Offroad-Express

Hi guys

So I'm wanting to increase the wank factor of my truck a little, and one of the things I was wanting to do to beef up the sound a bit is straight piping it and removing the muffler. I've got a decent sized turbo on it, a 3" exhaust pipe behind it. So I'm wondering if I could unbolt the section with the muffler in it, and put in a section of straight pipe. It wouldn't hurt back pressure as a) its a diesel and b) the turbo gives enough of it. And the turbo would do an alright job of silencing it. At least to get it below the 95dB limit on exhaust noise.

What are the legalities of this mod? Does a vehicle actually need a muffler, or just an effective silencing system.

My exhaust pipe is made in 4 sections. Each one has a flange and is bolted to the next. I'll make use of that if a muffler is required so that I can either bolt on the straight pipe, or the muffler.

cheers

td42?
no need for a muffler and it will never be loud. however you can tune the sound a bit with different style mufflers so it sounds nice.

tweake wrote:td42?
no need for a muffler and it will never be loud. however you can tune the sound a bit with different style mufflers so it sounds nice.

yeah TD42

I've heard a few of them with straight pipes behind a turbo and [insert words here]. It sounds mean!!! So Ill see what I can do. My real concern was whether or not a car actually NEEDS to have a muffler. I was under the impression it just needs to meet noise requirements (by what ever means).

just use a 3 inch cheese grater coby if the wof man wants some sort of baffle in place other wise 3 inch striaght is all good.

Right. So to the dispair of all our neighbours (although we're quite rural), I just unbolted the junction between the muffler and the section of pipe in front of it and let the front section rest on the transmission cross member (and the muffler and tail pipe were still on their supports). For all intents and purposes this made the truck straight pipe, just ending under the truck rather than out the back.

Started her up and it sounded like I was standing next to a real truck.

Took her for a drive and it went well. I think I may have noticed a bit of a difference too as it was starting to spool up a lot lower than useual as well. Sounded great. Not too loud either. I've been in muscle cars and on bikes far louder than that was. Sounded realllllyy throaty. Definately going to take the muffler section down to a local guy to make a section of straight pipe for it. Hopefully can have that done by Wednesday if luck is on my side.