Motec M-48 and FS coils

[RBT]

Hi,

I'm actually finishing to install a freshly built forged FS motor in our racecar and try to merge it with the Motec M48 that was driving the previous KL motor that was in that car.

I had a doubt about trigger polarity when I checked the cars wiring diagram so I've been reading most threads I found about coil drivers including MSII and HAltech install guide. From what I get FS coils have positive trigger ignition drivers built-in? The problem is I think my old Motec only supports sinking outputs so I'm not going to be able to control the ignition plug and play.

In your opinion, what is the best way to go: install other coil with or without external ignition module or use a driver to invert the signal?

Thanks for your help

 

[RBT]

BTW I'm not 100% sure about the fact that oem coils would trigger +12vdc, can someone tell me if I'm wrong? Would oem protege coils trigger on +12vdc or ground?

Thanks

 

[Ice88]

While I don't know the answer to your question I know that 1zz-fe coils will work in our car without changing the signal.

They also produce a much better spark

 

[RBT]

Thanks for the input, if I can't figure out how to make it work with my oem coils I'll consider the 1zz-fe.

 

[RBT]

I took a look again to the MSII install thread and I think I misunderstood it the first time... In fact according to the diagram I looks like those coils might trigger with 0V (gnd) and uses a TTL 5V signal. I looks like there's a pull-up resistor on the output that goes to the ignition...
I'll try to make a test on a bench to confirm that...

 

[mazda_sp20]

I use EMS aftermarket ecu with my FS. www.emsefi.com with factory coils and now running the FP-DE 1.8L coil packs.

Happy to send my setup file across if you want to decipher on how my trigger and ignition output.

P.S. my experience with the stock FS coils are sh*t. I haven't had a set that worked solid for 6 months unless I'm running 2.5ms of dwell