[T77911S]

i dont know if the multi spark function is a gimmick or it actually has "some" advantages, maybe not all the time but just perhaps, there may be times when it helps.
but i do know everthing else you have said negative about MSD is highly skewed and biased and to say these things about a product that you have no other proof of being a bad product on a board for people that dont know any better is not right and personally i think is bad for your buisiness. i know i tend to shy away from someone that tells me how much another product sucks.

Originally Posted by Lorenfb

A technical evaluation of the MSD capacitive discharge ignition (CDI) system
indicates a number of shortcomings compared to the original Bosch CDI used
by Porsche in the 911 up until the 911 3.2 with the inductive discharge ignition
system.

The MSD CDI's key marketing feature is its multiple sparks which produce
a maximum of nine sparks at about 100 RPMs while cranking to a single spark once
the RPMs reach 3000 RPMs. The time between sparks is about 1.5 milliseconds

acording to your oscope, it shows 200us between sparks, not 1.5ms, or am i interpreting your scope wrong? have you ever thought that maybe multiple sparks give more chances for a plug to fire vs ONE time with the bosch.

which contributes basically nothing to enhance the combustion process as the
significant part of the fuel charge burn time is less than 1.5 milliseconds.

again, a false statement. do you have any proof of this other than misquted pulse spacing? have you tested the MSD to see if this is true?

Additionally, the spark pulse width of 40 microseconds is half of the Bosch CDI

is there proof that the pulse width really matters? i would think the energy supplied by the units itself is more imoprtant, which i would think the bosch win there

which results in less time to fully facilitate complete fuel charge ignition resulting in
potential mis-fires and greater emissions.

The MSD CDI produces a primary pulse voltage over 450 volts compared to the
Bosch CDI's pulse of about 300-350 at typical engine RPMs,

the MSD WINS here in my opinion. 450v which turns into 450,000 volts over 350,000 volts?

thereby stressing the
ignition system wiring, the coil, and the rotor & cap.This further shortens the life of
these components beyond what the multiple spark effect does,

yes, rotors can be a problem. but the rest of the ignition system, NO. not to mention if you use the MSD coil, that takes that completely out of the equation.
again, the MSD replaces all that old brittle wiring, thus eliminating problems.


i.e. at idle the MSD
is producing four sparks, versus one for the Bosch CDI, resulting in significantly
shortened ignition component life.

To implement the multiple spark system, the MSD CDI requires a significant number
of components compared to the Bosch CDI and thereby significantly reduces its
reliability compared to the Bosch CDI, as the reliability of any system is reduced
as its component number is increased.

really? this is your argument? there are what, 4 chips, some transistors and a bunch of surface mounted caps and resistors? what about the age of the components in the bosch and the exposure to heat? that is a negative, no,?

Additionally, the MSD CDI requires additional wiring for power because of the its high current requirement to produce the multiple sparks,

this is a positive. the MSD gets its power from a direct wire to power, in my case the batter cable on the starter, vs going through a switch and running the length of the car on an old thin wire. this can create resistance and reduce current to the bosch unit causing porblems that most could not figure out.

whereas the Bosch CDI has a simple power and ground.

again, the MSD has a DIRECT ground to the coil, eliminating possible ground problems from the engine to the tranny

Since most all the torque is developed at RPMs greater than 3000 RPMs and the MSD
CDI produces just one spark there, it operates in a mode the same as the Bosch CDI and thus has no real advantage in performance, even if the multiple spark had a benefit.

most are not looking for more performance, perhaps just a cheaper option to the bosch, like myself.

So given the insignificant benefit of the multiple spark effect with the
additional complexity and number of components,

again with the number of components? if less is better, buy a permantune. the last one i opened, 10 or 15 years ago, had about 5-10 parts in it

and a shorter initial spark, a less desirable ignition system results with the MSD CDI than with the Bosch CDI ignition.

very simple and reliable Bosch CDI.

simple? there is not much difference between the bosch, the MSD and even the radar system i maintain, or use to, other than the MSD has added circuitry for the rev limiter. so you really cant compare the number of components because the MSD does more than the bosch

dont get me wrong, i am a VERY big fan of the bosch. if you had valid proof that the bosch was that much better, it would be different. for that matter, no one could even figure out which is more reliable because there are people that have had good luck with both and others have had bad luck with both.
if the bosch was perfect, you would not be repairing any bosch units and bosch CDs having been going bad since they have been putting them in cars. its not like they are just now starting to go bad.