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I'd be surprised by that. Most modern cars have two stages of cat, with the second being for cold start emissions. These secondary cats are usually a lot less dense so they can get to operating temp quicker.
I saw the schematics of the C63 exhaust and you are right; its called a catalyst not a resonator.
Hey mate, can you give us more details of what is involved?
I know the secondary cats have to be cut out but is there a pipe to replace it? I imagine once its cut out there will be a gap?
My shop advised it can't be done and recommend changing the down-pipes instead.
How is the sound on idle? - more raw?
Sounds like your shop would rather you spend $4000 getting downpipes and having them fitted than $200 having the cats cut out and pipe welded in place!
Regarding this Mod to the secondary cats, do you have to drop the transmission or anything to remove the cats? how do you actually get to the down pipe to cut the secondary cat out.
Also you might find this useful....
I have modded the Back box on my C63s, If you open the back box you will see 2 pipes, one for quiet mode and one for loud(Race), You will see there are little slits around the smaller pipe which is the pipe used when you have the exhaust flaps open (Loud). If you cover these up you gather much much louder bangs on down shifts and all round louder volume. you can cover them up by welding them up with a metal plate.
Just a note from me, i removed my 2 secondary cats from my RS3 a few years ago, we used a cutting torch and a chisel and removed it in about 20 mins.
Leaving the exhaust pipe looking stock but the cat removed and not having to weld any piping
so I was planning on getting cats removed today...when I looked under car and realised its already been done. LOL the last owner had it done. I bought my car with like 8k kms on it. so I saved a couple hundred bucks there! I had no idea it was done cos I havent heard the sound of another c63 yet. so with this done it does have some nice pops and a good sound. but I'd want louder so im looking at doing more. headers or anymore thoughts?
Here are some crappy videos from my iphone so you can hear sound. bit choppy at start. it vibrated my phone so mic cut in and out so i laid phone down at end to hear better.
so I was planning on getting cats removed today...when I looked under car and realised its already been done. LOL the last owner had it done. I bought my car with like 8k kms on it. so I saved a couple hundred bucks there! I had no idea it was done cos I havent heard the sound of another c63 yet. so with this done it does have some nice pops and a good sound. but I'd want louder so im looking at doing more. headers or anymore thoughts?
Here are some crappy videos from my iphone so you can hear sound. bit choppy at start. it vibrated my phone so mic cut in and out so i laid phone down at end to hear better.
I was particularly interested in the idle and normal daily noise. It's slightly elevated.
But on throttle it's a blast 20% more. Do it.
Finallllly!!!
I have found a shop that has done a few of these and will be taking my car to them end of this month.
Unfortunately, flat out this month and can't do it any sooner.
Looking forward to that extra 20% on kick down yewwwwwww.
I was also looking into these new FI downpipes with cats - They are not catless, I can't stand the catless fuel smell even though its better sounding and performance.
This is plan B if I want it louder but it will also involve a tune
2019 Audi SQ5, 2011 Toyota Tacoma TRD 4wd, 2016 Ford Focus se Hatchback
Originally Posted by Sanch
Finallllly!!!
I have found a shop that has done a few of these and will be taking my car to them end of this month.
Unfortunately, flat out this month and can't do it any sooner.
Looking forward to that extra 20% on kick down yewwwwwww.
I was also looking into these new FI downpipes with cats - They are not catless, I can't stand the catless fuel smell even though its better sounding and performance.
This is plan B if I want it louder but it will also involve a tune
Pic below - left with cats and right catless
Get a before and after video together for all of us on the fence.
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
