FAQ: The Exhaust Thread

dboydakid wrote:

SO IF I WAS TO GET A 3" DP AND JUST ADD MUFFLERS AND TIPS TO MY EXISTING EXHAUST SYSTEM I SHOULD BE OK? I WAS THINKING ABOUT MAGNAFLOWS JUST TO GIVE IT A LITTLE GROWL OR NOISE

Yeah.

KOOL....R MAGS GOOD??? OR SHOULD I GO WITH FLOWMASTER? LOL..

dboydakid wrote:

KOOL....R MAGS GOOD??? OR SHOULD I GO WITH FLOWMASTER? LOL..

you wanna go have a listen, check on line you'll find youtube vid of various ones. for my money I'd get Hooker "MaximumFLow" mufflers, though. You can get aftermarket AP parts to put more or less stock tailpipes on aft the muffs, they were on rockauto.com

Albertj

ok ill check em both out..thnx

So where the down pipe meets the catalytic converter, is the diameter 2 1/4 inlet diameter or 2 1/4 outlet diameter?

Has anyone installed a Corsa system on their Riv?

I know Corsa does not make a cat-back for the Riv, but supposedly part # 14150 for the Caddy Seville will work...

The system is beautiful and the sound it produces is nothing less than breathtaking.

http://www.corsaperf.com/product_display.aspx?product=615

Ron's Rocket Riv wrote:

Has anyone installed a Corsa system on their Riv?

I know Corsa does not make a cat-back for the Riv, but supposedly part # 14150 for the Caddy Seville will work...

The system is beautiful and the sound it produces is nothing less than breathtaking.

http://www.corsaperf.com/product_display.aspx?product=615

A certain member on this forum has like two sets and has yet to install one 'cause he's taking FOREVER

I contacted Corsa years ago and asked about a Riv cat-back. They wrote me back saying they couldn't help me. Maybe I didn't ask them the right questions, lol.

As long as we are on the topic, I'll just share for shits & giggles I contacted Corsa's tech support a while back to ask them about how the caddy setup might behave on a totally different engine (ours) provided it fits and the gist of their response was that since it's not tuned to manage the sound of that type of motor, it wouldn't work well. I'm paraphrasing and they didn't really go into much detail aside from telling me every kit is very specifically tuned for the car its for.

Personally, I wouldn't take for granted that all these exhaust kits from Magnaflow, Etc. are really that fine-tuned for the applications that they fit.. I could very well believe that when they create a kit for a vehicle, they just pick the best fitting parts (mufflers, resonators) out of what they manufacture, bend the pipe and make a bolt-on kit that fits perfect. Chances are, it'll sound pretty good for most cases and since the mufflers themselves flow very well, it functions as advertised. I dunno. Maybe I'm just being negative nancy here.

Ron's Rocket Riv wrote:

Has anyone installed a Corsa system on their Riv?
I know Corsa does not make a cat-back for the Riv, but supposedly part # 14150 for the Caddy Seville will work...
The system is beautiful and the sound it produces is nothing less than breathtaking.

AA wrote:

I contacted Corsa years ago and asked about a Riv cat-back. They wrote me back saying they couldn't help me. Maybe I didn't ask them the right questions, lol.

turtleman wrote:

I contacted Corsa's tech support a while back to ask them about how the caddy setup might behave on a totally different engine (ours) provided it fits and the gist of their response was that since it's not tuned to manage the sound of that type of motor, it wouldn't work well...

Ron, that breathtaking sound was with a 90-degree Cadillac V8... With the well-known peculiarities of the Buick V6, I would certainly believe them when they say that their system might FIT the car, but not sound good with a non-V8.....

Unfortunately, by now I think most of us agree that even a Chrysler Slant-6 sounds better with dual-exhaust than our 90-degree Buick 3800's. You can make more power, you might even be able to sound good at a certain RPM, but compared to a V8, these 'un-natural' 90-degree bent-sixes will never sound as good with twice-pipes as a plain ol' 350...
.

You know what, I just heard an uncorked 3.6L Camaro yesterday. It sounded freakin' terrible - worse than pretty much any 3800 I've heard. I have no idea what exhaust system it had on it or if it was a re-re job with no mufflers or something but there is still quite a bit a well tuned exhaust system can do for the 3800, IMO.

turtleman wrote:

You know what, I just heard an uncorked 3.6L Camaro yesterday.....

Isn't that motor 60 degrees, though?

turtleman wrote:

You know what, I just heard an uncorked 3.6L Camaro yesterday. It sounded freakin' terrible - worse than pretty much any 3800 I've heard. I have no idea what exhaust system it had on it or if it was a re-re job with no mufflers or something but there is still quite a bit a well tuned exhaust system can do for the 3800, IMO.

Hey Codith,

So far, I think the best sounding exhaust I have seen/heard on a Riv was yours during this video:
https://www.youtube.com/watch?v=0ZExZx3NZAA&list=UU90gBbZtSTNv7ZiaPJe2_rg&index=17&feature=plcp

What was the set up there? 3" pipes with cat and resonator deleted down to DynoMax Super Turbo mufflers, if I recall correctly from the description... Was it boomy and full of drone on the highway?

Ron's Rocket Riv wrote:

turtleman wrote:

You know what, I just heard an uncorked 3.6L Camaro yesterday. It sounded freakin' terrible - worse than pretty much any 3800 I've heard. I have no idea what exhaust system it had on it or if it was a re-re job with no mufflers or something but there is still quite a bit a well tuned exhaust system can do for the 3800, IMO.

Hey Codith,

So far, I think the best sounding exhaust I have seen/heard on a Riv was yours during this video:
https://www.youtube.com/watch?v=0ZExZx3NZAA&list=UU90gBbZtSTNv7ZiaPJe2_rg&index=17&feature=plcp

What was the set up there? 3" pipes with cat and resonator deleted down to DynoMax Super Turbo mufflers, if I recall correctly from the description... Was it boomy and full of drone on the highway?

That was a good sounding exhaust. Yeah that was stock exhaust manifolds with a 3" downpipe. Mufflers were 2.5". It had mild drone, not bad but actually sounded good with throttle. I later added a 4" x 18" body glasspack (dynomax race bullet muffler) where the original resonator was and it did nearly nothing except reduce the sound at idle a little. I think what turned me off to that setup was when I installed the headers. It changed the sound in a way I can't say I really like. Then I got a b.s. ticket because of my exhaust which honestly wasn't that loud but the thing is there was no way to really make it quiet as you're driving past the one dick cop in the wrong time in the wrong town. The drone frequencies carry even if it's not bad. But yeah aside my windy story, it was a nice sound.

Eldo wrote:

Ron's Rocket Riv wrote:

Has anyone installed a Corsa system on their Riv?
I know Corsa does not make a cat-back for the Riv, but supposedly part # 14150 for the Caddy Seville will work...
The system is beautiful and the sound it produces is nothing less than breathtaking.

AA wrote:

I contacted Corsa years ago and asked about a Riv cat-back. They wrote me back saying they couldn't help me. Maybe I didn't ask them the right questions, lol.

turtleman wrote:

I contacted Corsa's tech support a while back to ask them about how the caddy setup might behave on a totally different engine (ours) provided it fits and the gist of their response was that since it's not tuned to manage the sound of that type of motor, it wouldn't work well...

Ron, that breathtaking sound was with a 90-degree Cadillac V8... With the well-known peculiarities of the Buick V6, I would certainly believe them when they say that their system might FIT the car, but not sound good with a non-V8.....

Unfortunately, by now I think most of us agree that even a Chrysler Slant-6 sounds better with dual-exhaust than our 90-degree Buick 3800's. You can make more power, you might even be able to sound good at a certain RPM, but compared to a V8, these 'un-natural' 90-degree bent-sixes will never sound as good with twice-pipes as a plain ol' 350...
.

The Corsa will probably sound OK but not optimal because the number of detonations per second at a given speed is not *that* different for the bent 6 3800 versus the no'star 8. Here is a little high-level detail.

In the exhaust basically you are fighting the sound of the engine exhaust making a certain number of detonations per second. The number of detonations per revolution of the engine depends in part on the number of cylinders but due to the physical limitations is the same for a given number of cylinders on an engine. Here is a little more detail with help from Victoria High School teacher Michael Grew (LINK).

For all intents and purposes, a combustion cycle is two revolutions of the crankshaft, or 720 degrees long. The power stroke is the only stroke where power is actually added to the engine, and it's the one that makes the "bang" that we are controlling via the resonator and muffler(s). All other strokes use power from the engine and don't make their own "bang." In a single cylinder engine, the inertia of the flywheel is the only thing which keeps the engine running through its non-power strokes, and there is 720 degrees between power strokes in a single cylinder engine, so there is a "bang" every other crank rotation. (the flywheel has to spin the engine around to enable the next power stroke). This makes a single cylinder engine rough running especially at idle speed; and the larger the displacement, and the larger the piston, the more it vibrates (just ask my garden tractor). By taking the same displacement, splitting it up into two cylinders, the crank turns only 360 degrees between power strokes and the engine runs much smoother. Increasing cylinders makes smoother running engines - a four cylinder engine has 180 degrees between power strokes, a six has around 135 degrees, and an eight cylinder engine has only 90. So why is an 8 so smooth? Because with only 90 degrees between power strokes there is no time in the operation of the engine when there isn't a power stroke happening somewhere in the engine. And the greater the number of cylinders, the smoother running the engine will be if only because the power strokes will overlap.

OK so what the heck does this have to do with exhaust noise? A six cylinder engine will have three "bang" per crank rotation and an eight will have four. At 2000 RPM the six will bang about 11 times a second and an eight will bang about eight.

So if you are designing an exhaust not to drone at cruise you have to make it attenuate the "bang" which is a deep bass note (the drone) with a lot of harmonics. IIRC Corsa uses a Helmholz resonator - in order to get it right the resonator has to be a different configuration for a six versus an eight because they cruise at different RPM and in that there is a further difference in number of bangs per second. The six is turning faster, the frequency that must be attenuated is higher so the resonator has to be a different length - in theory. In practice the Corsa system probably will work on the 3800 but probably will drone at one or another end of the "cruise speed" range. I assume they tuned the Helmholz to make the exhaust not drone at cruise with the no'star between 40 and 80 MPH. (and to be sure to be quiet at 60 MPH being the center speed of that distribution). So I assume the problem is that installed on the Riv the Corsa might start droning at 65 or 70 MPH, which in much of the US is legal speed.

...and yeah, with no muffler or resonator that the 3800 is a raspy cuss, sounds like a hungover bumblebee with vengeance and larceny in its heart, to steal your comfort and peace at any cost. On the Riv most of the noise is eliminated in the factory resonator - the relatively small mufflers actually resonate with the drum-shaped spare tire well to make acceleration sounds. When I put the Park Ave exhaust on my car the different mufflers on it pretty much nixed that sound. (and they breathe better)

Albertj

turtleman wrote:

A certain member on this forum has like two sets and has yet to install one 'cause he's taking FOREVER

I've been busy with other projects. The green riv has basically been relegated to winter beater duty. Sadly the main holdup has been finding a 3 OD- 2.5" ID reducer in 304SS. I had to have one custom made and ran in to some issues with the company. I'm hoping on having it installed next week.

Also, I sold one of the exhausts. Couldn't pass up as since it was for more than twice what I paid.

Maybe? Link (would need welded in)

I was looking for something bolt-on. Also note the Corsa exhaust requires some tweaking to fit perfectly.

cammed 3800 with the Corsa Seville catback, OEM exhaust manifolds with 3" downpipe



sounds loud!

Another video of mine I almost forgot to post.
near pointless test of a Magnaflow 13749...
a 3ft long tuned chamber muffler tied right to the downpipe and dumping - pretty damn loud
but it seems to get quieter with throttle instead of louder like straight-through mufflers do which I may play with more before it's too cold right now!


beastly thing


test setup

If I were to run that muffler, it would be right in that cat/resonator section of the exhaust system and it'd have some help from another muffler at the back - probably a typical straight-through design. It's just very hard to test anything when I have a fully welded exhaust.

I am going to need to change something though because since the engine swap, the clearance between my current glasspack that's behind where the factory cat would be and the heat shield there is gone and I have a good bit of resonance because of that. I didn't really have any clearance there before but it wasn't as bad since the worthless jelly welly rear transmount had everything sitting lower than it should and so the vibration didn't really disturb the cabin.

Is that some new type of silicone rubber flex pipe that can withstand high temperatures?

That looks like an intake boot he stuck on there just to test the sound...

lmao. i can't tell if Aaron was being serious or not but i got a laugh out of it.