Do I really need a muffler?
 

I'm coming along pretty well on my OM617 turbo install into a '67 Land Rover. I'll be at the point where I'll need to build the exhaust next week. With the help of the turbo, do you think it is really necessary to run a muffler on this truck, or can I just run straight pipe? Keep in mind it's a truck so it needn't be as quiet as a passenger car. It will have 2.5" stainless pipe the whole way.

http://seriestrek.com/109/chassis5.jpg

jim

If you don't live in a state that will deny you an inspection sticker for a noisy exhaust then you can probably get away with a straight pipe...but you should check with the laws in your state to see if you are opening yourself up to harrasment by the police too as many states have noise ordinances and you can be ticketed for having a noisy exhaust even if there is no inspection for that.

I don't want the thing to sound like a hotrod, but I was hoping the turbo would make it quiet without a muffler. Maybe I'm wrong.

The turbo muffles the exhaust but it is still loud.

Thanks. That's what I needed to know.

A thing of beauty, Jim!

http://seriestrek.com/109/chassis5.jpg

I run a straight 2.5" pipe on my 300SD and its not all that loud. I'd say go for it. :D

Cat?
 

Some of our members are running a cat, or a high flow cat, either will quiet it a bit more, but no 'muffler'

That looks pretty cool so far. I figured you pretty much had to have a muffler anywhere these days. I live in a pretty densly populated area. I don't think you could get away with no muffler in the Washington, DC area.

I personally use a cherry bomb muffler, and now that its packed with soot it doesn't muffle very much. So it is in effect a straight pipe however it conforms to the letter of the my state law requiring my car have a muffler. My turbo, ox-cat, and resonator do a good job of muffling the engine.

I personally recommend that you install some form of resonator. It helps reduce the low end drone significantly. Also a exhaust tip that angles down at the ground helps too.

I agree with CC, something to temper the sound a bit. Personally, I don't think that most straight-pipe exhausts sound good, regardless of the sound level, I like a system that takes the snap out of long pipes with a muffler and/or resonator.

thats if you care about the people behind you ^_^

If I had a built cummins I would have a straight tipped pipe right at the level of a lowered civic... suck my soot rice boy


that reminds me..

the new diesels with the zoom tube exhausts, well the duramax, blow exhaust in your face if the truck is lifted.

One accelerated next to me, it was lifted slightly, and the zoom tube is straight and angled slightly down. I got a nice warm blast of air in my face. Kinda like a hair dryer on Max.. no diesel smell though

Actually the angled down exhaust tip reduced my in car noise. It helped by bouncing the sound waves off the pavement away from the car. Before I had the tip and again when I lost it, the sound tended to bounce off the curb and back into the cabin when I had the widows rolled down. Also some of the exhaust was hitting the bumper and transmitting the sound into the cabin.

I tried the system on my 82 300D with just the resonator and a straight pipe, still too much resonance in the cabin. Sounded o.k. outside though. But i'd say since you've done such good looking work so far just buy a round straight through diesel magnaflow muffler or something. THEN you'll be happy with the sound. :D

Wow, that project is looking nice!

Try it with no muffler, you can always add one.