1971 Mufflers

[Tom Daniels]

I bought a '71, LS5, 454 about five years ago. As part of the restoration process I bought and installed a complete after market stock exhaust system including the mufflers.

I have always been a little disatisfied with this system. It is too quiet. There is no "throatiness" with the exhaust tone, and you would not know that this is a Big Block engine just by listening.

So I was considering installing side exhausts, but I have read all the messages dealing with these and I now believe that they would be way to noisy.

My questions are:

Do after market mufflers exist (not chambered exhaust) that are more louder than the stock system? If so who makes them? What is the "off road exhaust"? Does it exist for '71 years? Any other thoughts?

---- Thx., Tom Daniels

[joevette57]

Re: 1971 Mufflers

Tom,

If yo have thought about side pipes, then don't discount chambered exhaust. After a club member put them on his 66/427, I was convinced! the best sound I've ever heard. A car that sounds like it has side pipes, but the noise doesn't make you ears ring like a side exhaust car.

He liked it so much, he put a chambered system on his '96 from the cats back, and that car sonds terrific as well.

As time and finances allow it's something I'm seriously considering for my 71 small block. The on;lt thinf holding me back is the previous owner of my car put a brand new aluminized exhaust on it, and it looks too good to just toss it. Hope this helps. Joe

[mike hom]

Re: 1971 Mufflers

I have a 65 L78 396 with factory side exhausts and I'll admit they're loud. But i wouldn't say they are too loud, not at all. if you want to announce that big block coming, this is the way to go. I really think a consideration here is how you drive the car. if it is a daily driver, you might get tired of side pipes. But if, like mine, it is a week end cruiser then you might reconsider. if you can find someone in your area whom has a side pipe equipped car, that would do the trick for you. I had the same reservations before I bought my car, but now I love those pipes!

[Patrick H.]

Re: 1971 Mufflers

Joe, Do you mean a chambered system similar to what MidAmerica sells, i.e. side exhaust "pipes" in an under car system? I, too, have been considering them for my small block 71, but was unsure how they sounded.

[Joe L.]

Re: 1971 Mufflers

There are lots of aftermarket mufflers/exhaust systems that will satisfy a quest for just about any exhaust note imaginable. Flowmaster and Borla are just two of the companies producing mufflers of several different configurations. However, NCRS is dedicated to restoration, not modification, so I'm going to provide a response that will, hopefully, address your exhaust note concerns, while allowing you to retain stock or near-stock configuration.

First of all, as you may or may not know, side exhaust was never factory-installed on a '71. The only C3 that ever had available side exhaust was 1969. Therefore, if you install side-exhaust your car will not only be non-original, but it will be a configuration that never existed in production. Personally, I've never liked side exhaust. I even had the opportunity to order it when I placed the factory order for my original owner 69 but, I didn't even consider it then and wouldn't consider it now. There are two reasons for this. First, I consider it too loud, tacky and reminiscent of the sound of "lake pipe-equipped" hot rods of the 50's. Second, side pipes destroy the beautifully sculpted, "coke bottle" shape lines of the 68-72 C3. Of course, it's all a matter of taste, I suppose.

Beyond that, Corvettes from 1963 until 1972 with stock mufflers had the most wonderful sound of any production car ever built. Not particularly loud, but a unique, sophisticated sound that was unmistakably Corvette. I could always tell a Corvette exhaust note even if I couldn't see the car. Absolutely unmistakable! Unfortunately, the unique muffler configuration that produced this sound is no longer available from GM. These mufflers, GM # 3943385 LH and GM # 3943386 RH for 2-1/2" systems and GM #3960601 LH and 3960602 RH for 2" systems, were discontinued several years ago. Ecklers is the GM-authorized reproduction source, but, like many so-called GM Restoration Parts, I am skeptical that these are faithful reproductions of the originals.

As far as "off-road" exhaust goes, this was not originally available as a 1971 option. In fact, the only C3 for which "off-road", or RPO N11, exhaust was available was 1968. Off-road exhaust used mufflers that were externally configured very similar to the standard mufflers. They produced the same unique, sophisticated Corvette sound but at a slightly higher decibel level. N11 exhaust could be fitted to your '71 without changing the external exhaust system configuration. Unfortunately, GM discontinued the 1968 N11 mufflers in 1973. These were GM # 3931803 LH and 3931804 RH.

Reproduction mufflers which closely duplicate the factory standard and "off-road" exhaust systems are available from Allen's Stainless Steel Exhaust located in Logansport, IN and from ****CO(formerly Zierden)located in Milwaukee, WI. Mike Allen is an old friend of mine and I know he'll treat you right. His sytems are available in carbon steel(stock), aluminized, and stainless steel. In my opinion, stainless steel is THE ONLY WAY TO GO. But, that's another subject for another time.

[Terry M.]

Re: 1971 Mufflers

Tom et al,

I just had the pleasure of going for a PV ride at Florida in a 1972 LS5 with 1728 miles (after the PV) and when I exited the car the sound of those original mufflers was still thundering in my head. It is, as Joe says, one of the sweetest sounds. There is no system I know of that makes those sounds except the original. Sadly there are not many opportunities to hear that sound any longer. That original sound, I believe, is what Joe is referring to.

I suspect that is also the sound you are longing for.

While other systems have pros and cons depending on the intended use of the car - as others have mentioned here - from a sound standpoint there is no substitute for the OEM systems.

While Joe and I can tell the original systems without seeing the car - and probably could get BB or SB as well - almost anyone can tell the Stainless Steel sound. It has a ring like no other material. Even my 67 Malabu SB has the same stainless tone - it has nothing to do with the car or engine - just the SS material. My Malibu is SS pipes and carbon steel mufflers (don't ask - it seemed like a good idea at the time). No judgement on the sound - it is in the ear of the beholder.

Best advice I can give you is listen to an LS5 through whatever system you purchase before you buy it. Each exhaust system brand and material is different and the engine and cam will also often make a difference. Sound is a very complicated area and the engineers spent a lot of time and effort achieving the end result (pardon the pun).

Terry

[Joe L.]

Re: 1971 Mufflers

Terry---

Yes, the stainless steel mufflers definitely lack that unique sound which the original Corvette mufflers possessed. As you say, the science of sound is very, very complicated and, for mufflers, just about every nuance of their construction affects the sound the muffler produces. Even if someone made a stainless muffler in the EXACT configuration as the original GM mufflers, it wouldn't sound the same. However, as much as I love my stainless steel mufflers, if someone brought to market an EXACT reproduction of the original Corvette mufflers, my stainless mufflers would come off my car the same day. I'd probably keep the stainless steel pipes, though. Until someone does re-create that muffler, and I pray for that day, I'll keep my stainless ones on the car.

[Jack H.]

Re: 1971 Mufflers

Having toured the Walker Research facility SW of Detroit, I can tell you Terry's comments are well thought out, expressed, and TRUE. Having been in various Detroit rock bands in the 60's, I was awed at Walker. Thought I was in some kind of 'wonderland' hybrid between a mechanical R&D facility and MoTown....

[Terry M.]

Re: 1971 Mufflers

Joe,

I wasn't trying to "slam" stainless steel. It has its place. I was only trying to make the point you are - it just sounds different.

I have been trying for a long time to interest someone - preferably Walker - in making a system identical to OEM. Convincing them that a market exists is critical. You and ma and the "restorers" just is not enough.

Terry

[Joe L.]

Re: 1971 Mufflers

Terry---------

I took no offense at your statement and I didn't interpret what you said as "slamming" stainless. I agree wholeheartedly; it sounds different. I only meant that as long as I couldn't get the original sound from any available muffler, I might as well have the other benefits of stainless. If I could get the EXACT original muffler, I'd put them on my car at virtually any cost(don't tell Walker I said that; it might give them ideas).

Actually, as I may have mentioned earlier, Ecklers is the "GM licensed" reproduction source for these part-numbered mufflers. However, when I spoke with Ecklers about their mufflers, the rep I talked with(a second tier guy, not the counter man)waffled with respect to their conformance with OEM specs. Incredibly, he even told me that they might not work with original type exhaust pipes! Since Ecklers is "licensed" to produce this part, and technically has sole access to the original tooling, it would seem that they might be the ones to pressure. If Walker still has possession of the tooling and Ecklers has the reproduction rights, maybe Ecklers could have Walker run off a production run that would satisfy their minimum order requirements.

Anyway, the way I see it Ecklers is the outfit that needs to find a way to get an OEM original out there on the market if they're going to sell the part as a GM-approved reproduction part. But, that's another story. I'd sure like to see those mufflers available again! And How!

[ken girven]

Re: 1971 Mufflers

I am restoring my 1969 and was pondering what type of exhaust system to put on it (stainless vs aluminized etc) Is there actually a different "sound" with stainless? I had never heard this before. If there is a difference what kind of sound is it (louder, throatier etc) Can anyone relate to me the benefits of stainless and any problems etc.

Thanks

Kenny -1969 conv 350/350

[Joe L.]

Re: 1971 Mufflers

Kenny-----

The sound produced by any muffler is the result of a WIDE ARRAY of factors. These factors include, but are not limited to, the internal configuration of the muffler and the thickness of and type of material that the muffler is constructed from. All of these contribute in various ways to the particular sound that the particular muffler emits. Some of the differences are very subtle, but the human ear is capable of detecting very subtle differences in sound. If it weren't, music wouldn't be very exciting or enjoyable. Stainless steel, which has different resonance characteristics than carbon steel consequently produces a different sound than carbon steel. Typically, stainless steel used for mufflers is of different thickness than carbon steel used in the same application. This accounts for some of the difference. Even a .001" difference in thickness will account for a significant difference in sound. Don't forget, too, that in a muffler there are many components. The thickness difference that I mentioned is applicable to each of them. Let's say that you had two nearly identical mufflers. The ONLY difference being the thickness of the end plates of the two mufflers. This, alone, would produce different sound characteristics.

As far as describing the difference in sound, I can't be of much help. It's like desribing the difference in sound of a Mozart symphony or a Wagner symphony.

Regarding the benefits of stainless, there are many. First and foremost, it does not rust. Therefore, it's virtually a lifetime system. It always looks good, too. It does yellow or blue just a bit, but it does not rust. That's important for a guy like me that HATES to see rust on a car---ANYWHERE. It's much easier to remove and reinstall if you have to remove it from the car to perform other service operations. On the negative side, it will lose you points in judging, but a rusty, stock carbon steel exhaust system will lose you points, also. And, unless you don't drive the car at all, the stock system will rust almost immediately. In addition, as we've been discussing, stainless mufflers don't sound like the originals. But, also as we've been discussing, there are currently no mufflers available which DO sound like the originals. So, if I'm going to have a muffler which doesn't sound like the originals, I'd rather have a stainless muffler that doesn't sound like the originals instead of a carbon steel muffler that doesn't sound like the originals.

"Aluminized" is, of course, another way to go. However, aluminized systems eventually rust just like carbon steel. Especially on the inside where any aluminized coating degrades quickly. Corvette mufflers usually rust from the inside out. In addition, aluminized is not original, so you lose points anyway.

One final point about stainless: there has been a lot of criticism bantered around regarding the fact that stainless expands at a far greater rate than carbon steel. THIS IS ABSOLUTE NONSENSE. The difference in the coefficient of expansion between carbon steel and stainless could not account for more than a 1/8" difference between the two in a system of typical Corvette length. I've performed the calcs myself and had a friend double-check them. As empirical evidence to support this, I've had a complete stainless system on my car for over 14 years and have NEVER experienced the slightest problem due to system expansion.

[ken girven]

Re: 1971 Mufflers

Joe , Thanks for that detailed and imformative response. I was leaning towards the stainless system anyway but your reply convinced me this was the way to go. For me ,as far as "judging" goes, this is one area where id rather lose points and have a nice rust free exhaust system.

Kenny-1969 350/350 P.S. could anybody estimate how many corvettes were produced with my combination in 1969? I have a convertible with the 350/350hp, 4 speed (m20), air conditioning, and 3:55 rear end. I know one can only guess because the production numbers wont tell you EXACTLY how many came with a combination of options but maybe a knowledgeable (good guesser?) ncrs member could approximate. Thanks again averyone!