Adding Speed Density to IR EFI?

The IR EFI that we have been discussing is essentially speed density depending upon who's ECU you're using and what it's doing with the sensor input. The only thing at issue is the MAP signal. Speed density relates to how the algorithims utilize the sensor input to generate and access the look up tables. As mentioned, IR makes accessing a meaningful MAP signal more difficult. I did a quick search and turned up this article.

It compares N Alpha, Speed Density, and MAF. It also talks about the challenges to speed density in more agressive street engines and blend modes.

Have a read. It's actually a pretty good short summary and addresses your questions.

Kelly

http://www.carcraft.com/techarticles/electronic_fuel_injection/

Yes, it helped.

How does the CPU compensate for a radical camshaft that delivers low engine vacuum at idle and tells the CPU that it is under load?

"On radical engines (those with cam duration over 240 degrees at 0.050 or less than 10 inches of idle vacuum), even user-programmable Speed Density systems have difficulty due to an erratic or insufficient manifold vacuum signal."

I guess the real answer is that they haven't made a good system for IR yet. MAF would require a single intake of some type, speed density requires vacuum sensing, which means you need a plenum before the runners, and N-whatever isn't any better than mechanical hillborns. I got a feeling all of them will work just fine, but one or the other may stumble or cough now and then.
You can't really go wrong cause you can always change it later, plus you get the fun of playing with it. So just buy the most programmable thing you can and read the instruction manual and play.

Yes I read that too DT. I think that the important thing is the amount of intake manifold vacuum.

I think of the IR EFI as a clean set of Webers, but what's the fun without the black exhaust clouds, the cylinder washing and the black slime that oozes out of the headers flanges?

I just talked to a FI coversion specialty shop and he says that FI are a piece of cake alongside of Webbers.
Don't you just hate these snakeoil salesman?

Well I don't know if it is snakeoil, all I know is FI makes engines last a lot longer. I bought a Mustang brand new back in 90. The only car I ever ordered from the factory exactly the way I wanted it. It has almost 200K miles now and it has never had the heads off and doesn't burn a drop of oil. It leaks plenty of oil, just doesn't burn it. I credit EFI for that.

Carburetion has got to contribute to the accellerated demise of an engine.

EFI is the way to go of choice if one can afford it.

Anyway you look at it in a Pantera, it isn't going to be a cheap conversion.

There are no 351c intakes for EFI MAF so you have to make one. The manifold itself is $700 plus it needs to be changed over from a Windsor verion to the Cleveland and will only match up with the A B or C Motorsport heads or equivelents.

A conversion harness for that system is $800 then you need a CPU. And you need to consider the estetic issues for the Pantera.

I'm taking the cheap way out. Mine is only $6000. I'd save up from my paper route but they don't have them anymore.

Even the paperboy has been replaced for cost reasons.

Dog gone it Doug, that sure seems real expensive to me! I have an idea though, you know how Marlin mounted twin 4 bbls on a tunnel ram? Well I bet he didn't pay no $700 bucks for a Cleveland tunnel ram. So if you can find as old Cleveland tunnel ram manifold on e-bay, fo less than a hundred buck, you could mount two of them holley fuel injection systems that look like they is a 4 bbl. That way you can have your mass flow and IR system too. I bet you could do the whole shebang for under a thousand bucks.

quote:

Originally posted by DeTom:
"On radical engines (those with cam duration over 240 degrees at 0.050 or less than 10 inches of idle vacuum), even user-programmable Speed Density systems have difficulty due to an erratic or insufficient manifold vacuum signal."

This issue is totally independent of IR.

quote:

I guess the real answer is that they haven't made a good system for IR yet.

How did you conclude this DeTom? It certainly wasn't from the article the first quote was lifted from.

MAF is adaptable but it's also not a cure all. If you read the article closely you will note that it touts the ability of MAF to adapt to changes you make to the engine.

The issues cited with MAP signal does not mean you can not effectively tune speed density systems for a fixed engine configuration. The blend modes do offer a lot of flexibility.

I guarentee that MAF is not a bolt on solution for high states of street tune and custom engine configurations.

If all you want is for your car to idle well, transition well, and want adaptability because you plan on making changes within a more modest range of tune, MAF is a fine. I still predict it will not be a bolt-on selfconfiguring system for your 351c without some significant effort. The closest route would be to buy a 5.4l Windsor MAF system and mod the intake, or mod a single plan intake for FI, and p[iece together all the rest. Cheaper than IR? Yup. Performance comes at a price and takes time. -To each his own.

quote:

Originally posted by DeTom:
Dog gone it Doug, that sure seems real expensive to me! I have an idea though, you know how Marlin mounted twin 4 bbls on a tunnel ram? Well I bet he didn't pay no $700 bucks for a Cleveland tunnel ram. So if you can find as old Cleveland tunnel ram manifold on e-bay, fo less than a hundred buck, you could mount two of them holley fuel injection systems that look like they is a 4 bbl. That way you can have your mass flow and IR system too. I bet you could do the whole shebang for under a thousand bucks.

DT, them ebay turkeys don't know that one can be purchased brand new for $338 from Summit.
They go out and pay more for the used one then a new one. Dum bastards.

Unfortunately that manifold is for the big port heads and I've got A3's, and I'm stickin' with 'em, at least they're American, just like my Pantera.

About 3/4" of the bottom of that port needs to be filled for my application.

Also I don't see the single 4v top for it around anywhere. That would adapt better to maybe a single throttle body and MAF.

That system should work decently but probably is going to have some issues. It certainly won't be as tunable and therefore won't be as powerfull.

Nope. It's the IR EFI for me. Geeze, talk about stupid bastards.

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So far the only manufacturer that has helped me is Haltech. They say that thier E6x unit is what I need.
They say that it interpolates (thier word, not mine) between lists and that it interfaces with my Motorcraft distributor and ignition.
They even gave me the wiring diagram for it.

I suppose interpolate and blend are a US to Aussie language thing.

Electromotive is elusive and information is through thier exclusive dealers.
So much for product support.

The dealers are experienced with Porsche Turbo's. They recommend systems that support that, not american naturally asperated v-8's.

So far I can't even get an exact price on the setup. They are being exactly what everyone warned against. At this point I don't see why they are the way to go unless those recommending them have vested interest, but that's just my initial reaction.
I can be wrong. That's usually a 50/50 thing with me so don't anyone take any personal offense because none is intended.
I realize some are just trying to help me out and thank you for that.

I'm just trying to keep everyone up to date.

I forgot to ask, does a IR EFI need an idle air valve/motor?

(If I recall correctly my memory is excellent, but my ability to access it is intermittent.) This discussion comes up because you want FI with Weber style horns on a Cleveland, right?

The simple thing to say is yes Jeff, and...?

I'm running a IR powered by Haltech. My cam runs a 240 duration at .05 and a 617 lift. It idle's just fine with out the assistance of an Idle air valve motor.

quote:

Originally posted by restoman:
I'm running a IR powered by Haltech. My cam runs a 240 duration at .05 and a 617 lift. It idle's just fine with out the assistance of an Idle air valve motor.

That's good to hear. Are you runnig a VSS?

Many people have had stalling problems upon decelleration without them. That's why I asked.

What Haltech CPU are you using?

I'm not sure what VSS is but I am using a Haltech F10X cpu. It contains throttle pump maps that you set to determine how much the fuel enrichment is reduced during the decay cycle or when you suddenly let off the throttle.
Another feature is the Decel Cut which stops the injector from firing at zero throttle until it reaches a pre deterimened RPM which should be set just above your idle RPM.
Go to Haltech's website. You can view all there software.

VSS is vehicle speed sensor. On new cars it is used for many things: Speedometer, cruise control, transmission shift pressure control, timing deceleration mode, etc.