CLA 45 Performance Exhaust System
Junior Member
Joined: Jan 2020
Posts: 46
Likes: 11
2021 CLA 45 AMG, Subaru WRX STI
Hah yeah I guess so. Im trying to add the Dynamic package to my order, which I should be able to. If were still not sure when I take delivery in Sept-ish Ill figure it out and report back.
Senior Member
Joined: Oct 2019
Posts: 381
Likes: 136
From: AZ
2018 C63S Coupe
Newbie
Joined: Aug 2020
Posts: 13
Likes: 0
CLA 45S
The exhaust button on the CLA 45S does two things:
1. Opens the exhaust valve on the backbox
2. Activates AMG Real Sound which pipes sound taken from the exhaust into the cabin through the speakers
The exhaust button allows you select this function at any time, regardless of drive mode, and here the UK is fitted as standard to every 45S.
The confusing thing is that the valve isn't just open or closed. It varies based on speed, throttle position and drive mode. This is mainly due to EU Regs but also protects the valve from damage.
A few scenarios:
1. If you press the button to open the valve with the car stationary on idle you will hear it open. As soon as you rev the car it will close and only reopen when the revs drop back to idle. This allows the car to pass EU noise tests.
2. If you apply full throttle, even in comfort with the exhaust button off, the valve will open a small amount to prevent excess pressure build up which could damage it.
3. Whilst driving with the exhaust button turned on the valve will vary to what degree it is open constantly to prevent resonance etc.
AMG Real Sound can also remain on even while the valve is shut, in scenario 1 for example.
Sorry for such a long reply but it's actually quite a complex setup on the 45S
1. Opens the exhaust valve on the backbox
2. Activates AMG Real Sound which pipes sound taken from the exhaust into the cabin through the speakers
The exhaust button allows you select this function at any time, regardless of drive mode, and here the UK is fitted as standard to every 45S.
The confusing thing is that the valve isn't just open or closed. It varies based on speed, throttle position and drive mode. This is mainly due to EU Regs but also protects the valve from damage.
A few scenarios:
1. If you press the button to open the valve with the car stationary on idle you will hear it open. As soon as you rev the car it will close and only reopen when the revs drop back to idle. This allows the car to pass EU noise tests.
2. If you apply full throttle, even in comfort with the exhaust button off, the valve will open a small amount to prevent excess pressure build up which could damage it.
3. Whilst driving with the exhaust button turned on the valve will vary to what degree it is open constantly to prevent resonance etc.
AMG Real Sound can also remain on even while the valve is shut, in scenario 1 for example.
Sorry for such a long reply but it's actually quite a complex setup on the 45S
Junior Member
Joined: Jan 2020
Posts: 46
Likes: 11
2021 CLA 45 AMG, Subaru WRX STI
The exhaust button on the CLA 45S does two things:
1. Opens the exhaust valve on the backbox
2. Activates AMG Real Sound which pipes sound taken from the exhaust into the cabin through the speakers
The exhaust button allows you select this function at any time, regardless of drive mode, and here the UK is fitted as standard to every 45S.
The confusing thing is that the valve isn't just open or closed. It varies based on speed, throttle position and drive mode. This is mainly due to EU Regs but also protects the valve from damage.
A few scenarios:
1. If you press the button to open the valve with the car stationary on idle you will hear it open. As soon as you rev the car it will close and only reopen when the revs drop back to idle. This allows the car to pass EU noise tests.
2. If you apply full throttle, even in comfort with the exhaust button off, the valve will open a small amount to prevent excess pressure build up which could damage it.
3. Whilst driving with the exhaust button turned on the valve will vary to what degree it is open constantly to prevent resonance etc.
AMG Real Sound can also remain on even while the valve is shut, in scenario 1 for example.
Sorry for such a long reply but it's actually quite a complex setup on the 45S
1. Opens the exhaust valve on the backbox
2. Activates AMG Real Sound which pipes sound taken from the exhaust into the cabin through the speakers
The exhaust button allows you select this function at any time, regardless of drive mode, and here the UK is fitted as standard to every 45S.
The confusing thing is that the valve isn't just open or closed. It varies based on speed, throttle position and drive mode. This is mainly due to EU Regs but also protects the valve from damage.
A few scenarios:
1. If you press the button to open the valve with the car stationary on idle you will hear it open. As soon as you rev the car it will close and only reopen when the revs drop back to idle. This allows the car to pass EU noise tests.
2. If you apply full throttle, even in comfort with the exhaust button off, the valve will open a small amount to prevent excess pressure build up which could damage it.
3. Whilst driving with the exhaust button turned on the valve will vary to what degree it is open constantly to prevent resonance etc.
AMG Real Sound can also remain on even while the valve is shut, in scenario 1 for example.
Sorry for such a long reply but it's actually quite a complex setup on the 45S
Newbie
Joined: Aug 2020
Posts: 6
Likes: 0
AMG CLA45
I don't have the exhaust button on my US 2020 CLA45, I guess you get it if you get the dynamic plus package but it doesn't say anything about exhaust in that package which is confusing I wish the order guide would have been more clear. I was thinking about an aftermarket exhaust anyway.
I'm curious if anything is different in how the exhaust works in the US vs the UK cars?
I'm curious if anything is different in how the exhaust works in the US vs the UK cars?
MBWorld Fanatic!
Joined: Jun 2019
Posts: 1,013
Likes: 194
C190
I don't have the exhaust button on my US 2020 CLA45, I guess you get it if you get the dynamic plus package but it doesn't say anything about exhaust in that package which is confusing I wish the order guide would have been more clear. I was thinking about an aftermarket exhaust anyway.
I'm curious if anything is different in how the exhaust works in the US vs the UK cars?
I'm curious if anything is different in how the exhaust works in the US vs the UK cars?
