i had the magnaflow muffler cutsom made at another location same set up though ive got 3inch cat back but no 2nd cat and no resinator and it sounds great! some drone at interstate speeds only abouve 3500 rpm's in 5th, 6th gear but hey im 18 so i like it

 

finally went and decided to go the modest route. left the 2nd cat and resonator and upgraded to 2.5 inch piping. i just had the shop weld the small inlet for the tip directly into the dual outlets.

sounds goood to my ears. the blowoff and and the spooling of the turbo is a bit quieter than the exhaust. like the low grumble...

 

Let me make sure I have this right: the downpipe has the first cat and O2 sensor, then there is a joint and a wiremesh covered thing that is what - a second cat or resonator? Then there is a cylinder looking thing followed immediately by a second joint - cat or resonator?

https://www.northamericanmotoring.co...d.php?t=145615

Then the cat-back section starts: a little muffler and a big muffler?

http://farm4.static.flickr.com/3076/...da82b3f0_b.jpg

The Invida in the last photo has a wiremesh covered thing, then an expanded are that looks like it swallowed something, then a muffler.

What's what in the stock and aftermarket exhausts?

 

For first link above, the top unit is the OEM exhaust and you are looking at the downpipe with the first catalyst, and past the bend is the flex pipe, then further down is the 2nd catalyst.

The aftermarket (lower unit) is what is referred to as a "turbo-back" exhaust, which usually has a higher flow catalyst (ie. less restrictive than the OEM catalyst) and some that remove the 1st catalyst too, this one has the 2nd catalyst removed.

For the second link:
The wiremesh=flex pipe and then the expanded=resonator.

Hope that helps.

 

On the second link:

The wiremesh looking bit is the flex pipe. It allows for expansion of the sysem when heating and cuts down on vibration.

On the stock exhaust (bottom), the can right after flex pipe is the second cat. After the second cat is the resonator (the longer can). then Finally after some pipe there is the muffler.

On the Invidia (top) there is only one longer resonator and then the muffler, it doesn't have the second cat.

 

Thanks for the descriptions - I never heard of a flex pipe...

 

its important! also leaves some room for error

 

I have removed my cats and resonators and would strongly advise anyone wishing to remove the resonator to think twice.... It made more difference to noise than removing the cats did... and I am getting terrible drone and rattles from all over the car because of it...

Take my advice, keep the resonator. It doesnt seem to make much (if any) difference to noise OUTSIDE the car (maybe 5% at most?) but INSIDE the car it makes it perhaps 60-70% louder?
I will be getting a custom made resonator welded in ASAP before my head explodes from the drone

 

hey futureal33 thanks for taking the hit!

what do you mean by custom made resonators... is it that easy to make? i thought they stuffed those things with fiberglass or some dampening thing. if you do decide to get a particular company (non DIY) tell me how it sounds.

 

When I say custom I mean, custom made to my requirements, ie length/width/bore etc. I have ordered from a UK company called Custom Chrome UK and it cost me £50 all in (about $75) and this is in 3" mild steel. It measures 24" long and 22" of that is the resonator chamber, with 1" either side of it of 3" pipe to connect to my exhaust. I am going to cut a 24" section of my exhaust out and weld this in its place... to do this I have had to remove the black plate under the middle of the car (i think it is for rigidity) but having had it removed now as a test for about 500 miles, it doesnt seem to make any difference at all!! So the resonator will be being welded in there as this is the only part of my exhaust that is flat and straight for it to go in...

I dont know how much sound difference it will make, its quite thin but hopefully because its so long that will help make it quieter.

Fingers crossed

 

yeah... i heard the location/length of the resonator will change the overall sound of cars. make sure you make a video

 

I was going to drop my R56 off at a muffler shop today and have them replace the resonator with a straight through pipe. It is on the stock system. Do you think this will be too loud? Im buying a cat-back in about 2 months but wanted to tweak the stock setup first. Should I remove the second cat instead of resonator? Im looking to get a little more sound, but not too loud, hopefully a bit of power as well. My r56 has intake, cowl, BOV, turbo muffler delete, alta turbo hoses, and some exterior stuff. Any advice?

 

i still get a lil drone on highway when my mini is under heavy load... aka 2 or more people.

that is with stock cat and stock resonator... if i could do it over again... i wouldnt change a thing

 

I installed the 2009 JCW exhaust which replaces everything from the first joint just behind the first CAT all the way to the back. It removed the 2nd CAT and gives you a larger resonator to reduce drone. Also the JCW exhaust is much better flowing.

It cost me lest than $800.00. It bolts right up so you can install it yourself with very basic tools. It also sounds great!