True Dual Exhaust

[Stallion]

What is this exactly? Can you give me an explanation to this? I hear this being talked about throughout the forum, but I can't take it out of text what it really means and it's not in the glossary.

Thanks!

 

[DDLS3]

Stallion,

Most stock corvettes come with a Y-pipe that connects the left and right pipes to a single catalitic convertor. Then another Y-pipe in the rear to twin mufflers giving it the appearence of dual exhaust. A corvette that is sporting "true duals" does not have a Y-pipe , but instead has two seperate right/left exhaust pipes from the exhaust header to the associated muffler.

 

[Stallion]

What is the benefit of having this true dual?

So, this is how it goes. There are two headers on a block. Then, the two headers (not in a true dual) come together for the catalytic converter? And then they go apart for the two mufflers? Is that if you have the stock setup?

I see. Thanks!

 

[Bob Chadwick]

True duals.

http://home.attbi.com/~jchadwick/exhaust.htm

 

[Stallion]

Wow, that's pretty nice. But, it looks like those two tail pipes are real close to the ground. Did you ever have a problem with scraping the bottom of your Vette on the ground over a hill or something? I've always wondered that for low-lying and low center of gravity sports cars. Is this a problem?

And in this picture, are the cats those two brass parts? Know what I'm referring to?

Thanks!

 

[Bob Chadwick]

No problem hitting the ground. In fact my stock Legend has more clearance problems than the Vette. Those two brass looking things on either side of the car are high flow cats.

 

[jetech]

Bobchad
What does the crossover pipe do.

 

[Bob Chadwick]

Two types are talked about. X & H. They are both supposed to smooth out the exhaust pulses.

the H-pipe is recommended for better low end torque and the X-pipe is recommended for better top end hp. Both X and H pipes are said to help reduce the "gurgle" and "popping" on deceleration.

 

[MsSchroder]

Bob, I love the audio of those flowmasters. Whenever I play it all
the kids come running to see what's up
-Tammy

 

[Bob Chadwick]

Thanks. I have to go listen to it every once in a while cause always driving the car I never get to hear it. My wife says she can hear the car as soon as I turn the corner into the neighborhood.

I pity the neighbor. The garage faces the wall where his bedroom is. On occassion I'll drive the car to work. Start it up at around 6:30am on a high idle until its warmed up. It's got to vibrate the walls.

Bob

 

[Stallion]

I love the sound of Vettes! I can't even imagine what side pipes would sound like. I would love to have them, but I'm not going to be picky. And, I'm not sure if I would put them in if they aren't stock. Would that be hard to do?

Thanks!

 

[cdhorn]

That's a really nice dual set-up. When I got my 81, it had a nice throaty sound and I assumed that the previous owner put on some glasspacks or something. When I got it up on the lift, I was surprised to find out that it had no mufflers. My cat is the muffler. Haven't had any problems so far in 5 years for too much noise either. Fortunately, my neighbor likes the sound as much as I do. The other thing that surprised me was that the 81 came with headers. I'm not sure, but they look like factory equipment. It looks like your set-up does have more ground clearance than the factory cat which seems bigger. Do you get much of a performance increase from the "true dual"?

Clark

 

[sscam69]

I didn't put and H/X pipe with my setup, though I should have.


The X/H pipe is suppose to help with scavenging the exhaust. In addition it helps improve low end torque, which is always good on a street vehicle, and its suppose to lower the exhaust sound. Thats for those neighbors that don't like the sound at 6:30 in the A.M. :L.

Supposedly, someone correct me if I am wrong, the way to tell where to put the X/H pipe is to paint the exhaust with a certain kind of paint, not to sure which one. You run the car at cruise to low rpm and watch where the paint starts to change color first. Thats the "hot spot". The suggestion goes thats where your suppose to install the X/H pipe.

How true it is I don't know, maybe some of the more seasoned professionals can chime in?

Frank

 

[Bob Chadwick]

CDHorn - I went with a slightly smaller pipe, 2 1/4 v. 2 1/2, on the low HP L48 in the car. I did not notice any decrease in low end torque that some people notice when they put a less restrictive exhaust on their car.

As to more power, I'm not sure. Off the line I don't think so. At higher RPM, possibly.

Stallion, I paid to have mine installed. I think labor was in the $200 - 250 range above and beyond the cost of the parts. I was concerned about having the tools if the exhaust didn't fit exactly right. Lots of people here have posted about buying the off the shelf kits and putting them in with no problem. Others have posted about them not going in exactly right with rattles and squeaks from contact with the frame where the bend is not exactly right. Murphy's Law would suggest that I would be in the latter. Not worth the headache so I paid to have it put in and am verry happy.

Bob

 

[Stallion]

I see what you mean, bobchad. Just a question about the side pipes. Do they act as the only exaust? Or are there still mufflers, etc. for that? And if they are the only, where are the cats placement on it?

Where do the side pipes actually come from? The headers give the exaust to them instead of normal? Is that how that would work?

Thanks!

 

[Bob Chadwick]

Side pipes are just the exhaust coming out of the side of the car rather than the back. They are generally more restrictive than a straight back exhaust of the same specs because of the bends.

Some people use muffling material in them, others don't.

I don't think you could get a cat in the system with side pipes.

Bob

 

[sscam69]

TR

The sidepipes come very restrictive with the glasspack inserts.

There are these things call spiral baffels that help free up the breathing BIG TIME. The gains ARE HUGE when it comes to power and torque. Honestly I have never seen gains like that from a bolt on deal short of a power adder i.e. supercharging, N2o etc. That says alot about the glasspack inserts.

You insert them and replace the glasspacks. I believe they are just as quiet but really flow which is what its all about when it comes to an engine. The look like a big screw except they don't taper.

Frank

 

[MaineShark]

Actually, I was browsing through Eckler's, and they have a cat-back side-pipe exhaust for the C4's.

It has a splitter immediately after the cat, and then pipes go out, then forward from there. There are mufflers, and then pipes that go back. Hard to explain, but if you search for "Lawrence Side Effects" on their web site, I'm sure you will find them. Or, if you have the 2002 Fall/Winter catalog, they are on page 131.

Joe

 

[Bob Chadwick]

I think Side Effects was what Ken had on his car at Bowling Green. No idea they had cats included. Sounded mean.

 

[Stallion]

But, if you have, say, a mid-70's Vette and you put side pipes on it without cats, then you couldn't pass the emission test, could you? Because aren't only, I think, '72 and below Vettes exempt from having to pass these emission tests? Then, I guess you could put the pipes on with no cats.

Would this be a conflict?

Thanks!