Wanted to know if there was a difference between the S3 and S4 ignition coils. I just installed an S4 alternator in my S3 (85) and wanted to look into other areas to 'upgrade.'

Dont know if its worth it to get the 86 rx7 coils, or to go a completely different route.

 

yes. they are different.

they can be used though. i believe there is an archived writeup on it, and a few other stray threads. finding one shouldn't be hard.

 

You can use just about any coil you want. The 2G coil will work fine. Based on your
other thread, I would solve the coil eating problem first before jumping to a new
one. Just do a search on 2GDFIS or just DFIS and lots of alternatives will come up.

I like the one I did thats linked in my siganture, TFIDFIS but I'm partial since I
wrote it up.

 

I have no idea how these systems work, or how to set them up. The diagram is awesome, but again, I would have no idea what to do with it.