Speaking of MFI, Man that sounds good.. Options

[redshift]

What are the limitations of it?

I am planning a /6, had considered a 2.7RS, guffawed at the video of that 2.8 RSR, but I like the 3.0-3.2s running forever, AFAWK...

Negativity will be ignored in favor of zooming noises, and high-pitched whining descriptions. (with pictures and exuberant hand gestures)

(IMG:style_emoticons/default/smile.gif)


M

[airsix]

This will sound wild and impractical (HA! That got everybody listening!) but I don't think it's as impractical as it sounds.

MIF as I understand it, provides mixture as a function of RPM and throttle possition. Pretty straight forward isn't it? Your first though is "How crude". All the modern systems of EFI use manifold pressure or mass-air-flow in combination with rpm to measure load. While this is a more refined and precice method of getting the mixture right, don't think MFI type sytstems aren't capable of getting the job done well.

A MODERN MFI:
Most of the programable ECU's on the market (even the megasquirt) are capable of running in alpha-n mode, meaning they don't have a reference to manifold pressure and just use RPM, temperature, and throttle possition to meter fuel. I ran and tuned my PEFI system in alpha-n mode just as an experiment to see how well it would run and I was totally amazed. I was able to make it run great, and I wouldn't be afraid to set up a hot six to run this way. You might not be able to keep the mileage and emissions as good as running EFI with MAP (manifold absolute pressure) or mass-air-flow metering, but you'll be able to make power. I think you could also make it every bit as "drivable" or even more-so than a MFI setup.

You would need:
ECU
Manifolds & Throttlebodies
Airfilters

The ECU could be as simple as a $200 megasquirt, or as fancy as a $3k+ Motec.
The manifolds and TB's could be carb manifolds and gutted carbs. Even cooler would be to use motor-bike TB's. Many of the late bikes have individual TB's with a bosch injector bung in the manifold. Several of the .9 and 1.0 litre bikes apear to have good sized TB's for a 2.7-3.0 six. The hard part would be adapting the bike manifold and the throttle linkage. You'd of course have to use two sets of bike intakes, and lop off one of the TB's from each set of four to end up with two sets of three.

I know it sounds nuts, but I think it would be pretty awsome. MFI power & sound with EFI reliability & drivability. Ok, the drivability part will still be a compromise, but the SOUND, MAN, THE SOUND! (IMG:style_emoticons/default/wink.gif)

-Ben M.

ps - I was told that that 2.8RSR made 250hp at the wheels at it's post-build dyno session (not pump gas though).
pps - There is a guy out there with a Lotus Europa (sp?) running individual bike TB's and I think an SDS ECU. He says it's awsome and he couldn't be happier.