[B58TUG30]

Hello and good day to all,

I’ve had my dream car, 2020 540i for two years now and I’ve loved every minute of owning it. Till this day the car never fails to put a smile on my face and I’m very grateful and fortunate to have it. I got it with 40k miles on it and currently I’m at 61k, and I’m thinking it’s time to take it to the next level. I’m very new to the tuning world and haven’t done anything in regards to performance before, I’ve been doing research latley and I’m thinking of getting MHD and xHP. In MHD I’d like to go stage 2 and on xHP I’m thinking stage 1 because I don’t want to jeopardize having anything malfunction in the transmission, what exactly would I need in terms of bolt-ons for the ECU tune ? Id really appreciate some help please, also trans wise would I be okay with this setup ? Or would stage 2 be the better move because I’m going stage 2 on MHD? I’m kinda lost and in desperate need of being pointed in the right direction, what steps should I take to start ? Do I get all bolt on first then tune ? Do I go xHP first so when I tune ECU it works reads it and works hand in hand from the jump ? What’s the best recipe ? generally how much reliability am I losing ?

Forgive me for dumping so many questions I just genuinely don’t know where to start. I’m super appreciative of any help and feed back. Thanks to anyone who took the time to read this and respond I really appreciate it.

Sorry if this post is in any way shape or form informal, it’s my first time here.

Thank you.

[drive_to_survive]

Good day to you too and cheers to you deciding to go for a tune.
Let's tackle your questions which are totally legit to have for a car that is loved dearly.

I have a similar setup to what you are planning.
2021 540i Gen 2 B58 with TU pump and I am on stage 2 MHD, MHD flexfuel kit and XHP stage 2 tune for the transmission. One of the best enhancements to have. Lots of fun, pretty safe and best bang for your buck.

Your transmission tune stage and engine tune stage are independent.
on xhp website you can see all the features each stage provides and choose accordingly.

https://rbttuning.atlassian.net/wiki...Flash+Settings

explore it and understand it to know better. But I would personally recommend stage 2 (also the most popular if I am not wrong.)

** BOT-ON **
You would just need a downpipe.
Charge pipe upgrade is not required for a stage 2 setup but given that the OEM one is plastic and might get brittle and crack as the miles pile on, for the peace of mind and given its relatively inexpensive given that you are getting work done on your car, might as well upgrade it now (prep for a stage 3 in the future)

For the downpipe I would recommend going for a good catted one. (AA catted downpipe)
Personally for me the smell is not worth it to live with and emission testing is not scary.
It still good for upto 800whp (fact check) so you are not missing out to a large extent.

Not required but highly recommended is installing a MHD flexfuel kit (TU Pump required at minimum for running upto E30-E40 mixture) that provides real time E content reading to your ECU and flashing a flexfuel map with it, allows your ECU to adjust power on the fly and makes the tune even safer and flexible.
For example if you flash with a base map of 91 Octane, your car would but safely optimizing for the max performance right from 91 Octane -> 93 -> E40 mixtures and you do not have to worry about the fuel quality.

E30 experience is superior to just running 93 Octane


** TRANSMISSION **
I have had the reliability concern for our transmission for the longest time and still am careful about it.
I think our zf8hp50 gearbox is still pretty safe for a stage 2 setup and even upto a good custom tuned stage 3 setup where the tuner has been careful with the torque output.

XHP transmission tune stage 2 on the contrary helps with a tuned car by increasing the clamping pressure and removing the torque limits that is needed with the increased engine output. You should be pretty safe there with a stage 2 XHP tune.

STEPS.

1. first get the MHD universal adapter (~$80) and install the MHD app for free and check if your car actually needs a FEMTO unlock (my guess is given its a 2020, you 99% chance do not need it) The adapter is super handy and allows you to work with bimmerlink, bimmercode and flashing MHD maps and flashing XHP map by yourself, also clearing out error codes. Following steps are assuming you have the Universal Wifi adapter.

2. XHP tune can flashed independently to an engine tune. your TCU is unlocked even if your ECU is locked. you can flash on a stock car, stage 1, stage 2 setup. Stock car also gets benefits but becomes mandatory with a tuned car due to reasons mentioned above.
once you have the adapter you can flash the XHP tune after purchasing the license online and by yourself. This, I did it myself as well. Look out for discount coupons before buying, might get lucky and save some money there.

3. Next up, buying the MHD super license. Once you buy it, without even buying installing an boltons and assuming you do not need a femto unlock you can flash Stage 1 tune by yourself and that should give you a massive increase in power compared to stock. By this point you have probably spent under $1100 dollars for a stage 1 tune and xhp tune and getting biggest power jump relative to a stock setup. You can run this setup for a while enjoy it or do it all at once an start with stage 2 (with flexfuel) directly, upto you.
EDIT: You would need a bench unlock which can be done for much cheaper.

4. for a stage 2 move, have the bolt-ons installed, flashing a stage 2 map from the MHD app is no different that flashing a stage 1 map.

** RELIABILITY **
There are many people who have put around 100k miles on a stage 2 setup and its pretty reliable. Make sure you are up on maintenance and you should be good. I personally have halved my oil change interval as I mostly run E30-E40. thats about it.

Enjoy.

[B58TUG30]

Originally Posted by drive_to_survive

Good day to you too and cheers to you deciding to go for a tune.
Let's tackle your questions which are totally legit to have for a car that is loved dearly.

I have a similar setup to what you are planning.
2021 540i Gen 2 B58 with TU pump and I am on stage 2 MHD, MHD flexfuel kit and XHP stage 2 tune for the transmission. One of the best enhancements to have. Lots of fun, pretty safe and best bang for your buck.

Your transmission tune stage and engine tune stage are independent.
on xhp website you can see all the features each stage provides and choose accordingly.

https://rbttuning.atlassian.net/wiki/spaces/RBTTUNING/pages/12058758/8-Speed+ZF+-+Flash+Settings

explore it and understand it to know better. But I would personally recommend stage 2 (also the most popular if I am not wrong.)

** BOT-ON **
You would just need a downpipe.
Charge pipe upgrade is not required for a stage 2 setup but given that the OEM one is plastic and might get brittle and crack as the miles pile on, for the peace of mind and given its relatively inexpensive given that you are getting work done on your car, might as well upgrade it now (prep for a stage 3 in the future)

For the downpipe I would recommend going for a good catted one. (AA catted downpipe)
Personally for me the smell is not worth it to live with and emission testing is not scary.
It still good for upto 800whp (fact check) so you are not missing out to a large extent.

Not required but highly recommended is installing a MHD flexfuel kit (TU Pump required at minimum for running upto E30-E40 mixture) that provides [...]

Holy crap dude you’re fucking awesome, thank you so very much for the full and thorough response. Tbis honestly has helped a lot with understanding where to start and how to go on about it. Also thank you for the link for the xhp tune I’m going to get real familiar with it, definitely gave me a little peace of mind as you made it sound quite simple, still a bit intimidating because I won’t be able to live with myslef if anythinh goes wrong with my precious. The advice to start stage 1 is great honestly because I was planning on jumping straight into 2 but this will allow me to enjoy the different levels through time. Plus it’ll help with spreading out the spending over time rather than having to dump cash all at once (getting married in a month so that was brilliant haha thank you) I don’t plan on going full stage 3 at all, simply just want a somewhat of a easy and headache free setup and enjoy that until it’s time to get into a new car years down the road (hopefully full M or proche but we’ll cross that bridge once we get there).

Is a flex fuel pump absolutely necessary? I kind of had no plans on getting a flex fuel kit and I plan on running 93oct which is all that’s been ever used in the car.

Luckily I keep everything all up to date maintenance wise but do you recommend anytbing specific in terms of after market ignition coils or spark plugs ? Things of that nature. Should I do a trans flush and refill before tuning ?

Any suggestions on tires ? Currently running all season Goodyear eagle runflats and in all honesty at higher speeds they don’t feel the best, they grip well though on turns.

Again dude thank you so much for this it’s helped out tremendously, I really can’t stress enough how helpful this is

[drive_to_survive]

happy to help and congratulations

No flexfuel kit is not necessary, but a good add on to get the most out of a stage 2 setup and the peace of mind when having to run different qualities of fuel as well as ethanol. ethanol is cheaper, your engine runs cooler and smoother (the "smoother" bit is more of a personal observation)

You can add it later on as you get bored with just stage 2 with 93. Now I cannot NOT put ethanol as the car feels slow on 93

I think your plan to do this gradually is spot on as one more benefit of this would be multiple AHA moments. Eventually you get used to any amount of power and always looking for the next step. Might as well be more granular and enjoy the journey.


OEM coils are superb and no need to change it uptil 900ish hp, unless you run into issues which is rare. Even then replacing them with a new set of OEM ones would be the way to go.

The OTS maps from MHD are pretty robust, safe and performant.
for spark plugs too, once you go custom tuning your tuner would be best person to ask, until then stock plugs are fine. (them waring out due to high milage might be another thing but for OTS maps they should be fine.)

For tires, my pick is Michelin PS4s summer tires but unless your tires are worn out or you are concerned about getting the best of a lap time on a circuit you should be fine for a light spirited driving.

Also
https://www.youtube.com/@kern417/videos

This is my goto place for info on all things B58. Great guy, awesome content.

EDIT:

I have recently become a fan of this channel as some of their B58 related videos provide a rare insight which I have not encountered anywhere else.

https://www.youtube.com/@HarmonixxTuning/videos

Particularly these 3 videos

super informative.

[JSKS76]

If you have an enet ethernet cable you can also use the MHD app to see if your ECU is locked or not. You can also use your VIN to find the manufacture date. If it's pre June 2020 it is unlocked if the software wasn't updated at a dealership. If it was updated at dealership you still need a bench unlock. If it's post June 2020 you need to send the ECU to Europe to be Femto unlock.

[B58TUG30]

Originally Posted by JSKS76

If you have an enet ethernet cable you can also use the MHD app to see if your ECU is locked or not. You can also use your VIN to find the manufacture date. If it's pre June 2020 it is unlocked if the software wasn't updated at a dealership. If it was updated at dealership you still need a bench unlock. If it's post June 2020 you need to send the ECU to Europe to be Femto unlock.

Yeah my build date is February of 2020 but I’m pretty sure the dealership probably locked it since I go there for any maintenance, which honestly sucks I hate that they do that. I already ordered the mhd Wi-Fi adapter to check just waiting on it to come in.