Egonvdv

optimized acceleration; (page 146 of the US manual)

- engage D
- steering wheel in straight ahead position
- select sportiest program (S, S+...)
- deactivate ESP
- depress/hold brake with left foot
- fully depress gaspedal with right foot
- take foot off brake
- car pulls away at max speed

Seems fun to try, but I'm wondering if this creates a burnout of the tires, as this is not mentioned ?
i guess the answer is yes, as otherwise you might as well just step on the gas as usual, but with ESP deactivated?

W205C43PFL

Please correct me if I am wrong, is that not simply RACE START (commonly known as launch control) in AMG vehicles?

Egonvdv

this i don't know . AMG models are mentioned in the manual, but nothing about "race start"

superswiss

It's a form of launch control if you will. Didn't know regular models had this. It's not RACE START like the AMGs have, though. The main difference is that AMGs with RACE START (43 and 53 models don't have RACE START) have a clutch between the engine and transmission and not a torque converter. They use either the MCT or DCT transmissions. So, the engine can freely rev at standstill, and then the computer drops the clutch. It's what launch control truly is, and only exists in cars that have a clutch based transmission. RACE START also works under wider parameters. ESP can be left on, and it works in S, S+ or Race modes, and in the latest AMG models you can adjust the launch RPM in increments of +/- 100 using the shift paddles.

This here is generally referred to as brake boosting. Since a torque converter can't decouple the engine, brake boosting takes the engine rpm just below what's called the stall speed of the torque converter. It's the point where the drivetrain force is not enough to overpower the brakes. This takes the slack out of the fluid coupling and gets the turbos spinning. Can be done manually in pretty much any torque converter automatic, but you have to be careful not to put too much stress on the torque converter and damage it. So, this here is a computer assisted brake boosting, effectively a soft rev limiter. It ensures that the torque converter doesn't get damaged. There are other models, but typically sportier models that have this. Many manufacturers still refer to it as launch control. Audi does, and so does BMW, but it's technically not launch control in the traditional sense as explained above, and is perhaps why AMG calls theirs RACE START as it is different.

Diesel Benz

Some of the Mercedes plug-in hybrids do not have a torque converter. I don't know about the 300De, the 350e did have a torque converter but the C 350e did not.

superswiss

PHEVs are an altogether different story. I know some use a clutch, but mainly the electric motor does torque fill so I'm guessing this does not apply to the PHEVs. OP, even though he doesn't appear to live in the US, is referring to the US owners manual. The PHEVs are not sold here.

Diesel Benz

I'm sure you are right as always, I was just saying "it could be possible on PHEVs like the one the OP has".

The electric motor on a PHEV like E300De is not only for torque fill, the car can drive fully electric at decent top speed and some 60 or was it 70 km if driving carefully.

Egonvdv

sorry i'm somewhat confused: does it mean that the tires WILL spin (burnout) ?
in the manual it says to hold the rake for no longer than 5 seconds, so i guess the answer is yes ...?

murman

Manual for which model year?

superswiss

No, they won't spin while stationary. That's the point. It holds the rpm just below the stall speed of the torque converter, so no movement in the driveline until you release the brakes. The reason it's limited to 5 seconds is because the fluid friction in the torque converter generates heat and if you do it too long it might overheat. However, once you let go off the brakes, the tires might spin depending on available traction, since ESP is turned off, although in the regular W213 ESP off is not completely off.

Egonvdv

latest one 2022:

https://1drv.ms/b/s!Ags7nPJiHj1IiIlM...Gakyw?e=0J7HOO

Egonvdv

I'll try this soon :-)

already put my last car on it's roof, so i'm sort of an expert now

murman

Son of a gun. I also see that in my MY2020 E450 wagon. I'd like to see how that works, but there's almost nowhere in my area where I could give it a whirl. The roads are all crap and there's too much traffic to give it a safe try. Maybe if I drive through the Canadian prairies in the summer time.

Frank Rizzo

I figured this out about a month ago and keep playing around with it. Since my car is AWD and it gets the turbos spooled up nicely, it launches HARD! Its lots of fun. I even showed my wife and she could not stop laughing!

Diesel Benz

Which car was it? Which engine?

mikapen

Doesn't the owner's manual say something about the shiny side?

skytop

You must first put 110 octane racing fuel in the car and also fit a set of drag racing slicks on the rear. Then hold on and let her rip!

Egonvdv

Tried it today but it's almost the same as just stepping hard on the gas from standstill.
I guess my engine is too small