Looking at a 6AL. Who's using it?
02-06-2016, 11:05 PM
#21
Team Owner
Pro Mechanic
The benefit of the thing is rev control. Other than that, it's simply a grounding device for what ever ignition coil you're using, just like a stock ignition module is...and similar, in function, to what points are. An "on/off relay", if you will..
Last edited by Tom400CFI; 02-06-2016 at 11:11 PM.
02-06-2016, 11:41 PM
#22
https://www.msdignition.com/uploaded...structions.pdf
02-07-2016, 12:06 AM
#23
Team Owner
Pro Mechanic
That first paragraph is either:
1. dead assed wrong/lying
or
2. VERY cleverly worded so it's not legally false advertising.
I can't determine which is going on there, but it is functionally wrong.
With a Capacitive Discharge Ignition, the Capacitor IS the coil....not the ignition module (which is what the MSD box is -an ignition module).
Anyone of us here, with a modicum of ignition system knowledge can realize that wording by MSD is bogus by this statement alone:
With the CD design, the voltage sent to the coil is always at full power even at high rpm.
Well....the "voltage sent to the coil" in ANY car is "always at full power even at high rpm." ....it's battery voltage from the ignition circuit!
Here is some READING.
From the first paragraph;
"The capacitive-discharge ignition uses capacitor discharge current output to fire the spark plugs."
What "fires the spark plugs"? The coil.
What fires the spark plugs in your car w/an MSD box? The MSD box? No. Your stock (or stock replacement) Inductive Discharge Ignition coil is what fires the plugs.
SO...How can a stock coil being triggered by an MSD box be a "CDI ignition" when the coil is an inductive coil?
1. dead assed wrong/lying
or
2. VERY cleverly worded so it's not legally false advertising.
I can't determine which is going on there, but it is functionally wrong.
With a Capacitive Discharge Ignition, the Capacitor IS the coil....not the ignition module (which is what the MSD box is -an ignition module).
Anyone of us here, with a modicum of ignition system knowledge can realize that wording by MSD is bogus by this statement alone:
With the CD design, the voltage sent to the coil is always at full power even at high rpm.
Well....the "voltage sent to the coil" in ANY car is "always at full power even at high rpm." ....it's battery voltage from the ignition circuit!
Here is some READING.
From the first paragraph;
"The capacitive-discharge ignition uses capacitor discharge current output to fire the spark plugs."
What "fires the spark plugs"? The coil.
What fires the spark plugs in your car w/an MSD box? The MSD box? No. Your stock (or stock replacement) Inductive Discharge Ignition coil is what fires the plugs.
SO...How can a stock coil being triggered by an MSD box be a "CDI ignition" when the coil is an inductive coil?
Last edited by Tom400CFI; 02-07-2016 at 12:28 AM.
02-07-2016, 01:47 AM
#24
That first paragraph is either:
1. dead assed wrong/lying
or
2. VERY cleverly worded so it's not legally false advertising.
I can't determine which is going on there, but it is functionally wrong.
With a Capacitive Discharge Ignition, the Capacitor IS the coil....not the ignition module (which is what the MSD box is -an ignition module).
Anyone of us here, with a modicum of ignition system knowledge can realize that wording by MSD is bogus by this statement alone:
With the CD design, the voltage sent to the coil is always at full power even at high rpm.
Well....the "voltage sent to the coil" in ANY car is "always at full power even at high rpm." ....it's battery voltage from the ignition circuit!
Here is some READING.
From the first paragraph;
"The capacitive-discharge ignition uses capacitor discharge current output to fire the spark plugs."
What "fires the spark plugs"? The coil.
What fires the spark plugs in your car w/an MSD box? The MSD box? No. Your stock (or stock replacement) Inductive Discharge Ignition coil is what fires the plugs.
SO...How can a stock coil being triggered by an MSD box be a "CDI ignition" when the coil is an inductive coil?
1. dead assed wrong/lying
or
2. VERY cleverly worded so it's not legally false advertising.
I can't determine which is going on there, but it is functionally wrong.
With a Capacitive Discharge Ignition, the Capacitor IS the coil....not the ignition module (which is what the MSD box is -an ignition module).
Anyone of us here, with a modicum of ignition system knowledge can realize that wording by MSD is bogus by this statement alone:
With the CD design, the voltage sent to the coil is always at full power even at high rpm.
Well....the "voltage sent to the coil" in ANY car is "always at full power even at high rpm." ....it's battery voltage from the ignition circuit!
Here is some READING.
From the first paragraph;
"The capacitive-discharge ignition uses capacitor discharge current output to fire the spark plugs."
What "fires the spark plugs"? The coil.
What fires the spark plugs in your car w/an MSD box? The MSD box? No. Your stock (or stock replacement) Inductive Discharge Ignition coil is what fires the plugs.
SO...How can a stock coil being triggered by an MSD box be a "CDI ignition" when the coil is an inductive coil?
https://www.msdignition.com/uploaded...tb_top_ten.pdf
"1. What’s the differences between a Capacitive Discharge (CD) ignition
like an MSD and my stock ignition system?
The biggest difference is that the majority of stock ignitions
are inductive ignitions. Inductive ignition systems are used
due to their simplicity and inexpensive production. For stock
applications these ignitions are adequate, but when it comes
to gaining performance, factory inductive ignitions fall short.
The primary weak link of a stock ignition is because the coil
serves double duty. The coil must act as a step-up transformer
to create a higher voltage spark, plus it needs to store this
power until the ignition is triggered. As engine rpm increases
there isn’t enough time to completely step-up the voltage
before the ignition is triggered resulting in a weaker spark.
This low voltage spark may not be enough to light the fuel
mixture in the cylinder which will result in a misfire and loss
of power.
A CD ignition, like an MSD 6 Series, is capable of producing
full power sparks throughout the entire rpm range. It draws
its energy directly from the battery where a custom wound
transformer steps it up to over 460 volts. This voltage is then
stored in a capacitor until the ignition is triggered. At this point,
all of the voltage is dumped into the coil where it is transformed
into even more voltage, anywhere from 30,000 - 45,000 volts
depending on the coil, which is sent to the distributor and
finally to the plugs.
The ability to produce high power sparks throughout the
entire rpm range of your engine is why you need a CD ignition. The payoff is complete combustion of the fuel mixture
which results in more power, increased throttle response, a smooth idle, quick starts, improved economy and
reduced plug fouling.
All engines will benefit from a CD ignition but when you’re planning on engine modifications, the need for an MSD
Ignition increases. In particular, if you’re planning these types of engine modifications, you should be installing a CD
ignition:
• Improving air flow into the engine or richening the fuel mixture (rejetting or larger injectors)
• Adding a super/turbocharger or a nitrous oxide system
• Increasing the compression ratio and consistent high rpm operation"
02-07-2016, 02:09 AM
#25
Le Mans Master
Thread Starter
High voltage and high power is for the high compression and high rpm motors, also the power adders.
For mild rpm, compression and power stay w/HEI. It has a nice long spark. Just use a smaller 0.030" gap if going above 5,000rpm. U will want a performance unit also as the stock HEI has some short comings.
For mild rpm, compression and power stay w/HEI. It has a nice long spark. Just use a smaller 0.030" gap if going above 5,000rpm. U will want a performance unit also as the stock HEI has some short comings.
02-07-2016, 11:17 AM
#26
Le Mans Master
Member Since: Oct 2002
Location: Las Vegas - Just stop perpetuating myths please.
Posts: 7,098
Received 373 Likes
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356 Posts
I think the MSD box would be helpful at 11:1 and defiantly above 6,000rpm. Let me say this i expect the MSD box to be a help with that combination but if driven daily u will need more frequent cap/rotor/plug changes.
And the rev limiter makes it worth it by itself i think. My GEN II optispark really doesnt need any help making spark. But not only having rev control but w/2,000rpm "chip" i have a valet control also. To me that may save not only the drive line from abuse during servicing but the whole car from a joy ride crash. To its worth it to me as all the work that goes into my car cannot be replaced.
And the rev limiter makes it worth it by itself i think. My GEN II optispark really doesnt need any help making spark. But not only having rev control but w/2,000rpm "chip" i have a valet control also. To me that may save not only the drive line from abuse during servicing but the whole car from a joy ride crash. To its worth it to me as all the work that goes into my car cannot be replaced.
02-07-2016, 01:37 PM
#27
Team Owner
Pro Mechanic
MSD explains their side of the story further in this article:
https://www.msdignition.com/uploaded...tb_top_ten.pdf
"1. What’s the differences between a Capacitive Discharge (CD) ignition
like an MSD and my stock ignition system?
The biggest difference is that the majority of stock ignitions
are inductive ignitions. Inductive ignition systems are used
due to their simplicity and inexpensive production. For stock
applications these ignitions are adequate, but when it comes
to gaining performance, factory inductive ignitions fall short.
The primary weak link of a stock ignition is because the coil
serves double duty. The coil must act as a step-up transformer
to create a higher voltage spark, plus it needs to store this
power until the ignition is triggered. As engine rpm increases
there isn’t enough time to completely step-up the voltage
before the ignition is triggered resulting in a weaker spark.
This low voltage spark may not be enough to light the fuel
mixture in the cylinder which will result in a misfire and loss
of power.
A CD ignition, like an MSD 6 Series, is capable of producing
full power sparks throughout the entire rpm range. It draws
its energy directly from the battery where a custom wound
transformer steps it up to over 460 volts. This voltage is then
stored in a capacitor until the ignition is triggered. At this point,
all of the voltage is dumped into the coil where it is transformed
into even more voltage, anywhere from 30,000 - 45,000 volts
depending on the coil, which is sent to the distributor and
finally to the plugs.
The ability to produce high power sparks throughout the
entire rpm range of your engine is why you need a CD ignition. The payoff is complete combustion of the fuel mixture
which results in more power, increased throttle response, a smooth idle, quick starts, improved economy and
reduced plug fouling.
All engines will benefit from a CD ignition but when you’re planning on engine modifications, the need for an MSD
Ignition increases. In particular, if you’re planning these types of engine modifications, you should be installing a CD
ignition:
• Improving air flow into the engine or richening the fuel mixture (rejetting or larger injectors)
• Adding a super/turbocharger or a nitrous oxide system
• Increasing the compression ratio and consistent high rpm operation"
https://www.msdignition.com/uploaded...tb_top_ten.pdf
"1. What’s the differences between a Capacitive Discharge (CD) ignition
like an MSD and my stock ignition system?
The biggest difference is that the majority of stock ignitions
are inductive ignitions. Inductive ignition systems are used
due to their simplicity and inexpensive production. For stock
applications these ignitions are adequate, but when it comes
to gaining performance, factory inductive ignitions fall short.
The primary weak link of a stock ignition is because the coil
serves double duty. The coil must act as a step-up transformer
to create a higher voltage spark, plus it needs to store this
power until the ignition is triggered. As engine rpm increases
there isn’t enough time to completely step-up the voltage
before the ignition is triggered resulting in a weaker spark.
This low voltage spark may not be enough to light the fuel
mixture in the cylinder which will result in a misfire and loss
of power.
A CD ignition, like an MSD 6 Series, is capable of producing
full power sparks throughout the entire rpm range. It draws
its energy directly from the battery where a custom wound
transformer steps it up to over 460 volts. This voltage is then
stored in a capacitor until the ignition is triggered. At this point,
all of the voltage is dumped into the coil where it is transformed
into even more voltage, anywhere from 30,000 - 45,000 volts
depending on the coil, which is sent to the distributor and
finally to the plugs.
The ability to produce high power sparks throughout the
entire rpm range of your engine is why you need a CD ignition. The payoff is complete combustion of the fuel mixture
which results in more power, increased throttle response, a smooth idle, quick starts, improved economy and
reduced plug fouling.
All engines will benefit from a CD ignition but when you’re planning on engine modifications, the need for an MSD
Ignition increases. In particular, if you’re planning these types of engine modifications, you should be installing a CD
ignition:
• Improving air flow into the engine or richening the fuel mixture (rejetting or larger injectors)
• Adding a super/turbocharger or a nitrous oxide system
• Increasing the compression ratio and consistent high rpm operation"
02-07-2016, 01:38 PM
#28
Race Director
I've noticed that Nascar cars have a MSD box or two mounted on the transmission tunnel. A good number of NHRA cars use the thing too (including mine, haha).
02-07-2016, 02:03 PM
#29
Team Owner
And if I were running NASCAR or NHRA, it might be a consideration. Question is whether it helps out a street car significantly or not.
02-07-2016, 02:05 PM
#30
02-07-2016, 02:10 PM
#31
Team Owner
02-07-2016, 02:14 PM
#32
Team Owner
Pro Mechanic
Exactly. But in the propaganda that you posted, there is not only an implication but an outright claim of increased powr. Where is that power? No one that I am aware of who puts an MSD box into their car has gained any meaningful power.
The coil is ultimately what determines the power to the spark plug. You're using the same inductive ignition coil whether you use the MSD box, or the stock ignition module.
Daniel, you've got an MSD box, go measure the voltage at the coil with it running. Tell us what you see? You putting 480-volts into your stock coil, like the MSD propaganda says you should be? Let's go on a little fact finding mission.
The coil is ultimately what determines the power to the spark plug. You're using the same inductive ignition coil whether you use the MSD box, or the stock ignition module.
Daniel, you've got an MSD box, go measure the voltage at the coil with it running. Tell us what you see? You putting 480-volts into your stock coil, like the MSD propaganda says you should be? Let's go on a little fact finding mission.
02-07-2016, 02:48 PM
#33
Exactly. But in the propaganda that you posted, there is not only an implication but an outright claim of increased powr. Where is that power? No one that I am aware of who puts an MSD box into their car has gained any meaningful power.
The coil is ultimately what determines the power to the spark plug. You're using the same inductive ignition coil whether you use the MSD box, or the stock ignition module.
Daniel, you've got an MSD box, go measure the voltage at the coil with it running. Tell us what you see? You putting 480-volts into your stock coil, like the MSD propaganda says you should be? Let's go on a little fact finding mission.
The coil is ultimately what determines the power to the spark plug. You're using the same inductive ignition coil whether you use the MSD box, or the stock ignition module.
Daniel, you've got an MSD box, go measure the voltage at the coil with it running. Tell us what you see? You putting 480-volts into your stock coil, like the MSD propaganda says you should be? Let's go on a little fact finding mission.
02-07-2016, 03:02 PM
#34
Team Owner
Pro Mechanic
02-07-2016, 03:31 PM
#35
I could. However, possibly at the expense of my meter. Lol. I will see if I can use a meter safe enough to find out without damaging the meter.
02-07-2016, 07:10 PM
#36
Team Owner
Pro Mechanic
02-07-2016, 07:16 PM
#37
Le Mans Master
Thread Starter
Lots of great input. Sounds like my build is still mild enough to take advantage of the stock HEI. Now I'm curious as to "enhancements" like the Flamethrower, ACCEL and other's versiosn of the coils and modules. Wonder if these are worth the while.
02-07-2016, 08:10 PM
#38
Team Owner
Pro Mechanic
Modules: An ignition module is a relay, in function. The coil is powered by 12v ignition and the relay grounds the circuit to charge the coil. The relay opens the circuit, to collapse the field and the coil throws a spark. SO, as long as the module is capable of doing this job up to the top of your RPM range, then I can't see how any other "relay" can do a better job of opening and closing a circuit, than the stock "relay". Even one with the name "flame thrower" on it.
Coil: I know that a coil with more windings will make more peak voltage and potentially throw a bigger spark than a cheaper coil. BUT no coil, no matter how "bad assed" will throw more peak voltage than your combo (plug gap, compression, etc) needs. If you've got a 8:1 compression engine with a .020" plug gap, you probably only need ~8000v to start the spark. That is what your coil will produce, even if it's a "60,000 volt "Flame Thrower" coil.
So, does your combo need more coil? Only if it's breaking up on top, due to lack of spark energy or saturation time....which is often easily fixed by simply closing the plug gap. Every aftermarket coil I've ever put on a car took a dump w/in a year. I've never had a stock coil fail...personal or fleet/work (though I know they can and do fail).
My conclusion: I won't change out stock ignition parts until I run into a tangible limitation from them.
02-07-2016, 10:25 PM
#39
Melting Slicks
http://www.summitracing.com/int/parts/acc-140003r
Use a quality cap, such as the MSD and one big tip, dont use a cheap rotor ! the stock GM part is actually a good rotor.
02-07-2016, 10:35 PM
#40
Team Owner
Every aftermarket coil I've ever put on a car took a dump w/in a year. I've never had a stock coil fail...personal or fleet/work (though I know they can and do fail).
My conclusion: I won't change out stock ignition parts until I run into a tangible limitation from them.
My conclusion: I won't change out stock ignition parts until I run into a tangible limitation from them.