Aloha from Maui

this is my car:
https://www.topgear.com/car-news/mot...-b-rally-car#1

Dual coils...what's the best way to set up an MSD ignition?
Do I really need 2 MSD units?

Mahalo from Maui

Gregg

 

It has been asked plenty of times, and there is a really good summary here, this is what I did on my car.
https://www.smbaker.com/sand-rail/ma...-rotary-engine

But honestly, I didn't feel such a change on my car (12A, stockport, Weber 45DCOE and Racing beat exhaust)


EDIT: I didn't realised you were the owner of that group B!!!
Honestly, those group B cars are running quite well, don't bother with the MSD setup.
I have been rather disappointed last year when I installed it on mine, it has been a lot of work for no real noticeable results.
The car was running great before, it is running great after...

 

You only need two MSDs if you want have one for both the leading and trailing sides of the ignition. What we have always done is just put an MSD on the leading side and left the trailing side alone.

Go here and look at the install instructions for the box you are going to use or already have: https://www.holley.com/products/igni...gnition_boxes/

How you wire in the MSD box depends on whether or not you are going to use the Mazda Ignitor or you are going get a signal straight from the magnetic pickup.

On my race car I have an analog MSD 6A on the leading side only. I am pulling from the leading magnetic pickup and I have the MSD firing a dual pole GM coli that is connected directly to the leading spark plugs (wasted spark). I used shielded wire from the distributor to the MSD and shielded wire from the MSD to the coil to avoid interference with the Tach.

Does it make a difference? I have nothing to compare it to. My race car has always had this setup. The only way to know would be to do an A/B comparison on a dyno