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Silencer advise wanted
Chippy - 13/5/09 at 10:48 PM

Hi, have done a couple of drawings, and would like any comment, good, bad or indiferent,
I have used information that I got of here, to do the lower one, but my maths may be a bit rusty.
V6 3 Ltr, so each cylinder is approx 500cc, or 30.5 cu. ins. this times 8 = 244 cu. ins, and a six inch pipe needs 3 inches to accomodate that figure? Yes or No?
Anyway what I want to know is which can will give the best silencing, (cossy is a noisey b*****d), and sap the least power. Cheers Ray
Silencer Dwg.
Silencer Dwg.


hughpinder - 14/5/09 at 09:31 AM

I'm no expert, but I did calcs for a 2 lt 4 cylinder engine and the calcs gave identical results to yours!
Regards
Hugh


smart51 - 14/5/09 at 10:28 AM

According to Vizard, the volume of the empty chamber at the start of the silencer should be 8 times the size of 1 cylinder of your engine (or bigger). I read a research paper about straight through silencers which said the baffle in the wadding should be 1/3 of the way along from the inlet to the outlet.

Other than that, the bigger the better, both in length and diameter.

A couple of other things, the pipe into the empty chamber should stick into the chamber by about a 1/2" for the best gas flow. Similarly, the exit from the chamber to the perforated pipe should have a nice radiused edge to allow the gas to flow out nicely.


Chippy - 14/5/09 at 10:47 PM

Thanks guy's, as i have two pieces of pipe 30" long, it's the long ones then. I just hope its quieter than it is at the moment, Cheers Ray