Hey everyone,

As I'm scrambling to get my new engine in (see gallery) I need to get the exhaust work done quickly and correctly. Those two rarely go well together, so I want to go in with a very good idea of *exactly* what I want. That's why I need some help, and preferably some pictures to take with me to make sure they do it right.

Here's what had been recommended to me previously on an exhaust setup for my dutra duals:

2" pipe from front/rear manifolds down to a Y. The Y would be located at the transmission cross member (PIC ANYONE?) so that its out of way. The Y is 2" in, and 2.25" out. Then 2.25" all the way back.

Muffler: what to get? I want something that is freeflowing but not obnoxious. I had thought about the flowmaster delta 50 series, but wouldn't mind recommendations from you guys on what you're using. I could also ask for something that is stock on a 360 engine and get it that way. Lastly, where should I locate the muffler to prevent cabin noise?

Ha! Last is tailpipe, how to tuck it up so its outta the way in case I put a rear sway bar on sometime down the road.

Pictures puuuulllease!

Thanks!

MJ

I have Walker super turbos. It is two 2" pipes and two mufflers. I don't think it is too loud, even on the highway. I would guess that one muffler would be even quieter.

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"Nothing in all creation is hidden from God's sight. Everything is uncovered and laid bare before the eyes of Him to whom we must give account."

I really want to like so-called "turbo" mufflers from e.g. Walker. The idea seems perfectly nifty on paper (or when the lazy exhaust shop guy is trying to get you to buy one 'cause to him yours is just a shìtty old car and he keeps 'em on the shelf), but my repeated experience with them, in terms of durability, sound quality and backpressure, is poor.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

i like the flowmaster 40 series delta flow. i dont think it is loud at all. i dont think it is bad about resonating, at least not at any of the rpm's that i usually drive at. i was told by the muffler shop that a 50 series would not fit in the stock location for the muffler because it was too large. i bought the muffler from jegs, so they weren't telling me that just because they had one to sell me. i dont know if this is true or not, maybe someone else can answer that.

That's interesting. I think I'll run down there today and see for myself what the size difference would be.

I do see by the specs the Delta 50 is 23" total vs the Delta 40's 19" total length. I wonder if that's the issue. I've never crawled down under there to look very closely.

What is a "turbo" muffler? Something that is supposed to be free flowing with low-back pressure? I tried asking my shop if they stock regular walker or goerlich (sp?) mufflers and they gave me a quizzical look. Argh. Its the only shop in town that has been recommeded to me several times. I have had work done there twice before, and wasn't all that pleased. They replaced the muffler in my wife's old car, only to have it rust out 13 months later. They did replace a pipe for me on my truck that went from the muffler to exit the rear fender, and it seems ok. The price they quoted me off the top of their head was $325 using whatever muffler they have lying around. I was suspicious of any place that didn't stock a bunch of name brand performance mufflers.

Am I being crazy?

MJ

Good question. The term is almost as hackneyed and abused as "Xenon headlights". The first (and only actual real) turbo muffler was the item that came from the factory on the turbocharged Chevrolet Corvair. Because a turbocharger acts as a "sound Cuisinart", the muffler on a turbocharged car has an easier job quietening down the exhaust. For that reason, a muffler with fewer internal works was used on the turbo Corvair (not so much to squeeze out more performance, but to cost-reduce the muffler!).

At the time, aftermarket performance muffler options were considerably less than they are today. Basically the choice was between stock or stock-type, or the cylindrical glasspack/steelpack items. Streetgoing hotrodders who had to comply with "stock type muffler" state laws soon caught on to the Corvair turbo muffler as a lower-restriction design in a stock-type case. International-Harvester also had a favored design, and the stock mufflers for the big Mopars with Hemi engines were also on the list. (NLM- your Petersen book talks about this in the "fuel economy" section).

The aftermarket manufacturers have since that time flooded the market with all kinds of different products being sold as "turbo mufflers". The term is loosely and generically used (abused) to refer to stock-type mufflers that are supposedly of "high performance" (low backpressure) design. Unfortunately, much of it's hype. I don't have it any more, but one of the performance mags ran a pretty thorough test of a bunch of mufflers in the mid '90s, and found that many of the so-called "turbo" mufflers just made more noise and didn't have particularly impressive backpressure figures. Some of them, on the other hand, produced both good flow and good noise readings. Wish I still had that article; it's hard to find good objective tests of backpressure and noise, 'cause most of the info is put out by the manufacturers themselves.

You have to be careful when looking at the numbers, though, because many "turbo" mufflers rely heavily on roving glass wool for exhaust noise reduction. This works, but as with most things, there's a right way to do it and a lot of wrong ways to do it, and if it's not done right, sound control and flow goes all to hell sooner than later as the glass wool packing settles, becomes compacted or gets loaded down with soot. Had this experience with a series of Magnaflow mufflers on a few different cars, which started out having near-perfect sound levels but quickly developed obnoxious noise artifacts as the packing settled and/or loaded up. Adding resonators, etc. did nothing to bring sound control back; all I could do was change mufflers, and that's what I did.

My 318/catalyst truck, on the other hand, has a really expensive polished stainless straight-through muffler (pretty sure it's a Walker DynoMax Ultraflo SS) the previous owner put on. For what it is, it's REALLY quiet, and has stayed that way for a few years now, so it's probably going to keep staying that way.

Another thing to remember is that as gas volume through the muffler increases, the muffler gets quieter. As gas volume through the muffler decreases, the muffler gets louder. Primary factors affecting gas volume through the muffler include the number of cylinders feeding the muffler (3 or 6 on a 6-cylinder engine, 4 or 8 on a V8), as well as the muffler's placement—closer to the engine = hotter exhaust = more gas volume = quieter. Closer to the rear of the car = cooler exhaust = less gas volume = louder.

Pipe size also exerts just as large an effect on noise as on flow. Exhaust cools considerably as it goes through the system. That's why factory systems decrease in pipe diameter as they go rearward: cooler gas requires less pipe cross-sectional area for any given level of flow/backpressure. Same-size-all-the-way-back systems can tend to be quite a bit noisier due to the megaphone effect.

Some of the newer muffler designs (the Flowmaster Delta, for instance) are starting to be able to get good control over the tougher noise-control problems such as the resonance inline Sixes set up. You may still have to use a resonator in the tailpipe.

For my part, I've tended to just use larger-than-stock, stock-type mufflers and had good results that way.
You spelt Goerlich correctly. I don't like it when an exhaust shop wants to throw on something that's "kind of close" to what I've asked for just 'cause they happen to have it in stock. It indicates to me they're more interested in getting my car out and my money in than they are in putting together the system I want.
Well, then, stay away from them!
See above.
Well, it's not so critical that they stock it all...many shops are too small to carry much stock, and most of them have a stocking arrangement with a local jobber. Nothing wrong with that. But if they're unwilling to get and install what you want, shop elsewhere.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Thanks Dan, that's the info I was looking for. I'll see what I can get setup. I have run a dynomax muffler before, didn't realize they are the same company as Walker. I have had a SS Borla muffler on my 4runner for over 7 years, and while its louder than stock, its hardly loud at all--you only notice it compared to a stock muffler. Its located is very near the rear axle, probably even farther back than a slant. I've always really liked it, and it was part of the reason I was considering investing in a stainless muffler if I can get a good recommendation. it may not still be shiny, but my truck has never spent a single day inside since we moved to ohio 7 years ago, and all of the stainless stuff is there and non-leaking. The aluminzed section from the muffler back to the "tailpipe" is what rusted and fell off and was replaced.

MJ

I bet the library does. What magazine, what month, what year? I wonder if any of the mufflers tested are still on the market, unchanged?
Sorry...

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

I paid $200 for my install ( I already had the mufflers - $40 each). My mufflers are just in front of the rear end. I had to have both pipes go past the tranny on the driver's side 'cause my car never came with dual exhast. Also, it was hard to get both pipes down past the "Z" bar for my clutch.

I would say that you shouldn't pay more since your install should be easier.

I will second not going back to a shop that I had a poor experience.

In the words of James T. Kirk, "There's got ...........to be .... a ... way!"

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"Nothing in all creation is hidden from God's sight. Everything is uncovered and laid bare before the eyes of Him to whom we must give account."

Make sure that the shop stands behind their work.

Remember, sh*t happens

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82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

...that way if you think they did a crummy job, you can just rev the engine and give 'em a faceful of exhaust!

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

"Aye caramba; I'm sure I don't remember!", and "Maybe a few but not many", respectively. If I recall correctly, the
"Sonic Turbo" muffler with "parabolic soundwave reflectors" was being heavily marketed at the time.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I remember that thing, Crappy Tire Special, so obviously I didnt trust it. Did it score well?

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.