Multiport Fuel Injection on a 250?

[Anonymous]

Hi guys, I've searched around, but I coudn't find exactly what I need. So here's the basic info first.

I own a 68 Mustang coupe and I'm running with a 250 that came from a 70 Mustang coupe. My plans are to build it up using the stage A and B mods from www.fordsixparts.com. Okay, I'll basically have a modified engine once all of these parts are installed, and it'll make better power, but I do not want to use a carberator setup.

I want Multiport Fuel Injection. Now, I'm a complete newbie at MPFI because I've never owned a car with it. I only know a little about TBI, which is no good for my application.

My question to you gurus of EFI is this:
Would you please educate me on what your basic MPFI system includes? I'm willing to fabricate almost anything to get this accomplished. I have excellent tools available to me, and I know how to run basic tools and machinery. I really would enjoy building it from scratch or from a few parts here and there, but I'm not sure about what I'll need.

What parts (computer, injectors, etc.) would I have to aquire to build a custom MPFI system?

I hope that you'll tell me I can use some components off of the big sixes, but if not, I'm willing to spend the cash to make my 250 a very rare thing, indeed. I have to say that money is not an issue here, because I want you guys/gals to give me the complete details.

I guess, I'm asking for a lot, but basically, I just want to know what kind of parts make up an MPFI system. And if you can recommend a company or person you know of that can sell me individual peices of the system, then that would be very helpful too.

Thank you for your time,
Colin

 

[Anonymous]

Hi Colin, I would suggest looking over the www.sdsefi.com webpage. They offer all kinds of stuff to help you build a custom setup - even show you how to make custom fuel rails.

Multi-port is cool, and has it's advantages over TBI, but something you have to consider is whether or not you want to spend this much time, effort, and energy into a US head.

1) You aren't going to get a lot more power with MPI - not on a US head

2) What if you get this thing running, and drop a valve, overheat, get a crack - something that would ruin the head. You have to start over with a whole new head. You can't just bolt your modified intake on a new one.

That said, if you really decided to go with MPI, I would consider starting on an Aussie or an Argie head. You'll have a lot easier time modifying the aluminum intake for injectors, rails, and throttle bodies.... not to mention the added power from a better breathing head.

 

[Anonymous]

Thanks Inliner! You are great

I'm currently looking at the SDS site and they really have it together. They will probably be the way I'll go for this project, so please wish me the best.

Thank you for replying so darn fast too

Colin

P.S. What's your take on doing the performance upgrades from fordsixparts.com?

 

[CougarT]

check this also

http://www.slantsix.org/articles/dibias ... ersion.htm

 

[CobraSix]

I've looked at this for awhile, and here is some of the information and ideas I've found.

LIke inliner said, I wouldn't do this on a log head. Look at aquiring an Aussie head/intake. Then you just need to modify the intake manfold. Also, the aussie head will give you better low end torque due to the longer runners. And then, if you kill the head, all you need is to source another head, but can keep the intake.

I looked as SDSEFI...but i found it required a lot more engineering, and the ECU seems very limited. Personally, if you are going EFI, you need to get an ECU that can do some timing control. SDSEFI doesn't do that IIRC.

I narrowed it down to two systems:

1) Holley Commander 950 (www.holley.com)
2) Electromotive TEC-3 (www.electromotive-inc.com)

Holley Commander 950:
Pros: the ECU can either do TBI or MPFI. MPFI is a batch or bank fire set up for HOlley. ECU can do timing control, but not on a DS2. It needs a ford TFI dizzy to control the timing. I talked with the main guy at Holley for EFI, and he said it is possible to do timing control with the DS2, but it would not be as solid as running it with the TFI. Rotor Phasing would be more of an issue. Holley can use Wideband O2. Also will work with Forced induction. Relatively cheap, $1100 for complete TBI system.

Cons: Can not do sequential MPFI. WOuld require some machining to get a Ford 300 TFI dizzy to fit in a 200/250 so you'd have better timing control. Also, not have SMPFI may be a factor for you, though SMPFI yields very minor results over batch fire MPFI.

Electromotive TEC-3:
Pros: Much more tunability then HOlley. Allows for true sequential MPFI (though you'll need to buy some other parts). Generally, a step up from Holley in quality and capability. Electromtove also has a direct fire ignition that can be programmed, and basically for a 6 cylinder, has 3 coils, 1 for every two cylinders, allowing for better spark and quicker charge up times.

Cons: Expensive. Complete system will run you about $2600 all said and done if you use the DFI system.

I think I'm leaning towards Holley, especially since I can start with a TBI and then if I feel I need to later, convert to MPFI.

Slade

 

[Anonymous]

Thank you,

This info is awesome.

I'm happy to be a member of this forum, because there's a great wealth of information just waiting and eager to be poured out into the minds of us who just don't know all that much about it.

I'm actually honored to be a member of the FordSix Forums

 

[Anonymous]

Another thing to consider is to chop the log and fab up a custom intake manifold replacement. That way if the head is destroyed for some reason, you haven't lost so much. The chopped log thread is here.

 

[twentyover]

Still another possibility is to use a megasquirt with multiple throttle bodies. In all hionesty, I'm beginning to believe that since you only need 1 TPS (to secure a rate of throttle opening and approximate thottle position, adding additional throttle bodies shouldn't be a big deal. Kind of like assuminug a Chevy TPI has two throttle bodies (two bores) on a common shaft. The log is now your dry plenum with REAL short intake runners.

Been thinging about this a little since the chopping the log post. May be a relatively easy way to get there from here.

 

[twentyover]

More on Megasquirt

Check out http://www.bgsoflex.com/megasquirt.html. this is user tunable w/ a laptop. I've ordered the parts (for a 6 cylinder MG), uses GM coolant temp, manifold air temp, and an internal MAP sensor, along with a throttle position sensor and an rpm input.

I think that with 2 or 3 throttle bodies (downdraft or side draft) on a common shaft with a single TPS, there should be no air volume or distribution issues with el loggo de intake manifoldo.

Use a screw in injector bung into the log right above the inltake port, and I'd think you're good to go

 

[MustangSix]

The SDS E and F systems do control timing. I have a 3E system on the Crossflow now. It is extremely easy to hook up and set up.

The E-system ECU controls an MSD6A and you can set timing according to load, as sensed by the MAP, or RPM, or both.

The F-system fires a DIS and is extremely powerful, capable of operating up to 12,000 rpm.

SEFI is useful as an emissions control, but all systems defacto revert to batch fire above a certain rpm. You just simply run out of time to pulse the injector above a certain speed (about 2000 rpm on a six).

 

[Anonymous]

What about using a system like the 4.0 Ford V6? Can the crank trigger be adapted/machined to fit the snout of the 250 crank. I have a 4.0 Ranger, maybe I will measure this one out.

 

[MustangSix]

Stock systems are optimized for emissions and economy on a single particular engine with a very specific volumetric charateristic. Said it before, will say it again: IMO, attempting to use a stock EFI system from some other engine is the hard, expensive way. By the time you get thru buying, adapting, and attempting to tune, you will have spent countless manhours and $$$ just trying to get it to run at all.

$1000 looks like a lot of money to buy a basic SDS, but once the hardware is done, the thing hooks up, fires first time, and takes just a few minutes to start tuning. Megasquirt with MegaJolt Lite is even cheaper.

 

[CobraSix]

I like HOlley since it is a complete system, including the TBI and can be converted to MPFI later. That is what I'm going with when I convert to EFI. Currently going for about $1100. Plus the HOlley guy in charge of EFI is a really great guy and will work with you if you have any problems. I don't know about SDS's customer service, but I know Holley is pretty good about it for their EFI systems.

Slade

 

[MustangSix]

Things must have changed at Holley. Four or five years ago they used to have a forum on their web site that was supposedly for tech support. It became a "bash Holley" site because the tech support was so lousy. Eventually the forum was shut down (wonder why). They went thru a couple of acquisitions and mergers since then, so maybe things are better.

I do know that SDS customer service is very responsive and they reply immediately by email or you can call and talk directly to the owner or anyone you like for support. Real people answer the phone and you can ask for specific people by name. It's a small business and they love to do oddball installations, not just small block Chevy and Fords. They were extremely helpful setting up the initial maps for the Crossflow.

Still, the next EFI I attempt will be Megasquirt w/ Megajolt Lite, just to see if I can do it.

 

[twentyover]

I'll be interested in following that thread. I've bought the boards and parts from MS and Digikey, but this is for the MGC, and that's behind a few others right now. I also havm't assembled an electronics kit for over 25 years, so i need to knock a few of those over 4 I screw the MS up.

So even though you're starting after me, You'll probably finish a few years B4 I do