[Rob. Smith]

Originally Posted by Excaliber

You know we are facing similiar problems here in the states at various race track events. One local "Hill Climb" I'd like to do this summer requires 95 DB, thats pretty darn quiet! Other tracks are around 103 DB, it varies.

SO, I contacted "Toms Motorsports" in California, they race, they been having this problem. They've tried all kinds of "things", it either takes away a LOT of horse power or builds up to much heat in the engine.

They are now using Spiral Turbo Baffles with great success! Limited horse power loss and ADJUSTABLE DB! http://www.spiralturbobaffles.com/index.html They also put a quick release out let tip on the end of the side pipes they can "turn", down,out, left, right, depending on where the sound reading is being taken at any given track.

I HAVE to get a handle on this sound issue, as everybody will eventually. I'm looking real hard at the Spiral Turbo stuff.

I'm curious as to what distance the Decibel measurements are taken in the US. Of all the US info I have read 90 odd decibels is OK. Here in OZ 92 decibels is the maximum legal reading at a distance of 20 inches 45 degrees from the exhaust exit at idle. There's no way the spiral turbo stuff or the car chemistry inserts would drop noise levels to a legal level even the classic chambered exhaust inserts are too loud. Most of the readings,that I have read about, are taken at 10 to 30 feet away in the US. Can you give me some sort of idea of the true 'legal' readings that meet the standard in the USA ?