I need another muffler for my '99 Z28 and don't know which.

I've searched a lot, nearly everyone seems to have other monifolds, tubes, no cats or something. I cannot compare with that, mine is all stock expect muffler and so it should stay. Soundclips do also not say much. And I also cannot compare with stock sound, I never heard it with stock muffler. These are my problems.

I can only compare these two mufflers:

I bought the car with a borla non adjustable dual out muffler. I got compliments for the sound but I didn't like it so much. At idle there was not really something to be called sound, at low rpm there was sound, but not enough rumble and I really hated that high frequency tinny screaming at high rpm. It sounded not healthy to me and sometimes I even thought it sounded almost like a 6 cylinder... So I had to change.

I put a flowmaster 80 on it and it sounds pretty good. Not too loud, deep rumble at idle and low rpm and great hammering sound at reving up. It really has the great musclecar sound flowmaster says. So far so good. But I can not much longer stand that droning inside the car, it's getting on my nerves.

I 've heard no other mufflers on the car, so I 'd like to know one with a good deep rumble to notice in the car without annoying droning. I want to stay with two outlets.

I hope someone can compare my experiences and can recommend a muffler. Perhaps dynomax super turbo or magnaflow would please me?

Thanks.

 

I have had two muffler systems, The first one I purchased was the SLP Loudmouth 2, Now I love a nice loud car but back then I didn't want it too be too loud, That exhaust system had a nice deep tone to it however, even with it being the "Quieter" Loudmouth Exhaust system it still was decently loud... Then I switched over to Magnaflow, The car was really quiet to be honest, I didn't really like it but I knew I was going Long tubes soon so I just sucked it up, That exhaust had a nice tone but wasn't too deep like the SLP Loudmouth!
I suggest looking at this post by FAST LS1: https://ls1tech.com/forums/generatio...al-street.html
He put the DB levels of a bunch of exhaust systems and it really helped out when picking my exhaust set up! I would say find the best guess of how loud you want it based off of what mufflers you had and find videos and reviews on the forums to see about how droney it is as well as how deep it is!
Good Luck, Mufflers are always fun
Forgot to add, you should be happy you never heard the stock muffler, You couldn't even hear the exhaust in the car, all you heard was the LS1 screaming... Wayyyy too quiet XD

 

To solve the droning, try tightening up the clamps and hangers on your existing Flowmaster system. Somehow, your system has a resonance vibration when it hits a certain RPM or speed and you need to dampen that resonance. Do your hangers have any rubber isolation between the pipe and the car body?

Rick

 

Thanks. This list is for true dual systems how I see.
You can not be legal with this car on the street with any aftermarket exhaust here in Germany. There is not one available which has documents for legal street use or some to make it legal by the Tüv. So I want to be as legal as possible and only change the muffler and let the stock pipes in. So no one will complain if it's not too loud.

I think the Flowmaster 80 I have is on the limit, it should not be louder. With it it's already the case that everyone looks after my car when I give a little gas

I already looked on the Loudmouths, these muffler or resonator is so damn small... I'm sure the Tüv or police would look closer if they'd see it. I didn't hear it in reality but I think they will both be too loud.

And B52:
I fixed it as high as possible with enogh space left and yes, it hangs on rubbers, I think they are the stock ones.

I had read about it before and I didn't want to believe it. Now I know why some call Flowmaster the Dronemaster

 

Hooker Aerochamber

 

Ahhh... The beauty of America! Hahahaha, Anyways I get what you are saying now, I would say try Magnaflow mufflers, I don't have any drone on mine, they might be a little quiet but at least you can hear the car!

 

I had the loudmouth on my Formula and one thing I did to help quiet it down a little was swap the resonator out for a Magnaflow Bullet. Search Magnamouth on here there are a couple write up's if a remember definitely brought the tone down and got ride of the rasp and drone.

 

Magnamouth seems to sound good, but how I said I let the stock pipes in.
I 've searched for reviews and videos now especially for the Hooker Aerochamber and the Magnaflow. I don't know but it seems they sound pretty similar? Quiet but noticable at cruising and screaming at WOT I read about both. Screaming is good but not like that awful high toned tinny screaming my Borla did! The Magnaflow is stainless and easier to buy for me, because it seems the Hooker is not available in Germany. I'm thinking of giving it a chance.

 

I've had about 10 different exhaust systems on various LS1 F-bodies, and installed several others on friend's cars as well, so I have a good deal of experience with the sound of many of these systems. Things such as volume and sound quality are very subjective categories and the same system/muffler might rank very differently in terms of good/bad between two different people.

Having said that, and based on everything you've stated so far, I don't think there is any one muffler that will be perfect for you. You'll have to compromise. The Magnaflow and Hooker individual mufflers are not that different from the Borla muffler which you didn't like. They don't sound like the Flowmaster at idle (they are quieter, smoother), and will generally have a similar sound at WOT as compared to the Borla that you didn't like (this is typical of any "turbo" style muffler, vs the "chambered" style of a Flowmaster). But, the thing about the chambered mufflers is that they typically have some drone at certain rpms - that's the trade-off for their distinctive sound at idle. You won't get that exact sound at idle from any sort of turbo-style muffler. Whether that's good or bad is strictly a matter of opinion. However, IMO, this "drone" condition is vastly overblown when it comes to still having stock manifolds and cats. I had that same setup on my '02 car for quite some time (Flowmaster 80-series, everything else stock) and whatever drone was present never bothered me at all, but much of this is very subjective so what's irritating to one individual might not be a concern (or could even be desirable) to someone else.

In summary, I don't know of any muffler that sounds like a Flowmaster at both idle and WOT, but that also won't have any sort of drone anywhere in the rpm range. Some turbo-style mufflers are louder and deeper than others but, to me, none of them sound like a chambered muffler at idle.

IMO, just about every system/muffler sounds very tame on an LS1 when you still have stock manifolds and cats, only exception would be a mufflerless system or a cutout. Beyond that, if you're using an actual muffler in the stock location with the rest of the stock system, it's going to be a pretty quiet setup after the cats and pipes get hot. But, again, "quiet" is somewhat relative/subjective.

 

You're right, it's always subjective.
To me the droning bothers
I didn't think that they'd rumble like the Flowmaster. With this I must compromise but it's ok. It can be a little quieter, but I want to hear it inside the car and a richer and deeper tone as with the Borla must be. At a US-car meeting I heard once a LS1 Trans Am with an adjustable Borla. It sounded completely different to my Borla, much deeper and too loud but I don't know how it was adjusted. I have also searched for the non adjustable Borla I had and could not find any review, experiences to compare with mine or soundclips. It seems no one haves this and it looks not exactly like that I can find at the catback on the Borla homepage. It's more square. I remember when I took off the Borla and shook it there was a rattle inside perhaps a reason for the tinny sound.

 

Several mufflers aren't available separate from a catback system, so that also limits your selection. Borla makes a few different mufflers, but the "adjustable" system you heard doesn't give much indication of what the actual muffler sounds like unless the block-off plate is used. Otherwise, you are getting a partial "mufflerless" sound from the passenger side. That's why it sounded so much different than yours.

The Bassani system on my '98 is pretty close to what you seem to want, except that it's been discontinued for many years and I don't think the muffler was ever available separately. Being in Europe, you probably wouldn't be able to find one used (they weren't very common systems in the first place). Bassani offered a few different systems for these cars over the years, including at least two different catbacks (Street Competition and Quiet Thunder) as well as one or two bolt-on true dual systems. What I have is the "Street Competition" system, which was the louder of the two catbacks. It's actually not all that loud with stock manifolds and cats, but it's very deep, can be heard at cruising speeds without being overpowering, and you certainly know it's there during WOT (on a side note, with headers and an ORY this setup was the perfect balance of volume and pitch - I loved it on my '00 car this way.)

A combination of mufflers might get you closer to what you want (such as adding a Dynomax race bullet to the intermediate pipe with the Flowmaster at the end, that would reduce some drone without doing much to the idle or WOT sound), but this would require cutting the stock pipe.

 

It's a trouble with that subjectivity.
I've searched the net for experiences and soundvideos for some mufflers or catbacks. It's difficult. One says that the Hooker sounds good but if you want the louder get the Magnaflow. Another says Magnaflow sounds like stock. One says Hooker is quiet as stock. Another says the Hooker sounds amazing. So what now? And so on... you know
But in the sum of what I found it seems both would not be bad.

Hm... But you say Magnaflow or Hooker would sound very similar to the Borla I had. So far videos can deliver, I have to say no, they sound much better than the Borla I had.

I try to describe it:
The best thing on this Borla was a cold start, it sounded like a thunder. Then it got worse, at idle it was very clean, zero rumble and quiet. At low rpm there was some dull bubbling that reminded me sometimes of a big 6 cylinder, noticable but still rather quiet. At WOT it got really loud and screamed furious, but so tinny and shrill, high frequency as if all the bass had been rigorously filtered out. I didn't like that at all. It sounded like a dying engine or so to me.

 

Some of the confusion might also have to do with pipe size. If you're reusing ALL factory piping with a replacement muffler, then you're stuck with a 2.75" intermediate pipe and 2.25" tail pipes with factory square tips. Most of these catbacks use a 3" intermediate pipe and 3" tail pipes (sometimes with 3.5" or bigger tips). Pipe size, and especially tail pipe size will have some impact on sound quality and volume. Also, sometimes the muffler that's offered in the catback system isn't exactly the same as the muffler that's sold separately (but this all depends on the system). For example, many years ago I bought a simple Magnaflow replacement muffler for my '99 Z28, it was 3" inlet, dual 2.5" outlet. This muffler was noticeably quieter than the one used in their catback system (which included 3" tail pipes and 3.5" tips - and they've offered more than one catback design over the years as well). Same with Flowmaster; their catback used a 5" case muffler with 3" inlet, dual 3" outlet and 3" tips, vs. their replacement muffler-only 80-series which is a 4" case muffler with only 2.5" outlets (the larger case size muffler with larger tail pipes offered in the catback sounded noticeably deeper than the muffler-only replacement).

So, in addition to subjectivity of sound, you're also dealing with these other variables when listening to videos or reading the opinions/descriptions of others.

 

Ok, thanks!
I mainly search for experiences with just a muffler and the rest stock. I search again and again

I don't have the stock tailpipes. I use those of the Borla. The Borla was with 2.25" tailpipes and the tips were the same 2x2 square as those of the adjustable one. That fitted not with the car for me, so I cut them off the connector and welded about 15" long and 3,5" diameter diagonally cut tips on it, shortened the tailpipes and connected it again. That was the first I had done to the camaro exhaust. Just for the better look, sound changed not.
Later I have the Borla cut off the stock inlet pipe, cut off the tailpipes and welded all onto the Flowmaster muffler.

The Flowmaster has a pretty deep sound with these pipes. But it makes sense to me that a smoother muffler should better have a 3" inlet and 2,5" or more at the outlets and tailpipes.

 

Sometimes I will probably miss the old school sound of the Flowmaster, but it has to go. The droning is annoying too much. At driving with open window it's ok, but I have chronic pain in my neck and can't stand the airstream all the time so I have to close...

So I just ordered a Hooker Aerochamber muffler, I think it will give sound I like and also hope it will not falling apart internally and ratteling after a short time how I read in some reviews. I 'll see.