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Terry @ BMS Terry @ BMS is offline
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Default JB4 N55 Electronic Wastegate Control - 03-08-2014, 03:47 PM

NOTE: We've moved EWG firmware to the main F Series N55 Thread.

Hey guys,

Have made rather significant break through in controlling BMW's new electronic wastegates found on 2014+ N20 and N55 engines. Figured I'd make this thread to centrally locate all the information. I'll update this thread as more info is available.

The new electronic wastegate is used on most 2014+ N20 and N55 motors. They mixed it in to some 2013 models and seems to be present in every 2014 model except the F10. It replaced the old pneumatic vacuum canister/solenoid wastegate we've all grown to know and love since the 335 was first released in late 2006. In theory this new electronic wastegate eliminates a lot of "slop" and unnecessary hardware from the boost control. So this should be a positive upgrade. But unfortunately the new style is much more difficult to alter via piggyback. Perhaps intentionally. Which means without special extra control when tuning duty cycle is limited to maybe 10% over stock values. Another way of putting that is tuned boost has been limited to roughly 2-5psi over stock depending on the engine and speed.

Fortunately for us we recently found an electronic "vulnerability" in this new control scheme which allows us to fool the wastegate in to running a modified (and dynamically higher) duty cycle electronically. This is done through a combination of a digital signal manipulation and CANbus data. The new control channel is then connected to our JB4 PID duty cycle control system which is returned for the new wastegate control. The net result is with this new control the JB4 can now make as much boost as the turbo will safely support. Just like the older pneumatic cars.

Some random thoughts:

1) This post is only relevant to those with electronic wastegates. Those with pneumatic wastegates please move along. Nothing to see here.

2) To add this functionality you'll need a JB4 using special firmware & an add on harness similar to the FF add on harness. With the N55 JB4 board (shared by both the N20 and N55) we had the forethought to add a lot of extra random input and output capacity to the board. Which means we can accommodate this via firmware and harness changes only.

3) For the N20 motor the wastegate harness is relatively easy to reach but there is little benefit to be had. The JB4 can control up to map 2 levels well and the N20 motor is not reliable at higher boost levels. For these reasons we've not done much N20 EWG development.

4) For the N55 motor the wastegate harness is difficult to reach but the gains are considerable for more aggressive enthusiasts running absolute maps 5+. Even if installed the EWG connector is not active on maps 1 or 2. This is suggested for those who want to use race gas, meth, E85, etc.

5) The EWG harness is $35 and can be ordered here:

6) To use the EWG add on harness the FF add on harness is also required.

7) As a general rule EWG cars are not very E85 friendly. If reliability is a concern no more than 30% E85 should be used and the highest map used should be map 2. Using map 5 or map 7 with E85 mixtures may result in boost running high enough to exceed your fueling capacity triggering various codes and/or JB4 safety map 4 switches. If you are more experienced and able to analyze your own logs you are welcome to play around, but we've instructed technical support NOT to provide assistance or advice to anyone exceeding map 2 when using E85 with the EWG platform. If you run map 5 or 7 on E85, run in to problems, and ask for help, you'll get the company line of "for E85 use no higher than 30% and map 2". For more power consider race gas instead of E85, or add in a methanol kit allowing use of map 3.

Install Directions

I'll post install notes here for use by those helping with testing.

1) Before updating the harness you should update the JB4 firmware. The correct firmware for the new wastegate will have a EWG in it which stands for "electronic waste gate". For example the N55 firmware is "N55_EWG" and the N20/N26 firmware is "N20_EWG". After uploading the firmware you can disconnect the negative battery cable to perform the remaining steps. Firmware is attached. Set pid gain to 12.

2) The new harness has two long wires coming from it. Purple and blue. Each will have a gold DSUB pin which is to be inserted in the JB4 harness similar to how the FlexFuel connector is added.

3) The purple wire (going to the male pin on the wastegate harness) connects to position #9 on the DB25 connector.

4) The blue wire (going to the female pin on the wastegate harness) connects to position #16 on the DB25 connector.

Note if equipped with a BMS methanol kit then the FSB blue wire going to the FSB must be relocated. If you do not have a methanol kit installed disregard this note. If using an older PWG board (firmware version does not end in //5) then relocate the blue FSB wire to the DB9 (usb cable) position #9. If using a newer EWG specific board, connect the blue FSB wire to position #14 on the DB25 connector.

5) The connector itself must be routed to the wastegate. We'll add some addl reference photos of where that is based on model. Unplug the OEM connector, attach it to the male connection, and plug the new female connection in to the wastegate.

6) Do a few datalogs to adapt the JB4/car and ensure boost is close to target.

EWG Firmware

Firmware is posted in the main F Series JB4 thread. Be sure you use the firmware starting with "EWG" in the file name.

Here's a video showing how to avoid a possible startup code bug with the EWG harness in place.

Attached Images

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