My 2020 GLC 63 does not launch like it should. (As I've seen on many videos)


It literally builds power, I left off the break, it loses power and then builds again. If ANYONE has any insight on this please let me know! It is literally killing my 0-60 times!

 

It looks like you are just letting go of the brakes to soon. Hold that beast still for a few seconds, let it settle in and then let go. That's why these things can be tricky at the drag strip.

You have a tune, correct?

 

When I hold it for too long.. it cancels race start. I am going back out to try again right now.
Yes, I have it tuned. Renntech HHT, but the launch problem happens with or without the tune.
I'm really frustrated..

 

Interesting, have you tried changing the launch RPM with your paddles? That may change how it reacts.

It could also just be plain on engine bogging if your tires are not slipping at all.

 

I have not tried that. I just tried to go out and do what you told me to do (hold it for longer) still the same exactly results. It's not tire slip. It's definitely engine bog or something.
Here is another video of me holding it for longer. If anyone has any insight on this please let me know...

 

I am not sure this is a fault. the power reduction you notice really depends on the road surface grip. Asphalt has much less grip than concrete, for example. Ambient temperature and tyre pressures/condition are also factors. It may be normal behavior, unless you notice this as a recent problem. As you know, the whole point of launch control is if the power was not reduced at that moment, the tires would go up in smoke! (And possibly give you far more excitement than you bargained for when they did hook up.)

The V8 TT AMG are launching against a VERY expensive multi-plate clutch setup. Unlike a standard single plate clutch mechanism, multi-plate setups will not tolerate excessive slip. Even in normal use they wear out in fewer miles than a single plate setup, a 'feature' of the stacked multi-plate design. They may be lighter, more compact, but have shorter service life and are expensive to replace.

In any event, the launch control lets the clutch hook up fully, with as little clutch slip as possible, while at the same time the ABS sensors monitor wheel spin. You could notice this slight sag at launch, but believe me, the car is putting down all the power the tires can use at that instant. Think of this as Stig Blomqvist in a can.

In closing, perhaps you should consider how many miles are on the car? Is it launched several times per month over time? It would be possible the clutch disks are worn down, near the end of the service life. Clutch slippage is at the early stages difficult for a driver to detect. Early slip could to some degree also be masked by modern control electronics. The car still drives, especially at moderate acceleration and everyday driving, but a noticeable sag getting off the line would be one of the first clues of a worn out clutch pack. Might be best to have a qualified AMG mechanic evaluate clutch condition, if you have doubts.

 

The car is 8 months old, 13k miles. It's been launched maybe 20 times.

 

In this instance, tire slip is a wanted thing, it keeps the RPMs up. That second run seems about normal to me, it is hooking hard and causing a little engine bog.

 

Wait OP, are you doing these runs with your seatbelt off? You're insane.

That's all.

Carry on.

R.K.

 

• get the trans software upgrade. Trans goes in fail safe mode. Too much power and trans goes in bog mode for split second or two
• Eurocharge is the best in the business on 2020.
• renntech offers tunes, etc. I have spent 10s of thousands between my s63 glc63.
• eurocharge is the way to go

 

I can't see anything, videos deleted?

 

Curious if anyone figured this out. When it was cooler outside.. Under 70F, my Launches were fine.. Slight chirp rocket fast.. Fast forward to now... upper 80's low 90's and they do the same as the above. Bogs down and then builds again.....

 

Not sure if heat is related or all 2020 models since I've just broke into 1k miles and started dragy'ing her to see what she can do. I'm pretty disappointed in my 4.2-4.5 0-60 times because of a similar bogging feeling especially when going from 1st to 2nd. Though the weather isn't the best I'd thought it would least see high a 4.0 or lower. The delayed bucking feeling from 1st to 2nd is pretty bad which I'm thinking is causing this. Waiting for TCU and CPU tune this week, followed by ECU tune. Should help greatly but expected a little more from the none S GLC63

OP what were you 1/4 mile times?