Randy, I think the PN for the wiring harness is #8874.

 

This is extremely interesting information, as I have a 96' F-150 300CI I-6 on the way

 

sounds interesting,but when you have a cylinder under pressure with fuel vapor and air in it, and a spark ignites it, I would expect that everything that can burn explodes...multispark keeps on sparking after the fact? what is that going to do to help? And if this was such a benefit for MPG and power, wouldn't the OEM's make this as part of the stock system to appease the EPA on fuel economy? or at least to differentiate themselves?

 

Without getting too engineery, There is an optimal spark temperature, at an optimum time, to ignite the combustion chamber. If the first spark is hotter, it should definately help the burn process (flame kernel) start better. I couldget into the flame front and all that, but I only have a basic understanding of it.

I would agree in theory, that once the fuel in the immediate vicinity of the plug is burned, more sparks will not help any more. It does sound a little gimmicky, although cool too. The extra power of the spark would seem to make the biggest differance in setting off the combustion (flamefront) as opposed to multi-spark. It does say it switches to one spark above 3000 rpm
Tech PDF Link I put a pic of MSD's ford wiring diagram and a couple other bits in my gallery. It looks easy to hook up.

I would think when a better ignition control would help the most at higher rpm, under heavy load. That's when the factory ignition system starts to bog down. Based off of the pinging at heavy load (with a trailer) on 87 octane, that is corrected by 89 octane. I guess, it's harder to generate spark at higher temps, and higher rpm, and higher load?

The idea that it gets better mileage from the same engine and settings, says the burn pattern isn't very good with the factory ignition.

I would be interested to know if you guys with this system feel like you run better at 87 octane (less potential for pinging) than before. In addition to any other milage improvements.

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Ok, I spent a little time reading. http://www.rmlautomotive.com/ignition.html That's why it cuts out multi-spark over 3000 rpm.

It sounds like, based on all that, that if you don't let your engine get much over 3000 rpm, you won't be taking full advantage of a capacitive discharge ignition system. What are your average rpms cruisning Hack?

I also saw crane has a similar system, has anyone used that?


Ok, so maybe I dead get a little geeky.

 

I guess I don't know for certain... 3000 rpm is a little under my "taking it easy" shift point, and is probably around my cruise speed, depending on the speed limit. Not real sure, though; I've not honestly paid that much attention. I do know that before I put in the system, once the rpm's went above 3000, the engine seemed to struggle as it climbed above that; now it doesn't hesitate at all (struggle might be a bit of a stretch; it just didn't jump like it does now).

As for the gas octane... I only use 87 octane, and the truck never pings. It certainly runs great with 87; I have not tried this with 89.

Randy

 

Sorry guys, I moved this to the wrong forum. Another moderator will move it to the correct one shortly.

 

Should this be in i6 since the system works on 4-6-and 8 cylinders?

 

hrmm......

 

Moved to approrpriate forum...

 

I'm just posting here so I can refer to this thread later.

 

As for the O2 sensors... I replaced them because of a fouled O2 sensor triggering a "Check Engine" light.

I'll bet most of your preformance upgrade happened when you replace those faulty O2 sensors.

 

Yep. With all the upgrades done at the same time it would be hard to tell which is responsible.

My experience with MSD was mixed. It helped a little at first then I started having problems with idling and stalling. I'd disconnect it and all would be back to normal.

A few months after upgrading to MAF, which required a new computer, I reinstalled the MSD. It works fine now. The jury's still out as to any gains in HP or mileage but it does run a little smoother. The real gain, for sure, was from the MAF conversion.

 

A few comments, the fuel air mixture is supposed to burn not explode. Spark knock occurs when the mixture is exploding. Octane slows down the rate of burn, preventing exploding. A gasoline engine is most efficient when the air fuel mixture burns continuosly and evenly as the piston is forced down from TDC to near the bottom of the stroke. That is for the best transfer of energy to the crankshaft.

The combustion chamber is turbulant and the burning mixture moves around almost like currents. In a properly maintained and tuned engine most of the fuel will burn anyway without multiple spark ignition. The theory behind multiple spark discharge is that it can keep igniting the mixture as it moves around the combustion chamber and for small increments of time it can ignite fuel that has not burned yet. I agree MSD is proven high technology and racers use it, but most people are not going to see any significant increase in fuel efficiency or horsepower with this upgrade. If it could improve gas mileage significantly it would be installed on every single vehicle built today.

As someone already stated in the post, if your gas mileage went from 12 mpg to 22 mpg with this upgrade, then you were long overdue for your tune up, and new OEM parts would have done the same thing.

 

Extra voltage and spark can never burn up spark plugs. The coil provides enough voltage to jump the gap of the plug. It does not fire any hotter then necessary to jump that gap. The adding of "high voltage" coils allow the plug to fire under higher compression, lean fuel mixtures, etc. The adding of double platinum plugs doesn't add anything but expensive plugs. HIgher voltage coils sometimes help with older engines because they have more voltage available. If it takes 23,000 volts to fire the engine, then the stock 20,000 volt coil won't, but a 30,000 volt coil will. Most of the gain is probably coming from the addition of the system overall and certainly from the three O2 sensors reading correctly for the computer. Great system.

 

I purchased a Blaster coil when I bought the MSD and left it on after I pulled the MSD. The coil alone seemed to make a seat of the pants difference to me.