Coil Questions

[TwinScrew20v]

Hey guys, I'm in the planning stages of upgrading from MS1e to MS3 on a VW VR6. I've been running the OEM coil pack direct from 3 BIP373's, but it is notoriously junk. A while back I attempted to upgrade to 3 MSD coils but had an issue with it shutting down the ECU. At the time, I needed the car for an event and pulled the assembly and put it on the shelf, but I did a little bit of digging and it seems the resistance is about .7ohms lower on the MSD coils than on the VW coil pack, and some of the VW guys are adding a resistor between 12v and each coil on the OEM fuel system (but some guys have been running without it for quite some time). Is this higher current an issue for MS3? I was told at the time that there were software filters needed to run these coild and that they were available in MS2 but that didnt make sense as this looks like a hardware/current issue.

Also, I just want to clarify my understanding on the high current setup for MS3. I will be running the 3 coils via 3 BIP373's similar to the MS1e method due to the high current nature (OEM or MSD) correct? And can this be run through either the main DB37 or the MS3X DB37? I previously ran the triggers out to an external project box and housed my coil drivers and the output cabling there, but I'd like to keep this assembly internal to the MS3 case for the new installation. Thanks guys.

[dontz125]

Unless the MSD coils have a much lower primary resistance than the OEMs (0.7 Ohms doesn't count, the BIPs should have no issues. What might cause problems is too much dwell causing the BIPs to overheat and shut down.

Route the BIP wiring the the main DB37, as the MS3X connector has most (or all) of its pins dedicated. Actually, I don't think you'll need to change much of anything regarding the ignition drivers.

[Matt Cramer]

Unless the MSD coils have a much lower primary resistance than the OEMs (0.7 Ohms doesn't count, the BIPs should have no issues. What might cause problems is too much dwell causing the BIPs to overheat and shut down.

We've run some of MSD's coils that were supposedly only for use with an MSD box off BIP373s before. The key is setting the dwell correctly. You can calculate this from MSD's published coil data.

[TwinScrew20v]

So a new development in this hook-up, I am going to be using the knock module for the dual knock sensor set-up and I saw the part where the 'LED spark' cant be used as I've done in the past. does this mean I need to use the MS3x Spark A, B, & C outputs to feed the BIP373 and run it as an external module again?

[dontz125]

That would probably be the easiest way. If you're in a contrary, DIY kind of mood, you could run internal wires from the spark A/B/C pins on the DB37-X to the base pins of the BIPs. Include a 120 Ohm resistor in each lead; the spark channels include 200 Ohm resistors, and the BIPs want around 330.