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Picked up a "barn" find recently, a one off injector system less the electronics. It was a development piece fabricated circa late 1990's and used on a well funded Trans Am Mustang. According to the friend (Team manager) I got it from.... It did not produce any more power than their very worked over Barry Grant Holley 830, but tuning was much easier and the idle characteristics were a whole bunch better...
I got it for pennies on the dollar and thought it would make a nice addition to my build.

Question... I'm starting from scratch on the injection electronics and it was originally an analog system. I do have access to some of the analog information but would not know what I'm looking at, (remedial understanding of neutrons, electrons, fig newtons and morons!). Is there an easier path to travel with an "off the shelf" system or possibly a DIY Mega-squirt attempt. Given I know very little about electronics, I'm guessing an "off the shelf" direction may be the best choice, eg: Fast, Edelbrock, Accel, Holley.. etc..

I sure would appreciate thoughts on this somewhat tandem project to my build. Does a DIY effort make sense for those with a digitally challenged make sense?
Cheers,
M

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McSorely 442 / SBF - track day, autocross, street licensed toy. Build in process.

IIRC the injectors in the stacks is like an old Holley or Edelbrock system so you might look there.

There's no reason a MS system wouldn't work, but with the injectors in the stacks instead of the cylinder might give you a different starting point than the standard beginning maps.

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mobilito ergo sum
I drive therefore I am

I can explain it to you,
but I can't understand it for you.

That looks too "alpha" stage to trust to me. Meaning you'd turn anything you bolted it to into a rolling fire hazard... I would guess it was very carefully watched when it was being run.

You could figure out how to run it with Megasquirt, but something off the shelf should be far easier to install, tune and should be safer.

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traynee rockit serjun

DD#1 '95 Ford Escort Wagon 1.9 Auto, self PnPed stage 2-3ish head, 11ish CR, Airhog panel filter, awaiting headers and intake mods. ~110-120 BDHP
DD#2 '88 Plymouth Voyager, 3.0 Auto, shift kitted, alloys, walker exhaust, timing advance. Awaiting PnP heads. ~150 BDHP

That looks like fun. Megasquirt or any of the other programmable computers should be able to handle that. The big issue that you'll run into is the fact that it's an individual throttle body system and they can be a little difficult to tune in general. If you want to read up more on it there are a few guides out there and a good search term would probably be "ITB alpha-n" I think it might be worth it in the end just for the ungodly wail that will come out of them.

Hey C123: Thank you for your thoughts!
There well could be a meaningful delay in the timing of injector pulses using the nozzles where they are. It also speaks to another point and that is of batch vs. sequential injector activation. I've read a little of the discussion on this topic and there seems to be value and problems with each! If memory serves, the earlier Holley and Edelbrock systems were batch fired and using a carburetor like butterfly assembly with injectors either in a spray bar or through metering jets similar to a carb. Perhaps the earlier fuel maps would be a good place to explore that issue as the fuel was introduced at the "carb", instead of current practice - as close as possible in back of the intake valve.

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McSorely 442 / SBF - track day, autocross, street licensed toy. Build in process.

Hey RR222:

And thank you as well for your comments.

I inquired of the injector placement as well... It apparently was a design decision based on the potential cooling of the intake charge the nozzle placement represented. Although I didn't consider the potential danger of a backfire with the fuel so close to the rim of the intake stack, it did seem a bit rudimentary not to mention very un-sexy!!! The system was developed for the 310 with an operating range topping out at 9,100 rpms! (Hard to imagine what that sounds like in the car)!! As well, the complete system includes an air box / filtration assembly and a Pi-tot tube that somehow (my assumption) figures into the rich / lean CPU calcs. Bottom line, the air box does offer a measure of safety and the fuel introduction point is not all that different than a carburetor, and hiding the injector placement wiring... bumps it up a bit on the sexy scale!!

Do you have any experience with the off the shelf systems and their respective tech support, which will be needed in my case big time?

Best,
M

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McSorely 442 / SBF - track day, autocross, street licensed toy. Build in process.

Hey C: Thank you for the thoughts...
Does the tuning issue of individual throttle bodies (TB) become ever more complicated by possibly opting for a sequential injection firing order vs. the batch configuration? Is there one off the shelf company out there that is more inclined to support Sequential than batch or is this a simple option all offer?

Thanks also for the leads on Google. Looks like I have my research cut out for me this evening!

PS: Could not help but notice you are in my home town! Are you a transplant or a native!?

Cheers,
Monte

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McSorely 442 / SBF - track day, autocross, street licensed toy. Build in process.

I'm a transplant. I was also talking to you a while ago about spec Renaults because I work in a shop with a few SRF's in it at the moment. At this point I belive that megasquirt 3x will support sequential injectors, but I believe that you might be looking at more advanced ecu's like AEM or Motec if you want something that really is stable. The injector placement that high into the trumpet is tell tale of a system that really was designed for higher rpm power. You get great atomization of the fuel, but at lower throttle angles, it ends up puddling on the back of the throttle plates.

Also judging by the looks of it, there maybe have been a plenum that covered all of the trumpets at one point. That would certainly make a difference with the ability to use a filter of some sort on it.

I hope I don't sound like I'm being negative about the set up, I just think that there is a place for it, and you need to make sure that you plan on using it where it was designed to be. I also think that I have a customer or two that would love to get their hands on that depending on the application.

Hi C! I do remember the SRF discussion! Hope things are well with you and I most certainly do not consider your thoughts negative! Sharing knowledge, opinion and experience is what the forum is all about! It makes for one heck of an education and keeps one from reinventing the wheel or stepping on one's private parts!!!!

Very observant re: the injector system. The engines were contract leased as routinely used in the Trans Am series. The dyno sheets indicated red lines at 9,100 with 740 hp ratings! Stout motors to put out that much power from a 310 inch Ford. Additionally, you are right that the injection system included a filter / plenum set up, which included a pitot tube to measure pressure values for the CPU. Heavy duty stuff for sure and well above my immediate understanding..... While much of it is a stiff learning curve, it's part of the fun of it all....
The injector "barn find" included a pro prepped Ford SVO R block, 5.7 Carrillo rods, JE pistons, Jesel valve train, Comp cam solid roller lifters. Steff custom dry sump pan and a bunch of other goodies as well. I'm essentially a set of bare heads, cam, crank and reasonable CR pistons away from a complete engine. Current vision is a streetable 7100 rpm /450 horse version in my locost build. The injection would be the cream on top if I could civilize it enough for the street! Fun stuff........ puddles huh!?

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McSorely 442 / SBF - track day, autocross, street licensed toy. Build in process.

In a past life I did racing ECU development with Magneti Marelli, I will be happy to help you out. To start with, can you measure the resistance across each injector and post it?

X, I think you just made a bunch of new good friends

Yeah, I think the puddling would be a major problem in a street car, you'd need to keep goosing the throttle sitting in traffic, also I've known that kind of problem to cause a car to flood out while traveling at steady slow speeds.

If you wanna get creative though, depending on where the fuel is ending up, you could close the idle ports or screw completely then drill tiny holes where the fuel is ending up to let it bleed through a bit, then readjust idle..

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traynee rockit serjun

DD#1 '95 Ford Escort Wagon 1.9 Auto, self PnPed stage 2-3ish head, 11ish CR, Airhog panel filter, awaiting headers and intake mods. ~110-120 BDHP
DD#2 '88 Plymouth Voyager, 3.0 Auto, shift kitted, alloys, walker exhaust, timing advance. Awaiting PnP heads. ~150 BDHP

Well my 2 cents. ..

Properly calibrated I don't think that puddling would be a problem. GM used the TBI system for years (injector above throttle plate) which also doesn't have a direct way of measuring the airflow (I'm assuming that the pitot tube was used to calculate a derivative value for manifold vacuum) and they worked just fine as a 670 CFM unit on a small block. ..

Duty cycle, injector sizing and fuel rail pressure are the 3 things you can vary. Injector sizing is fixed so. ..
A more complex set of calculations but still doable I would think.
A pair of O2 sensors (assuming true dual exhaust of course) would probably be capable of a more exacting control and easier to find beginning fuel maps for in my opinion.

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"There are times when a broken tool is better than a sound one, or a twisted personality more useful than a whole one.
For instance, a whole beer bottle isn't half the weapon that half a beer bottle is ..." Randall Garrett

I really like those TBs and injectors. They should be put on display under a plexi window on the bonnet. However I see several issues with them as they are. One is already mentioned. I think that a smooth idle control will be difficult to control with the injectors outside the plates of the TB. Also, the TB's have been sized for that HP/air flow demand. Off idle stability may be and issue. It will be tough to idle smoothly down the subdivision roads. A second issue is that the injectors are sized for that 740+HP. Even if you get to the 450HP you are looking for, the new injector timing will only be working at ~60% of the original. You might want to replace them with smaller units.

Of course, if you are a track only car, who cares about idle and off-idle issues.

I too, believe that the MS3 can do sequential injection. MS2 can do batch firing or sequential firing of the injectors. One or the other. Megasquirt can handle it. Problem is, can you handle MS?

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Chuck.

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Hi X,
Welcome to the party and many thanks for your help, up front!
[*]Each injector has two leads terminating into a good size cannon plug with 26 active pins. Besides the injector leads there are several other sensor leads terminating at the plug as well.
[*]In measuring resistance (ohms (?)), do you read across the injector coil spades. or across the cannon end of the leads from the injectors?
[*]Never having worked with injectors before, is there a numbering system or otherwise sizing nomenclature used in identification?

Thanks for your interest,
Regards,
M

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McSorely 442 / SBF - track day, autocross, street licensed toy. Build in process.