I would like to control my ignition with a ecu. Does the large cap 7 pin, coil in cap, have any advantages/disadvantages when compared to the 8 pin separate coil distributor? The 8 pin small cap distributors are easy to find. The 7 pin large cap are a little harder. Does anyone know which year the 7 pin went into production? The 8 pin? This will be used in my 6500 rpm 427 SBC.
I would like to control my ignition with a ecu. Does the large cap 7 pin, coil in cap, have any advantages/disadvantages when compared to the 8 pin separate coil distributor?
You will never have the coil wire go bad.
What ECM are you thinking of using? Are you going to be fuel injected?
I am going fuel injection. I noticed on the Megasquirt web sit the coil in cap takes less dwell time setting than the small cap HEI with separate coil. Am I right that the large cap without vacuum and centrifugal advance was used a few years starting in 81?
I also vote for the in-cap coil. I'm running a separate coil setup on my 383 TBI truck (like it was stock), but the carbed intake doesn't have provision for a separate coil, and I haven't really found a good place for it elsewhere yet. I got that distributor before I knew about the in-cap EFI capable distributors.
I think the big coil in cap is going to be my choice. I have used the non-EFI big caps and always been pleased with them. It's nice not to worry about making a coil mount but mostly they eliminate clutter. Megasquirt is saying the spark needs lless time to saturate the coil in a coil in cap versus the divorced coil. It's wayyyyyyyy below 0 here and will be for the next few weeks. May be a while before I can hit the u pull it lots for the wire harness parts. Anyone have any ideas for new wire plugs?
I am going fuel injection. I noticed on the Megasquirt web sit the coil in cap takes less dwell time setting than the small cap HEI with separate coil. Am I right that the large cap without vacuum and centrifugal advance was used a few years starting in 81?
Thanks, Woody
My 81 Vette had the coil in cap distributor that was computer controlled if that helps. All the vettes between 81 and when ever the optispark came along should be the same type. Anything GM V8 in the the '80s with the TPI intake or a TBI should have used that distributor.
I'm not any kind of expert, but off the top of my head, I would look for a late 80's early 90's f-body with the 7730(?) ECM. It will have the spark control and there is lot's of programming help available.
Thanks Bob. I know this forum is loaded with talent. I decided to get the new FAST 2.0. It is a complete system and has all the stuff I need to convert my carbed single plane roller cammed 427. Your suggestion for the ECM is a good one but I needed everything else to go along with it. Unlike the first FAST EZ tbi the new one lets you get into the program to do some fine tuning. It is an all new ecm. It is more sophisticated and faster then the first FAST ECM. It also has 8 injectors and modulates them so only 4 are used for low fuel requirements such as idle and cruising. I ordered my 81 Vet distributor this morning.
