C2 Quieter Sidepipes?

[Bob B.]

Hi all,

I am looking at a possible midyear resto project that has sidepipes that I would eventually drive after all the judging process. I have had midyears with sidepipes before and the noise is just too much for long highway distances. Someone told me they thought there was a supplier of pipes that act as mufflers and are pretty quiet. Does anyone know if something like this is available?

Thanks,

Bob

[Jack H.]

Re: C2 Quieter Sidepipes?

Several of the catalog houses (Mid America for one) offer an exhaust system that installs in place of the conventional through-frame pipes, but has no discrete mufflers and uses the ribbed pipes typical of side exhaust. The benefits of this system are:

(1) Lower cost because there are no expensive covers.

(2) Ease of installation (no need to modify the car from existing through-frame configuation).

(3) Some noise relief as the exhaust exits at the REAR of the car away from the cockpit and your ear.

[Bob B.]

Re: C2 Quieter Sidepipes?

Jack,

Thanks, but the car I'm looking at has sidepipes and I was wanting to keep them and have a car that will pass judging once completed. I am just checking to see if there are sidepipes that are quiet because someone told me there were. He just didn't know where to get them. Any idea about those?

Thanks,

Bob

[Joe C.]

Re: C2 Quieter Sidepipes?

Bob,

Tell us more about your car. What year is it, engine, serial number (or production month)? Is it an original sidepipe car?
If it IS an original sidepiper, and you wish to keep it so, then I am afraid that there is no option which minimizes noise, and maximizes flow, given the packaging constraints. If you want a relatively quiet exhaust note with low exhaust restriction, then I think that the N14 (off road) muffler option is your best bet. Unfortunately, with chambered muffler design, "quiet" is synonymous with "potato in the tailpipe".

Joe

[Donald M.]

Re: Quiet Sidepeipes-An Oxymoron? *NM*

[Joe C.]

*&^%$#@(!) Can't Edit The Goddam Post

I always get N11 mixed up with N14.

[Duke W.]

Potato up the exhaust

I haven't pulled that stunt since high school!

Duke

[Richard S.]

Re: C2 Quieter Sidepipes?

Bob'

Actually, for some reason as yet unknown to me, some sidepipe systems ARE not as loud as others. My 67 427/435 sidepipes are VERY loud.....but the pipes on my 66 427/390 are quiet in comparison. Many people have noticed the difference and commented to me. Unfortunately, I can't help you out with why this actually is...or who makes these pipes.....but keep looking/listening....you may yet find someone who can put you on the right track.

[Joe C.]

Re: C2 Quieter Sidepipes?

Rick,

To draw a comparison with a famous quote by a former president, "It all depends on what your definition of IS, is". In terms of sound, it all depends on what your definition of "quiet" is. I can tell you with absolute certainty, that if you have IDENTICAL mufflers installed on both of your BBC, then the set that is older will always be louder. The inner, perforated pipe on all original GM (NOS, etc)and all Allens reproductions (until VERY RECENTLY), are made of very thin walled steel. Reason is that the thin walled resonates to produce that characteristic "ping" sound. Consequently, they corrode rather quickly and cause significant volume increase in a relatively short time, with day-to-day use. With limited use, any perceptible increase in volume could take many years!

Allens reproduction pipes (the ones that are supposed to look like the originals) actually use a slightly larger diameter inner tube than GM issued mufflers, and, consequently are somewhat louder. The Allens also use a different process to perforate the inner tube, which causes some projection into the flow stream. The original GM issued pipes had minimal projection into the flow stream due to the perfs, albeit, a smaller diameter tube.

MC Productions, Inc., makers of the Sweet Thunder system uses yet ANOTHER config for their perfs. Both Allens and Sweet Thunder are available with inner tube diameters up to 2 1/2".

Joe

[Wayne K.]

It's a safety issue, " loud pipes save lives" . *NM*

[George J.]

Re: C2 Quieter Sidepipes?

Rick,

I have noticed, too, that all solid lifter engines with sidepipes are louder. I think that is the difference between your two cars.

George

[Drew P.]

Re: C2 Quieter Sidepipes?

Hello Rick,
The compression in the 435 HP is 11.0 to 1. and the 390 HP is 10.25 to 1.
The higher compression will produce a higher level of exhaust noise.
Regards,
Drew Papsun

[Mark #28455]

Re: C2 Quieter Sidepipes?

Not only is the compression higher, but the exhaust valve opens a little sooner on the 435 so the pressure in the cylinder is a little higher too.
Mark