Usually a tune goes somewhere in the middle of my build list but given how easy it is to put a tune on a Mini Cooper S and immediately get gains even in stock form, I didn't see the need to wait for other mods to be installed. The 2019 Mini Cooper S runs a BMW B48 engine which is shared with a number of BMWs such as the 2 and 3 series (maybe even some of the X series?)...except it's detuned from the factory. Burger Motorsports JB4 Tune is a nice solution as it's a piggy back that leaves no permanent changes to your ECU. It's also very likely that my ECU, being a 2019+ is updated and locked from the factory, meaning I'd have to ship it out in order to get it reflashed if I went with a reflash based solution instead. I'm going for an OEM+ build this time around so I'm trying to make minimal changes or at the very least, make changes that are super easy to reverse, so the JB4 was the right match for my needs.
JB4 for B36/B46/B48 Kit with Optional JB4 Wireless Kit
I ordered the kit along with the optional JB4 Wireless kit that allows you to connect to it via Bluetooth using the JB4 Mobile app so you can see various engine parameters, update firmware and select engine modes. The wireless module isn't pre-installed even if you buy it directly from Burger Motorsports so the first task was to open the very nice aluminum case all the electronics is packed in and connect the wireless module. It's pretty straight forward, just remove the 4 screws hold it in place using a 3mm hex wrench, connect the D-pin connector and screw it down with the provided screws then reseal the case.
JB24 Wireless Module Installed
Next up was to remove the air intake duct so you can remove the connector for the MAP and TMAP sensors, connecting it to provided wire loom instead and then plugging the loom back into the sensors. To remove the connectors, just slide the white clip down to unlock it then I just used a small flat blade screw driver to just push the tab away from the sensor and the plug just slides right out. If you're fighting it, then you're probably pushing the tab towards the sensor than away from it (lesson learned lol). I then used some zip ties to firmly secure everything together so nothing was just dangling around.
MAP sensor piggy-backed
TMAP sensor piggy-backed and loom zip-tied to factory wires for an OEM look
Next you just had to remove the battery tray cover so you can place the JB4 unit in the space between the battery and under the windshield wiper motor. I was going to zip tie it in place but it's so snug in there, it's not going anywhere even if you wanted it to.
JB4 housing shoved under the wiper motor
For the ODB2 connector (so it can read the CAN bus and use that to get all kinds of useful data), there was a convenient rubber grommet in the firewall you can just take to feed the wire from the OBD2 cable to the engine bay. The instructions didn't say to put the grommet back after you go the wire through but it didn't seem to make sense to just leave the whole there so I cut a slot in the grommet and reinstalled it for a cleaner install.
Grommet to firewall removed
OBD2 cable fed from under the dash and grommet slit and reinstalled
OBD2 connector connected and excess wire zip-tied out of the way
At this stage, the JB4 should just work so I turned the ignition on to power the unit up, connected to it using the JB4 Mobile App (which I still find strange that you had to pay for separately), had it downloaded the latest stable firmware for the Mini and uploaded it. The process took a short 3 minutes.
Updating the firmware
Tune map selection
By default, it is set to Map 1 which is ideal for a stock car. It's got a small bump in boost pressure (+4 PSI to be exact). This should give me about an extra 40hp or so in sport mode on pump 93.
Slot cut to route cables through
I used a Dremel to cut a little slot in the factory plastics under where the rubber hood trim gasket goes, routed the rest of the cable by the intake box and put all the plastics back on. I think the install is nice and clean and very OEM. To an untrained eye you probably couldn't even tell the car is now just "almost stock".
Panels back on the car, looking OEM - 2-20-2023
Clean install
Clean install
The car is definitely peppier in sport mode and you can even hear some crackles as you downshift via the paddle shifters through the stock exhaust. It's not obnoxious but something you do notice a bit especially when getting onto highway off ramps. Drivability is still very good especially if you dial it back to "green" or "mid" mode. The bonus of having the JB4 mobile app is I can display a number of gauges pulling data from the OBD2 connector straight to my phone for both viewing and data logging.
JB4 Mobile App
Now I just need my intake and exhaust to arrive so we can switch to Mode 2 and and have a bit more fun. Unfortunately, the auto transmission can really only hold about an additional 60hp so that will keep me honest and not allow to me to get nuts with power adders. It's interesting, though not surprising that these engines dyno higher than their advertised power figures. That seems to be a very BMW thing. While this won't get me to the same power levels of my IS38 powered MK7 GTI, it'll at least start getting close.
Interesting video of a 2-Door Cooper S (same engine) on mode 1 JB4 tune
