Quieting performance exhaust?

[jszuba]

I just got my Magnaflow cat-back installed with a high-flow cat (in place of the stock one) and the whole thing is just too loud for me.
I wasn't expecting it to be that loud when I ordered it, so, can anybody tell me if there is any way to quiet the whole thing down?
Would replacing the high-flow cat with a regular cat help any?

[visualpoet]

The cat probably won't make much difference. Back in the day, guys used to load their exhaust with some steel wool to tone it down. I'd recommend Stainless Steel Choreboy (so it doesn't rust), and I'd probably stuff it in way up front, close to the DP. You'll have to experiment until you find out how much it takes to get the levels you want.

[jszuba]

Sorry if its a dumb question, but do I just ram the ss wool through the tailpipe and poke it with a long rod?
The bulk of the noise seems to come from the rear.
How do I prevent it from being blown out?
(I realise that if I want it up to the DP, I'd have to take the exhaust off)

[Jccck]

Bigger resonator, or install a silencer in the tip (If its 4.5" circle it's cake, otherwise it'll have to be custom)

[visualpoet]

I'd take it apart at the front of the cat, and put it into the cat. I don't think it'll blow out from that far up the line. I'd go for a long loosely packed wad, rather than a tightly packed one. The idea is to disrupt and slow the airflow a little bit, not create a bottleneck or blockage. If you're running rich, I've been told it might build up a carbon residue, but I can't see it being any worse than you'd get on the inside of the pipe itself.
I've never done it myself, but I have been considering it on my own exhaust. I plan on trying it when I replace some leaking gaskets in the system. I heard about it from old school hot rodders back in my domestic days. The regular steel wool will get red hot and disintegrate, (because it's a fine wire instead of the more solid ribbon they use for stainless) blowing out of the muffler (which would look pretty cool but defeat the purpose.),

And, uh, I'd expect most of the noise to come from the rear, it's where the biggest hole in the system is.

Bigger resonator, or install a silencer in the tip (If its 4.5" circle it's cake, otherwise it'll have to be custom)

A bigger resonator will definitely do it, I just figured since he's in Poland (where parts are probably hard to get), and just got half the pipes done anyway, might want a cheaper alternative. My silencer actually makes the car raspier. I tried it for about two weeks and then took it out and put it away.

[xkjnboix]

u could just wrap the whole thing in header wrap. including the muffler. that would be a great improvement guaranteed. im running my oem muffler on a 2 3/8 aftermarket exhaust now. i had to make my own copper gaskets but it works great, no leaks, and sound is awesome.

[deevergote]

Resonators definitely help to a point, as would a silencer (though you'd lose some performance with it in).

The steel wool idea is outdated. It'd be better to just buy a new system, though you'll be spending more money. I would suggest the Apexi World Sport 2 system. It's extremely quiet. So quiet that while in my friend's car, I forgot he even had an exhuast!
The GReddy SP and RS*R ExMag also have a good reputation, but I don't have any personal experience with either to suggest them as strongly as the Apexi.

The only problem with the Apexi World Sport 2 is that it seems to hang low, and the exhaust tip is quite large. I don't have one for those reasons (but I don't mind the noise... I have another car that's stock )



As for a high-flow cat, most people report a louder exhaust when they get one of those. www.sms-products.com has a nice high-flow cat, and it's the only one I would ever buy for my car (I'm just running a normal cat now). You'd have to check to see if they'd ship to Poland, though.

[jszuba]

The header wrap seems like an interesting idea, though, like Visualpoet said, I just got all my pipes done so I'll also look into silencers not to throw any more $$$ at the car...
I suppose the exhaust being standard 2.25in with a 4in tip, there should be plenty to choose from.

[Jon]

OP, I have the Magnaflow exhaust as well and it wasn't the fact that it was loud, it was the fact that it has such a LOW resonance and exhaust note.

What I did was I installed a Car Chemisty CC insert. It surprised the crap out of me how much of a difference it made.

[deevergote]

I have never seen that before... but yeah, I can certainly see how it'd quiet things down! Is that an easily removable piece?

[Jon]

I have never seen that before... but yeah, I can certainly see how it'd quiet things down! Is that an easily removable piece?

Here is a link to their site for anybody who wants to take a look at them.

Mine is sort of easily removable. They are meant to be tack welded into place just after the catalytic converter. The higher upstream the quieter it'll make the exhaust note. I of course did mine differently... The insert actually was/is too large to fit into the exhaust pipe. So what I did was I tossed the insert into the freezer for a day and heated up the exhaust pipe to about 500°F to expand it and shoved the two together! Basically created a compression fitting. Then I drilled a hole into the exhaust pipe and installed a set screw to make sure it wont go anywhere. I've had it installed for almost two years like that and the insert doesn't rattle and no exhaust leak whatsoever.





To remove it all I do is slide underneath the car, unbolt the exhaust from the catalytic converter, undo the set screw and slide the insert out.
So like I said, mine is sort of easy to remove.

[deevergote]

That's a hell of a restriction, though. I know I'd never go through the trouble of removing it once it's in place!


I'd probably have a new flanged exhaust segment created with that piece installed, and another one that's straight through. That way, all you'd have to do is unbolt a length of pipe and replace it with another.

[Jon]

I was worried about exhaust restriction, but to be honest there really isn't any noticeable change. There is a science behind how they work and why they aren't restrictive and have shown gains.
However when I install the Bisi header it's going to be removed.

I thought about installing it that way as well but I really never planned on removing it.

[jszuba]

Haha, do laundry, do exhaust :P

Looks nice and probably does the job, but pricey...

[AndyD]

If I were in your shoes, I would first try to sell your exhaust to see if anyone will buy it so you can take the money and buy the correct exhaust you are looking for.

All of these "fixes" look risky.