Club Cobra - Theoretical problem

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Theoretical problem

IF...I was going to put side pipes on my car and they consisted of four 2" collector pipes, a 3 foot glass pack hot dog muffler (3" ID) and a 3-1/2" outlet. (Which is a copy of the original set up.) I can imagine this set up would be a little loud. Can anyone suggest additional "muffling" to add to the pipe ?
Please be assured that this is only a theoretical question. I don't have these pipes I just would like to know how to make them quieter !

Are they even allowed in NSW?

For a stock 351 3"id is too big and of little muffling value. Check out reverse flow chambered mufflers or cobra pack 2 1/2" spiral louvered mufflers.

You can get the spiral louver made here in Australia to whatever length you want.

Too big is not always good you will want to keep the gas velocity up to assist in extracting the next pulse.

Check out this for some ideas.

http://www.classicchambered.com/clas...cts.html#cobra

Quote:

Originally Posted by Merv and Sharon (Post 1023108)

Are they even allowed in NSW?

SHUSHHH...some one might hear you !

*Cobber*
Can you supply me with the info for the spiral baffles and how much do they suppress the noise.?

Thanks Sambo...they look simple enough to build a couple and play with them to make less noise.
The owner is smart he says they are 'tuneable' but doesn't say how. I can imagine it's by lengthening or shortening them. As far as noise reduction the yanks seem to have a different idea about the sound of a V8 and sound levels compared to what we are allowed.

Rob, If you can graft a cat conveter into the collector it would help.

I have a home made 4" outer with 2" perf tube and had to fit a mini version of the spiral to sit in the 2" to get through rego, though I only had to comply with 96dBa

Quote:

Originally Posted by David Hodgson (Post 1024394)

Dave you've read my mind....I'm also looking at 'Car Chrmistry' muffler inserts and 'Aero Tech Turbo Flow' designs to build and insert inside the hot dog.

Summit Racing have a perforated cone - see their exhaust section.

www.summitracing.com

This I am told breaks the exhaust up. The total area of the holes equals the internal diameter of the pipes which does not restrict flow.

:confused:

It may be worth dropping Aussie Mike on the forum a PM, as he has experimented with exhausts - building a high quality side pipe system for my Cobra. You will find him on the Dark Side forum on the right of the main clubcobra page also..%/

I was talking to a guy today (in NSW) who has a 2004 ford falcon v8. He has made some mods ecu, injectors, cams, and exhaust. Currently he claims it is producing 320kw.

He was pulled over by a mobile testing station and fined for being over the allowable noise level and also outside the emmisions requirements. He was fined close to $5000!

Makes me question installing live side pipes!

I was asking that too Rob but you suggested: "Shhh they might hear you."

But they might hear you?

If they are not too noisy however ....

That's what I'm on about...making things quiet...If any one's curious have a look at http://www.youtube.com/watch?v=iDTTOa77efs and check out 'Car Chemistry' exhaust inserts. They both work on the same principal. I will have a go at building a similar insert to go into the mufflers which will reduce noise and create the needed back pressure for the engine. My sound level meter arrived today so soon I will start to 'create'.

Quote:

Originally Posted by BMK (Post 1024560)

Thanks Bernie...I've seen these cones...a bit expensive for a bit of perforated s.s. rolled into a cone. (I mean to buy , import and then find out they don't work) I'll have a go at making up a pair and see what happens.

Quote:

Originally Posted by Zedn (Post 1024733)

What else did he do ? the fine for noise is $253.00

Road Rules 2008
Current version for 11 September 2009 to date (accessed 2 February 2010 at 20:18)
Part 18Division 1Rule 291
<< page >>
291 Making unnecessary noise or smoke

A person must not start a vehicle, or drive a vehicle, in a way that makes unnecessary noise or smoke.
Maximum penalty: 20 penalty units.

Example. Causing the wheels of the driver’s vehicle to lose traction and spin on the road surface may make unnecessary noise or smoke.
Note. Other laws of this jurisdiction also deal with vehicles and equipment that make noise or smoke.

He said the major part of the fine was for emmissions. But i think that what you have posted is using a car to make noise rather than modifying a car exhaust.

He said that it was a mobile set up on the side of the road. He thought they were signalling him for a breath test, but when he pulled over it was the EPA and RTA.

The fine seemed a little excessive to me, but i dont think he was lying. I am seeing him again tomorrow so i will ask what the name of the offences were.

Apparently the EPA guy that did the sniff test told him that he can tell he has modified the motor but is not going to go that far into it. He had no cats on the car so that is probably the main culpret combined with the ecu tweek.

I found the where it fits into the law.

Its under the protection of environmental operations (clean air) reg 2002.

Quote:

15 Use of motor vehicle without prescribed anti-pollution device prohibited

(1) An owner of a motor vehicle who uses the motor vehicle, or causes or allows it to be used, is guilty of an offence if:
(a) this Regulation requires motor vehicles of the class to which it belongs to be fitted with a prescribed anti-pollution device, and
(b) the vehicle is not fitted in the prescribed manner with such a device.

Maximum penalty: 400 penalty units in the case of a corporation, or 200 penalty units in the case of an individual.

Quote:

17 Removal or adjustment of anti-pollution devices

(1) The owner of a motor vehicle who uses the motor vehicle, or causes or allows it to be used, is guilty of an offence if:
(a) an anti-pollution device had been fitted to the motor vehicle, and
(b) at the time of that use the device had been:
(i) removed, disconnected or impaired, or
(ii) adjusted or modified and the adjustment or modification results in the emission of excessive air impurities by the motor vehicle.

Maximum penalty: 400 penalty units in the case of a corporation, or 200 penalty units in the case of an individual.

Thats a maximum of $22000 for an idividual.

And for the noise it comes under POEO (noise control) reg 2008

Quote:

12 Use of motor vehicles on road or road related area

(1) A person must not cause or permit a motor vehicle to be used on a road or road related area if the motor vehicle is capable of emitting noise at a level in excess of the level prescribed by clause 4 (b) or (c) for that type of motor vehicle (the prescribed noise level).

Maximum penalty:

(a) if the vehicle is capable of emitting noise at a level that exceeds the prescribed noise level for that type of motor vehicle but does not exceed that prescribed noise level by 5 dB(A)—100 penalty units in the case of a corporation, 50 penalty units in the case of an individual, or
(b) if the vehicle is capable of emitting noise at a level that exceeds the prescribed noise level for that type of motor vehicle by 5 dB(A) but does not exceed that prescribed noise level by 15 dB(A)—150 penalty units in the case of a corporation, 75 penalty units in the case of an individual, or
(c) if the vehicle is capable of emitting noise at a level that exceeds the prescribed noise level for that type of motor vehicle by 15 dB(A) or more—300 penalty units in the case of a corporation, 150 penalty units in the case of an individual.

this is 4 (b) or (c) that it refers to

Quote:

(b) the prescribed level for a motor vehicle of a particular type that is certified to ADR 83/00 is:
(i) if the compliance plate date of the vehicle is on or before the date that is 2 years after the commencement of this Regulation—the noise level established by ADR 83/00 for a motor vehicle of that type when stationary plus 5 dB(A) or the noise level specified in Schedule 1 for a motor vehicle of that type, whichever is the greater, and
(ii) in any other case—the noise level established by ADR 83/00 for a motor vehicle of that type when stationary plus 5 dB(A), and
(c) the prescribed level for a motor vehicle of a particular type that is not certified to ADR 83/00 is the noise level specified in Schedule 1 for a motor vehicle of that type.

So thats max of $5500 for up to 5dba over, $8250 for up to 15dba over and $16500 for more than 15dba over.

I guess he got off lightly!

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