Mopar ECU Ignition Box Dyno Shootout

[rumblefish360]

IMO....at RPMs in excess of 3000, MSD (Multiple Spark Discharge) boxes simply do not have enough time to generate more than one spark per cylinder, although, the spark generated can be of a higher voltage depending on the coil's design and its turns ratio (primary to secondary or voltage applied to the primary winding resulting in the secondary voltage produced). One could observe the high voltage spark waveform using a storage oscilloscope, to watch the shape (amplitude and voltage) and number of pulses (time base) that occurs as RPM's increase. And then compare the control box's ability to work as intended or desired..... Just a thought....
BOB RENTON

Bang on there RJ.

WOW.....the "blue box went past 7000 & the MSD well past 8000 RPM"....@ well past 8000 RPM, one eould think valve float and maybe rod stretch would cause a catastrophic failure long b4 the ignition system gave up...but not knowing the specifics of the engine or test conditions....one can only speculate. Just my opinion of course.
BOB RENTON

Valve float control is the valve springs job to what ever rpm it’s intended for and set up at.
Con-rod stretch (amount) is a quality & type of material issue.

Dont get me wrong as even though my car was no faster with the MSD 6AL box I like that ign better the my MP orange box. It does start faster and seems to run cleaner and keeps the plugs much cleaner all year. As said the MSD is only multi-spark up to about 3000 rpm but it does still fire a capacitor of higher volts then normal ign after 3000 rpm. Ron

That’s one thing I liked about the MSD. Easier starts with longer lasting cleaner plugs. The whole ignition system is a little pricey vs a MP set up. The extended period between spark plug changes is nice but not worth the cost which would never be recouped. (LMAO!) Though the changing of plugs is easy, it can be annoying.

The orange box tends to test with some to a good bit of retard at higher rpm’s. I do not remember the figures off hand.

 

[66Satellite47]

WOW.....the "blue box went past 7000 & the MSD well past 8000 RPM"....@ well past 8000 RPM, one eould think valve float and maybe rretch would cause a catastrophic failure long b4 the ignition system gave up...but not knowing the specifics of the engine or test conditions....one can only speculate. Just my opinion of course.
BOB RENTON

Bob, as I said the MSD 404BC was still firing at 8400 RPM when the valvetrain failed. Several bent pushrods. couple broken valve springs, turned out a mushroom lifter had also broken the wide part off and by the next race had flattened the lobe. I didn't notice the broken lifter, just replaced the pushrods and springs. It was a 400/452 low deck, in my Arrow, a fast 8 race, big 60 foot long wheel stand 9.30-9.40 car. Not sure why I didn't shift, expect I was waiting to come down from the wheel stand. I was up harder on the footbrake than normal since it was a fast 8 pro lite race.
The Blue box also would go well past 7000 RPM.

 

[66Satellite47]

BTW, back in the day I never put anything on a dyno, just at the dragstrip. Lots of guys bragged about dyno numbers that didn't prove out at the track.

 

[RJRENTON]

Dont get me wrong as even though my car was no faster with the MSD 6AL box I like that ign better the my MP orange box. It does start faster and seems to run cleaner and keeps the plugs much cleaner all year. As said the MSD is only multi-spark up to about 3000 rpm but it does still fire a capacitor of higher volts then normal ign after 3000 rpm. Ron

The capacitor furnishes an approximate 400 volt pulse, to the coil's primary winding, which, in turn, is due to the coil's primary to secondary winding turns ratio, to generate the high spark voltage. The spark voltage produced is solely dependant on the coil's design. The voltage produced by the capacitor is determined by the control box's (MSD) ability to charge and discharge this capacitor in the time availablity to do so....the higher the RPM's the engine produces, the less time is available to perform the charge/discharge cycle for the capacitor, but results in one spark per cylinder. The higher the spark voltage can insure more complete combustion but is dependent on the ignitability (mixture ratio) of fuel charge.
BOB RENTON

 

[383man]

The capacitor furnishes an approximate 400 volt pulse, to the coil's primary winding, which, in turn, is due to the coil's primary to secondary winding turns ratio, to generate the high spark voltage. The spark voltage produced is solely dependant on the coil's design. The voltage produced by the capacitor is determined by the control box's (MSD) ability to charge and discharge this capacitor in the time availablity to do so....the higher the RPM's the engine produces, the less time is available to perform the charge/discharge cycle for the capacitor, but results in one spark per cylinder. The higher the spark voltage can insure more complete combustion but is dependent on the ignitability (mixture ratio) of fuel charge.
BOB RENTON

I agree and thats why I use the MSD coil with there setup. Not like normal ign where the coil primary saturates to build up the magnetic field everytime the box grounds the coil primary circuit. Then the box stops that primary flow and the primary winding collaspes and induces the spark in the secondry winding. But the MSD capacitor builds up and when it see's the pickup signal fires the 300 to 500 volts into the primary and collaspes fast enough to fire the coil a few times up to about 3000 rpm. I also agree its just not enough time to fire the coil more then once at higher speed but with MSD its firing a capacitor that shoots the 300 to 500 volts into the coil primary and then collaspes fast enough to fire the plug. It will put out more then normal ign that saturates the coil while the primary is grounded. Ron

 

[383man]

That’s one thing I liked about the MSD. Easier starts with longer lasting cleaner plugs. The whole ignition system is a little pricey vs a MP set up. The extended period between spark plug changes is nice but not worth the cost which would never be recouped. (LMAO!) Though the changing of plugs is easy, it can be annoying.

The orange box tends to test with some to a good bit of retard at higher rpm’s. I do not remember the figures off hand.[/QUOTE]

The funny thing is many times a small amount of ign timing retard at high rpm in high gear can give a tad more power. But I dont think MP made the orange box to work like that but mine did work good for many years. Ron

 

[RJRENTON]

I agree and thats why I use the MSD coil with there setup. Not like normal ign where the coil primary saturates to build up the magnetic field everytime the box grounds the coil primary circuit. Then the box stops that primary flow and the primary winding collaspes and induces the spark in the secondry winding. But the MSD capacitor builds up and when it see's the pickup signal fires the 300 to 500 volts into the primary and collaspes fast enough to fire the coil a few times up to about 3000 rpm. I also agree its just not enough time to fire the coil more then once at higher speed but with MSD its firing a capacitor that shoots the 300 to 500 volts into the coil primary and then collaspes fast enough to fire the plug. It will put out more then normal ign that saturates the coil while the primary is grounded. Ron

The RATE at which the coil's magnetic field initially builds up and then consequently collapses to generate the induced secondary voltage is a function of the coil's inductive reactance. The secondary voltage is a function of the turns ratio, which "amplifies" or increases the primary winding voltage applied. The greater the turns ratio, the higher the secondary voltage will be produced, regardless of what generated the primary winding supply, albeit 12 volts or 400 volts. The MSD box, at less than 3000 RPM, applies a pulsed 400 nominal volts, controlled by an internal SCR (electronic switch), and the internal circuitry that looks at the rate of decay of the coil's primary voltage (and current) or the inductive reactance of the circuit, to detetmine when and if, a second (or third or 4th pulse) could be realized and executed, in the time availablity to do so (RPM). Basically, it's a Di/Dt and Dv/Dt function...(a derritive of the current and voltage relationship) with respect to time to realize how much energy is transferred. The term Capacitor Discharge (CD) is somewhat a mis-nomer, in that the circuit is still an inductive reactance system (the coil), with the energy furnished by a capacitor rather than a simple switched voltage supply (points). Just additional information to ponder.......
BOB RENTON

 

[Robbins]

Sweet

 

[SlinktRR]

Is the orange box they tested the one in the proform kit? I have a grey box (junk in the trunk for emergency), a chrome box (I run this) now I just need to have an orange box to complete the set. I haven't purchased an orange since I had one leave me stranded. I also see jegs has an orange box for 30 dollars. Who knows how good any of these are. Chrome has always been good for me up to 6500rpm but no longer available.

 

[66Satellite47]

The color of the box is not important, the electronics inside is. The aftermarket boxes, possibly made in China, are not the same as the Mopar ECU's from the '70' & 80's. Wonder where the Proform orange box is made?

 

[rumblefish360]

Is the orange box they tested the one in the proform kit? I have a grey box (junk in the trunk for emergency), a chrome box (I run this) now I just need to have an orange box to complete the set. I haven't purchased an orange since I had one leave me stranded. I also see jegs has an orange box for 30 dollars. Who knows how good any of these are. Chrome has always been good for me up to 6500rpm but no longer available.

The orange box tested is NOT the MoPar ignition box.
IIRC, Proform is made over seas. 100% sure or this O am not.

Chrome boxes can be found on e-bay or here (or FABO) through member Halifaxhops. As seen in the video, you can also go to 4secondsflat.com (FBO) and talk to them for there own box which I owned before and will tell you it’ll perform as well if not better than the Chrysler Chrome box. I used there box and coil. Thumbs up.
They also have a better set up if you want to move away from the OE style set up.

 

[F4R/T]

I wondered about that! I would try an old USA orange box and compare for giggles..

 

[66Satellite47]

Again in my opinion the Mopar orange box was not that good for drag racing, I'm sure it was good for a HP street car. My Blue box & coil were a drag race deal, not at all recommended for the street. The MSD 404BC was a step up from the Blue box. It all depends on what your application is.. Not sure what the current aftermarket ECU's do.
I bet my 404BC would out perform a 6AL.

 

[383man]

The RATE at which the coil's magnetic field initially builds up and then consequently collapses to generate the induced secondary voltage is a function of the coil's inductive reactance. The secondary voltage is a function of the turns ratio, which "amplifies" or increases the primary winding voltage applied. The greater the turns ratio, the higher the secondary voltage will be produced, regardless of what generated the primary winding supply, albeit 12 volts or 400 volts. The MSD box, at less than 3000 RPM, applies a pulsed 400 nominal volts, controlled by an internal SCR (electronic switch), and the internal circuitry that looks at the rate of decay of the coil's primary voltage (and current) or the inductive reactance of the circuit, to detetmine when and if, a second (or third or 4th pulse) could be realized and executed, in the time availablity to do so (RPM). Basically, it's a Di/Dt and Dv/Dt function...(a derritive of the current and voltage relationship) with respect to time to realize how much energy is transferred. The term Capacitor Discharge (CD) is somewhat a mis-nomer, in that the circuit is still an inductive reactance system (the coil), with the energy furnished by a capacitor rather than a simple switched voltage supply (points). Just additional information to ponder.......
BOB RENTON

I do agree with you about these ignitions. One thing I know is the ohm is also a good bit different in some MSD coils. When I worked as a tech which I started in 1974 I made a gradual rule of thumb when doing a quick test on coils as most were somewhere near about 1 ohm in the primary and about 10,000 in the secondary. I just used it if I was checking a coil real quick on a car without looking up the specs but now I know some MSD coils are around 3,000 ohms in the secondary side so I make sure I look up the specs of the coils I check as the turns make a difference in the ohm readings alot. As you stated usually more turns means more voltage generated in the secondary but more turns at the same size wire is more ohms so they may use slightly larger wire also and again to large wire and less ohms may make coil hotter which of course applies to the outer primary also. I am no expert on MSD coils but I have learned enough over the years as I always wanted to know just how what ever system I had to work on works. I figure then if I know how it works I can diagnose it. Thanks for your post. Ron

 

[rumblefish360]

And knowing is half the battle.

 

[SlinktRR]

GI Joe!

 

[SlinktRR]

I installed a rev n nator today in place of the chrome. Runs good so far with a blaster 2, firecore dist and 499 stroker. Haven't detected the 3-5 horsepower yet but the rev limiter is a cool feature.

 

[furyus]

Is the orange box they tested the one in the proform kit? I have a grey box (junk in the trunk for emergency), a chrome box (I run this) now I just need to have an orange box to complete the set. I haven't purchased an orange since I had one leave me stranded. I also see jegs has an orange box for 30 dollars. Who knows how good any of these are. Chrome has always been good for me up to 6500rpm but no longer available.

 

[66Satellite47]

Back in the day, it was very important to have the proper coil to match the ECU or the MSD. My Blue box needed a different coil than the other ECU's and my MSD 404BC used a special coil too. Both needed the correct turns ratio and response time to give the ignition the total response. Also the Blue box & coil were not for street use. The MSD 404BC and the Mallory CD coil were also recommended as a drag strip combo. The later Mopar ECU's & coils had different designs that made them streetable, same for the MSD's. As with all things, the proper combination is key.

 

[Bee1971]

Yes

The Chinese dont care about combinations

We had Direct Connection and Mopar Performance providing that information

Now its all trial and error and money , then add the durabilty factor on all this junk made today

More of a crap shoot