[1ExotiiC]

I’m very new to the JB4 platform and still learning the basics, so I was hoping to get some help with a custom tune for my 2021 BMW 540i xDrive.

Right now, the only modification on the car is a full catback exhaust. I’ve placed an order for a 5-inch CATLAS DP and might get a charge pipe as well, although I’m not sure if it’s necessary. I haven’t decided yet on an aftermarket intake either. Also if there’s any specific mods I should go for please, please give me some advice!

For now, I plan to stay on 93 octane fuel. If I decide to switch to E85, would I need a port injection kit, or is that only required at certain blend levels?

Lastly, I’ve attached some logs and was wondering if you could let me know if I did them correctly. I tried to record in map 3 and 4 but i dont know if it worked properly.

Thanks so much for your help!

[drive_to_survive]

You do not require a chargepipe upgrade for a stage 2 setup.
It is a relatively cheap upgrade though, so I would do it if I am changing the intake as well. (future investment)

Intake upgrade would only help with the sound, no performance benefits for a stage 2 setup.

I would highly recommend a flexfuel kit. You can comfortably go upto E40 I think and it makes a substantial difference in my opinion along with the comfort and peace of mind to put anything between 91 and E50. (also a future investment)

As for a custom tune, I wouldn't put my money there until going stage 3, as the stage 2 OTS maps are pretty solid.

You do not need port injection until you are targeting 700+ whp.

Watch this and follow the channel too.

this channel is lit for all B58 related info and should answer most of your other questions too.

[1ExotiiC]

Originally Posted by drive_to_survive

You do not require a chargepipe upgrade for a stage 2 setup.
It is a relatively cheap upgrade though, so I would do it if I am changing the intake as well. (future investment)

Intake upgrade would only help with the sound, no performance benefits for a stage 2 setup.

I would highly recommend a flexfuel kit. You can comfortably go upto E40 I think and it makes a substantial difference in my opinion along with the comfort and peace of mind to put anything between 91 and E50. (also a future investment)

As for a custom tune, I wouldn't put my money there until going stage 3, as the stage 2 OTS maps are pretty solid.

You do not need port injection until you are targeting 700+ whp.

Watch this and follow the channel too.

this channel is lit for all B58 related info and should answer most of your other questions too.

Ahhh that makes sense. However my ecu is still locked and I havnt really decided to go femto yet so I got JB4 in the meantime. But I want to push alot more power, obviously nothing crazy but possibly 500whp reliability. So what would my roadmap be to reach that goal, and what should i get in terms of the bolts on and mods.

[drive_to_survive]

Originally Posted by 1ExotiiC

Ahhh that makes sense. However my ecu is still locked and I havnt really decided to go femto yet so I got JB4 in the meantime. But I want to push alot more power, obviously nothing crazy but possibly 500whp reliability. So what would my roadmap be to reach that goal, and what should i get in terms of the bolts on and mods.

I think the JB4 alone is doing wonders on the Gen3 platform but for us Gen2 B58 owners, femto unlock and stage 2 is needed.

The minimum for close to 500whp, the recommendation is

bolt ons:
a downpipe
MHD flexfuel kit.

femto unlock
MHD license
XHP license

Once you get your ECU unlocked through femto with MHD base

you can pretty much buy the licenses yourself online (sometimes there are good discount codes available) and flash them with the MHD universal adapter.
the adapter works really well with clearing out error codes, bimmercode and bimmerlink too so also a must buy for ~$70

with the above setup, once you start running E30 or E40, I think you almost pushing close to 480-500 whp.

I haven't dynoed my car but I get consistent 3.3-3.4 0-60 on the dragy and 11.6, 11.7 quarter mile times.

Ethanol really makes a difference.

[1ExotiiC]

Originally Posted by drive_to_survive

I think the JB4 alone is doing wonders on the Gen3 platform but for us Gen2 B58 owners, femto unlock and stage 2 is needed.

The minimum for close to 500whp, the recommendation is

bolt ons:
a downpipe
MHD flexfuel kit.

femto unlock
MHD license
XHP license

Once you get your ECU unlocked through femto with MHD base

you can pretty much buy the licenses yourself online (sometimes there are good discount codes available) and flash them with the MHD universal adapter.
the adapter works really well with clearing out error codes, bimmercode and bimmerlink too so also a must buy for ~$70

with the above setup, once you start running E30 or E40, I think you almost pushing close to 480-500 whp.

I haven't dynoed my car but I get consistent 3.3-3.4 0-60 on the dragy and 11.6, 11.7 quarter mile times.

Ethanol really makes a difference.

Damnn bruhh, this is annoying. I really wasn’t trying to do femto for a while. Eventually i will. How long did the process take for you to send it out and get it back?

Either ways I want to stick to jb4 for a bit. What’s my best bet in making decent amount of power? Direct injections with intakes, DP? Or more

[drive_to_survive]

Originally Posted by 1ExotiiC

Damnn bruhh, this is annoying. I really wasn’t trying to do femto for a while. Eventually i will. How long did the process take for you to send it out and get it back?

Either ways I want to stick to jb4 for a bit. What’s my best bet in making decent amount of power? Direct injections with intakes, DP? Or more

Took me about a week to get back the ECU.

Before femto I was running racechip and an AA downpipe. Adding 2-3 gallons of ethanol made the car smoother. JB4 probably has better support for Ethanol I assume. not much idea there.

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

Here you will find info about why a downpipe change without a supporting tune map is not the best idea. (something I didn't know even with my downpipe installation.)

Like I mentioned, after market intakes wont help with power gains, atleast in the stage 2 range we are talking about. Our stock filters are pretty good to begin with. They are purely for the sound.

I would suggest to go through the 2 channesl shared above. Should give you better insight and make an informed decision.

All the best with your tuning journey. Cheers.