Midnight Koop

Hey Everyone,

I have had many changes in my exhaust through the years (performance --> maintenance --> failures --> etc...) that has led to my current setup. Unfortunately, what I have now is too loud/raspy/etc... for my taste, yet I like the newfound power from it.

My goal is to quiet it down and improve the sound, but I was hoping for some advice from experienced exhaust gurus.

Here is my exhaust history:

1. Kleemann Headers / Kleemann CAT - OEM 2ndary CAT - OEM Resonator - REMUS Muffler
SOUND: quiet
VIBRATION: not noticeable
RESPONSIVENESS: great

2. Kleemann Headers / Kleemann CAT - OEM 2ndary CAT - OEM Resonator DELETED - REMUS Muffler
SOUND: no noticable change
VIBRATION: slight vibration at certain RPM
RESPONSIVENESS: same

3. Kleemann Headers / Kleemann CAT - OEM 2ndary CAT - BOTTLE RESONATOR - REMUS Muffler
SOUND: still quiet
VIBRATION: no difference
RESPONSIVENESS: same

4 (current). Kleemann Headers / Kleemann CAT - OEM 2ndary CAT DELETED - BOTTLE RESONATOR - REMUS Muffler
SOUND: much louder during acceleration only & when vibration peaks throughout RPM
VIBRATION: pretty constant through out RPM, with few peaks throughout range
RESPONSIVENESS: better

Right now my car sounds/behaves exactly like (same setup, except not sure if he deleted the 2ndary CAT delete). *Credit to hieracity*

The noise "seems" to come mostly from the rear at its peak, but the drone when cruising is throughout.

I am thinking of adding a , but wanted to check if anyone had experience with this... particularly on an m271.

This feedback seems promising:

"Was running a straight pipe exhaust on a 1999 Saab 9-3 turbo. Was way too loud and obnoxious. Bought this cherry bomb because it was the smallest body available. Cleaned the paint off the ends and welded it in, painted it all black, and bolted it in. Fired it up and what a difference! Low growly idle, and a little snarl when you get on the throttle. Got rid of the loud, firecracker, chopped pipe sound. You can still hear some wastegate pop when you let off the throttle. If you need to quiet down a small four banger, without spending an arm and leg, this is it."

Exhaust accoustics can be complicated, so I'm also not sure on the placement. I plan to try putting it right on the bend where the 2ndary cat was to start, but I wasn't sure if this was the best place. The 2ndary cat circled in red is now deleted and straight pipe, this is where I'm thinking of putting it:



I will take sound clips along the way, but my first combination will be this:

CURRENT STATE: Kleeman headers/CAT, straight pipe (bend), bottle resonator, remus muffler

TENTATIVE TRIAL 1: Kleeman headers/CAT, Glasspack, bottle resonator, remus exhaust
-based on cost effectiveness of only installing one item at a time and possibly placing it where the largest change in flow may occur (where the 2ndary cat was deleted). but i'm not sure if this is ideal

QUESTIONS:
-Do you think this is the best first place to test it?
-Or do you think I should remove everything and go straight pipe between headers/cat to remus muffler as a baseline... then add the glassback later
-And where would the "ideal" place for it be?

phister

you can put one or two glasspacks along the exhaust before the muffler. it'll help quiet it down quiet a bit. my friend has two on his car and it quieted a lot, almost sounds stock until you get on it. if you don't want to do a glasspack there's also the vibrant ultra quiet resonator.

here's a link to their site. you can find it cheaper on Ebay and elsewhere.

http://vibrantperformance.com/catalo...1022_1033_1055



here's a double setup

Midnight Koop

ah thanks phister...

what kind of glasspack does your friend have? i'm trying to find out which one is the "best"

i also wonder what works better: glasspack vs "ultraquiet" resonator

also, does anyone know off hand if the standard m271 exhaust diameter 2.5''? (so i dont have to crawl under my lowered car)

phister

you can go to any muffler shop and ask just for a glasspack to be installed. theyre just mini resonators really it doesn't matter the brand. but if you really want to quiet it I'd do two glasspacks or a vibrant ultra quiet you don't need to spend a lot on brands like cherry bomb or anything with the glasspack just get the cheap one that the shop carries and it'll do the job.

Midnight Koop

ah ok thanks...

since there is currently a bottle resonator between the cat and muffler... do you recommend i just leave that on there?

i just feel that the placement of ultraquiet resonator OR glasspack should be right next to the muffler (since i can hear the vibration/rasp/noise coming from the rear). right now that is where the bottle resonator is, and it doesn't seem to be doing the job very well.

is there an ideal placement for these? i just dont have experience with tampering with exhaust accoustics.

(thanks)

phister

you can put it anywhere on the exhaust really. You can put it before the bottle resonator or after it right before the muffler. Or you can completely remove it and put two glasspacks back to back of one another or do a glasspack and the ultra quiet back to back or two ultra quiets. I plan on doing two glasspacks right in front of my tips since thats the only real location I can put mine at because of my muffler placement. Sometimes the packing in the resonators eventually deteriorate. I would replace the bottle resonator with the Vibrant ultra quiet and see how it sounds at the muffler shop. If its still too loud/rasp I'd tell them to put a glasspack in front of it.

splinter

Just last month pitched an OE resonator, or I’d have donated it to your cause.

That Kleemann & Remus setup does sound good at full tilt though!

BradfordSil

you can go to any muffler shop and ask just for a glasspack to be installed. theyre just mini resonators really

phister

i posted that in the second post lol

Midnight Koop

Thanks, I'm intrigued by the ultra quiet vibrant resonator (partly because of the cool name!). I think these will be my options:

1. Ultra Quiet Vibrant Resonator
2. Magnaflow Resonator (my shop carries it)
3. Glasspack (whatever they carry)

I will most likely remove the bottle resonator (dont think its doing anything), and will probably go with 2 of the above. I'm just not sure whether to do double resonators or combine resonator/glasspack (my goal is to get closest to stock).

This seems like a discussion better suited on a honda forum

thanks man!

phister

the more mufflers/resonators you put on your exhaust the quieter it'll be.

Midnight Koop

haha yeah that is true...

but if I can make a more informed approach, I'd like to.

To my understanding, the glasspacks absorb vibrations through their fiberglass architecture, and the resonators messes with the turbulent/laminar flow. In the end it will probably make little difference what combination I use.

I could go least expensive: 2 cherry bomb glasspacks ($60 total)
I could go most expensive: 2 ultra quiet vibrant resonators ($170 total)

or somewhere between with magnaflow or combinations of glasspacks and resonators...

I guess I'm just searching for some type of grounds/motivation to favor the less expensive over the more expensive if they all quite down the sound. And if one sounds better than the other... then I dont mind paying more for better sound... but it would suck to pay more and for it to sound either the same or worse.

If money didn't matter, I'd just pay for installing all the different combinations and I'd choose, but I'd like to minimize that if I can.

FrankW

How big is your bottle resonator? Im guessing it doesnt have enough volumn to chamber the noise and because the secondary are actually small resonator once you took them off the noise became louder. You should get the c32 resonator take-off as it has a bigger camber as splinter posted.

I think mine is in the garage somewhere but it'll probably be more convenient if you get one locally as this thing is dead weight to ship.

Midnight Koop

i think its 14'' or 16''. its pretty slim (almost like a straight pipe).

thanks for the offer, but yeah... i haven't found anyone local to do that. there are salvage yards, but i haven't had any luck.

Midnight Koop

I decided to do both glasspack and ultraquiet resonator...

I'm deciding on what size glasspack now and came across this description in another forum... (can someone on here confirm?):

"shorter=louder
longer=quieter
larger diameter=louder
smaller diameter=quieter
perforated core=louder
louvered core=quieter"

Right now I'm looking at 2.5x12'', but considering longer...

I think the vibrant ultra quiet resonator is 14''

any advice?

Midnight Koop

Just ordered these two:


and



I decided that it would be the most cost effective to install both of these and either remove the glasspack all together OR remove and replace with another resonator.

Will have pre/post sound clips once shipment is arrived and installed on car.

cheers

C230 Sport Coup

I added on of these...cleaned up the rasp.
http://www.custom-performance.net/pr...?idproduct=999
It was hard to find a place to mount it though.
It sits very close to the diff.

Midnight Koop

ah thanks for the suggestion... are you running with no 2ndary cat? (or is that only an m271 thing?)

if you are running straight pipe from primary cat to exhaust and are happy with this... then i may cancel my order and try it out. although.. 4'' center is pretty huge. i'd probably scrape on speed bumps.

i also noticed that 2.0'' inlet/outlet. i thought our coupes needed 2.5'' inlet/outlet? also, when i click on "details".. they change it to 2.0'' core... hmmm

do you have pre and post soundclips?

let me know... thanks

hieracity

Hey, getting a tune to incorporate the headers as well as the exhaust did help the raspiness. Sounded more "wholer" than what you see in that video. FYI.

I'll try to pay more attention to the exhaust today to see how raspy it still is.

Midnight Koop

thanks hieracity... (sorry for stealing your vid). i was about to make one of my own... but it sounds exactly like yours so i got a little lazy.

is your 2ndary cat deleted?

who did your tune?

hieracity

No, I didn't delete my cats. I had to install a spacer on the secondary cat though because i was getting the CEL. The kleeman cats are apparently not made of the best (*cough*) quality. I did lose some power and gas mileage as a function of installing that spacer.

I got the tune from EuroCharged. I had a tune before i installed the headers and DP and definitely noticed a difference with the second tune which incorporated the kleeman goodies.

Midnight Koop

hmmm... are you sure you mean the secondary cat? there are/were no 02 sensors next to my secondary cat. there are only pre/post 02 sensors for the m271 primary cat. thus, the reason why i removed the secondary, because it wouldn't give me any CEL's.

do you mean the spacer on the 2nd/downstream 02 sensor?

OFF TOPIC: question about your tune... is your ECU bosch or siemens? i've had no luck getting tunes with my siemens ECU with Eurocharged, but am still willing to try again.

hieracity

Sorry, I meant post cat.

Not sure which ECU I have but I can check later on. Does it just say on top of the connector?

Midnight Koop

mine says it right on the face of it. i tried to remove it once and realized how much of a pain in the a$$ it is. i really want to tune my car, and have 2 failed remote tuning attempts. i might want to try again if yours is a similar setup.

thanks

hieracity

It's Siemens and the tune worked for me