dennisbernal91z

iTrader: (2)

Ok so if you know my car then great, for the rest of you... here is what I have now.



Here is a side shot... maybe you can get a better idea with this one.



Ok, with that out of the way, here is my question...

What is the quietest tube style muffler that I can buy that is not huge. I wanna still be able to tuck them up pretty good. The dynomax bullets are only 4" in dia. Main problem is I can see right through them. This motor has a BIG cam and I want it to shut up. The damn thing sounds like a drag car. Granted the motor is probably something that only drag cars should have, but thats not the point..haha...

I might be able to stuff a small square like muffler up there, but I don't think so... The DS where there are not supposed to be any pipes in the first place would never hold a big muffler well. That is why I wanna just cut the pipe I have and replace it with a nice QUIET tube.

Right now I have 3 disk inserts in my headers, they helped quite a bit, and dual dynomax bullets... these do nothing ... I plan on taking these pipes off and keeping them for the day I go do a run at the track maybe.

Well anyways, thanks for any help.

jbenge

iTrader: (2)

I've never heard a tube type muffler that I would consider to be quiet. I would look at the Spin Tech Mufflers, they aren't real quiet but would be a lot more quiet than what you have. They are quiet enough to keep you from getting pulled over but still sound good, my dad has them on his 408 Duster. You can get them in small sizes too if you look at the Pro Street series. If I ever change my exhaust I'll go with Spin Tech.

Spin Tech Mufflers

84 z28

Try checking out checking out flowmaster hushpower II mufflers or there's a a exhaust part that just came out that you just put between the header and collector. The company is called car chemistry and its a 3 disc street application.

dennisbernal91z

iTrader: (2)

Sorry if it was unclear, but I do have those inserts allready. I have the 3 disk vertion as well. They have helped, but this is a really loud motor. Moves a lot of air. I will look into the hushpower II that you guys mentioned.

As for spintech, I used to read about them all the time and I planed an entire set up around their products, but then $ ran short and I made the set up I have now. I will search their site again and see what I can find. Maybe they can help. thanks so far...


Anyone else...

xpndbl3

iTrader: (5)

still haven't found a way to mount up my turbo mufflers under the chassis and still have some ok ground clearance, otherwise i'd have something to report to you on the fullsize mufflers.

1991CamaroRslow

iTrader: (3)

Try Classic Chambered 3in mufflers, they have louvered cores and will flow slightly less than what you have but will probably sound better and be quieter. You should also consider an H pipe. I put an H pipe on my car and it made the exhaust tone way better and quieter.

dennisbernal91z

iTrader: (2)

yeah I am considering and H-pipe now. I will do that when I change the mufflers.

Lets just put it this way, when I have the car on and am standing next to it, I can feel my stomach shake and I can't talk to anyone without yelling, very loudly. My neighbor says it sounds like a tank. haha.

I really don't give a crap about flow anymore, I just want to shut it up. That is why the louvered tubes are a no-no. They are too straight through. I want more "stuff" to be in there.

Flowmaster hushpower IIs? Or Spintech whatever, they sell some good stuff.

Anyone wanna weigh in?

xpndbl3: Happy to see you are trying to find a solution, if you run into any answers, please share. I would love to hear what you have to say once you get those on.

tommy z-28

iTrader: (1)

I have the SAME problem. Motor is too f'ing loud with my hedman LTs and summit race mufflers mounted in the same fashion as your tubes. They are the normal muffler shape and summit just came out with them last year. I only have a LT4 hot cam and ported heads, but with this exhaust and no cats its too loud to have neighbors. I dont drive it anywhere yet, but i see that being a problem as well with the noise.

Please post up some quieter mufflers that wont entirely kill flow. These race mufflers seem to flow extremely well.

Gumby

Key to toning it down is a decent length tail pipe.
Mufflers aren't ment to just dump into the open.

I got a cherrybomb on my V8 wagon that is straigth through but it has about a 4ft tail pipe. Keeps it at a nice quiet rumble.

On my Firebird I got the same muffler but it only has about a ft long tail pipe that turns out for a side pipe, LOUD. That extra 3ft of pipe going over the axle and out the back really tones it down to just a nice rumble that lets it flow still. And since I was using the full length stock like system; I wanted it to free flow as much as possiable, hence the cherrybomb use.

X pipes work much better if you can afford that.


But read this

"You can build a quiet exhaust system that performs almost like open headers."
http://www.pontiacstreetperformance....p/exhaust.html

firebirdjosh

iTrader: (1)

I was going to say running over the axle is probably necessary to keep it down but others have already pointed that out. Plus, once back there you can fit almost any mufflers you'd like.

88 350 tpi formula

iTrader: (9)

my plan is to go over the axle with the duals. right now I just have the long tubes merged into the single slp catback (which is pretty much a strait through muffler) and it is not too bad at all. alot of mustangs with stock motors and dumped flows are way louder so I would guess it has to be the full length of pipe and bends that does it.

dennisbernal91z

iTrader: (2)

Duely noted. i will incorporate more pipe. The next set up will most likely have oval piping and be "longer". I am just worried about my fuel lines getting hot. (not in stock location).

If I move them and use a good amount of heat wrap and stuff, i might be able to go ove the axle. It is gonna be tight.

I think the best set up will be smaller oval pipes, finding a way to get over the axle and putting some big *** mufflers back there and maybe even find a way to have decent pipe after the mufflers by crossing back there before the tips turn down and dump.

tommy z-28

iTrader: (1)

So for my setup, duals with short straight piping, there really is not an option to go over the axle with my funds because I cannot bend tubes. Is there a muffler that will be much quieter even when dumped before the axle straight from the muffler?

I looked in summit and saw the Thrush or Thrust mufflers for 20$ a piece, anyone tried those?

Gumby

Any muffler that just dumps into the open will be loud or have bad sound.
Its almost like a horn or ported speaker box.

Loop your first finger and thumb into a circle, put it to your lips and blow.
Then do the same thing inside a paper towl roll.

Ya want a bit of tail pipe, nothing wrong with some cheap flex pipe to run over the axle. I got a bunch the other day on sale for $2 per 6ft piece. To cheap not to buy.

Gumby

Think of how most nice trucks sound. Same like my wagon, they have the room for a decent full length tail pipes but still can run good flowing exhaust/mufflers. Mufflers mounted before the axle so you get a 3-4ft tail pipe.
[Any pipe after the muffler is the tail.]



On the 3rd gen you could move the gas line and run the open straight mufflers down the sides real easy. [looks neat] There is enough room between the floor and door, kind of a valley there. Its how I got the side pipe look with a cherrybomb on my Bird. Just member its a V6 so its side pipe, not pipes. On a V8 with dual you should move the gas lines before ya run it down the left.

Change to steel braided line or just use some to move it and run it over and down the middle of the car.

You can see my cherry bomb side pipe here.
https://www.thirdgen.org/forums/exha...ight=side+pipe

dennisbernal91z

iTrader: (2)

maybe I can keep some of my set up that I have now and just put bigger mufflers on there and then snake up and over axle pipe for cheap....hmmmmm.....

Chris Etemadi

Dude Im in the same boat as you. Im running the 12" bullets with 2210's and an xpipe. I have been looking into some options. if your running the shorter bullets you could go to a longer one. also Magnaflow has smillar bullet mufflers you can get in 4" diameter. these are shaped differently as they do not round off when they expand to 4". I think Im just going to keep my bullets where they are, reduce to 2 1/2 inches and up and over the axle to some 5"x8" oval magnaflows.

dennisbernal91z

iTrader: (2)

sounds resonable. I am gonna see what i can do once I get my car back from the paint shop. I wanna see how much room I have to pass pipes through back there before I order anything. If you complete that set-up. Take pics so I can copy you

firebirdjosh

iTrader: (1)

I have a pair of cheap Summit turbo mufflers under my car, even with my old 305 they sounded awesome. It was loud, but I've had louder setups. It was the point where the volume starts to get annoying, but it wasn't awful. I always had compliments on the awesome sound and how "I must have a monster engine under there".

dennisbernal91z

iTrader: (2)

sounds like I need to stay away from those kind of mufflers then. I have the motor, but want people to think I have the 305, haha.


DAMN

Tru2Chevy

You should go with a set of chambered mufflers if you wanna keep the dumps before the axle. The longer the better. They really do quiet the car down more than bullet mufflers do.

- Justin

Fullsizewagon

I have no experience in this but i read somewhere that downturns, especially if exiting underneath the car, will make it loud. Maybe if you just bring the exits out to free air it will be quieter?

dennisbernal91z

iTrader: (2)

it will, that is a part of the future plans

83 Crossfire TA

iTrader: (2)

OK, lots of thoughts reading through this…

First, what sounds good on a stockish car usually sounds all out race/opnoxious/loud/LOUD on something with a big cam moving a lot of air. My mildly modded 305 crossfire motor sounded great, and not too loud through headers, 2 x 2.5” high flow cats, a flowmaster Y and 3” running all the way back with no muffler, not too loud but just right and smooth. That just doesn’t work when you add cubic inches and cam.

Second, you basically quiet the exhaust by removing energy from the exhaust stream. With less energy it’s not as loud. The 2 basic ways to do that is through absorption (muffler with some kind of packing around the flow tubes) and reflection (muffler with baffles causing the sound to reflect around the inside of the case. You get some of each even in a straight piece of pipe, especially in a pipe with some bends in it, so a longer exhaust is quieter. Also a larger muffler case does both better, so with a larger case you can have more sound deadening or the same sound deadening and more flow.

Flat surfaces and wide open pieces on the other hand will resonate with the exhaust and possibly amplify it (sympathetic resonance), and straight turn downs like you have them definitely do that, they make the ground an the floor pan of the car sympathetic resonators amplifying some frequencies… one thing to do about that is to turn the turndowns inward somewhat (about 15* or more) to get a reflection towards the other outlet which will result in both sides canceling each other.

Other things to take into account is that this is just like trying to absorb/dissipate any other energy, it’s usually a differential game and you should take advantage of it. To oversimplify this a little bit, this means that the muffler, even if you’re just using a bullet, is probably going to make a bigger difference WRT to sound output then anything else, and the biggest difference (where the exhaust is the loudest and can potentially be quieted the most) is going to be as close to the exhaust port as possible, so even using the same muffler and the same length of pipe, putting a muffler right on the exhaust collector and then putting all the pipe behind it will be quieter then putting all the exhaust pipe in between the collector and the muffler, even though you’re using all the same parts.

Even sounding at least sounds quieter, that is one reason why if you had headers and manifolds that flowed the same the headers would sound quieter. It is also part of the reason that X and H pipes work (another reason is that they reflect and cancel some of the exhaust energy and prevent one side of the other from resonating more then it has to if there was an imbalance of flow, so they actually kill some sound, usually h-pipes work better then X pipes)

Finally, this energy that we’re talking about is the heat and flow in the exhaust, as you dissipate it you don’t need as large a pipe to carry it, and that big pipe becomes one of those wide open spaces that make noise. A perfect example of this is that if you need the flow of a 3” to the muffler, you can often get away with 2.5” or even 2.25” tailpipes behind the muffler with no loss in performance, just a quieter car.

Ideas based on what I’m seeing… Well, if you want to stay with something like you have now I’d bet that you could make a big difference going with longer bullets (there are similar muffler designs that are up to 40some inches long, or just string multiple ones together) to at least increase muffler volume, add an h-pipe (even if it’s significantly smaller in diameter then the main pipes to clear the TA/tranny mount/tranny…) and then taper the turndowns down to 2.5” and turn them towards each other. I’d bet that you could get a big decrease in noise without any decrease in performance.

Past that… pipes going all the way back would help, any muffler with a larger chamber (I’ve wondered about cutting out the lumps where the rear seats are to mount full sized mufflers back there), or even mount 2 mufflers where the stock muffler was and have the exhaust cross (inlet on the driver’s side, outlet on the passenger and out to the tailpipe and vice versa).

Going back to a stock type configuration will also help (more bends, the y-pipe quiets things, more/longer pipe…)

dennisbernal91z

iTrader: (2)

Thanks for the input.

In all honesty, not saying your advice didn't help others, but for me. I am aware of all the things you are talking about. I have learned most of this stuff in my text books on a scientific level. I am a Mechanical engineer major. Almost done with my school. I know that I need more pipe and I am aware about resonance and the turndown angle. It is good how you put all the info in one nice big post though.


I guess what my problem is mainly is that I can't put the mufflers any closer to the collectors....I am gonna have major problems trying to squeeze in a Y pipe someplace and going over the axle is almost impossible, as the stock location of my muffer is now taken up by my fuel system.

I am hoping that someone has some info on maybe a muffler this size, but acctually has baffles in it... I am going to make all the pipes 2.5" in dia for the next set up. Also the turndowns will be pointed out and there will be an H pipe.

Just wondering if there is any other significant thing that can kill more decibles here. A lot of the common kill sound things are not available to me.

Thanks for all the help so far.

83 Crossfire TA

iTrader: (2)

Well, Moroso and DNA do make baffled mufflers in that size range, but I doubt that they'll be much quieter unless you can find room for a larger/longer muffler case

Gumby

Put the mufflers like I did on the sides. Plenty of room in that valley there.

https://www.thirdgen.org/forums/exha...ight=side+pipe

Id stop trying to use the stock muffler location for anything but a place to run exhaust pipe. Though I would also forget the H or X pipe for now. Sure it does add something but all your clearance problems, front to back will be solved if you just run each pipe down the side of the car. Maybe later pay somone to figure out a h or X.

The bit you lose without the h or x can be regained else where easy if your gonna do real racing.

dennisbernal91z

iTrader: (2)

If I do go out there, I will def use oval pipe. But who knows, maybe 2.5" will tuck up there nicely. Too bad I have my SFC in that notch area now, not to mention my battery cable and my fuel lines. I kinda wanna stay in the tunnel. I have built the car around the idea that I would. I think with more time and being very carful, I can put in two tube style mufflers close to the headers, sorta. And work my way all the way back out to the rear and add another couple street mufflers. And maybe make a simple H pipe by the tail of the tranny.

Gumby

Bolt on or weld on?

Id dump em 4 now and or move them inside the car, much cleaner app. Or Id just get a $200 4 point cage. The SFC won't stop it from tearing in half. You got some juice in that car and have ya ever seen one that got lose on a guy and side swiped a poll or other? They just ripe in half like paper. Top is only brazed on. Need cage for real power cars. a know you ned a good excuess to get a cage n e ways.... here ya go.

1991CamaroRslow

iTrader: (3)

They make cone inserts that you may want to look into. They usually are put on open headers, or the header type mufflers like purple hornys. That would be a cheap thing to try and it may get you where you want to be for now.

83 Crossfire TA

iTrader: (2)

If you keep sticking baffles and cones in your exhaust eventually you will get it quieter, but you’ll hurt performance much more then even putting the stock exhaust back on it. I used to have an issue with one side of my exhaust flowing more then the other and automatically failing emissions tests because the computer would detect it and assume that I had a leak in that side, so I took a dogfood can, roughly a 1” hole in it and made it fit in the 3” tailpipe on that side. Fixed the flow problem and made a BIG difference in volume, but it was also a big enough restriction that I had to run a completely different tune.

dennisbernal91z

iTrader: (2)

Gumby: They are welded on. Also, I have seen these cars get hit, it is scary. And lastly I allready have a cage. 6 point that I customed up a little for my street car. It too is welded in.

1991CamaroRslow: I allready have the cine insert baffles in my header collectors. They made a difference, but not enough for the price and I would rather not add more baffled like things. I just need a real exhaust.

83 Crossfire TA: That is interesting what you said about you set up with flow unbalance. Don't worry, I am not adding anymore baffles. I am just gonna stick to the plan, and reduce diameter, add mufflers and make it over the axle. Then maybe add more mufflers, haha.

Gumby

Well Im glad your being safe, so many guys skip that part.
Kid next door caught the 3rd gen fever from me and built a hot hot engine for his camaro, his first car. Sounds like a top fuel dragster and it only has two throtle positions, idle and full bore. I cring ever time I hear him nail it around the turns in our twisty neighborhood. That mystical 17yr old bullet proff shield wont save him if he catches that sucker on a pole.

Have you looked at any bolt righ to the header glass pack mufflers?

dennisbernal91z

iTrader: (2)

yeah, won't work with my sphoon adj TQ arm.

Gumby

Your screwed huh? There is no easy way.

Could go old school and get some lakwood side pipes. They would mount on the outside of that valley, nothing you have would be in the way. They look like my side pipe but they turn outs have block off plates. THey are really just a nice fancy exhaust pipe. There is a hook up on the other side to continue the system. But when race day comes you can uncap the turn outs and run straight pipes, so to speak.

Or maybe go to a super trap type muffles or exhaust tip that has tuneable plates you can add or remove.


They also got some tips with flaps in them like big rigs. Keeps ya from making them loud pops n stuff and tones it down as exhaust only free flows once you build enough pressure. Suppose to aid in mileage.

dennisbernal91z

iTrader: (2)

I have considered all those things matter of fact.

I think I am gonna bit the bullet, dimple the pipes as I got by the x-member, then use the bullets up front, then reduce the pipe to 2.5", and work my way back and over the axle, if I snake it just right, I can make it over. Then I will add a couple 17749 dynomax turbo mufflers after the axle where there is room, and turndowns. I think this will be quiet enough, and not be a huge cap on the flow.

pairtoe

iTrader: (4)

Thrush glass pack mufflers. you can get them at any autozone or advanced auto, etc. my dad has them one his 5.9L 360 jeep and its quiet but sounds really good. and they are only like $20 each.

dennisbernal91z

iTrader: (2)

Too long. There is no good place for a long muffler like that. I mean I am sure I can find one, but.... i dunno. I need to go over the axle anyways. And once I am back there I can just put in a nice big box stayle muffler. I was gonna just re-use my dynomax bullets to save $ and have those be the first things that the exhaust hits....


Unless I can get somemore votes for the glasspacks... ????


I am allways open to more opinions.

One thing I am really worried about, is that I really want this to quiet down. A lot. And this motor has a BIG cam, at least for me. So I wanna do this once and right. So make sure that if you guys are suggesting something that sounds good or quiet, double check that you herd it on a cammed motor. What sounds good and "rumbling" on a bolt on kinda motor, will sound like open headers on my car.

This thing is moveing a lot of air.

pairtoe

iTrader: (4)

not just any glass pack. if you get just a regular glasspack its gonna be wicked loud and raspy, but the thrush ack mufflers are a quiet glass pack they calm and mellow tone but still sound good. my freind has an 89 camaro with a cam, and headers and thrush pack and they letterally shut his car up. but it has to be a thrush pack muffler.

dennisbernal91z

iTrader: (2)

Allright, well sounds like you have an idea of what I want. Maybe I can find a place under there to stuff these things. And my bullets, just cuz I have them, and some turbo stle mufflers after the axle. haha.

6 mufflers. even though I don't count bullets really at all. Maybe I can omit the rears and add them later if I need them. I bet all the new pipes that goes over the axles and the reduced diameter will help a lot too.

It would be sick if this thing got down right quiet. So I could sneek up on other cars instead of them all running away. haha.

We will see. Now if the body shop would just hurry up.

ghost7.62

these two are available from Jegs, the first is the Moroso Spiral Flow the second is a Dynatech Vertex Cone insert. Both are availabe from Jegs High Performance and neithe cost much or any Hp.

dennisbernal91z

iTrader: (2)

I am aware, but the spiral flows don't quiet much down and the cone insert dones't so enough to quiet down either. I have inserts in my header collectors allready. 3 disk inserts. I am done with inserts. I need MUFFLERS and more pipe.

I have only herd bad things about the spiral flow. Guys with bolt ons daying that they are too loud. So for me I bet they would do a whole bunch of nothing, pretty much what my bullets do.

83 Crossfire TA

iTrader: (2)

I suspect that most of the volume from spiral flows is from the center, open tube. I bet that they’d be a lot quieter without much loss in flow if you blocked it off, but I haven’t tried it.

Glass packs are _a lot_ quieter then bullets. When I was looking for a truck (full size chevy 350) I found a used one that had a single glass pack and dual outlets on the back that I have to say was the best sounding truck I’ve ever heard (the thing was kind of a piece of junk, but we went back and looked at it 2x just because it sounded so good running/driving, even my wife, who just wants things quiet thought so), but again, what sounds really nice on a 9:1 350 with no cam and a cat is not the same thing as what sounds nice on something more aggressive.

Judging from how much you’re emphasizing quiet and not really worrying about power loss I’m getting the impression that you’re really going to have to go with something with a real muffler case to get things down to where you want them.

dennisbernal91z

iTrader: (2)

83 Crossfire TA: I think you are the only one that understands me. Power I will worry about later, for now I just wanna be able to drive this car past sundown.

xpndbl3

iTrader: (5)

hacked up my exhaust last night at my buddies shop trying to get those full size turbo mufflers to fit....well we got them in there with 2inches of ground clearance....so back in goes the spiralflows today...ack. Going to try to dump them out the sides instead of turndowns today to see if that even remotely helps. If not it's going in the garage for the winter and I'll deal with it in the sping.

1991CamaroRslow

iTrader: (3)

I don't see why you haven't just stuck an H pipe and a pair of cheapo Auto Zone glass packs on it if you don't care about performance. Make SURE you get the louvered core glasspacks, not the flow throughs like the bullets, and make sure they're the original style glass packs with the 2in cores. This will quiet the car down enough to cruise through your neighborhood and will be cheap, plus you can do clamps or ball and socket fittings and go back to your old style bullets later if you want. Even IF you do the glasspacks and H pipe and aren't happy with it, you're out what... 60 bucks. I'de say it would be worth just doing it and telling us how it works.

dennisbernal91z

iTrader: (2)

Yeah, I understand that point^^^^...

I guess I just am the kinda person that wants to try really hard to get it right the first time. ANd also use what I have laying around.

Swapping down to 2.5" will be fine right? I mean I don't mind lossing some HP, but I don't wanna be killling my motor by having a tinny exhaust.

I mean it is supposed to put out 500HP at the fly. So I am only gonna be riding with around 400 or so at the wheels. I would guess. I do have nitrouse to get it back up to 500 at the wheels if I want. I just want to get this right the first time and not make that fly HP drop more than it has to.

I also don't mind spending some $ on this. I would rather get a better louvered glasspack if one exists.

My plan is 2 glasspacks, or "really quiet tube style muffler" then and H of course and go over the axle and put some full size tubo style mufflers one there. All done with 2.5" pipe.

To me this doesn't sound like it is going to be restictive at all. I mean the biggest wall that the gasses are faced with is the over axle pipes and the turbo mufflers after the axle, but my then the gasses are much cooler and much more dense, so they move slower and are affected by the mufflers less.

Let me know what you guys think... After all these damn posts, I would like to start drawing some conclutions here.

There are plenty of guys in here that have good experience... please wiegh in.




Oh one last thing... What if I went with a mufflex Y pipe. And just modded it to fit around the sphoon x-member. Then went single 4". Have a 4" glasspack of some kind. Maybe reduce it to 3" when I go over the axle or maybe just keep it 4" and have a 4" in maybe 3" out tubo muffler?????

Lets call that ^^^ option 2. Or idea 2.

Thanks for all the help and insight so far. If my car is done in the next week or two, I will need to have some final ideas so I can start ordering parts.


Thanks again.

1991CamaroRslow

iTrader: (3)

This is my stone cold recommendation, I think it will perform well and get you exactly where you want to be on sound. Buy a pair of 2.5in Classic Chambered mufflers Classic Chambered Exhaust Inc. - Products get them as long as you can tuck under there. Get an H pipe done, and go with 2.5 piping out of the mufflers and take it all the way back to a pair of tips that aim out, not down. This will quiet the car down ALOT, how do I know? I went from a single 2.5in core, 24in bullet muffler with 2.5in piping and about 18in of tail pipe before a turn down to a pair of dual chambered mufflers with turn downs (the louder through shot old style, not the classic chambered louvered style). At first the car was only a bit quieter than the old glass pack, but I had the turn downs cut flat so they wouldn't scrape and an H pipe put in. Now I can start the car up and drive around without anyone noticing and thats through the 3000rpm stall. This setup will perform close to what your old setup did, have a nice throaty sound especially at higher RPM's and while cruising will quiet the car down a good bit. I honestly think this will put you where you want to be without having to put a restrictive style muffler on the end, PLUS if you do need it toned down more then you can weld on a set of turbo mufflers and reuse the tips. Those who have chimed in and are still with this post, tell me if you agree or disagree on this being a good plan of action?

PROPHET69

So you find your car loud? Hm... sucks, for me cuz...the car i'm building.. i'm installing 2 straight 2.5 inch cherry bombs with cutouts on a true dual. I'm planning on building it like yours.

Well... i guess this changes things around for me. I'll have to go with a 4000 watt amp instead of my 2000

xpndbl3

iTrader: (5)

i just ran two mandrel bent pipes out the side of my camaro tonight in front of the rear tires and it helped compared to turndowns. BUT you can still tell my car is cam'n and it's still loud compared to how I wanted it....albeit a much more improved tone and not echoing off the pavement at least. I'd say 20% quieter than turndowns. Also I'm running an H-pipe as well like always.