EFI musings and requests for advice

Quickstep192 · Quickstep192's Garage

The pandemic has left me with plenty of time to fantasize about projects for the car.

My car was originally MFI, so I still have the ports in the heads. I really like the idea of using the adapters and RSR style tubing that Jamie has. I like the simplicity and it looks COOL! I think in the builds Jamie has done, he kept the original distributor and CDI, but I figure if I'm going for it, I might as well go for the gusto. I'm wondering about the advantages of using a 123 distributor versus an ECU that can do complete fuel and spark control.

This is mostly just a dream at this point, but I'd love to get opinions in case I take it to the next level.

pampadori · pampadori's Garage

My opinion - 100% do ignition and fuel.

Its not even about the max power, its so much better at part throttle torque and fuel efficiency. You cruise at 70mph only opening the throttle about 5-10%.

With fully programmable ignition you can run ~40-45 degrees of advance and run quite lean to get a nice bump in MPG. It will feel much more torquey at part throttle since you can run more advance too. Just opens up so much more tuning ability. Nailing the AFR is the easy part and isn't really where power is made so the more attention you can give the ignition events the better.

You can also be prepared for the corn juice future and add a flex fuel sensor and blend your maps based on the level of ethanol in the fuel. That reality might be a few years off but who knows. Might be a requirement sooner than later.

Ok, just my opinion and I'll shut up now.

Jeff Alton · 09:11 PM

ZERO advantage using a 123 distributor. Don't screw around. If going through the expense of doing a proper efi system, have it include ignition. Porsche went that route in 1984 with the 911. Why try to tune two systems that don't communicate with each other?

We have had great experiences with the AEM Infinity products. Our go to source for them is Rasant. Yes, we buy direct and can source all of the individual components. But, Rasant provides it complete in a package.

If your run your fuel side separate from your ignition, may as well put carbs on it. If you want maps that adjust with temp, load etc you need to control spark along with that to get it perfect. Make Sense?