Anyone using chambered/turbo mufflers?

It seems like every exhaust for our cars uses a straight-through design. While good for flow, they are loud as hell! I've got an HKS "silent" hipower catback with a cobb catted DP, TurboXS UP, Perrin ELH, and a 20g. Now my car is way louder than it was with the stock turbo and I'm looking for a more muted sound.

 

I'm considering replacing the HKS resonator with a magnaflow muffler, but I'm afraid it'll still be too loud and I don't want to ruin my beautiful, perfect fitting exhaust!

 

I've also thought about putting the stock catback back on, but I want good flow and they'd sound like crap with my UP/DP/20g combo...

 

Is anyone on here running dual flowmasters/flowtech terminators/turbo mufflers on their LGT? I know these don't flow as well as a similarly sized, straight-through muffler, but I'd make up for that with larger diameter inlet/outlet mufflers.

Don't do it. You don't want a Flowmaster anywhere near a turbo.

Sorry for bumping an old thread.

 

TRSCobra, have you found a solution? I'm in the same boat as you are except I have a Borla.

 

Rao, would you happen to have a suggestion?

 

Thanks.

My solution: going back to the stock catback and considering a cutout for when i need flow.

Sorry for bumping an old thread.

 

TRSCobra, have you found a solution? I'm in the same boat as you are except I have a Borla.

 

Rao, would you happen to have a suggestion?

 

Thanks.

 

Anything that isn't a chambered muffler will do the job.

Ah, I see.

Thanks

This thread says that the SPT v2 is not a straight through muffler; it's baffled.

http://legacygt.com/forums/showthread.php/so-cut-off-my-spt-ypipe-and-mufflers-148104.html?p=3137970

Dynomax super turbo inline 3" welded in

Dynomax super turbo inline 3" welded in

 

Pics/Video?

I wish I have a hunch but haven't tried it.... Yet

 

I do know my 4.6liter 9.6/1 CR (stroker) jeep i6 was almost silent with no cats and that muffler.

I bet with two of those, it would be even quieter.

 

I've got a flowtech terminator (thick-cased, welded turbo muffler) on my 4.0 jeep WITH a cat and it's anything BUT quiet!

I think its the S turn in a fiberglass lined muffler that does it..

 

I know S turns in lined HVAC ductwork stops fan noise 98% of the time.

I ended up with a 4x9x14 center in, offset out. It cut the noise level down very nicely.

Sound clip coming ?

I don't know how:redface:. It sounds little lounder compare to when I was at stage 1. It's amazing how much noise that upper cat. suppresses the sound.

So I guess in summary that no aftermarket exhaust is remotely quiet? I have somekind of perrins that were on my car when I bought it, but they fit horribly and sound like a pissed off bumble bee at highway speeds (80ish) which I'm not a huge fan off. I love my car, and was considering replacing them with something else, but it appears that no one has a better solution. I guess I could still buy something else for fitment reasons, but I doubt I will spend the money just for a better fitment.

If you want an exhaust that's really quiet like stock, then surprise... you should stay with the stock exhaust.

 

There are quiet ones and loud ones, check the exhaust video thread for how they sound... Even then, it's hard to say.

 

The OP isn't a good reference to use since you have to realize he has a significantly larger turbo on there than stock. A lot of things will affect how the car sounds, not just the catback.

 

A fully stock car will obviously be the quieter. One that has had the DP replaced will be louder, but with the stock cans should still be fairly subdued. Following that, I would think that the OP's HKS silent hi-power exhaust should be on the quieter side compared to other aftermarket exhausts because from my findings, their exhaust diameter is only 2.36" (the exhaust specs list 60mm) compared to say... 2.5" or 3" that a lot of aftermarkets are.

 

If I'm not mistaken, your Perrins are a full 3", with no taper at the joint.

http://legacygt.com/forums/showthread.php/which-cbes-mate-up-invidia-dp-perfectlyi-115489.html?t=115489

 

As for the fitment, lots of people say Perrin fitment sucks in general, so there you go.

 

As for myself, I have an SPT v2, and like you, I found highway drone to be absolutely intolerable. Car sounds great driving around local roads and sounds super mean when I get on the pedal.

 

I ended up lopping off a section of the mid/y-pipe (it's a one-piece on the SPT) and having a 5" round Magnaflow straight-through muffler welded in. I lost a tiny bit of ground clearance as a result, but it's okay. It cut down on the droning significantly and made things much more tolerable, without losing too much of that mean growl I get when I punch it. I think my neighbors appreciate the muffler too, since it reduced the idle noise as well.

 

Sometimes I wonder if a 4" round Magnaflow would have done the trick but I didn't want to chance it and still have intolerable drone.

Since i put the stock catback back on, it's super-quiet. Now all i hear is the whine of the turbo when I'm driving... I've got a e-cutout on the way to gain my lost power back.

Yeah I'm still stuck in the middle, cars with catted down pipes seem to sound better but what's worse for flow catted dp with aftermarket cans or stock cans and catted dp ? And what does the car sound like with a catless dp and stock cat back ? I'm sure the stock cutback is heavy too, the extra mufflered cars sound great but I think all the ones I heard had a catted dp.

 

I want to be able to shift off engine noise but all I can here right now is turbo whine

Most aftermarket catted dp's use high flow race cats and only cost like 5 hp or so, no where near what the stock catback restricts with a larger turbo. The stock catback seemed to be a few pounds lighter than the HKS system i took off, too.

 

If this whole cutout thing fails, i'll seal it up and have a 3" stainless system made with a dynomax ultraflow center muffler and 2 3" super turbos in the back. That should satisfy my flow requirements without being too loud...

Keep us posted on that setup if you go that route, because I definitely want to do something different.

You all are close...

 

http://dynomax.com/mufflers.php?muffler=vt

 

just watch out as there are a lot of quality control issues with the valve clanging at idle. It's very hit or miss with the evo guys.

I looked into those, but the stories of the valve clanging quickly changed my mind.

Supposedly they fixed the issue. It was a quality control issue with the valve supplier last spring/summer and has since been fixed since they switched their supplier.

 

I'd still be wary though.

Supposedly they fixed the issue. It was a quality control issue with the valve supplier last spring/summer and has since been fixed since they switched their supplier.

 

I'd still be wary though.

 

There was a design change, yet brand new units are still producing the issue (sometimes). These turbo 4-banger engines simply pulse the exhaust enough to bump the valve. At say 750 rpm idle that's 1500 pulses a minute, or 25 pulses a second, as few as you're going to get. Pulses are more punchy than a V6/I6 or V8 when you hold your hand behind the muffler, because there are 33% or 50% fewer pulses per unit time than 6 or 8 cylinder engines.

 

Then our cams are setup for turbo applications. I don't know much about cams, so maybe someone else who does may know if they should make any difference in the exhaust pulsation

 

Perhaps the "engineers" at dynomax mocked up designs on a V8 and a V6, found two good spring rates to use, found it to not rattle, and moved on to the next project.

 

I have not written off the Dynomax VT myself. The warranty is excellent, and a different muffler can be clamped on in its place if it ends up a repeated fail. I personally am not opposed to putting a dremmel to the valve if it becomes clear that a bit of grinding will solve a rattle problem. Hell I would even cut open the muffler and add a dampener inside the spring if that would stop the rattle. That is if it's worth it to do so. Something to consider that you could attempt these things.