Mufflers on turbo's?

rickeolis · 12-04-2003, 10:12 AM

Simple question here- Why do turbos need mufflers? Wouldn't the sound die out while pushing the impellers?
(Wastegates I can understand)

carmad · 12-04-2003, 10:24 AM

The turbo will help to suppress some of the sound. When I drove mine with no muffler, it sounded awesome but was to loud for the street.
Some guys do use just a straight pipe off the turbo for street use.

masraum · 12-04-2003, 10:26 AM

I think it depends on how loud you want your car. Car's with cats don't really need one as the cat does a pretty good amount of muffling, but in the states so many people like cars to be nearly silent that running with no muffler through a cat sounds pretty loud.

lendaddy · 12-04-2003, 10:29 AM

Yep, it's a matter of preference. For what it's worth my brother in law just got the Dodge ST-4 (the little neon screamer) and they don't use mufflers at all, just turbo/cats/tail pipe. It actually sound pretty good and I have to admit it's neat little car that GLH.

Az911 · 12-04-2003, 12:41 PM

Quote:

Originally posted by carmad
The turbo will help to suppress some of the sound. When I drove mine with no muffler, it sounded awesome but was to loud for the street.
Some guys do use just a straight pipe off the turbo for street use.

My friends has an 80 930 with a dump pipe and it is very loud. But it does sound like a 935 now so I guess it's a trade off

rickeolis · 12-04-2003, 02:50 PM

I saw an SRT-4 the other night getting on it hard, and although it sounded like a 4 cylinder, it still sounded sweet.

So the answer is that you still get a lot of noise out of it, but not as much as an open muffler on a naturally aspirated model...

I had a Honda CRX-Si that I took the muffler off of completely. It sounded very nice, and not RICEY. The catalyst did a lot of that I guess.

sammyg2 · 12-04-2003, 04:09 PM

When I built the 914 turbo I used a 2 1/2" pipe from the turbo to the back of the car where i installed a 2 1/2" x 18" glasspack (backwards).
Normally that big of an exhaust would sound like crap, but with the turbo it sounded sweet. Almost as quiet as stock until it hit full throttle and the waste gate opened up, then it got a little louder but not bad.
BTW I installed the glasspack backwards so it would have less disruption to the flow.
The inside of one of them looks like a cheese grater, installed backwards the grates didn't mess with the exhaust as much.

RarlyL8 · RarlyL8's Garage

You don't honestly expect a tiny turbo to perform the same function as an exhaust system?

I put a dump pipe on mine during the initial build after hearing all the jive about how "quiet" tubos were. I couldn's see how but what the heck I'd give it a try. What a joke! That thing was soooo loud I couldn't stand it! A stock muffler went on before I could do any tuning.

Another issue that follows noise level is vehicle perception. A loud car sounds junky. Period. An exhaust note that has a low rumble sounds powerful. Not a question of taste but respect. Believe me you will get nothing but bad looks from the general public when exposing them to anything above 90db. I have experimented with many mufflers, mostly home made. Haven't found one yet that does the trick. These cars need a deep rich tone to match their exotic look. You can always let the gates of he!l open with a dump pipe on the waste gate. That way you control the noise level.

tobluforu · tobluforu's Garage

You can run a straight pipe on a front engine car to the rear and it wont be to loud-yeah right!. But do it to a porsche where there is really no length of pipe to muffle it and what a screamer it will-to loud. I ran a straight pipe off my saab for about a week-still to loud for me. I then installed a 3" catco hi flow cat-still to loud for a commuter. On w\the dynomax muffler-perfect as rarly8 states. Nice low rumble for a saab.