Have a C4 vette.
You all over here are much better than some of the vette forums.

On my old car the Exhaust has a Y coming into a Cat with a single inlet. then single outlet..then to the back and the mufflers at the back.
I assume this is similar to the stock stuff on a 3rd Gen..Cant really remember.

What I am looking at doing jsut to get the thing running as I have all the Exhaust out now. Is to remove the cat. Put either a single inlet and outlet muffler in its place..the run it all the way back as normal, yet remove the rear mufflers and jsut run pipes out the bumper.
Or I thought about replacing the cat with just a pipe..then putting some different mufflers on the back.

What do you all think would sound better?

 

Either way will be a little bit louder than with the cat. I don't think I would put a muffler where the cat was...

 

None of it.

The Corvette platform isn't conducive to great sound, IMO. I don't think that there would be meaningful diff between a single muff in the center, or no cat/two muffs in the rear. I have an '89 and did both for a short period.

Later, I made and exhaust for that car with side pipe exits and with the theory that "lots of bends" is what leads to better sounds quality, and it worked out pretty good.....not awesome ("awesome" for me, being: '80's F-bodies w/a good exhaust, 80's Fox bodies), but it was pretty good. Then I put in H pipe in it and now it doesn't sound as great. My theory at this point is that unequal length exhausts (L&R sides) and unequal length header tubes or tube length from head to collector are what contribute to fantastic exhaust sound quality, but I haven't tested that theory, yet.

For the purposes of your situation, I'd throw a set of Flowmasters on it, if it's not loud enough, add some cam...keep the cat in place.
A better option is to buy a take-off LT1 or LT4 exhaust and put that on. It is quiet, true dual, has way better cat(s) and flows more than your L98 will need, giving you an actual HP/Tq gain, which loud/removed mufflers won't do.

 

Your question in this case probably should be asked on the Vette forums.

C4 Vettes and Fox Body Mustangs have one great advantage over 3rd gen Camaro & Firebirds. The ability to run a true symmetrical full length high performance exhaust system. We can't do it. One of the biggest drawbacks to a 3rd gen is its horrible exhaust system routing. No matter what we try to do to the exhaust system on our cars it's nothing but a bunch of compromises.

Just to get to the stock level of a C4 Vette or Fox body Mustang we would need a new firewall, floor pan, and rear suspension system.

Your question is also like asking what is the best flavor of ice cream.

 

Waste of time. Because....

 

True.

The flavor I pick is Corsa.

 

Ha ha ha...Ewww. Which proves what you said. I put a Corsa on my C6, b/c it was "the best" on thr 'Vette forums. They said.

Had to sell it and liked the GHL better

 

any chambered muffs like a flowmaster sound tinny/metallic.. which was all the rage when those first arrived on the scene 30 years ago.

borla/magnaflow and the like to me sound the best anymore. a true 'muscle car type of noise.

but asking which exhaust sounds better is like asking which type of woman is the best.

 

Yeah?


"Tinny"? IDK.....

 

I don't like the sound of chambered mufflers (and I have a car with them).
A Magnaflow, or Flowmaster Flo-FX is a better choice...

 

Right on. I've had both, and even both Magnaflow's that I liked and Magnaflows that sounded like poo -one was on the '89 C4, mid mounted like the OP is asking about here. You can hear that Magnaflow-on-a-C4, right here:


....Not great. OTOH, THe best sounding exhaust *I*''ve ever had was the SLP TOTL which is a glass packed, straight through, perforated tube muff, just like a Magnaflow. SO, it depends on the car, (and the rest of that car's exhaust system) more than the muff itself. The Muff should be used to tune the exhaust of the car....not "define it", b/c it won't. That GTO I posted had Flowmasters and it would be hard to argue that it sounded bad...or "tinny".

 

I hate Flowmaster mufflers from a performance standpoint but nothing sounds better to me than a Fox body Mustang 5.0L 5 speed with 3.73 gears singing through a Flowmaster exhaust system. One of the favorite sounds of my youth.

 

F'n-A, my man....SPOT ON. ^That^ is about a perfect automotive experience. Love it! (And I agree too about Flowmaster for perf.

But yeah...that was a package back in the day, and from an experiential stand point, it totally is, even today.

 

I'm curious what you like the sound of on 80's f-bodies? I've recently been weighing good sound, volume and cutouts and have decided that things don't sound the way I remember them.

 

As far as the question goes, my instinct (and Tom might disagree) is to either get rid of the center cat, put a pair of whatever you like the sound of muffers on the back and then put an H or X where the cat was depending on what you like the sound of more (to me H sounds more muscle car, X more sports car). My second choice would be to get rid of the rear mufflers and use a 2in/2out center muffler like Magnaflow and dynomax make

 

Yeah, good question.

I think '80's Fox bodies are the "gold standard" for exhaust sound....but I think that 3rd gens are pretty fantastic too and higher than most others, including Y body. I'll do my best to explain a subjective thing as objectively as I can...but I hosted a massive thread about exhaust sound HERE, back when I owned my C6 and was frustrated and disappointed w/the quality and character of the exhaust sound....and I was trying to "fix" it.

First, we have to define preference: MINE has been stated w/the Fox example, but deep, bubbly, multi tonal....I'd describe the ultimate as producing sound that is almost "3D", and/or stereophonic, but most definitely, character changes across the RPM and throttle spectrum so that the act of driving the car produces different characteristics of sound all the time, and not just "volume and pitch".

To that end, and for comparison purposes, the C4^ exhausts produce a rather boring, character lacking sound. The C6 was worse than the 4, so I'll use that as an example; no matter the exhaust system, the sound is 2D: volume and pitch. The volume is driven by throttle input, pitch, by RPM. The sound is essentially created by the firing pulses, so it's mostly a "hum", but there is a "blub" added to that basic hum, by the syncopated firing order of each bank. At idle, that sound is a bland hum of the cyl's firing...almost like a typical gen I engine if you retard the timing way too much and throttle it to compensate the RPM? That sound. Not a great sound, IMO. Revving it produces more of that same lame sound, but changes the pitch mostly and volume slightly....and you can see that in the vids that I posted in the link above.

In comparison, the best sounding car that *I* have owned was my '83 CFI car, after I put the Edelbrock "headers", Y and SLP TOTL on it. Idle was smooth and luscious, deep, the "hum" of the cyls makes a underlying tone....but that is overlayed by another sound with more interesting features that is defined by the whole system, I think...and that creates what I call a "3D" sound -it's several sounds at the same time. Anyway, in regular driving the combo gave all kinds of feed back to varying throttles, RPM's gears, etc. That was interesting/awesome, and correlated strongly when what you felt in your backside. THEN, as one of my friends said back then, "At 5000 RPM, it sounds like a Winston Cup NASCAR". That was a stretch, but it speaks to "3D", as it would transform from mellow to something entirely different at full song. "3D".

That GTO in the vid that I posted above has that "3D" character to it, IMO. All the burble, thunder, Bass....even at or around idle. Then you listen to any C6 exhaust (vid or real life) and it's just this lame, "monotone" blase' sound that just goes up and down in pitch with RPM and that's about it.

So what do I like about 3rd Gen sounds? Smooth, bubbly luscious down low and general driving, sweet wail at full song...character, interesting to listen to....corresponds with output...I guess, it's like a living creature (not some fake sounding/robot sound). That's what I like about it.

Lame (my car w/different exhausts):
and
^^^BLAAAAA-BLAAAAA-BLAAAAA-BLAAAAA-BLAAAAA-........

Nice:

 

Now we are talking!

I'm a little biased but the SLP Loudmouth II is *chefs kiss*. Especially with a big cube and big cam motor.

 

I think Ford went to a lot of effort to get the "mustang sound" and it showed. I was especially surprised when they went from the 5.0 to the mod motor and it took no retrainng to the muscle car guy's ears, you still knew it was a mustang by sound alone it was so similar.

F-bodies I'm not so sure about. The early ones were the best sounding, and as they went along they lost something. the 4th gens were not the same, my '97 WS6 just didn't sound like my 3rd gens no matter what I did to it, I even swapped the same exhaust between the 2 and it wasn't the same. I attributed it to something with a 305, I just didn't get the same sound out of a 350LT1 even though it should make the same sounds, but then later I got a '87 Formula 350 and noticed it wasn't quite as bad as the LT1 but it was harder to get it to sound "right."

Where I generally disagree with you is with the flowmaster sound, the classic mustang with flowmaster 40's sound annoys me, it's too metallic. Super 40s, Super 44s, 50s... all get better but most flowmaster exhausts have a metallic sound to them that I don't like. Interestingly, you put them on some imports, especially inline 6's and they sound INCREDIBLE.

I agree with that, a deep, bubbly idle, it doesn't even need to be loud is the best, and a lot of character and feedback to what the engine is doing is part of it.

OK, there is something MAGICAL about the exhaust (overall sound?) of the '83 Crossfire Cars. Mine was EASILY, BY FAR the best sounding car that I've ever owned, and it didn't matter what exhaust was on it, and it's not just you and me, but I used to get compliments on it constantly. My ultimate exhaust ended up being Hedman headers, custom Y pipe with dual cats into a flowmaster Y, 3" over the axle pipe and most of the time it was split into a U shape with 3" tips on either side, but it also spent some time with a single 3" outlet on the driver's side and with that single 3" split into 2 tips, still o the driver's side. it had other setups behind the axle (an SLP TTL muffler and tailpipes, 3" dynomax ultraflow welded, Magnaflow stock layout muffler...) they all sounded better then the rest of my f-bodies and other cars, but the no muffler setup was the king.

That GTO in the vid that I posted above has that "3D" character to it, IMO. All the burble, thunder, Bass....even at or around idle. Then you listen to any C6 exhaust (vid or real life) and it's just this lame, "monotone" blase' sound that just goes up and down in pitch with RPM and that's about it.

3rd gens with no muffler definitely sound good, especially with dual cats...

I'd like to pursue this further. A friend of mine and I got into it about the sound of my car last night (with a drivetrain that started as an 87 LB9, 305 TPI), which just doesn't sound like I want or like I expect this setup to. I can start another thread, but if you guys are OK with it I'd like to continue it here because I believe that Tom and I have established a good baseline for the conversation.

 

Well, let's continue unless someone disagrees. This is certainly a subject that I'd like to understand better.

FWIW, I totally agree with you that the early two-muffler F-bods sounded the best. IDK why, b/c it was by far the most terrible flowing system (as you well know)...but it sure sounded good. I've had other people comment that the CFI sounds best, IDK why it would sound any different than any other SBC connected to that same exhaust (more cam than the LG4 could help, but IDK about vs. TPI). OTOH, CFI 'Vettes sound about the same to me as TPI 'Vettes, so I have a hard time believing from a technical AND an anecdotal stand point, that the intake manifold would have much to do w/exhaust sound.

When I embarked on the C6 "AIP" (Auditory Improvement Project), I had a theory that creating space to mix the left/right sounds would help. I bough/built/tried 6 different exhaust system solutions on that thing, using that theory as a guide....as you can hear in the vids above, it was a total failure. "Mixing", chambers, different mufflers, NO mufflers...none of it helped at all. It only changed the volume.

Years later, when I built the Kart exhaust, I had a theory that bends in the pipe, reduces the BLAAAAAAAAA sound, and improved the "bubbly" aspect of the sound. You can read more about that RIGHT HERE and see pics of my anecdotal evidence. That theory may hold some water, b/c that exhaust DID turn out pretty awesome and sounded pretty damn wicked. Not 5.0 awesome, but definitely good F-bod awesome. UNFORTUNATELY, I added a crossover pipe into the system (H-pipe) and that made it sound a lot, "less great"....a lot more like a "C6".

Now, my thinking is more focused on where the collector is, relative to the head ports, and un-equal length secondary pipes. In all Corvettes from C4-C6, the Collector is centered on the head. Comparing a C6 LS2 to a GTO LS2, they're identical engines, same power and tq, Only diff is the manifolds, where the GTO has a "collector" in the rear, and the manifold back exhaust. Totally different sound; quality and character. Same goes for the sounds of a C4 and an F-bod; same exact engine (in the case of an L98), but different collector location and obviously radically different secondary pipe lengths.

The Mustang, it has a rear collector. The secondary pipes are similar lengths though. It has more "bends" than a C4-C6 though.

So what have I learned? Not much!

 

Getting back to the OP's original question... I've always wondered if the C4 Vettes sound they way they do because the mufflers are all the way back at the very end of the exhaust system with no real tailpipe to speak of.

I have no idea if this is a dumb idea or not or if something like this would even fit into that space in the center of the car where his cat is now. It's 4.5" x 9.75" x 20" muffler body and 25" overall length from inlet to outlet. I have no idea what size the C4 Vette exhaust pipes are but a 2.25" or 2.5" version should be enough for a L98 engine. 3" is just way overkill.




Ultra Flo™ Welded X Mufflers - DynoMax® Performance Exhaust

I don't like the stench of a car without cats. Some are "OK" and some are better than others. Might be I'm close to AARP age now and not a teenager to late 20s anymore or maybe todays gas just stinks worse then the gas of the good old days.

I also don't like cars so loud I can't even think inside them or rattling the fillings out of my teeth either. I'd probably try the DynoMax Welded X in the middle and a pair of the normal DynoMax Welded straight through mufflers at the rear end before the tips.

I like the idea of the later LT1/LT4 exhaust with the little cats up close to the manifolds, then maybe this Welded X muffler in the middle, then straight pipes back to the exhaust tips of your liking but make sure the straights pipe portion is designed so you can experiment with a pair of straight through mufflers, bullet mufflers, or resonators until you find something you like.

 

Nope. I don't believe so. That was discussed the massive exhaust thread that I posted above. The problem is that there are too many examples of awesome sounding cars, where the muff is all the way in the back, no tail pipe, but they sounds great:
GTO
CTS-V
Later Mustangs
Jeeps w/side pipes
AC Cobras
etc. etc. etc.



I've thought about trying an X Flow, but it would likely sound similar to the Magnaflow that was on the kart in that burn out vid. Samey style deal.

The LT1 and LT4 already have a glass packed, straight through "resonator" 2 in/2out in the middle under the trans tunnel. So any later C4 you hear w/muffler deletes...that's the sound you end up with. Not terrible, but not great.

 

This

Not that I'm in favor of the health damage lead causes, cause I'm not, but to me when they took the lead out and then eventually put the corn juice in, it ruined the smell of the exhaust....

 

 

I bet that did sound amazing.

 

I agree, I don't think that most people could tell a CFI corvette from a TPI corvette by sound, but for sure you could tell a CFI f-body from a 305 or 350 TPI f-body. Even more interesting, when I bought my 83 it had a "factory replacement," style Walker/Dynomax exhaust (only available in the later, crossflow muffler style muffler) and it still sounded more like the twin muffler early cars then a TPI car (only a hair quieter then the twin muffler setup). Why are they so different???

2 friends of mine had an 83 and an 84, one an LG4 and the other an L69, and we did all 3 cars at the same time (exhaust at one point, headers at another point, suspension...) and we added an early TPI car to the mix eventually. Mine ended up Headman 3/4 length (most call them shortie but they're not like mustang or corvette shorties), dual cats, flowmaster y, 3" open pipes I described earlier. the other 83 got ebrock TES + the early dynomax cat back (single 3" muffler and single 3" tailpipe), the 84 got Hooker 3/4 headers, later dynomax cat back (essentially mild steel TTL), and the TPI got edlebrock TES + SLP TTL. My CFI remained distinctly crossfire sounding, the other 3 were pretty hard to tell apart, I remember that the TPI car ended up quieter than the rest.

I kind of wonder if part of the CFI sound is compression and cam. They were advertised as having 9.8:1 with iron heads, and the cam was similar to the later TPI cam with less LSA.

This is for sure a thing. There used to be a knockoff of the Hooker Aerochamber that I put on my '92 K1500 2 door blazer. That had an interesting exhaust- driver's side Y into the passenger side, from there straight back to the muffler (cat went in that pipe but I removed it), straight back out of the muffler, 1 bend to the outlet. That one sounded BLAAAAA, almost like a bad open exhaust (muffler fell off) on axis with the tailpipe, and sounded deep, Aerochamber like off axis.

I'm not sure what to make of that, I mean the f-body shorter headers are closer to the corvette then the rest, for sure on the driver's side where the collector is typically below 3/5 and against the back of the K member. I guess they don't have the symmetry of the c4 corvette headers.

Mustangs sound pretty much the same with snake's nest equal-length headers as well as the standard non-equal ones. They don't sound that different outside the car with dumps before the axles either

 

I decided to post a video with the specific question about my car here:
https://www.thirdgen.org/forums/exha...ml#post6561950

 

The GOAT factory exhaust system.

 

Using an empty cat in place of a full function cat isn't crazy different. Just louder. Because you're trying to get it running, maybe making a test pipe out of 3" pipe made oval and steel plate would be better than trying to fab a whole setup. The 85 Y-body cat is near identical to the L69 F/G-body cat with 2.5" x 3" opening.

 

An empty cat will resonate and sometimes pop. It tends to make the exhaust noisier, and not in a good way. It also flows less than a straight pipe. If you want to make something that looks like a cat but doesn't block the few horsepower that it does, just put a tube through the case.

 

My M6 (V10) runs this in the very back. https://www.realoem.com/bmw/enUS/sho...diagId=18_0606 You will also find a similar part on my 545. Item #1. https://www.realoem.com/bmw/enUS/sho...diagId=18_0533.

The M6 version would adapt nicely to your vette exhaust with a little finagling of the inlet and outlet pipes. The M5 also probably runs something similar. Guys tear their factory M5/M6 exhaust systems off all the time and you can find them sold on ebay. They are made from premium stainless steel.

For example (probably too much asking $$): https://www.ebay.com/itm/16577098143...tedSearch=true

https://www.ebay.com/itm/13481797387...tedSearch=true

 

Curious, am I seeing 2 different shaped mufflers for each of the exhaust tips?