gr8corvette

I have a new previously enjoyed 1971 Corvette Coupe with side pipes. The side pipes give the car a nice look, but I can't stand the loud noise.
I may be a heretic, but I want my Corvette to be quiet. In fact, I would prefer there be no sound at all while the engine is running. No growl, no roar, no sound at all; just quiet.
I did a search and only found people that switched to side pipes that sounded better or louder. There a few references to STS inserts, but in reading about them, it seems they are still louder than an ordinary muffler.
Can anyone recommend a specific side pipe that is really a muffler with quiet sound?

Tim81

You might want to try a pair of Doug's side pipes with the Reverse Flow mufflers in them. I just installed a set on my 81 and was very surprised at how quiet they sound.

gr8corvette

Are these what you are referring to?
http://www.jegs.com/i/Dougs-Headers/776/D951/10002/-1

Tim81

Yes those are them...I don't known what style side pipes on on your car, but these will fit a 4inch pipe.

jr73

Will these restrict the flow?
I mean more than most other mufflers

69ttop502

On a 600 hp big block the reverse flows lost 145 horsepower on my car when I was Dyno testing side exhaust mufflers. They are definitely the quietest option though!

imariver

Wow . . . . That's a pretty big hunk of HP to be losing! What range did you lose the most?

gr8corvette

Wowzers! That is a lot of HP to lose. However, I am more interested in looks than power. I doubt that I will ever dyno any of my cars, so I might not even know the difference. For normal street driving, would I notice the difference? The only time I ever "jump" on the accelerator really hard, is when I am pulling out of McDonald's into traffic.

7T1vette

Leave exhaust alone but turn exhaust outlets down behind rear facia. Then you can bolt up some non-functioning side pipes on your car.

All you wanted was the "look" anyway. No burned legs, quiet, no installation headaches. What's not to like?

gr8corvette

I think what you are saying is to install standard muffler system with exhaust out the rear. To do that, the rear facia needs exhaust "holes". My car does not have them.

72 Project

What he meant was install turn down exhaust tips on the stock exhaust like on late model c3s. Then put fake side exhaust on for looks only.

7T1vette

Didn't understand that you already had side pipes and just wanted them 'quiet'. Look for chambered/baffled pipe inserts. Not sure that anything out there will make them actually quiet.

doorgunner

Everyone knows how loud Harley Davidsons can be. In the 1980s Harley produced chrome mufflers which made the engine so quiet that the transmission whine was louder than the exhaust!

There shouldn't be a problem making side pipes quiet(er) while giving up a hundred horsepower.

69ttop502

I have the old Dyno sheets somewhere, but it lost everywhere. The engine lost well over 100 from about 5000 to peak which was 6100 on this engine. When you see the size of the "pea shooter" hole in the reverse flows, you can understand why. Interestingly, the glass packs weren't much better. A funny story from the Dyno session. I had an hour of time, so I had three different sets of side tubes to help me speed up the changes. I was running out of time when I got to the last test, which was the reverse flows. So I just clamped the side tubes on at the header junction and not the back frame slot. We started the pull and I saw a flash of light out of the corner of my eye and the guy telling me to shut it down. Turns out I blew one of the tubes right off the car. Lots of back pressure I guess.

69ttop502

It really depends on the engine. A 300 horsepower engine certainly won't lose anywhere near that much hp. I am with you on the noise though. I finally ditched the side pipes and had a nice undercar system built. If you are just street driving, you won't notice it as much, assuming you don't have a very high strung engine. In those Dyno tests, the STS baffles made the best hp of all the mufflers. This was before the bigger diameter glass packs came out though. I did like the baffles, but had to cut and uncap them to minimize losses.