M50b2x VAG coils conversion in progress/ MS2 (kDFi)

[haCR]

Hello, i would like to share with you guys, my upgrade from stock m50b25 coils to 4pin logic - VAG/Audi R8 coils. I´ve been trying to solve my ignition problems ( missfires under boost) million different ways, but nothing did not really help. So i decided to try VAG coils which should give stronger spark with less noise due to build-in ignitor.

Engine management is MS2 (kDFi), modded to sequentional ignition (COP).

So first I´ve bought Audi R8 coils. I´ve been told they fit on m50 valve cover without any mods. (Beru ZSE032, OEM : 06E 905 115) and piggytails from aliexpress for few $.
First I´ve cut old piggytails and found out that the stock m50 ignition wiring thickness is really insufficient in comparsion of AUDI stock wires. Here is the picture of OLD and NEW connectors and wirings:

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Here is the photo of coils and how they sit on the valvecover. And the mess in wires.

21390664_10207934956972228_1541224458_o.jpg21362371_10207935217178733_1807407355_o.jpg

After I finished the wiring of the coils, according to wiring schema of a logic coil, I though that it will be ok to only desolder stock IGBTs and jumper them (run MS2 spark signal output straight to the signal pin of the each coils). But then I double checked the MS2 manual and found out, that I need to add some buffer circuit, with the TC4427s and 15R rezistors.

Audi+COP1263563147.jpgout2.jpeg

Now im waiting for delivery of the TC4427s and maybe tommorow i will continue with it. Im very curious if this will help me.

[being3]

Is this circuit needed because ms ems has built in igniters ?


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[someguy2800]

Is this circuit needed because ms ems has built in igniters ?


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An MS2 needs a transistor added between the processor and the coil. The processor cannot handle the current load to switch the coil directly. An MS3x or MS3pro already has this built in.

[haCR]

So i made the circuit with TC4427s and connect between the processor and the coil pins, checked everything and tried to start the car. Car started easily but only on 5 cylinders. 5th cylinder was not firing. So i´ve checked and resolder pins leading to the 5th coil (which should be spark b output from the processor)

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My tacho stopped working aswell. Ive tried to switch from Coil on plug to Wasted COP but it run even worse.
Any ideas what to check or try??

Edit: Now its running on all 6. There was bad contact in one pin of MS processor. After i clean and secure the wirings i will go to test, if it still misfires.

[haCR]

Tested. No more missfires. After a whole day of drifting, not even a sign of misfire!! I´m so happy.

[Matich]

Reviving an old thread here, was this KDFI v1.4? This video shows wiring of AEM coils and no buffer was needed to run them? how come he didn't need to?

https://youtu.be/WTlu0SQXsx8?t=12m32s

[jimmyzx6]

any updates

[JRwhipE36]

Do you by chance of how to wire in the pigtails to the factory harness and what does the 4th pin need to be hooked up to on the audi coils? I’m hoping these can be run off the factory ecu thanks for the help

[Alternat0r]

Factory ECU won't run these coils, M5x coils are switched by ground signal from the factory ECU through the use of ignition-capable IGBTs.
VAG coils are signaled with +5v logic level signals, you can't run them without modding your ECU.