EFI for big block MOPARs?

[Mr. Cuda]

The engine in my 'Cuda (383 c.i.d.) is in dire need of rebuilding/replacing. I've been reading quite a bit about the 431/451 stoker engines and have decided to go that route for the rebuild.

A friend of mine who has some experience tweaking fox chassis Mustangs suggested that I update to EFI while I'm at it and recommended mass air style EFI over MAP because mass air more readily adjusts to engine modifications. However, the EFI setups that I've run across, i.e., ForceEFI, SpeedPro, etc, use MAPs.

If anyone has done an EFI conversion I would appreciate your input on what it takes to do the conversion and what it takes to dial in. Also, does anyone know if it is possible to adapt the ECU and harnessing/sensors from an EFI 360 for this application?

Thanks

[kudah440]

Just for the sake of conversation...Somewhere in my stack of mopar magazines there is an article about an ebody cuda where the guy built a manifold to adapt in a chebby tuned port injection on top of his 440. Not sure if theres any technical info in the article (from around 1997 i think) but sure is food for thought.

[RogerH]

Ok...I'll quote you some info between a MAF and a MAP setup...

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MAF: uses RPM and inlet flow as a means for control
MAP: uses RPM and inlet density as a means for control

Mass Air Flow (MAF) systems are used on many OEM engines. These systems do not directly measure the mass air-flow, but infer it from another input; such as the electrical current required to keep a heated wire (located in the air-flow) at a known constant temperature. One advantage of MAF is that it is able to "track" air-flow changes in the engine over time as the engine wears and accumulates deposits. Another is that it can adjust to changes in the base engine - such as camshaft profile - provided the changes are fairly modest. The disadvantages are the flow restriction and slow response of the air-flow meter. The slow response requires the system to depend heavily upon "other means" during and rapid changes in load (such as stabbing the throttle to WOT). There may also be problems with finding a flow meter location that does not result in inaccuracies that arise from pulsing reversion flows.

Speed-Density systems (MAP) are also used on many OEM engines. In some cases, the inlet density (derived fromt he measures of Manifold Absolute Pressure - MAP and the Air Charge Temperature - ACT) is used to calculate an estimate of air-flow into the engine. In others the density measure is used (along with RPM) to directly describe the operating point and the output values are derived from "look-up tables" in the ECU calibration. A disadvantage of Speed-Density is sensitivity to the base engine configuration. Advantages include very fast response to changes in load, a high air-flow potential, and good resolution at light loads.
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Hope that helps a little!

Roger

[dkn1997]

Was that cuda gold???? I remember that article, I think he hand fabricated a sheetmetal intake for it, lots of fun!!! Not much tech in that article, though.

I run a holley projection on my big block charger. Cheap and drives much better. It is not anywhere near as sophisticated as the other systems discussed here, but very simple and cheap to install. I got one used and was up and running for less than a grand.

Don't get me wrong, it is not the be all and end all of efi, but I look at it as a stepping stone for when I move up to a nice port injected set up.

I like the idea of talking to the guys at rance fuel injection, or force. They will get you on the right track, and you can buy parts or a turnkey system from them. also check out mopar action or mopar muscle (forget which one) one of them had a tech article last year on home built port efi on a 383. very technical with drawings, etc.....

[kudah440]

Yeah, It was the gold one, now thinking about it, theres also an article out there about "the green bricks" stroked 340 getting the fuel injection treatment.

[c318cuin]

http://www.rancefi.com right there on the home page
So they might be able to come up with some nice ideas.

[Mr. Cuda]

Thanks for the input, guys!

I've e-mailed Force EFI (http://force-efi.com/) with some questions and it looks like they too can fabricate EFI for me. Their base ECU is the Haltec F9A which appears to be a MAP setup.

Apparently you can upgrade to a Speed Pro unit, which BTW supports timing retard for a single stage of nitrous, that is also a MAP setup.

Accel also makes an EFI kit (MAP style). Someone was telling me that it was recently detailed in either Mopar Muscle or Mopar Action magazine.

The Force EFI kit is nice in that it comes with the high pressure fuel pump, pressure regulator, fuel filter, logs, injectors, throttle body, sensors, harness, and ECU. Seems like a complete kit to me.

If I did it right, there should be an attachment .zip with .PDF of the Haltec ECU. I like how it supports RPMs up to 16,000

[Marc]

Rance is doing the sequential multiport EFI for my Coupe. He is not only VERY knowledgeable, he is also an EXTREMELY NICE GUY!!!
http://www.rancefi.com

BTW- I will post what the EFI works like when it's up and running.

[RogerH]

Great to hear that EFI is catching on! For those of you who are budget minded, Edelbrock is coming out with a Pro-Flo EFI kit for the 440 real soon, with a small block on the way as well. Don't know if a 383 will be in the works soon or not, though. And that will come with a distributor (probably MSD) so the computer can adjust the timing. All for about $2100 for a kit. But, for right now no power adders can be used with it, one of the few downsides to it, no nitrous or blowers.

Roger

[Mopar Man]

How soon is the Edelbrock kit coming out? Do you know how it will compare to Rance's kit?

[dkn1997]

that article about the green brick was cool, and recently, they installed a new kit on that same car with many upgrades. Better (more user friendly) fuel maps, and converts it from batch fired.

I would love to get the edelbrock set/up. I read about it on this post a couple of months ago, but until now, never heard another word about it.

So, anyone out there know when this thing will come out? and will it be adjustable enough for mods like different cams, heads etc....?

[RogerH]

The Edelbrock Pro-Flo EFI wont be available for a while....initial castings should be ariving shortly and then it needs to get tested and other things need to be done, like get MSD to make a distributor for timing control and modify wire harness from SB chevy. It probably wont be until the end of this year that a complete kit will be ready.

Sorry, the system wont be as freely adjustable. Will be just like the other Pro-Flo systems. Although, there has been rumors of a new computer in the works that will probably be more orientated toward racing and be able to adjust mapping with a laptop. Hopefully a confirmation will be available in the near future....keep your fingers crossed....I hope that a new line of EFI components will come along, like a Victor series EFI line.

[Mopar Man]

So which kit do you think will be better, Edelbrock or Rance FI?

[turbododge]

I would put the Rance kit as better, because the will use a better ECU, such as a Speedpro or Accel. There are also a lot of other installers that will do the job besides Rance, and may be closer to you, and cheaper.

[mauve66]

the April 2002 Mopar Action had article on the Rance system that they are putting into the Green Brick using an Accel DFI box for sequential multipoint FI, they also have pictures of some of the other systems that they are developing and one of them is for a six-pak......... oh yeah baby.........

[Marc]

Mine will be sequential multi-port with the DFI.
I'm putting in the wideband o2 sensors and every sensor that makes sense, from a drivability standpoint.
I think it's the BASIC system you start with that will determine just how far you can go, tunability wise?

[RogerH]

What system is better????

All depends on your application and desire for the amount of tunability. A Edelbrock Pro-Flo will probably take the least amount of tuning time, but has the least amount of user tunability. More advanced systems, like what Rance and others use will give you more flexibility, tunability, and more room to add power adders.

The Edelbrock will be along the lines of a bolt-on EFI kit, and more for someone who will not add nitrous or forced induction. Although, I am hoping that a few changes will be made, and Edelbrock will be able to offer similar systems to Holley and the others. Also, the Edelbrock system has a Pro-Flo specific manifold, with injectors targeted to the intake valve.

Basicly, it all comes down to the end users requirements.

Roger

[turbododge]

I have heard several different theories on having the injector spraying towards the valve. The most common theory is that you should only do it only on a sequential injection system, with very careful spray timing, as you do not want to spray on a hot, closed valve, or into the reversion flow. With a batch fire, most people recommend spraying straight into the runner. I don't know if anyone has done any side by side testing to prove anything, however.

[RogerH]

We have done some testing on targeting of the injectors. Dyno tests have shown about a 5 horsepower increase on about a 400 hp engine between a targeted and nontargeted injector.

Having the gas hit the back of a hot intake valve is a good thing, the heat will cause the gas to vaporize. I have seen prototype direction injection where they target the injector to the exhaust valve, for the same effect, to vaporize the fuel.

[turbododge]

Roger: Did any of your testing get done on batch fire? I know most everything now is sequential from the factory, so I would assume you were spraying on the valve just as it opened? Besides targeting, did you also test the timing of the spray in relation to valve action? A lot of questions, but I find this stuff very interesting!

[RogerH]

That's my extent of knowledge on that subject. I can ask around here and find out more for you. The testing was probably done with our computer system, which is a cross between a batch and sequential. It fires two injectors at a time, instead of four, in a V8 application.

I will see what information I can dig up on injector timing.

[dkn1997]

will the edelbrock system be batch fired, or sequential? also, is it meant more for driveability than speed?

[RogerH]

The Edelbrock system is not really a batch or sequential. There are four injector drivers, one driver per two fuel injectors. On a V8 engine, technically, a batch system will fire 4 fuel injectors at a time, where sequential is a single injector. The manual for the Pro-Flo says its a sequential system, but I have a feeling that's for a 4 cylinder engine. So its a little of both.

Since the 440 Pro-Flo is a RPM type manifold, but a single plane, it is meant for both street rodding and where you want speed. I would not reccommend it for race applications.

I think the system will be capable of about 475 or more horsepower. We'll see what it can do on the dyno!

I am hoping that soon we can expand beyond the Pro-Flo series and add a more advanced computer system. Although, going through internet boards, I see a lot of people seeking help with Holley systems and almost nothing for Edelbrock systems. There are a good number of both systems out there, so I guess as far as a more simple bolt-on type EFI, the Pro-Flo is a fairly good system. I think people also like having the hand-held modual in the car, it give the driver a lot of info that other people would need a laptop hooked up in the car.

Roger

[Mopar Man]

So has anybody installed the Rance FI system? If so, how hard is it to install and was it worth it?