[MICAH1]

I have searched and read many of the threads on the exhaust system for the GT that detail many of the pros and cons for the proper type of muffler. I have also read that flowmasters are not desirable and that some of the turbo glass packs may be a bit unbearable and loud. I would like to go with a custom design and reading Rally Bob's recommendations on pipe dimensions I am only left with purchasing the best free-flow muffler(s). Can a system be designed with one muffler with the pipe being shaped to bend over the rear axle and split into two pipes as in the stock or would that be to loud and require a second muffler or resonator. I have a 32/36, ported intake with sprint exhaust and stock 1.9. Can anyone out there point me to a website or dealer for the proper muffler. I have had a ANSA system on a previous GT but want something better or current.

 

[Travis]

One free flowing muffler is going to be too loud. It will annoy you and the especially the neighbors. I'm currently using two 4" round stainless Magnaflow mufflers, each with a 2-1/2" core and while it's not load, it's not quiet either. Most people will be better off with a mixture of a 2" core and a 2-1/2" core which should be quieter.

I've been very happy with the price and quality of the magnaflow mufflers. They sound great too

-Travis

 

[RallyBob]

Travis, perhaps you should clarify that your engine is also in a higher state of tune than most.

Wayne Torman's GT has a mild engine: flat-tops, big valve head but a small cam. He has a 2" exhaust with one single Simons muffler in front, splitting out back to two exhaust tips. It's not loud at all. I think that the headwork and cam on your engine have a lot to do with the sound.

Bob

 

[Travis]

Yes and No. I originally ran a cherry bomb with a stock early motor and it was loud. When I installed the new motor it did get louder which supports your comments. However, I then installed a single 4" Magnaflow and while the tone was better it wasn't really much quieter. Based on this, one could theorize that the Magnaflow would be 'similiar' to the cherry bomb with a stock motor, which was loud. There is one caveat here however which is that the cherry bomb had a 2" core and the Magnaflow a 2-1/2" core which makes it difficult to compare.

If I were to daily drive my GT I would not do so with the existing exhaust, both because I couldn't stand the noise and because my neighbor has already called the cops to complain (both mufflers installed). However, I could imagine that if I were to go back to a stock or nearly stock motor with the existing exhaust it would be OK.

Also, on the Magnaflow site it reccomends the 4" muffler for use as a resonator or for a more sporty sound. I would interpret that as 'it will be loud if used alone'....

What size is Waynes Simmons? both core and body size.... The larger the body the more effective the damping

-Travis

 

[oldopelguy]

kadett

On my Kadett I ran a single 2.25" inlet and outlet $19 Thrush turbo muffler and was constantly annoyed by it being too loud. The motor is an almost bone stock 1900 with a header and 2.25 inch pipe all the way back.

I recently got so annoyed, in fact, that I moved the turbo muffler all the way to the back and added a glass-pack (cherry bomb) in front of the axle. The tone and volume are much better with this set-up and I'm very pleased.

On a GT I would recommend taking a look at the stock replacement muffler meant for the newest model of Camaro. It mounts the same, is not a lot bigger, and won't possibly offer enough restriction to affect the GT. If it was too loud, and I really can't imagine it being so, you could add almost anything in front of the axle to get it super quiet.

 

[MICAH1]

"The Right Stuff"

Rally Bob are you saying that a single Simon muffler with the pipe running back over the rear splitting into the two tips (w/o resonator) should work for the stock engine?

 

[Travis]

Note that the Simmons mufflers are not available in the US. You'd have to have them imported from Europe...

-Travis

 

[MICAH1]

TRAVIS, WHAT IS A GREAT SUB TO THE SIMON THAT IS AVAILABLE IN THE STATES...

 

[opelbits]

Hmm, I have an interest in this subject as well....

Euro 2.0, 32/36 Dgev or 38 DGAS(depending), intake manifold matched to 38 DGAS, and a stock or 75 f.i. exhaust manifold (also depending), Pertronix coil and ignition, stock exhaust.

Runs out of chuff about 3-3.5k (I am assuming it is the restrictive exhaust), so I need to replace my exhaust with 2" pipe and a good muffler, but I don't like loud cars.

The late model Camaro muffler seems like it might be a bit big to put in back (I'm assuming it goes behind the axle from what Oldopelguy says). Also, if it did go in back, how would it affect the engines performance with it so far back?


BTW-Micah1, how are you doing with that manifold?

 

[MICAH1]

HEY TONY P THE MANIFOLD IS ALL CLEANED UP AND READY FOR INSTALL AS SOON AS THE BOTTOM HALF OF THIS EXHAUST SYSTEM IS DECIDED. WHAT ARE YOUR THOUGHTS ON MY PROJECT?

 

[opelbits]

I don't know. I'm in the same position myself.

 

[Old Hippie]

The muff for the Camero was designed for the Hi-performer V6, so there shouldn't be any problem for the 1.9L (+) engine. As oldopelguy said: "mounts the same and is slightly larger". And probably cheaper than gett a stock Opel muff.

 

[bear]

Being we're talking mufflers, I guess I can relate to you what I did on my old raggedy 71 Dodge van with a full blown go fast 340 cu in engine. (I needed an engine that would move 3 1/2 tons.) I put a set of hedman hedders on it and looked for a stock muffler that had 2 1/2" in and out. I found at my local Pep Boys for $19.95 a single exhaust muffler for a Lincoln with a 460 cu in V-8. So I bought a pair. Easy mathematics, each muffler was designed to flow exhaust on 460, so now each muffler would flow 170 cu in. Minimal back pressure. Nice and fairly quiet until 3800 RPM. Then it made some really good rumblings. I didn't have to worry about the size on my van, but it wasn't a real large muffler anyway. My suggestion and what I'm going to have to do on my V-6 GT, find something the flows or is designed for more than what you've got. Just my $.02.

Ron

 

[oldopelguy]

what I mean

This is a stock muffler for a Camaro currently on e-bay for $10. I think worst case you would have to rotate the pipes and maybe shorten them, but it should work great in a GT. At least I think it should.

 

[kwilford]

Camaro Rear Muffler in a GT

It looks like it would also need to have the pipes re-bent to be closer together, to exit with the spacing of the stock pipes. Does the Camaro use a front muffler as well, or is this all it uses? Has anyone actually tried this yet?

 

[madhatterpdc]

I've seen that muffler before (Camaro) and it is a good size bigger than the stock GT muffler or resonator. I honestly don't think that there would be enough room for the Camaro muffler to mount in the stock GT resonator position. You might be able to fit it in the stock muffler location rotated 90 degs, but then you are looking at having to use the inlet as the second outlet...

If I remember correctly, I *think* that the Camaro only uses that muffler and a Catalytic converter. (could be mistaken)

Does anyone know width of the Camaro muffler itself? Take that measurement and then factor that you are going to have the arch the outlets around and back to get it anywhere near the factory location.

I am interested to see if this can work.

 

[oldopelguy]

options

The Camaro only uses the one muffler. Obviously the pipes going in and goming out would have to be fabricated, but that configuration of muffler should fit across the back of the GT. Ther are a lot of aftermarket options available, in different sizes, configured for the Camaro, that might be adapted to the GT. Someone would probably have to get one of the mufflers in hand to actually find out. You could probably ask at the local muffler shop and see what they carry and just how big it really is without actually buying it.

Another option similar in nature might be one of the two Corvette mufflers below. Again, the inlet and outlet pipes would have to be fabricated, but it probably would mount across the back. You would only have outlets on the one side with this option, but it should work OK.

Again, I'm only talking about the mufflers, not the pipes in and out, as I'm sure they won't work. These 2 muffler options are different configurations than the standard in-one-side-out-the-other mufflers and I'm only suggesting them as options in case people weren't aware they existed. The easiest solution would obviously be to buy a Kadett and just use a regular muffler in the back, like most new cars.

 

[bear]

O.K., let me see now. The Corvette has a 350 cu in engine, which equates to a 5.7 liter, divided by 2 = 2.87 liter flow per muffler. I have a 3.4 liter V-6 divided by 2 = 1.7 liter flow. Yep, I should be able to have a nice, quiet, non restricted flow through those from my 3.4. Now if the inlet and outlet are 2 1/2" that would be perfect, if they would both fit behind the rear axle.

Ron

 

[MICAH1]

Still Looking for the Right Stuff

Okay guys lets see, camero's, corvette's, whew... and Namba209 you have really missed your calling. You are right up there with Einstein. The Airforce lost a major player when you retired. At the top of this page you see what I have to work with, based on that is there a design and muffler name that could work for me without much fabrication?

I do appreciate all of the expert suggestions and help.

 

[RallyBob]

What size is Waynes Simmons? both core and body size.... The larger the body the more effective the damping

-Travis

This photo shows the muffler size as installed on Wayne's GT. A 2" headpipe feeds the 2" muffler, and then goes to 2.5" over the axle, splitting into two tips.