All that damn noise -- Again!

oleyellar · #1 (**permalink**) 08-06-2001, 11:09 PM

What is the preferred method of meeting the noise restrictions at the track events. I have seen alot of the Supertrapp ends added to the side pipes. Is that happening more often than not? I had trapps on a small block chevy and never got used to the sound. I have the old Superformance pipes and they are way noisier than a 540 inch big block Super Comp dragster with Borlas. What are your suggestions? Should I just do newer, better side pipe mufflers, Supertrapps, cones, spiral inserts? What is the latest drug on the market...What's right.
Currently ear plugs are required, just for a cruze and a road trip is brutal. Thanks

Chad Johnson · #2 (**permalink**) 08-07-2001, 12:15 AM

You might just want to get a new set of Superformance pipes. I have SPF #908 with a 514" stroker and it is actually quieter than a friend's 351 (except when wfo)

CobraEd · #3 (**permalink**) 08-07-2001, 06:23 AM

There are lots of threads on this subject out there. Check them out.

Ed

oleyellar · #4 (**permalink**) 08-07-2001, 07:08 PM

Thanks for the responces, but I have already read through the endless conversation about sidepipe contruction. There are as many opinions as Cobras. I posted in this section to see what the racers are doing to meet the track requirements. Who is happy with what ?
Thanks

a427sc · #5 (**permalink**) 08-07-2001, 09:08 PM

What are the noise restriction level you need to meet? And how is it to be measured? WFO on the front straight with aluminum grandstands and walls all around (NHIS-99), at the end of pit lane on the front straight or where ever the sound person wants to go, with wide open spaces all around (LRP-86), 3000rpm @ 50 ft? or...

The cones are good for about 1-1 1/2db, Trapps about 2 before it all goes to h**l. CCI's I have no experience with. You need a good muffler to get most of the noise out, these other pieces are for final tuning out the last couple of db.

I worked out a set-up for NHIS that passes by trial and error. 24" Lobacs, 3 1/2" vortex cones, and Trapps (actually the set-up shown in Kit Car Louden article). Got a sound meter at Radio shack (same as they use) and set up a test facility to compare differences. 99 at NHIS worked out to 92 @6500/3rd gear at 50 ft out in the farm country. I now have a base line to compare different combos for sound/performance degredation. Burns stainless makes clamps that make changing mufflers easy. good luck.

Don

colin mullaney · #6 (**permalink**) 08-09-2001, 11:55 PM

This winter I bought Dynomax collector mufflers but haven't had time to install them yet. Sounds like a great idea but i don't know if they'll meet the 95 db requirement of NHRA by themselves as promised by dynomax. I intend to still use the sidepipes as well for the street.
Colin