No mufflers in commercial vehicles

[RustyNav09]

So I started a bit of researching on this topic about the legality of having mufflers fitted to diesels. I gave up as I got such a big twist in information . Just received my new modified 4wd magazine and it so happens there is a small article in one of the car build write outs saying that in commercial vehicles with diesel motors we do not need to install mufflers to our vehicles. This is purely for diesel commercial vehicles. I know my vehicle is registered as a turbo diesel commercial vehicle.

So any ideas? Can anyone clarify this information for me as it will save me a bit of stuffing around and money when I redo my exhaust?

 

[sparra04]

not sure rusty
but after running my new beaudesert exhaust with no muffler for a week i put muffler on and i reckon it has increased the performance
i miss the noise but
might take it back off

 

[04SilverSTR]

i think its more along the lines of no cat, pretty sure they still need a mufler.

 

[Bryce]

Talking to the exhaust guys (you think they would be up on the rules) Cat is a must muffler is not required as long as it doesnt produce more than 90db(might be less than that i wasnt that interested in the number)

 

[bigkev]

Hey I went to the exhaust shop not to long ago and asked for a 3 inch exhaust turbo back and they asked for if I wanted a cat in the dump pipe or not so I wasn't sure if we needed them or not

 

[RustyNav09]

I was always told you must have both. Its different at each shop. Some shops claim that the cat in a diesel exhaust are just purifiers. Also cops can't test the catalytic numbers of diesels

 

[bigkev]

Some of the people I have spoke to said diesels with cats just get blocked up and then just puts the car into limp mod

 

[myoldhk]

Cats are a law, EPA!
As for mufflers no! as long as it doesn't breach noise pollution. Once again EPA! They are just a silencer!

 

[ourd40]

You dont have to have any mufflers if its not breaking any EPA laws (noise polution) only Cats if your ute came out with them and you would want at least a high flow on there for a bit of back pressure

 

[RustyNav09]

Yay I don't have to install a muffler in my exhaust. So my simple 100cell cat and tornado muffler is completely fine. Woot

 

[Aussie Frontier]

As long as you dont break 96db no vehicle really needs a muffler

 

[jaymac90210]

Silly question but when I went to my mates exhaust place he said that if you gut the cat then there is basically a 3 inch dump pipe from the turbo back without replacing anything... True?