed the "Range" AFM killer that plugs into the OVD port and tricked the system into staying on all 8 cylinders all the time. No more "drone" and full power on demand. Actually increased my milage since most of it is in the city...daily driver.

It can easly be removed by reaching down by the port and unplugging anytime, and it does not ever set a code or even show up on GM diagnostics if you remove it before going to the dealership.

Bought mine from Amazon.com, search Range Technology. Best $200.00 I ever spent.

Just my two cents worth.

 

[BigRed585Lbs]

And that's a mighty fine 2 cents! I've got one of those in my truck right now. I just saw one for sale on the Silverado/Sierra forum for $160 if anybody wants one. A wise investment.

 

[CamaroSSpence]

Just put a Solo Mach XL on my ride last weekend - totally killed the highway drone, and I don't even have an automatic!

 

[BigRed585Lbs]

Figures for j-pipe length: