I知 debating deleting my Secondary Cats...
#77
Just go for it ,I went the long way and cut open and cleaned out. You need some sheet metal skills as the outer shield is very thin and to look like it's never been operated on takes time.
Best mod when combined with high flow air filters. If I'd need more info just pm me or near buffalo NY hear the car in person
Best mod when combined with high flow air filters. If I'd need more info just pm me or near buffalo NY hear the car in person
#78
Super Member
Just go for it ,I went the long way and cut open and cleaned out. You need some sheet metal skills as the outer shield is very thin and to look like it's never been operated on takes time.
Best mod when combined with high flow air filters. If I'd need more info just pm me or near buffalo NY hear the car in person
Best mod when combined with high flow air filters. If I'd need more info just pm me or near buffalo NY hear the car in person
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Skilly (05-31-2020)
#79
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adds noise to my car without me having to cut the secondary cats. The module was not done for any track purposes only street to ADD noise without any hassles of removing anything.
At the track I don稚 need the module really because at full throttle in Race Mode everything will be wide open already.
When you are noise tested at the track they are wise to exhaust valves and make sure that your system is set to open when they measure. Thus removing cats could possibly mean not being able to run because I知 too loud.
Sorry for the confusion.
At the track I don稚 need the module really because at full throttle in Race Mode everything will be wide open already.
When you are noise tested at the track they are wise to exhaust valves and make sure that your system is set to open when they measure. Thus removing cats could possibly mean not being able to run because I知 too loud.
Sorry for the confusion.
#80
Super Member
Thread Starter
I知 not aware of any bolt on kits for the secondary cats
Im looking at the EVM too - curious though, is there a straight pipe available to slip into the resonator removal, or does it require cutting the factory exhaust? I havent put my car on a lift yet, but I would rather lean towards something that is also reversible without creating permanent scars. Fabspeed had this kind of thing for my 911 that you could bolt on in place of the first set of mufflers in about an hour. Be nice as an option here too.
#81
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My guess is that it's a great consideration for the crackle/pop increase - the remaining unburned fuel that would cause that is getting consumed here. I just hate cutting up exhaust in such a noticeable way. The question in California is would it pass SMOG. Visually, no, but most of the shops just stuff the probe in the tailpipe and test away.
#82
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I can稚 be certain about CA smog regs
But my understanding is removal of the secondaries has no effect whatsoever on emissions. I知 sure there are members on this thread from CA that can chime in. I do know for a fact that up here in Toronto, removal has zero effect. If your questioning removal try the EVM. I guarantee you will be pleased.
#83
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But my understanding is removal of the secondaries has no effect whatsoever on emissions. I’m sure there are members on this thread from CA that can chime in. I do know for a fact that up here in Toronto, removal has zero effect. If your questioning removal try the EVM. I guarantee you will be pleased.
#84
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But my understanding is removal of the secondaries has no effect whatsoever on emissions. I知 sure there are members on this thread from CA that can chime in. I do know for a fact that up here in Toronto, removal has zero effect. If your questioning removal try the EVM. I guarantee you will be pleased.
#85
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Thread Starter
Sure.
Any chance that you can take a video of your car in Race, so the stock exhaust flap is open and then compare it with the RENNtech module on/off? I havent been able to find anything that lets you hear the effect - their engineers said it was significant because the stock system doesn't fully open the valve. Be nice to get a real world account of the change.
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x96535 (06-05-2020)
#86
Any chance that you can take a video of your car in Race, so the stock exhaust flap is open and then compare it with the RENNtech module on/off? I havent been able to find anything that lets you hear the effect - their engineers said it was significant because the stock system doesn't fully open the valve. Be nice to get a real world account of the change.
#88
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Ok. Let’s try this again. The first video is cold start. The other is S+ Just after the cold start after it settles down. Turn the volume up and enjoy.
https://streamable.com/k21zd8
https://streamable.com/3i4klt
https://streamable.com/k21zd8
https://streamable.com/3i4klt
Last edited by DriveAMG; 06-05-2020 at 04:27 PM.
#89
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Ok. Let痴 try this again. The first video is cold start. The other is S+ Just after the cold start after it settles down. Turn the volume up and enjoy.
https://streamable.com/k21zd8
https://streamable.com/3i4klt
https://streamable.com/k21zd8
https://streamable.com/3i4klt
#90
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#91
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Someone chime in if I am wrong, there is nothing wrong with being a perfectionist, in my opinion, and I have owned and modified a lot of high end vehicles over the last 35+ years, that mod no matter what you use, pipe, material etc, is not going to make much difference in performance or sound, upgrading down pipes, exhaust system will, but not just the pipe used for removing secondary cats, just make sure that the weld is good but sounds like he is a perfectionist. lastly there is a debate on if the pipe should go over or inside the removed cat ends, and X pipe is another debate that can go on as well.
That means when you cut the secondaries out, you bugger up the complete downpipe. I had been looking for a secondary bypass - I could see that the aftermarket downpipes came in two sections byt couldn't figure out why it was so hard to find just a bypass (I think Weistec sells it but couldn't find others). Just a further consideration if you are planning on cutting out the secondaries - living in CA, or anywhere that requires smog checking (with visual inspection) that could end up being an issue.
#93
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I live in CA, have had my car inspected, they do not even check, or would not even know as most cars do not have secondaries, there is no emissions related systems in the secondaries, so it will not show up in any test.
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I dont disagree about their value - no sensors inline past them so they wont affect the CEL - I'm just a little uncomfortable having to rip into what is really the complete downpipe and figure others might want to know. I suppose if you can find a good exhaust specialist, the surgery can be done with minimal scarring.
#95
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My Shop used the exact tubing as factory and based on the placement of the curve of the pipe you can稚 tell unless you go in there with a scope LOL. You池e not bugging up anything except standard exhaust pipe.
The 3000 degrees your eliminating will certainly help wear in long term as well.
The 3000 degrees your eliminating will certainly help wear in long term as well.
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Skilly (06-08-2020)
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My Shop used the exact tubing as factory and based on the placement of the curve of the pipe you can’t tell unless you go in there with a scope LOL. You’re not bugging up anything except standard exhaust pipe.
The 3000 degrees your eliminating will certainly help wear in long term as well.
The 3000 degrees your eliminating will certainly help wear in long term as well.
Did you replace the secondaries with a pipe or just emptied the factory secondaries that looks like a pineapple.
if you have a picture of ur car from under i would love to see.
#98
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Man. I swear. The zombie thread from hell, only reason I’m responding is I’m still self isolating LOL. Replaced it with standard muffler pipe exactly like what Mercedes uses and I did not clear out cans or do anything fancy it was $175. There is nothing else to be said here you guys it’s all been covered ...............make a decision and live with it and close this damn thread.
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Skilly (07-31-2020)
#99
Senior Member
After a week of owning my GTS I had the secondary cats removed. $120 bucks. Wayyyyyy better, perfect "loudness" way more pops and crackles. If you are contemplating just do it. Cannot beat it for the price you will be very happy. PLUS in comfort mode the car is as quiet as stock, best of both worlds.
#100
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I did a secondary cat delete and resonator delete on my w204 c63.
is the consensus for the guys doing it on the GT to just replace the secondary cats and not touch the resonator (if there is one).
is the consensus for the guys doing it on the GT to just replace the secondary cats and not touch the resonator (if there is one).