C63 vs E63 engine differences
You floored it in 4th gear at 1800rpm what did you think was going to happen? Turbos are exhaust driven power adders, not plutonium powered flux capacitors. Be in the correct gear at the correct rpm and there is almost zero lag. Do your exact same “test” in second gear and see what happens.
Not at all. Someone stated, the C63 does not have turbo lag. That is wrong. The M177 has a relatively small displacement and therefore uses huge turbochargers. As a result there is turbolag - which is fine for me, as one can use higher RPMs to minimize it. The higher the rpms, the higher the exhaustflow - the faster those turbines spool up!
However: To be honest: In every day driving, especially when commuting, I usually don't use 2nd gear at that speed... so when I floor it, the car has to downshift and those turbos have to spool up - which takes it's time. An N/A car simply starts pulling. Even an ordinary Mercedes M278 (4.7 V8 BiTurbo) in the old E550 has a lot less turbo lag (due to the higher displacement and those smaller turbochargers) - which makes it in my opinion the better engine for a daily driver.
...on the other hand...a backroad and an M177 is a fabulous combination!
A 4 litre V8 that revs to past 7k is anything but a relatively small displacement.
The Best of Mercedes & AMG
"Boost threshold is the engine speed at which you have enough exhaust gas flow in order to create boost. Turbo lag is the additional time delay above boost threshold, when the engine's throttle valve is open and the turbocharger needs to accelerate to deliver positive pressure to the engine".
There is very little turbo lag with this engine, but with any turbocharged engine there is a boost threshold. You need engine RPM to increase the exhaust gas velocity and spool the turbo. There is no magic to get rid of that, short of installing an electric turbo to use as a torque-fill.
To whoever said we have huge turbochargers, thanks for the laugh. These things are so small they run out of breath at higher RPM, but that trade off allows for the massive torque down low which is great for driving around town.
"Boost threshold is the engine speed at which you have enough exhaust gas flow in order to create boost. Turbo lag is the additional time delay above boost threshold, when the engine's throttle valve is open and the turbocharger needs to accelerate to deliver positive pressure to the engine".
There is very little turbo lag with this engine, but with any turbocharged engine there is a boost threshold. You need engine RPM to increase the exhaust gas velocity and spool the turbo. There is no magic to get rid of that, short of installing an electric turbo to use as a torque-fill.
To whoever said we have huge turbochargers, thanks for the laugh. These things are so small they run out of breath at higher RPM, but that trade off allows for the massive torque down low which is great for driving around town.
Now, there are some cars that are starting to use electrically operated turbos like the Audi SQ7 - three turbos, two normal and one electric - to fill the gaping hole that is turbo lag that can exist in turbocharged big diesels. But as someone who has driven early turbo charged cars, its pretty bloody obvious that the AMG engine has virtually no turbo lag! Its seriously an incredible engine and so responsive that its shocking! Turbocharging engines is actually quite a sophisticated process - balance the throttle, response and tune the inlets and exhausts for response, power and where exactly you want that power to be. If anyone has driven a BMW 2002 Turbo knows what turbo lag is - and how far the process has come in years since. Those BMW's were terrible, shocking and huge fun.... but I will take a modern turbo engine like the AMG one every day of the week.
"Boost threshold is the engine speed at which you have enough exhaust gas flow in order to create boost. Turbo lag is the additional time delay above boost threshold, when the engine's throttle valve is open and the turbocharger needs to accelerate to deliver positive pressure to the engine".
There is very little turbo lag with this engine, but with any turbocharged engine there is a boost threshold. You need engine RPM to increase the exhaust gas velocity and spool the turbo. There is no magic to get rid of that, short of installing an electric turbo to use as a torque-fill.
To whoever said we have huge turbochargers, thanks for the laugh. These things are so small they run out of breath at higher RPM, but that trade off allows for the massive torque down low which is great for driving around town.




If you have a turbo that takes an unusually high rpm to fully spool (turbo lag), that's turbo size mismatch and/or trading spool time for big HP #s, that's boost lag.
From the published data (2017 C63 S Coupe):
503 hp at 5500-6250 rpm
516 lb-ft at 1750-4500 rpm
Generally speaking, making so much torque at low rpm (barely off idle) means you have small turbos that will run outta steam up to (no additional torque past 4500rpm, and hp runs out at 6250rpm). But it also means there's virtually little to no turbo lag.
Our C63s have VERY little turbo lag AND a very low boost threshold (based on the turbos being small, so they're fully spooled at a low rpm).
Conversely, if you wanna talk about turbo lag, Youtube a Supra race. Watch whatever car getting a full 1-2 car lengths on the turbo, while the Supra's huge turbo spools up at 5,000rpm lol and the thing takes off like a rocketship. THAT'S turbo lag...
Surely this topic is now dead (I hope).
Last edited by AlexZTuned; Mar 2, 2019 at 10:07 PM.




Not saying you won’t break anything at that power level, but it’ll be the trans or diff before the engine.
I actually haven’t heard of anyone blowing their M177, stock or built. The trans on the other hand...
Not saying you won’t break anything at that power level, but it’ll be the trans or diff before the engine.
I actually haven’t heard of anyone blowing their M177, stock or built. The trans on the other hand...
exactly my thoughts. There are more than 2. Just 2 are out there showing it off. I’m sure many more will pop up as well. Lots of people buying stage 4 turbos. And since I should go try it, I have too. Lol.
I hate the electronic diff in the car anyway so that’s the first thing being changed.


