Theoretical problem

[gjkrv8]

Gee, I was playing Tennis last night near a main highway, and I reckon there was about 50 Harley's that went past that would be in this boat. Actually I dont think I have heard one that wouldnt be below the noise levels. Do bikes have different noices ADRs?

Rgds

Gregg

[Modena]

Zedn are those state (NSW) rules? I thought in Vic that for noise you just get some sort of $x00 fine and get a canary slapped on your windscreen, but that is all ????

The Harley point is excellent and one I have never understood, why ARE they allowed to be SO loud?

[48ford]

A place I worked at installed a 6" steam jet to produce vacuumed. We received noise complaints from folks 2 miles away. Our plant engineer had us build a muffler for it.
The muffler was nothing more than a section of 12" pipe with a roll of chicken wire fencing inside it. The center of the muffler was totally open because he wanted no back pressure to hurt the effienceny of the steam jet. The muffler was very quiet and after 6 years of operation it was still working. I think you could do the same with a side pipe. If the tips were tacked in place you could experiment to get the sound level you want very easily and inexpensive to try.

[Rob. Smith]

That's what I like about this site...all sorts of ideas and information.. Re the bikes. those dills just get fined and either fit another pipe to pass the test then refit the noisy pipe or... don't pay the fine and spend a week in jail...no problem !
Zedn, my car is registered pre uber emissions rules 2002 and I'm still building it !

[boxhead]

The Harley exhaust (and lack of shielding) is why I was approved with just shielding over the cabin entry exit area on my car with the MVR.

They where happy with mine as in there own words "The Harleys have less shielding"

[David Hodgson]

My engineer flagged shielding as a potential issue as the intent is that you are not to exose anyone to the possibilty of burns. I didn't want a hassle at inspection so I made a full lenght shield from perforated electrical cable tray covering the muffler and collector. Was effective and cheap.

Rob, if you go live pipes, you want to make sure the are well shielded, don't want to burn the bride or you'll never live it down, and reasonably well muffled. You get home pretty beat up after a day out in the sun and buffeting wind with a constant, although sweet, roar in your ear all day.

[Rob. Smith]

Thanks for the advice SLIPRY.....once the 'muffling' is sorted the heat shields won't be a problem at all.
Smithy

[Rob. Smith]

All of this is becoming too much I think I will stick with my original system...it's there and the dummy sidepipes are fitted. They look pretty good and the noise is approved. I've got too many other things to finish before the car is on the road.

[Baz]

That's what I call thinking on your feet Rob.

Baz

[Merv and Sharon]

I agree Rob. My son is an acoustic engineer working for various State enviro projects. The people who check do the right thing. The ones who get fined, make a temporary adjustment and then often revert to their original faults. Fines mean little to them unless that are major ones.

Merv

[Rob. Smith]

Now that I have decided to stick with my original system. I will think about making it better...the mufflers suffered serious damage when the blue slip inspector tried to drive the car onto an old style hoist/ramp and put big grooves in the bottom of the mufflers. In my search for muffling ideas I've seen low profile 'oval' pipe and inline muffling systems that negate the need for bulky mufflers. Once the car is on the road and all the other issues are sorted I will look into making a more 'streamlined low profile' system. i think I saw on one of the "Rides" programs where the whole exhaust system was made of "flat" oval pipe and the mufflers were inside that pipe.....nice and neat !

[Baz]

Rob,

Here are some pics of my under car exhaust system which passed RTA emmisions at first attempt. Notice the two small 'Cats'.






Hope this helps.

Baz

[Rob. Smith]

G'Day Baz, What's the muffler your using ? looks pretty neat. (brand and pipe size )

[Baz]

Rob,

It's made by Kirrawee Mufflers, the same mob who suppplied the cats. They also fitted the entire system. If you contact them on 9542-4111 and mention my Cobra's under-car exhaust system, I'm sure they will supply you with all the info that you require.

Baz