More wires = Less wires

The pictures tell the story. Wanted to see if this would work for some time now: use a NA Miata ECU for wasted spark (skipped the Miata setup and went straight for Corolla COPs) in a BG ('90 323 shown here).

The wiring to the COPs is plug and play. I only had to run 2 wires for the Miata ECU and remove the Defroster wire from the harness (Protege LX). Everything else in the Protege LX harness matches up to the Miata ECU (or isn't used by it).

Wanted to keep the Protege LX CAS (distributor) instead of using the Miata CAS. I like the fact that it bolts to the head on both sides instead of just the 1 side of the Miata's. But to do that I had to modify the 4/1 Protege Wheel and make it a 4/2 Wheel like the Miata. Used a dremel, started right up after I got that done.

By going to the Miata ECU, you lose VICS and the Pressure Regulator Control System(PRCS). VICS is no problem here since I'm using the BPT GTX Intake Manifold. But the PRCS may be more of a problem: may have trouble during hot restarts...

I haven't driven the car yet, but it idles/revs good. Still need to secure the COPs and bundle/finish the wiring.

And... no tach so far, haven't solved that one yet.

Nice engine bay...You could eat off that engine!

Do the COP's get warm when the engine idles? I recall something about Toyota COPs needing a real short dwell time.

Wow, what did you paint the valve covers with?

fujioko wrote: Nice engine bay...You could eat off that engine! Do the COP's get warm when the engine idles? I recall something about Toyota COPs needing a real short dwell time.

Thanks. Hadn't noticed anything unusual about them yet, but yes the dwell time is an issue... I hope to have a better idea soon after some driving time with them

GameboyRMH wrote: Wow, what did you paint the valve covers with?

The valve cover was powdercoated by a guy off ebay, he did a great job

tobg wrote:

fujioko wrote: Nice engine bay...You could eat off that engine! Do the COP's get warm when the engine idles? I recall something about Toyota COPs needing a real short dwell time.

Thanks. Hadn't noticed anything unusual about them yet, but yes the dwell time is an issue... I hope to have a better idea soon after some driving time with them

I cooked one Corolla COP within a hundred miles of installing it, while running on the stock Miata ECU. The other three worked well enough to allow me to finish the trip, but it was not a pleasant experience. (note to self, shake the car down real good before embarking on a 4 hour road trip)

There doesn't seem to be a consensus on whether dwell reduction is really necessary on these or just a good idea. I think most of the people doing this ended up going to stand-alones rather than working out the circuitry/logic for the dwell reducer.

Good luck!

peter wrote: I cooked one Corolla COP within a hundred miles of installing it, while running on the stock Miata ECU. The other three worked well enough to allow me to finish the trip, but it was not a pleasant experience. (note to self, shake the car down real good before embarking on a 4 hour road trip) There doesn't seem to be a consensus on whether dwell reduction is really necessary on these or just a good idea. I think most of the people doing this ended up going to stand-alones rather than working out the circuitry/logic for the dwell reducer. Good luck!

Thanks... I'll carry some spares with me. I had seen mention of dwell reducer boards in the past, but it's too bad they don't seem to be currently available.

The stock spark plug wire setup on the BP BG looks good, but the wires decay so readily. The ones in the pic above look brand new but they're a good 8yrs old w/very low miles. When I was on the dynojet recently, the ignition was so bad that they lost the signal making the rpm based chart useless. So just 1 of the good reasons for me to go COP.

Almost 800 miles with this setup in my stock BP (w/VICS) Protege with no issues, and no failures. May be one of my favorite upgrades. There is a lot of mention of adding a Cap to the wiring, but I didn't do it. Just using the stock condensor. I installed an RPM switch for the VICS and that has become my tach as well(never got the stock tach to work).

(pic isn't good, here's a link)

https://www.facebook.com/media/set/?set=a.895857867095522.1073741827.226674604013855&type=1