GT/C192/R192: New GT55, thoughts from a previous C63s owner
Thread Starter
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Joined: Sep 2018
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24 AMG GT55
I did ask my local tuning shop about the muffler delete btw and they said they wouldn’t recommend it. Something about our engines needing that back pressure and it hurting performance. *shrug* I think it would still be worth it for me for the sound
Junior Member
Joined: Sep 2022
Posts: 59
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From: Montreal
2022 SL 63
Ordered the EVM! Hoping to ride this mod out for a while so I have something to look forward to when (following your footsteps) and doing a muffler delete later down the road.
Next up is some appearance work. I really want a discrete spoiler like the Brabus one that I recently saw online. I also have a $1k ceramic coating package that I have sitting before I got this car with the matte paint. I’m reading both ways, some places say not to mess with ceramic on matte cars.
Next up is some appearance work. I really want a discrete spoiler like the Brabus one that I recently saw online. I also have a $1k ceramic coating package that I have sitting before I got this car with the matte paint. I’m reading both ways, some places say not to mess with ceramic on matte cars.
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From: THE Orange County, California
2024 C8 Z06- 2025 BMW CS- 2022 Porsche 992 GTS
Obviously I dont have a dyno to prove this one way or the other but if I felt a loss of power on my roads where I test the car to about 140mph; I would revert back.
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From: THE Orange County, California
2024 C8 Z06- 2025 BMW CS- 2022 Porsche 992 GTS
The install is not fun
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From: Naples, FL
2025 AMG CLE53, 2025 Range Rover P550E, 2025 Ford F150 Raptor
"Backpressure". LOL. That was a 'thing' back in the day with naturally aspirated engines. Gee, I cut mufflers off my 289s and 428s back in the day and never had any back pressure issues...and @Vic55 is on point by saying the turbo engines don't have any need, zero need, for back pressure.
Sounds like someone just didn't want to do it and feed you a line of BS.
Sounds like someone just didn't want to do it and feed you a line of BS.
Administrator
Joined: Nov 2001
Posts: 12,263
Likes: 901
From: THE Orange County, California
2024 C8 Z06- 2025 BMW CS- 2022 Porsche 992 GTS
"Backpressure". LOL. That was a 'thing' back in the day with naturally aspirated engines. Gee, I cut mufflers off my 289s and 428s back in the day and never had any back pressure issues...and @Vic55 is on point by saying the turbo engines don't have any need, zero need, for back pressure.
Sounds like someone just didn't want to do it and feed you a line of BS.
Sounds like someone just didn't want to do it and feed you a line of BS.
There are quite a few videos from experts on YT about the BS back pressure myth on turbos... I need to post that up.
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Newbie
Joined: Aug 2025
Posts: 6
Likes: 0
2025 gt63 coupe
Video might be tough since Im not driving the car for a few weeks but will do my best...
My guy is straight chop style in Santa Ana = 300 but no exhaust leaks
The Renntech Valve Controller does make a difference. You can do the ACC start up mod so that its open on firing but once you start driving in low rpms the valves do shut and open based on the rpm range. Mine never close ever.
Here is a vid of the RT rear can section = not loud enough vs stock.
Its on the SL but same sht
https://www.youtube.com/watch?v=V4VhSICcM9w
My guy is straight chop style in Santa Ana = 300 but no exhaust leaks
The Renntech Valve Controller does make a difference. You can do the ACC start up mod so that its open on firing but once you start driving in low rpms the valves do shut and open based on the rpm range. Mine never close ever.
Here is a vid of the RT rear can section = not loud enough vs stock.
Its on the SL but same sht
https://www.youtube.com/watch?v=V4VhSICcM9w
Thread Starter
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Joined: Sep 2018
Posts: 154
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24 AMG GT55
Its a turbo engine, the free flow helps and I have not noticed a single thing. The hard facts is the oem muffler is hardly restrictive so the gains are probably around 20-30 percent in decibels but I needed it LOL.
Obviously I dont have a dyno to prove this one way or the other but if I felt a loss of power on my roads where I test the car to about 140mph; I would revert back.
Obviously I dont have a dyno to prove this one way or the other but if I felt a loss of power on my roads where I test the car to about 140mph; I would revert back.
"Backpressure". LOL. That was a 'thing' back in the day with naturally aspirated engines. Gee, I cut mufflers off my 289s and 428s back in the day and never had any back pressure issues...and @Vic55 is on point by saying the turbo engines don't have any need, zero need, for back pressure.
Sounds like someone just didn't want to do it and feed you a line of BS.
Sounds like someone just didn't want to do it and feed you a line of BS.
Administrator
Joined: Nov 2001
Posts: 12,263
Likes: 901
From: THE Orange County, California
2024 C8 Z06- 2025 BMW CS- 2022 Porsche 992 GTS
Administrator
Joined: Nov 2001
Posts: 12,263
Likes: 901
From: THE Orange County, California
2024 C8 Z06- 2025 BMW CS- 2022 Porsche 992 GTS
Neon ... thoughts?
I do see your guy did go a different route than mine did.
Mine used the non valve section to be more thru and thru... 6 or 1/2 dozen
I do see your guy did go a different route than mine did.
Mine used the non valve section to be more thru and thru... 6 or 1/2 dozen
Last edited by Vic55; Aug 8, 2025 at 06:49 PM.
Senior Member
Joined: Mar 2025
Posts: 406
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From: Toronto
2025 AMG G 63 SUV /// 2025 AMG GT 63 S E Performance 4 Door Coupé
@theprototype Did you try my method of entering accessory mode, changing the drive select to sports +, then starting the car? I’d be very interested in knowing why my two AMG’s (‘25 G63 / ‘25 GT63S E-Perf 4-Door) allow this but other models don’t. I do it all the time on my GT, through an individual mode that has everything in comfort except the exhaust in powerful and the engine in sport so it actually starts. I can’t stand starting in comfort mode which defaults to electric drive and having the cold engine, with cold coolant and oil, turn on right before I’m about to get on the Highway/Freeway!
Cheers
Cheers
Last edited by G63GT63SE; Aug 8, 2025 at 10:59 PM. Reason: Directed question at OP
Thread Starter
Member
Joined: Sep 2018
Posts: 154
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24 AMG GT55
@theprototype Did you try my method of entering accessory mode, changing the drive select to sports +, then starting the car? I’d be very interested in knowing why my two AMG’s (‘25 G63 / ‘25 GT63S E-Perf 4-Door) allow this but other models don’t. I do it all the time on my GT, through an individual mode that has everything in comfort except the exhaust in powerful and the engine in sport so it actually starts. I can’t stand starting in comfort mode which defaults to electric drive and having the cold engine, with cold coolant and oil, turn on right before I’m about to get on the Highway/Freeway!
Cheers
Cheers
Member
Joined: Jan 2004
Posts: 115
Likes: 8
After some more testing/listening, I think I need to replace the smaller pipe with the same diameter as the bigger one, I can hear some type of whistle at times, it is very subtle, but now I know it is there and my OCD kicks in, I believe coming from the smaller pipe.
Thread Starter
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Joined: Sep 2018
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24 AMG GT55
Good to know. If I can ever find a shop that’s able to mod this for me will pass it on
Thread Starter
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24 AMG GT55
Anyone have issues pairing their car to their garage door opener? I never had issues pairing with 4 other cars but for some reason the amg just isn't "learning" the garage door opener. It's a rolling unit so have to pair directly to the machine and not the remote. No matter how many times I've tried I can't seem to get it to stick to either of our garage door openers which lends me to believe it's a problem with the car.
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Joined: Nov 2001
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From: THE Orange County, California
2024 C8 Z06- 2025 BMW CS- 2022 Porsche 992 GTS
Anyone have issues pairing their car to their garage door opener? I never had issues pairing with 4 other cars but for some reason the amg just isn't "learning" the garage door opener. It's a rolling unit so have to pair directly to the machine and not the remote. No matter how many times I've tried I can't seem to get it to stick to either of our garage door openers which lends me to believe it's a problem with the car.
Thread Starter
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Joined: Sep 2018
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24 AMG GT55
Ill try it again a few times but I tried both ways maybe a dozen times each with no luck. It’s a weirdly difficult thing to troubleshoot
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Are you pressing the learn button on the actual opener or the keypad that connects to the wall your installer installed? I mean, either way should work fine. Hold far left and right button with AAC mode until it resets, wait like 5 seconds then press any button, let it flash slowly and just point the remote at it. Hold the remote button until you see it flash rapidly, go and press learn then just kept on pressing the homelink button until door responds... That said, should be the same as the other vehicles... Are there any interference?
Thread Starter
Member
Joined: Sep 2018
Posts: 154
Likes: 21
24 AMG GT55
Are you pressing the learn button on the actual opener or the keypad that connects to the wall your installer installed? I mean, either way should work fine. Hold far left and right button with AAC mode until it resets, wait like 5 seconds then press any button, let it flash slowly and just point the remote at it. Hold the remote button until you see it flash rapidly, go and press learn then just kept on pressing the homelink button until door responds... That said, should be the same as the other vehicles... Are there any interference?
MBWorld God!
Joined: Dec 2019
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