Too Loud

[Cobranut]

I don't think I'd let some government employee try that in my car.
I doubt his skills are up to controlling a big smokey burnout past the guy holding the meter.
Not to mention that the exhaust combined with the screaming tires would probably blow the sound meter.

David

[quote=Hans-Olof Blom]In Sweden the measurements are done during full acceleration. The person doing the test will drive about 30mph in second gear and approx. 30ft before the measuring point he floors it. The allowed level is 85dBA.

[Hans-Olof Blom]

I tried to keep the plug in place with the 2 piano wires that can be seen in the picture. That was not enough so I added a threaded rod with 2 long nuts. I just expand it inside the pipe so it can't move. So far it seems to stay in place.

It is also important to decrease the sound from the inlet which can be substantial.

The person doing the test is not a government employee. He is a member of a non profit organization of inspectors for this kind of vehicles. The inspectors are usually experienced builders of cars.

For the next try I have the Al discs on the wire, 6 steel wool balls, and the plug made from expanded metal in each pipe. I have also disconnected the second stage on my carburetor. I really hope this will be enough!

[Don]

Hans, regarding the inlet sound supression. The Car Chemistry discs and the Vortex cone are more effective just after the primaries and before the muffler. From the CC specs: " The further back the insert is installed, the less effective they are at reducing sound " " The insets work off of the strength of the exhaust pulse as well as the heat of the exhaust " " A rich fuel mix will create a much louder exhaust note "

There are also two models of the CC discs, one having additional sound control.

They also make a series of their discs, 7 in total, which will fit inside an exhaust pipe, i.e. make your own muffler, referred to as " Side Pipe Inserts ", 3", 3 1/2 " and 4". However, the length is 33".There is a " Side Pipe Silencer Kit " which has 4 discs. Intended to replace the existing turn down on the side pipe as a bolt on rather than welding. From the picture, does not have a support bracket.

A contact at CC is Ken Mullinex, 972-937-7735, or

Car Chemistry
PO Box 455
Waxahachie, TX 75168