[Boosted_8]

Crazy idea time... ECU swap with a M850i would be interesting.

[Mike.L]

Originally Posted by Boosted_8

Crazy idea time... ECU swap with a M850i would be interesting.

I'm not sure if thats an option. There are something like 30 different computers and modules in the FlexRay system and they all have to talk to each other. It would have to be coded with all the other modules. When they put in the VIN to do the coding, I have a feeling it would write the M550 program.

[choppedliver]

Originally Posted by Mike.L

I'm sure tuners could easily fix the problem. Except they can't. Nothing newer then 6/20 builds can be flash tuned. The DMEs are locked down. And piggybacks won't fix the launch control issue.

I thought all it required was a bench flash?

I.e.
https://www.bm3tuning.com/g30/n63t3-m550m850-2020

[Mike.L]

Originally Posted by choppedliver

I thought all it required was a bench flash?

I.e.
https://www.bm3tuning.com/g30/n63t3-m550m850-2020

Unless they just unlocked them, the 2021s can't be bench unlocked. RKTunes has a bar at the top of their website saying produced after June 2020 aren't tuneable.

https://www.rktunes.com/

And its also on ProTuning Freaks page as well.

https://www.protuningfreaks.com/coll...0i-x7m50i-tune

[smackdownM]

Originally Posted by Mike.L

Actually, this was in Sport + with Launch control (got the flags). I'm 345lbs, which hurts the time somewhat, but not a seconds worth. The car is just slow off the line. I wouldn't be surprised in the least if BMW was limiting first gear, because once it shifts you can feel it pulling a lot harder.

Finally went from the same old tired "325lbs" to 300 and nunya business lbs.

[Mike.L]

Originally Posted by smackdownM

Finally went from the same old tired "325lbs" to 300 and nunya business lbs.

Nobody asked you.

[choppedliver]

Originally Posted by Mike.L

Unless they just unlocked them, the 2021s can't be bench unlocked. RKTunes has a bar at the top of their website saying produced after June 2020 aren't tuneable.

https://www.rktunes.com/

And its also on ProTuning Freaks page as well.

https://www.protuningfreaks.com/coll...0i-x7m50i-tune

Interesting. My car is a 26th June 2020 so I hope its tunable (I'm sure it will happen in time).

[Cabbage]

Originally Posted by Mike.L

Nobody asked you.

Agreed.

[Boosted_8]

Originally Posted by choppedliver

I thought all it required was a bench flash?

I.e.
https://www.bm3tuning.com/g30/n63t3-m550m850-2020

I've spoken to two well know BMW tuners in the UK that say the ECU is un-tuneable with their kit in the 2021 cars.

I wasn't aware of this Bootmod3 patching method. Will send some emails to UK dealers of this software and get feedback for the thread.

[BMWGUYinCO]

Originally Posted by Mike.L

The problem is, we're seeing 6 cylinder performance from our V8s. Thats a major issue. If I wanted a mid-4 second car I could have spent $70k and gotten an M340i. I dropped $95k though for a mid-3 second car. Its a big difference.

I'm sure tuners could easily fix the problem. Except they can't. Nothing newer then 6/20 builds can be flash tuned. The DMEs are locked down. And piggybacks won't fix the launch control issue.

I'm joining this conversation late...just curious - have you tried reaching out to any other earlier my M550 owners in your area to do a side by side launch control to see a difference?

My '18 launches hard. If I were near you I would set up such a test.

[Scotty B]

My 2018 launches hard as well at around 3k rpm. Have a feeling that is the root cause. But, why they changed it? Who knows. Heard that you should hold launch for a few seconds to build boost though.

[BMWGUYinCO]

Originally Posted by Duta569

What RPM does your 2018 launch at?

My problem is I cant get over 2,000 RPM at launch. No power at 2K RPM!

Mine launches around 3K rpm also.

[Mike.L]

Originally Posted by Duta569

Ok first off I would like to state that i have catless downpipes and a JB4.

I've been testing all day. The best i could get was between 4.0 and 4.03 seconds 0 to 60 mph.

So i turned DCS completely off, which gave me a few hundred higher rpm's at launch. I was able to get a 3.83. That was my best.

Note that theses runs were at 52 degrees outside.

Bottom line... this car is pathetic off the line.

With catless pipes and a JB4, that car should be making over 600hp and be matching the M5's 3.0-3.2sec runs. Even 3.83 shows that something is very wrong with the low gear programming. Curious, have you tried brake torquing it without launch control? Still won't go over 2000rpm?

[Tk718]

C&D commented on this too when they reviewed 2021 m550i

"We couldn't quite match BMW's claimed zero-to-60 time of 3.6 seconds. Our 5287-mile test car did the 60 run in 4.1 seconds and sailed through the quarter in 12.3 seconds at 120 mph. All-wheel drive makes launches easy and repeatable, but an M5 Competition shatters those numbers with a 2.6-second run to 60 and a 10.7-second quarter at 130 mph. We're not sure why our Michigan test car wasn't quicker, and it certainly should have been considering the X5 50i we tested hit 60 in 3.9 seconds and weighed 857 more pounds than the 5-series. Furthering our suspicions, our 5742-pound long-term BMW X7 M50i raced to 60 mph in 4.1 seconds."

[PaLaKaT]

Originally Posted by Duta569

Ok first off I would like to state that i have catless downpipes and a JB4.

I've been testing all day. The best i could get was between 4.0 and 4.03 seconds 0 to 60 mph.

So i turned DCS completely off, which gave me a few hundred higher rpm's at launch. I was able to get a 3.83. That was my best.

Note that theses runs were at 52 degrees outside.

Bottom line... this car is pathetic off the line.

It is pathetic... i hate it. Have you tested your 100-200kmh? This car is super fast after 2nd gear. Here is the best result i got so far 100-200, im almost on par with M5. I didnt do downpipes yet..



Now here is another news as of 04/22/2021, APR was able to crack 2021 Audi Ecu it looks like:

https://www.goapr.com/blog/post/apr_...s4_s5_and_sq5/

According to Manhart Performance
"Not just BMW and MINI models are affected, other manufacturers like Audi, VAG and Mercedes will also have the same issue."
They are saying its the same ecu lock pretty much, if thats case it shouldnt be too long till BMW is unlocked. Hopefully our launch issue will be solved soon for those who will go with a tune.

Manhart link:

https://www.manhart-performance.de/e...ked-bosch-ecu/

[Leindurstit]

This is really crazy, especially given the revised 5.5 first gear ratio in the 2021 M550i vs. the 5.0 in the 2020. I would have guessed that alone would have gotten the 2021 closer to the advertised 3.6 second figure to 60 assuming grip is held, which the 2020 doesn't always seem quite able to get out of the box.

[Boosted_8]

I've a Jb4 on the way to data log what BMW have done to slow this car down...

[ksoze]

Originally Posted by Duta569

II'm just pissed off that BMW detuned our cars for whatever reason.

Did they "detune" it or change the launch control parameters? Other tests besides 0-60 should comfirm that.

[Mike.L]

Its certainly not for the xDrive. That would make zero sense to just neuter the M550.

The 750, M850 and X5/6 M50i's are pretty much identical. They all use a version of the 8HP76X, with the ATC13 transfer case. Both the M550 and M850 have the same 225ALS rear end too (the 750 uses the weaker 225AL from the earlier TU2 M550s. the M50i uses the 225LWS with better gearing). All the cars share the 175AL front diffs as well. And the M550 is the lightest of the bunch, so it would put the least stress on the drivertrain. It would make more sense to neuter the 750 and 850.

FWIW, the M5 and M8, as well as the Alpina B7 and XB7, and Rolls Royce Cullinan also use the same transmission and transfer case.

[Bimmerhead1]

I purchased a 2021 M550i in January and have over 2,000 miles on it. I am also extremely disappointed in the performance of the car as it is nowhere near 3.6 sec. in 0-60. I purchased it based on all the older 2018, 2019 and 2020 youtube reviews of how wonderful the engine performed in the car. The acceleration starting from a standstill is poor. it is a nice luxurious car, but I didn't spend $80k just for luxury. Many times I ask where is the 523 hp and all the torque. My M240i convertible is as fast off the line and its quoted 0-60 time is 4.5 sec.

I am working with the BMW and the dealership, but I don't expect they will do anything. I debated getting the M550i vs a new M3, but the first year model and the grill turned me off. I though the LCI of the M550i had nice improvements and better performance than the earlier model.

[ASG99]

If the market wasn't so tight now I might jump ship on my order and grab a brokered M5. I too wanted a well sub 4 car to 60. It appears like the 550 would have a hard time hitting that with the tank on E, going downhill with a good tailwind.

[crypto]

Originally Posted by ASG99

If the market wasn't so tight now I might jump ship on my order and grab a brokered M5. I too wanted a well sub 4 car to 60. It appears like the 550 would have a hard time hitting that with the tank on E, going downhill with a good tailwind.

4.09 is what I got on all seasons, flat road, no wind and nearly empty tank. 😬

Not going to lie. I'm contemplating a new or lightly used (<3k miles) M5 now. Wife is not going to be happy. Hah