New exhaust setup/AFR/ECU/ power question
Thread Starter
Super Member
Joined: May 2011
Posts: 883
Likes: 72
From: Vancouver
2018 e63s edition 1
New exhaust setup/AFR/ECU/ power question
I essentially just did a AWE track style setup but had it custom built by a talented local fab guy. So it's a three inch straight pipe rear section with no mufflers (i already had awe valve simulators) and also second cat delete. Still have primary cats and that valved H pipe. I got the exhaust done today and it seems spin the tires even easier than normal in second gear from a good 60km roll but when doing a pull through a couple gears it seems slower. In a turbo car, I'd assume a more free flowing is good because after the turbos have done their job you're not looking for scavenging, back pressure, etc. My question is, is there maybe a period of time where the ECU might need to compensate for a more free flowing exhaust? Would it even matter since the more free flowing section is after the 02 sensors anyways? If the car was naturally aspirated I'm sure the argument could be made for lose of back pressure, or no X pipe for scavenging, or something to that affect but not on a turbo car. If anything I would have thought I'd lose down low power and make more up top, but again that's probably more of a N/A motor thing. Is it likely just in my head or....?
MBWorld Fanatic!
Joined: Nov 2016
Posts: 1,527
Likes: 287
From: Toronto, ON
2021 Mercedes C63s AMG Coupe
Generally for these new Mercedes, a free flowing exhaust system seems to confuse the ECU enough that it pulls power at the beginning. But slowly after the ECU readapts, it should normalize.
Thread Starter
Super Member
Joined: May 2011
Posts: 883
Likes: 72
From: Vancouver
2018 e63s edition 1
That's what I was thinking/hoping. The stock performance exhaust is pretty free flowing so just the difference of secondary cats being gone shouldn't be that big of a change.
MBWorld Fanatic!
Joined: Jul 2011
Posts: 1,146
Likes: 206
2019 AMG GT R
As for youre exhaust setup.. are you saying that most of the exhaust is the stock 2.5" but then just the last muffler section is 3".. shouldnt it all be the same?
Thread Starter
Super Member
Joined: May 2011
Posts: 883
Likes: 72
From: Vancouver
2018 e63s edition 1
Factory exhaust is 2.75. The awe catback is 3", so after the secondary cats the exhaust steps up to 3.
MBWorld Fanatic!
Joined: Jul 2011
Posts: 1,146
Likes: 206
2019 AMG GT R
Thread Starter
Super Member
Joined: May 2011
Posts: 883
Likes: 72
From: Vancouver
2018 e63s edition 1
It's still there on my setup, and the AWE setup. My exhaust starts right after that point. The stock exhaust actually has a SECOND H pipe further back that is not valved, that is gone for me now since it is gone on the AWE. I basically just had him replicate the AWE catback in a somewhat similar design at a 1/3 of the cost to see if it'd even be loud enough for me. I'd still like to do downpipes one day and then maybe go back to stock mufflers in the rear. This is my first turbo car and I had no idea how much they really quiet down the car at WOT. It sounds quite loud at idle, low rpm, and cruising though. Over all I'm quite happy with it for the time being though, it should get me through winter until I decide if I want to do dp's/tune. Also, I think the loss of power was in my head, in fact it might have gained a couple as it spins the tires in second gear much easier than before, but maybe my tires just happen to be getting worn out right around the same time. They're still above the wear bar but getting low-ish.
Trending Topics
MBWorld Fanatic!
Joined: Jul 2011
Posts: 1,146
Likes: 206
2019 AMG GT R
It's still there on my setup, and the AWE setup. My exhaust starts right after that point. The stock exhaust actually has a SECOND H pipe further back that is not valved, that is gone for me now since it is gone on the AWE. I basically just had him replicate the AWE catback in a somewhat similar design at a 1/3 of the cost to see if it'd even be loud enough for me. I'd still like to do downpipes one day and then maybe go back to stock mufflers in the rear. This is my first turbo car and I had no idea how much they really quiet down the car at WOT. It sounds quite loud at idle, low rpm, and cruising though. Over all I'm quite happy with it for the time being though, it should get me through winter until I decide if I want to do dp's/tune. Also, I think the loss of power was in my head, in fact it might have gained a couple as it spins the tires in second gear much easier than before, but maybe my tires just happen to be getting worn out right around the same time. They're still above the wear bar but getting low-ish.
is the exhaust burble deeper?
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
