Hey guys.

I have a question on the side pipes on a C2. I heard that the chambered pipes on the C2 are a better flowing and sounding design vs the ones on the C3’s?

can anyone confirm this?, also is there a better flowing setup for side pipes when it comes to these cars? I read somewhere that the side pipes held quite a bit of HP back because of the chambered design.

thanks guys!

 

That's a great question... I've been looking for a replacement setup that is 2.5" mandrel bent without the diameter reduction and crimping but cannot find anyone that makes one. Hopefully someone has input.

Here's my stock setup, it's easy to see how bad it is

 

I found this on YouTube... interesting for sure.

 

Maybe this helps:
https://www.corvetteforum.com/forums...-finished.html

 

The 67's sound better than the 69's. 67's will fit if you shorten them where the pipe is welded to the muffler to fit under the stock 69 covers. From what I've seen allen's and sweet thunder crush bend the pipes, Gardner's look like stock, at least looking at their pictures. I forget who it is that made 67 style side pipes in the correct length with the 69 tip.

 

Thank you for sharing this! I really appreciate that.

 

Awesome! I’ll look into these other places. How are the ‘67’s as far as flow restriction? Do they flow any different than the ‘69’s?

 

My cousin had a 1967 SB convertible C2 with side-pipes and I have a 1968 BB convertible C3 with chambered exhaust and long tube headers. Both cars share a very similar frame and chassis, the exhaust system probably attaches in a very similar fashion.

The side-pipes are able to generate enough noise that I would have to wear ear plugs every time I drove in the 1967 C2. They were just plain LOUD and I could only tolerate a few minutes at a time in that car before my ears hurt. The same drive in my C3 with the chambered exhaust was much more tolerable as the noise is going out behind you. The noise output level was very similar, but the noise in the cabin was much reduced and you could even hear the stereo or a passenger speaking. I can hear the stereo at 70 mph with my top down, you can still hear the noise going out the back of the car but it is not as distracting. try that with a set of side-pipes.

The sound of the chambered exhaust is wonderful, I even put a catalytic-back chambered exhaust on my 1988 C4 with it's meager 255 hp. The sound that engine makes through the chambered exhaust was like a bigger more ferocious engine and it was enough to get people to leave my C4 alone. Here in NOVA we have a problem with too many people that think their Asian cars are fast so you can hardly go out without some fool trying to race you. After switching to the chambered exhaust the sounds alone were enough to deter them.

I have heard so many people try to tell me that the chambered exhaust systems are "restrictive" and "hard on horse power". Before I installed the chambered system I had a clear view through the exhaust pipe from one end to the other. The systems work well on both of my Corvettes. On the 427 the exhaust sounds like it is spitting and popping through the exhaust due to the high compression. After adding the chambered system I did check and using a GTECH Pro I was able to see a gain of horsepower after the installation of just the chambered exhaust.

With a good set of headers, a chambered exhaust would be my choice for a good sounding and better running engine. It also gets rid of the big clunky mufflers from hanging out back....

 

I appreciate the input bud. When you say a chambered exhaust, are you referring to the stock style side pipes on a 69, or another brand?

 

Go watch Engine Masters episode where they test what bashing and denting headers do to performance. Just a note - Nothing. I wouldn't worry about your pipes.

 

My Vette (1971) had side pipes on it when I bought it. They sounded great and were loud. I drove from Georgia (where I bought my Vette) to Round Rock, Tx where I used to live and I couldn't hear out of my left ear for days after that trip. I started working on the car shortly after I got it home and took the side pipes off. Not to get rid of them but to do other stuff. They were so rusted out that I was going to replace them with new side pipes the remember that my hearing just came back. I went with undercar exhaust.

 

Ah, absolutely no comparison.... bashing and putting dents in multi tube header pipes is not similar in any way to reducing the pipe diameter on a single exhaust pipe from a single exit factory manifold.

So putting a potato in the exhaust pipe does nothing LOL SMH

 

Thanks! Very interesting, and especially since it looks like they are running cast manifolds. I don't run my C3 BB at high RPMs so HP isn't as important to me as Torque. I tried shorty headers and they made higher HP but less torque than the stock cast iron manifolds.

 

I can't find the link now. But IIRC, the side pipe headers that Hooker, Dougs, and others sell, were all based on quasi-factory items build for the 1968 race cars.

While they likely leave some performance on the table due to their length, and lack of X-pipe, they are leaps and bounds ahead of the stock 69 design. And, technically, a factory homage.

You'll need earplugs to drive the car, though.

 

Okay....69 pipes are similar to a regular muffler...easiest wat to describe it is they run two pipes parallel to each other and have baffles between so the pressure waves run down the pipe, hit the end bounce back and through the baffles to the opposite chamber and out the rear. Stock was a 2 inch pipe...kind of lousey performance. a company called sweet thunder made a performance version in various pipe sizes that will bolt into rams horns or big block stock exhaust. They make c2 versions or c3 versions.
The C2 chambered pipe is a straight pipe with perferations on the inner chamber that brakes up the pressure wave at a low rpm, low pressure cruise, jump on it and it barks

They changed their name and are now high flo performance. The c3 stock version is nice but not like the c2 version
They offer them in quiet, stock and wild....wild will wake the dead...really loud, 1/8th mile away hear you coming loud...harley straight pipe loud...but sound very nice.
I had the small block 2.5 inch version and the big block C2 version with the C3 tips installed in the wild version...you should call and talk to them about what you want...the owner usually answers.

You probably want the c2 in the quiet version....they can squeeze them into a 2.25 pipe...the 2.5 is too big with the baffling for quiet pipes to fit in the stock shields...call them.
https://highfloperformance.com/
https://www.ebay.com/str/highfloperf....m4084.l113337

Stock style 2.5 inch

Same motor same cam, same carbs

Oct last year with the C2 wild pipes

Weber carbs last week. Stayed at 2000 rpm in cruise in fourth, when i go to fifth and get to 1500 rpm they quiet down alot...but too loud for most people...i have racing communication headsets for long drives

 

Here's another thread that may give you some ideas.

https://www.corvetteforum.com/forums...-finished.html

EDIT: Oops. I see someone already posted it!

 

Thank you for those videos… just what the Dr. Ordered!

I appreciate your help.

 

I forgot to say I use Hedman side exhaust headers into those pipes. Stock manifolds to these pipes should be a bit mellower

 

Hedman side pipes? What diameter header is it on your car if you don’t mind me asking?

 

I found the Borla was the lowest restriction with a noise level I was able to tolerate.