FI Ignition

I am using the Holley FI system on my MG. Different then what you are working with no doubt. The system had sample software maps but nothing which mapped what I was using/doing. I picked one with similar compression ratios and lift even though the engine was totally different.

If you have the software on a pc it's not that hard. The fuel maps, the ignition maps are all in front of you and it has a box indicating where it is when it's running.

Gary

Ahh yes, EFI fun. I have a multi-port 427 winsor in my pantera. Was it easy, no! Would I do it again, yes!

A carb is great for simple plug and play where as an EFI system takes time to tune. Once you have some experience and understand how the tuning works it becomes easier and more fun. Nothing like plugging in a laptop and changing advance, fuel deliver and the idle speed at the touch of a key from inside your car.

Expect to spend some time on a chassis dyno. A dyno session makes tuning the EFI much faster. Even better if the dyno operator knows EFI systems and tuning. Hint - find someone who know EFI systems and has a dyno. You can tune on the street but it takes much more time and trial and error to get it right.

Most ECU's come with various canned fuel and spark maps. These are a good starting point but they all will need adjustment. Gear ratios, cams, intakes all change the fuel map. Best to find a map that closely matched your engine and go from there.

I got a hint from Jim Murch, I finally listened and I am now sold. Get a wide-band O2 sensor. Most kits use a narrow band, but the wide band provides much better readings for fine tuning. Some ECU's come or have options for using a wide band sensor. If you can afford it, get it. They are not cheap but they read much faster and report true air fuel mixture so it is easy to tell if your are rich or lean.

Having the spark map controlled by the ECU is one more benefit of a EFI system. People like Mallory or MSD have distributors that can be controlled by the ECU.

Many people have used a standard Ford OEM ECU. Sticking with factory Ford parts and ECU's have the advantage of being solid, well tested and easily available if replacement is needed.

Closing remark, if you do not like eletronics and dealing with computers do not do an EFI system. EFI systems requires a propeller head (aka geek squad)but it can be fun. Do your homework, check out various ECU models (Motec, Holley, Ford etc). Some are easier to work on then others.

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Dan Jones mentioned that there is software that blends MAP and throttle position.The reason being that neither system was optimum for either economy or performance alone.

There are probably others but Dan was referring to the Electromotive ECU (we bought ours at the same time). It has a blend mode that allows you to assign authority to the various sensors inputs (i.e. MAP and TPS for example). In IR EFI, this has benefit because manifold vacuum goes to ambient pressure very early in throttle rotation. This makes the MAP only useful for idle/low speed signal and atmospheric pressure correction. Some people people favor teeing a line from each cylinder to small plenums and vary the orifice and plenum size to tune. It's difficult to make such a signal correlate to anything meaningful. I think the blended mode is a better solution.

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If that is so, with an IRFI system, what would be the best to consider for ignition? Would a mechanical advance distributor now be obsolete?

You could still run any distributor you want independent of the EFI but as ROVERLTD mentioned, most of the modern electronic ignitions can receive siganl from ECU. If you spent the bucks on an ECU why not buy a distributor that allows you infinite control of your ignition MAPS. And, yes, you can prescribe any ignition MAP you desire and also have modified MAPS that are driven off input from coolant (and other) sensors for good cold and hot starting. All at your finger tips through your laptop. It's great. I bought the EM direct fire coil packs and went crank triggered. All I have in the distributor hole is an MSD plug to drive the oil pump and a cam sync sensor on top so I can go full sequential injection.

Kelly

I don't mind some tuning. I don't want to spend the rest of my life trying to get it to run.

I haven't selected the ECU yet. That's why I am probing you guys. It sounds like the Electromotive would be better then the Haltec.

The point of the infinite ignition tuning is probably much over rated.

Initial, rate of advance and possibly high rpm retard will most likely be what's needed.

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Originally posted by PanteraDoug:
I don't mind some tuning. I don't want to spend the rest of my life trying to get it to run.

IMO, you'll have some learning curve, but after you become familiar, it will much easier for you to maintain fine tune.

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I haven't selected the ECU yet. That's why I am probing you guys. It sounds like the Electromotive would be better then the Haltec.

The Haltecs are a good value. I think you can get the E6 for under $1000. No blend mode the last I checked. The knock on them was very poor after sales support. The Electromotive Tec3r will run you $1800-$2000. Go to

http://www.Kinsler.com

and look at the tech catalogue. They have a comparison of ECUs in there that's a pretty good summary.

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The point of the infinite ignition tuning is probably much over rated.

Tell ya what, in Panteras especially, point click and drag on the key pad beats the sh!t out of reaching for your distributor with a timing light in your hand. It also beats recurving your distributor, jacking with springs, weights in the mechanical advance, vacuum advance, and all the other temp/vacuum widgets that used to be thrown at cold start, emmissions, and fuel economy. Also, the knock sensors really work. They back off your timing when they accoustically sense detonation. You can definitely set your timing much more aggressively during your tuning sessions without the fear of detonation from too much advance or variations in engine temp, bad gas, or hard hot starting, etc.

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Initial, rate of advance and possibly high rpm retard will most likely be what's needed.

Full and active control of your fuel and ignition MAPs is a great tool to have when you're trying to get good street manners from high states of tune. Have a go Doug. You'll like it.

Kelly

Now days, almost any ECU will work well. Except some of those overly simple ones like Megasquirt. I have seen the Holley ECU run engines just as well as the multi thousand dollar units. Most High dollar units just give you more seldom used features, not better running and driving on a street car. The holley ECU can be bought for $600.

For your ignition, use what you want. Systems like Electromotive come with direct fire ignitions. Other systems can use almost any distributor and ignition system. I recommend mallory or Stock distributor with Crane module.

I use Electromotive on one car, and My own home designed EFI on another car. I have also tuned Holleys, Haltecs, Accel, etc. They are all about the same.

All exceptional information. CD, don't you find the blend feature in the Electromotive valuable of haven't you tried it?

It would seem that it is very important. At some point I have to decide if it is going to be single or dual injectors per port and the size of them.
I think that because of that the blend feature is going to valuable.

At $1,000 per shot for an ECU, I can't be guessing at this.

This isn't a race car, a killer street car that can be docile in traffic and run with the race cars. That's one of the reasons I'm going to the IR FI.

The Australian IDA fuel body, made for the RX7 Mazdas basically, offers the option of two injectors in the same body.

It seems that the Wankle likes staged fuel.
I got my doubts that it is worthwhile for me.
This is your typical 7,500 rpm 357 cleveland and doesn't require that kind of flex.

Of course there is this new XE block laying around and those nice steel stroker cranks, and ...

fyi - good forum

http://www.efi101.com/

One of the benefits of using the ECU to manage the spark is the ability to tune out mid-range advance. One of the hardest things to work around is called "low speed high load bping". Think of this as lugging the engine. The load is high but you are in too low of a gear. If an engine will ping it will be in this range. With the ECU you can specifically retard the timing in the section of the MAP/RPM map to back out the ping.

With a mechanical advance things are linear more RPM more Advance. With a ECU the advance can be increased or decreased at any RPM band.

Do any of the ECU systems you are looking at have a knock-sensor to automatically retard the timing to avoid pinging.

This has the advantage of being able to take advantage of higher octane fuel when it is available, and automatically retarding it to avoid 'pinging' when needed.

This means that you can just fill up with higher octane fuel whenever you want some more power, the Engine Management will adjust the spark timing automatically.

Some tests have been in the UK done on high-performance Japanese cars and found that filling up with higher octane fuel (which is about 3 octane points higher than the usual stuff) gets you between 20 and 60bhp.

Good point. I would say"theoretically" they will help.
The engine needs to be able to take advatage of higher octane.
Clevelands are very touchy on the subject and the pump gas available known as premium isn't high enough, octane wise, in my experience, to help the situation.
The 289 is just the opposite. That thing will run on Buttery Nipples and not ping.
I think it has to do with the shape of the...combustion champers. Whew, almost slipped again.

You cant use a knock sensor that way. They are not reliable enough. They often will get triggered on noise from valves or pistons and retard timing when there is no knock. Many experts recommend not using Knock retard or setting its sensativity low to only retard for extreeme knock.

Kind of follows with the idea that while you can depend on the wide band O2 sensor controling your fuel mixture, you shouldnt. Fuel ratio should be within 5% before the O2 sensor is turned on.

The ECU's I have seen do have provisions for a knock sensor, but as Crazy Dave points out, a hot rodded motor will cause the sensor to false trigger.