I'm looking HARD at going multi-port EFI on my 360 mopar. its got a medium sized cam, and with an 850 double pumper and a victor Jr. single plane, it made 390 horse at the rear wheels at 5700.

i since swapped in an edelbrock 750 and dual plane to get some drivability for the car, as well as some more manifold vacuum.

this current combo, though more drivable, is down on power and STILL does not give me the drivability and such that i am looking for.


therefore, I'm looking at going MPFI. i have decided against TBI, even though it would look more correct under the hood. the drivability benefits of multi-port are just so much better.

i have not decided whether I'm going to modify the dual or single plane yet. more research on that one before i spend the money.


where I'm really struggling is the decision for the ECM. I'm looking to do this inexpensively (not exactly free, but not over 1000 for the ecm) in the end i want ultimate drivability and reliability, with no hiccups, gremlins, oddities, etc.


so, with these parameters of motor and injection style in place, Ive got a few options for ecm that i know of, and two that REALLY stand out to me.


1. use a TPI corvette/camaro ECM. reasons being that they are dirt cheap, i have a vague understanding on tuner pro (not good AT ALL), and the injection and displacement are similar to what i want to do. harnesses are easy to make and modify, lots of support, and also the ability to run knock sensors and timing control. don't know if i have the option for auto tune or wide band o2 control with these systems and tuner pro, though. also have no idea where id mount a knock sensor on my motor. have to do data logging and burn many chips to get the combo dialed I'm though.


2. megasquirt 2 or 3. they have a really good auto tune feature, the tuner studio looks pretty straightforward, i know they accept a wide band o2 sensor. can use pretty much anything i want and this ECU will support it. seems to have a bunch of support for them, reasonable price. have to custom fab a whole harness instead of modifying a stocker, and have to figure out a lot more of the engineering for the system than the GM ECM. but more tunability, no chips, etc. lots of pros, lots of cons. can also control pretty much any accessory, and does timing.


so, i know there are others out there as well, it just seems like these are the two that are right up my alley.

so, which system would you use (even if its not either one of these) and why?

Michael

Here's an option to consider as well. This is the F.A.S.T EZ EFI but it is not their standard throttle body setup.

http://www.summitracing.com/parts/FST-302000/

This version does not have the throttle body and is designed for multiport. Granted it is batch fire and as with all EZ EFI units, it doesn't have spark control, but it has great support. Rich at Fastman EFI here on this board sells and supports it.

MS system II and III you can also control spark too. Much more support out there as well. You can use a factory harness to tie into the MS system as well. I'm a fan of the capabilities of the MS system. It will be the last computer you would have to buy.

What is MS?

Mega Squirt!

I really like the FAST EZ EFI and that is what I am going with on my 408 Stroker. I like the idea of the self learning and self tuning. As already mentioned they sell the ECU as a "Retrofit" unit. I think using GM parts you could easily assemble what you need.

I started going down that road but in the end decided ton the EZ unit, for me, the convenience outweighed any small performance gain that might see over the multiport.

For the ultimate in driveability, economy and user control your want sequential port injection (which requires a cam signal), on a single plane manifold with a self learning ECU controlling the timing. For a system like this you should consider the FAST XFI system. I would not suggest the EZ retro kit (that's the one that for port injection), because it's bank-to-bank only and it does not control the timing.

The FAST XFI is more expensive than the MS and a fully built-up MS system can do the same thing as the XFI. Here are my comments:

1) The GM ECU would work fine as long as you can get a hold of good tuning software. I like the HpTuners for serious manipulation of GM ECUs. The ECUs are wide band compatible, they do not auto tune, they do not data log, and the tuning software can be expensive. However the hardware is "junkyard cheap" so this is probably the least expensive way to go.

2) The MS-III can do everything you need, but you sort of have to "join the club". If making harnesses, reading schematics, and if you are fairly technical in electronics, it's a great way to go. It's an open system which means it doesn't really have a feature list. You more or less decide what you want and build it from there, but you can buy a complete ECU already assembled. The MS-III can do sequential injection, use a wideband, control ignition and data log.

3) FAST XFI. This system can control anything you want, it does self learn, is very well known and well supported. Heck, Summit sells the parts and FAST offers an off-the-shelf dual-sync distributor for your motor. But it is the most expensive too. A typical FAST XFI system will run about $1500 more than the MS-III. The other ECUs in this range are the Accel DFI, and Big Stuff -3.

From your post it looks like you are up to any of these solutions so good luck and lets see some pics of whatever you decide to do.

That's what I like about Rich (FastMan EFI) - no BS.
Sounds like good advice

Ran

I bought a megasquirt-2 for the 440 I'm building right now. I bought it before ms-3 came out. You can buy a generic, premade megasquirt engine wiring harness for about $60. I did anyway, bought it from diyautotune.com, the generic harness comes with wires of all different colors, they are labeled and you need to crimp on your own sensor connectors. But at least I don't have to make the whole harness from scratch. MS-2 will do everything MS-3 does, except MS-2 is batch fire only, not sequential. I don't think it's that big of a deal, some guys do. It's still a huge upgrade over carb and better than tbi. Batch fire is what the oem port efi systems were in the 80's for the most part. I think I paid $60 for the engine harness and $250 for the ms-2 unit, however I did have to solder it together myself. MS-2 was primarily designed to use MAP or Alpha-N for calculating fueling but is also able to use a MAF sensor should you wish to go that route instead.

I have played with many of the options mentioned, and agree with virtually everything already written. My two cents is this - when will somebody introduce a GUI for JTEC controllers? Except for detonation sensors, they do it all, dirt cheap, and stone-axe reliable. (There is a dedicated cal written for 400-425 HP 360s, and I've been driving it for years -- flawless!)

And a question for MS III gurus...will the new version do DIS - COP or coil packs?

Rick E.

+1 for MegaSquirt. Currently tuning the MS2 in the W350 and it's driving better every time I get out in it. Pay for the Tuner Studio full version and let it tune itself.

I believe MS3 will do all of the spark options but you may need the add on board to make it happen. I know for sure you can do full sequential on 8 cylinders now.