Didn't want to fill up the main thread so posting new.... ok car is '01 AE manual 87xxx. I went in on the group Cattman buy and got the full system, front to back. Had a shop do the work, just picked it up last night. Car was completely stock prior to install.

Power gain is noticeable, and that is super cool. I see why many of you guys like the sound, especially above 3k rpms. At the high end it's even better.... really sweet.

However, on the low end, it's just too loud for me. It sounds like my '00 max when the muffler blew. I mean I knew it would be louder, and I wanted more sound..... and I took the risk going in "blind". But it's just too much, especially around 1800-2800ish rpm's, which is where I cruise, and starting from stoplights/stopsigns, etc.... I feel like a local ricer lol.

What are my options? I realize I can go back to all stock (which is SO quiet), but are there any "in between" options?

 

sound deadener. Also see if the system is sitting on the rear axel. I know mine is and i put a piece of deadener on the axel to minimize the vibration and that made a big difference.

 

So, all you have is the catback, or headers too?

The only 2 options are hack that beautiful system and add a resonator or another muffler ... or both, or go back to stock.

 

From what I read, it will quiet down a little in about 2-3 weeks so try and tough it out.

 

The installer put some kind of heat resistant bushing on the rear axle (I think its called a bushing) so the pipe rests on that and doesn't rattle against it. There's no rattling whatsoever while driving, just that low-end 'I don't have a muffler' sound.

I have the full system front to back: headers, y-pipe, etc... everything that was offered in the group buy.

I'm hesitant to hack it up because I can still sell it if I take it off... I mean the thing is still shiny so I should be able to get a decent 'used' price for it. I thought it already has a resonator? Sorry if that's a dumb question I'm a newb and still learning here.

A while back when I talked to Brian he mentioned something about it being quieter w a stock muffler, but I didn't think a stock muffler would fit onto the 3in pipe?

 

You could just put the stock rear section onto the cattman b-pipe. From what I understand, hardly any performance is lost. I have a stock axle back on my megan b-pipe and the sound is throaty at most. Changed the feel more than the sound from stock. Want to sell me your cattman axleback portion if you go this route? By the way I have full headers too and still on the quieter side.

 

For this to occur, you need to modify the stock flange to mate up to the 3" flange, I tried it and it wont work as is.

And also, as strange as it may sound, I've read about time and time again, until recently, I tried it and was amazed.

OP, get yourself a 3" testpipe. It quiets it down, sound weird, but it does.

 

^ Unless OP already has a fast cat he did say "full system"

 

I had a full system, dumped the fast cat, and put a 3" test pipe.


3" test pipe is quieter than the fastcat.

 

Hmm who wouldve thunk it? TP resonated or non?

 

youtube is the OP's friend /thread

 

troof

 

IDK. Looks it from the outside, but not really inside.



Center:

 

Doesnt look like its resonated. Is that the 240 3" TP?

 

This, I remember when I did the Exhaust like WTF did I do but after a couple of weeks it majorly died down so give it a couple weeks.....

 

No, it's not, just solid metal through the internal.

Yup, that's it.

ISIS is the brand IIRC.

Weird that they add all that mass/size, whether hollow or not, but no resonation, just mass, although it doesn't feel any heavier than the FastCat, it (ISIS) actually feels lighter.

 

Thx for all your help you guys are awesome. I drove it home from work today getting off then back on the freeway over and over at every exit..... so much fun. This system really makes this car's driving experience so much better especially since it handles like manure. I've been following the suspension thread for a while now but that's another topic.

Gustle not sure what u mean about YouTube, all I can find are vids of drive-bys and audio you can't hear very well.

I will try this thx for your encouragement. If it doesn't cool down a bit in that 2200 range I'll try the test pipe. Unless you guys would suggest something else that would work better. A friend recommended a 2.5in. baffle between the connection points after the cat. Good idea?

 

I dont have a full Cattman system, but I have hotshot headers nad y which are similar, stock b-pipe and cattman axle back and the volume (not the tone) is on par with the stock RWD VQ powered vehicles. Loud enough to notice, but not loud enough to annoy you. Get comments on how civilized it sounds when I drive it easy all the time.

 

Dont know how much you drive but give it about 3 weeks or 500 miles or more it will tone down alot, all Cattman also, oh got some Vids in my Sig, In Cabin and all, they say the Carbon has to build up on the pipes since they are New to Tone down the sound.....First Day with Catback was like **** I need to put Stock on ASAP, but now Never.....

 

Haha yep me too... ok hope I feel the same soon. Would a road trip help u think? Letting it run in the low 2's in 5th for a few hours?

 

How many miles you drive in a week, Im sure it will help but dont just go blowing Gas money to break it in....

 

Lol agree sounds way loud when install at first but couple weeks everything tone down a little.

 

Not only will the sound drop a bit after a break-in....but, sound deadening is still a good option. My full Cattman system (w/fastcat) is louder with the windows down then up because I have some basic deadening on my back deck (behind back seats) and some thin heating and air duck work insulation on the trunk floor and spare tire well. Cheap stuff and looks stock. I've also wrapped my headers and some of my y-pipe...which I think helps with tone and volume as well.

As mentioned though, do make sure the exaust is not hitting the rear cross member or that the muffler is hitting the bottom of the rear bumper.

 

Is it a 3" or 2.5"?
If it's a 2.5" you can remove the Cattman rear muffler and install the OEM! If it's a 3" then you can hold on for a week or 2, I'm building and experimenting with a Magnaflow 6" round x 18" long muffler as the resonator which is bigger than the 4" round Cattman resonator.....Go to the Cattman 3" thread I'm presently waiting on some parts (Flanges and tubing) till I get this thing welded and installed.....Your system will quiet down considerably after about 500-1000 miles with the soot accumulation and build up in the exhaust system.....GL....be patient....Help is on it's way!

 

Can u point me in the right direction for the stuff to wrap the headers & y-pipe? If that will help I will try that.

The guy who did the install said there was no way around the exhaust pipe resting on the rear cross member (it may have been the axle I can't remember), so he wrapped a heat resistant bushing on the cross member and the exhaust pipe rests on top of that. Did you guys set yours up the same way?

 

That has nothing to do with reducing the volume you need a larger resonator....instead of the 4" round x 20" long Cattman...I'm trying a 6" round x 18" Magnaflow....volume wise it's Cattman's 251.36 Cu in vs Magnaflow's 508.68 cu in which is twice the sound reducing volume than the Cattman resonator!!!!!!!

 

Yes, if you have any of the exhaust resting on the car, that is why your exhaust is unbearable.
There are ways to get it installed so there is no contact. You can slightly loosen the exhaust where it bolts together and twist it away from the rear section it's making contact with. I would start with where the b pipe bolts to the cat. Then where the c section (or whatever letter) bolts to the b pipe. You can gain about an 1/4" doing this.
Subsequently, you may have to loosen and adjust the short L pipe that connect to the muffler section so you can get the right angle. Then you need to go to autozone and purchase replacement hangers. I found the to be tight fitting on both the stock studs as well as the Cattman. Ensuring the muffler is firmly in place significantly reduces the chances of further pipe movement which would cause banging and vibration.

I promise, your noise will drop by 50% once you do this. This is exactly what I went through after installing my Cattman catback.

Although wrapping headers and y will not help you in this situation, as Cmax stated correctly. I still stand by my opinion wrapping does, in a properly installed setup, improve abbrassiveness of tone and does slightly improve noise.
Ill take some pics of what I've done. I felt I had to go to a bit of an extreme to get my system to not move around. But, I definately know it's not going anywhere and what I've done was not expensive. Be back later with pics.

 

Yup my B-pipe is sitting on that lil exhaust support and that shyt is hella annoying lol.... havent really messed with it since, hopefully ill have it fixed when and if i get a catback

 

If yall install your catbacks correctly they will clear all the support brackets...New heavy duty exhaust hangers Nismo or Poly bushing:http://www.perrinperformance.com/p/2152
plus there are other little things that help have a flawlessly installed 3" exhaust and positioned everything with it all loose helps as stated by ChrisGregg.....here's a few pics:

A Few Washers Between the Bracket and Body will Help!




Limits Catback From Sliding in Hard R/H Turns



Installng the dot @ 12 o'clock on your resonator section fwd flange will help 100%

 

I'm glad you posted your images, I was going to suggest you do.

Similar, here is what I've done at the muffler. This image is of a longer isolator so the muffler is allowed to move a bit more to the passenger side and ensure just enough clearance between my tips and bumper.


This is of the rear right/ passenger side of the muffler. Yes, two isolators together.


And here is the passenger side on the back end of the muffler. As Cmax has indicated, adding a half peice of an isolator to keep the main isolator pushed to the right side helps ensure the system stays to that side, eliminating right turn banging.

 

Nice, got to give this a Shot....

 

Another option is to trim the Bpipe hanger hook by about 1/4" cause that's what's banging against the floorboard in hard right hand turns.....it's not at the rear muffler but just aft of the resonator on the bpipe......I'll order some poly units just 2 see how they perform but they will have to be the same size as NAPA's 35460 cause the 35725's are too small.....I found a decent priced vender with black poly exhaust hangers: http://www2.kartboy.com/x4/ check it at I'll measure our rod size but the long ones will be choice.....people used WD40 and grease to install your hanger is a no no...use soapy water it dries will no ill effects on your rubber hangers, oil breaks rubber down and causes premature failure!

 

Ok so I'm about 150 miles in w the new exhaust and the sound has definitely been changing. It's still really loud in cabin (especially at that 2300 mark), but the idle has quieted down considerably. The tone has also been changing. Getting deeper. I notice it more when downshifting then accelerating actually. Above 3k still sounds awesome.

Based on what you guys have said, I'm convinced the in-cabin noise is due to the piping resting on a bushing which is wrapped on that rear axle.

Last night I bought my first floor jack and two jack stands (off CL), so wish me luck. I've demo'd/remodeled houses from studs to finish before.... Hoping that helps. I'm curious to see if removing that bushing on the axle helps. Those pictures are awesome thx again everyone for posting I'm going to have them right next to me as I do this. *nervous I've never jacked up a car before will try not to die*

 

Never posted about the sound deadening. Two things, especially if you do work in home renovations.

First, you can use rubberized metal tape on the rear deck both on top and underneath part in trunk. Also use inside doors and such....blah blah. But back deck will decrease a lot of exhaust noise.

Second, here is an image of the insulation used in heat/air. Its thin, light, resists heat, adds cushion, and is really cheap. Here are some images.

 

Yeah I spray the inside of the spare tire well with rubberized undercoating inside and out plus I have some 1/2" styrofoam under my trunk carpet...

 

Nice mockup. Have the 6" installed yet?

 

Of course not! Trying to get it cut , tested fitted one more time and then welded.....then test fitted again! I'll be a little tight but I don't have a lot of movement and If do start having contact problem I'll switch too Poly hangers.....I joined a Sonata forum tonite ...man are we fortunate too have performance parts!!! They've been around awhile since 1985....and thereis hardly anything available

 

All new isolators help as well. The longer one on the drivers side of the muffler (I posted with images) is the walker unit Cmax recommends. My issue with the walker is that the holes for the hangers are too big, resulting in them failing to hold onto the system to keep it in place. If I ever find the proper length isolated with smaller holes, I'll replace this one. Works well for now, so not an immediate concern. If you're wanting a walker isolator, I've got a few new ones I'm not using.

The other isolators I picked up at Autozone. They are stiff and the openings for the hangers are tight. It will take some muscle to get them on, but there is comfort in knowing my stuff is not going to slide around. Here is an image of one style from autozone I'm using and the packaging. You can find the oval units I'm using in the same section.

 

That's because its a Sonata...

 

Thanks for those tips. Reminded me of a job once where we sound-proofed a room using MLV, http://www.soundaway.com/Mass_Loaded...rrier_s/31.htm We used the 2lb/sqft stuff for that job and it was a bear to work with. Made me wonder if that could work in a trunk.... stuff is really heavy though. I wouldn't think that's worth it... (?)


Crawled under the car tonight for the first time ever. It's going to take some time until it feels comfortable under there haha.... but I lasted long enough to take some pics of that bushing. You can see the bushing zip tied to the rear cross member, and the pipe rests on that:



Also, it's sitting slightly towards the back, it's super close to the heat shield. Just about touching it.


If I pull that bushing out the pipe will def hit the cross member. There is some room to go higher, but then the tips touch the bumper when raised. Not sure what to try next... you've said to loosen the bolts after the resonator and playing w it that way and it sounds like I should buy new isolators.... did you guys have a second person helping you? Sorry for all the questions thanks for helping a noob.