Ignition coil compatibilility
04-03-2013, 12:00 AM
#31
"http://www.centuryperformance.com/fo...tion-Coil-Tech"
So! Another post that quotes another post who quotes another post.
One can ALWAYS find something that infers what he believes.
And this link is from someone promoting products.
"While shorting the coil primary to stop the engine should not, NEVER, be standard practice I am standing ground that a one-time event should not damage the SCR."
- wwest -
Explain to all what the SCR and capacitor current is when the output is shorted.
I (SCR & capacitor) = V (capacitor) / R
but R = 0 when shorting the coil
Maybe the simple division maybe a little difficult for most to understand,
but the current will exceed the SCR & capacitor's rating and for sure destroy
the SCR as happened in the 'Dark Side' thread.
So! Another post that quotes another post who quotes another post.
One can ALWAYS find something that infers what he believes.
And this link is from someone promoting products.
"While shorting the coil primary to stop the engine should not, NEVER, be standard practice I am standing ground that a one-time event should not damage the SCR."
- wwest -
Explain to all what the SCR and capacitor current is when the output is shorted.
I (SCR & capacitor) = V (capacitor) / R
but R = 0 when shorting the coil
Maybe the simple division maybe a little difficult for most to understand,
but the current will exceed the SCR & capacitor's rating and for sure destroy
the SCR as happened in the 'Dark Side' thread.
04-03-2013, 12:50 AM
#33
Drifting
As a rule a 1.4 microfarad capacitor cannot store enough energy even at 300 volts to damage an SCR of the period. How long would the engine run with no ignition source?
Most DEFINITELY not good practice but once only....??
Most DEFINITELY not good practice but once only....??
04-03-2013, 12:59 AM
#34
"As a rule a 1.4 microfarad capacitor cannot store enough energy even at 300 volts to damage an SCR of the period."
Really, like whose rule? Obviously can't do simple math. So start your car and then short the
CDI unit I rebuilt for you and tell us what happens. By the way, there's NO warranty
when it fails.
By the way, the normal peak current for the SCR & capacitor is 25 amps and the SCR
is only rated for less that 40 amps. So a short will far exceed the SCR rating and destroy
the SCR and goodbye to your CDI.
Bottom line: DO THE MATH!
Really, like whose rule? Obviously can't do simple math. So start your car and then short the
CDI unit I rebuilt for you and tell us what happens. By the way, there's NO warranty
when it fails.
By the way, the normal peak current for the SCR & capacitor is 25 amps and the SCR
is only rated for less that 40 amps. So a short will far exceed the SCR rating and destroy
the SCR and goodbye to your CDI.
Bottom line: DO THE MATH!
Last edited by Lorenfb; 04-03-2013 at 01:22 AM.
04-03-2013, 01:06 AM
#35
"If it goes south then just put an MSD unit in place with their coil"
Another 'performance' joke! Read here:
https://rennlist.com/forums/911-foru...n-exposed.html
But then again, you'll be all set for that Chevy engine install (like NASCAR) as both will
match with their nice red paint!
Another 'performance' joke! Read here:
https://rennlist.com/forums/911-foru...n-exposed.html
But then again, you'll be all set for that Chevy engine install (like NASCAR) as both will
match with their nice red paint!
Last edited by Lorenfb; 04-03-2013 at 01:25 AM.
04-03-2013, 08:12 AM
#36
Drifting
"As a rule a 1.4 microfarad capacitor cannot store enough energy even at 300 volts to damage an SCR of the period."
Really, like whose rule? Obviously can't do simple math. So start your car and then short the
CDI unit I rebuilt for you and tell us what happens. By the way, there's NO warranty
when it fails.
By the way, the normal peak current for the SCR & capacitor is 25 amps and the SCR
is only rated for less that 40 amps. So a short will far exceed the SCR rating and destroy
the SCR and goodbye to your CDI.
Bottom line: DO THE MATH!
Really, like whose rule? Obviously can't do simple math. So start your car and then short the
CDI unit I rebuilt for you and tell us what happens. By the way, there's NO warranty
when it fails.
By the way, the normal peak current for the SCR & capacitor is 25 amps and the SCR
is only rated for less that 40 amps. So a short will far exceed the SCR rating and destroy
the SCR and goodbye to your CDI.
Bottom line: DO THE MATH!
I suspect the failure mode would be more due to heating of the SCR's internal silicon composition, CSA, thickness, etc. rather that a brief instant of "excessive" current flow. And that would depend on how many firing pulses occur before the engine stops turning.
*** Lack of basic SCR theory of operation...?
04-03-2013, 09:19 AM
#37
Drifting
Loren..
Begin reading at page 71...
Subject is the use of SCRs for "crowbarring" power supply outputs, example: Shorting out 300,000 microfarads of filter capacitance charged to 100 volts and ~70 milliohms of total circuit resistance.
http://www.google.com/url?sa=t&rct=j...PZHz4ljx5T7Hjw
Begin reading at page 71...
Subject is the use of SCRs for "crowbarring" power supply outputs, example: Shorting out 300,000 microfarads of filter capacitance charged to 100 volts and ~70 milliohms of total circuit resistance.
http://www.google.com/url?sa=t&rct=j...PZHz4ljx5T7Hjw
04-03-2013, 11:04 AM
#38
Still waiting for you to short your CDI coil and your link to YouTube to show
actual the results.
More mis-information posted on the 'Dark Side'.
"With one of three stator windings shorted the VR would be forced to "pump up" the voltage output of the remaining 2 windings in order to reach an average of the correct voltage across the battery posts."
http://forums.pelicanparts.com/porsc...sues-87-a.html
- wwest -
An alternator regulator regulates the alternator's peak output voltage via the D+
and NOT its average voltage. So an alternator will not output a higher voltage
than its regulator is set for to compensate for a bad winding, assuming the
regulator is functioning O.K. If that were the case, then all the car's electronics
could be damaged, as most alternators can easily output 25 - 30 peak volts.
And that's why an alternator light glows when there's a bad winding
and/or connection in the alternator. If the regulator regulated the average
voltage as mis-stated, then there would be no glowing light.
"Intermittent shorting of alternator stator windings (when you hit bump in the road??) causes HUGE magnetic field (RFI/EMI)which couples into the magnetic pickup wihin the distributor. That, in turn, results in multiple false firing of the CDI (or even otherwise). Tach "hits" the rev-limit, rev-limit shuts the fuel pump down."
http://forums.pelicanparts.com/porsc...questions.html
- wwest -
The magnetic pickup input from the distributor to the CDI ('87 930 or 911SC) is shielded
and would not 'see' any RFI from the alternator. Remember, the pickup is in the distributor
where it's 'seeing' 15-20KV sparks as the spark jumps from the rotor to the cap and there's
no problem.
actual the results.
More mis-information posted on the 'Dark Side'.
"With one of three stator windings shorted the VR would be forced to "pump up" the voltage output of the remaining 2 windings in order to reach an average of the correct voltage across the battery posts."
http://forums.pelicanparts.com/porsc...sues-87-a.html
- wwest -
An alternator regulator regulates the alternator's peak output voltage via the D+
and NOT its average voltage. So an alternator will not output a higher voltage
than its regulator is set for to compensate for a bad winding, assuming the
regulator is functioning O.K. If that were the case, then all the car's electronics
could be damaged, as most alternators can easily output 25 - 30 peak volts.
And that's why an alternator light glows when there's a bad winding
and/or connection in the alternator. If the regulator regulated the average
voltage as mis-stated, then there would be no glowing light.
"Intermittent shorting of alternator stator windings (when you hit bump in the road??) causes HUGE magnetic field (RFI/EMI)which couples into the magnetic pickup wihin the distributor. That, in turn, results in multiple false firing of the CDI (or even otherwise). Tach "hits" the rev-limit, rev-limit shuts the fuel pump down."
http://forums.pelicanparts.com/porsc...questions.html
- wwest -
The magnetic pickup input from the distributor to the CDI ('87 930 or 911SC) is shielded
and would not 'see' any RFI from the alternator. Remember, the pickup is in the distributor
where it's 'seeing' 15-20KV sparks as the spark jumps from the rotor to the cap and there's
no problem.
Last edited by Lorenfb; 04-03-2013 at 12:49 PM.
04-03-2013, 06:17 PM
#39
"If it goes south then just put an MSD unit in place with their coil"
Another 'performance' joke! Read here:
https://rennlist.com/forums/911-foru...n-exposed.html
But then again, you'll be all set for that Chevy engine install (like NASCAR) as both will
match with their nice red paint!
Another 'performance' joke! Read here:
https://rennlist.com/forums/911-foru...n-exposed.html
But then again, you'll be all set for that Chevy engine install (like NASCAR) as both will
match with their nice red paint!
That was an excellent display of Porsche snobdob tho
04-04-2013, 08:44 AM
#40
Team Owner
Thread Starter
okay well after reveiwing all the information from all parties i got myself a coil.
i decided to go with the MSD Blaster 8222. One of the main reasons was a few people contacted me and old me they were using this coil and had been for years in their SC and there were no issues with it . It is a little different from my original in specs but fairly close to the Bosch blue coil and more readily available.
Thanks All.
i decided to go with the MSD Blaster 8222. One of the main reasons was a few people contacted me and old me they were using this coil and had been for years in their SC and there were no issues with it . It is a little different from my original in specs but fairly close to the Bosch blue coil and more readily available.
Thanks All.
04-04-2013, 12:46 PM
#41
okay well after reveiwing all the information from all parties i got myself a coil.
i decided to go with the MSD Blaster 8222. One of the main reasons was a few people contacted me and old me they were using this coil and had been for years in their SC and there were no issues with it . It is a little different from my original in specs but fairly close to the Bosch blue coil and more readily available.
Thanks All.
i decided to go with the MSD Blaster 8222. One of the main reasons was a few people contacted me and old me they were using this coil and had been for years in their SC and there were no issues with it . It is a little different from my original in specs but fairly close to the Bosch blue coil and more readily available.
Thanks All.
04-04-2013, 12:59 PM
#42
Bosch TCI (black/silver) - R(primary) = .70 ohms, R(secondary) = 6200 ohms, N = 90,
L(primary) = 3.6 mH, L(secondary) = 30 H, ~ 60 mjoules @ 6K RPM - 6 cylinders TCI
Bosch Blue Coil - R(primary) = 3.5 ohms, R(secondary) = 8800 ohms, N = 65,
L(primary) = 12 mH, L(secondary) = 50 H, ~ 30 mjoules @ 6K RPM - 6 cylinders TCI
Bosch CDI (small black) - R(primary) = .30 ohms, R(secondary) = 700 ohms, N = 78,
L(primary) = .20 mH, L(secondary) = 1.2 H
Bosch CDI (small silver) - R(primary) = .70 ohms, R(secondary) = 720 ohms, N = 63,
L(primary) = .40 mH, L(secondary) = 1.6 H
Bosch TCI (Porsche 993) - R(primary) = .70 ohms, R(secondary) = 8200 ohms, N = 90,
L(primary) = 3.1 mH, L(secondary) = 25.3 H
MSD Blaster (8222) - R(primary) = 1.1 ohms, R(secondary) = 4700 ohms, N = 95,
L(primary) = 4.2 mH, L(secondary) = 38 H
Perma-Tune - R(primary) = .90 ohms, R(secondary) = 10000 ohms, N = 125,
L(primary) = 4.7 mH, L(secondary) = 74 H
As can be seen from the above which were linked to in an earlier post,
the MSD 8222 (MSD's CDI coil) has basically the identical spec to most
all the TCI coils. So using the 8222 coil should not be a problem for the
Bosch CDI, as would be the case when using most any TCI coil.
L(primary) = 3.6 mH, L(secondary) = 30 H, ~ 60 mjoules @ 6K RPM - 6 cylinders TCI
Bosch Blue Coil - R(primary) = 3.5 ohms, R(secondary) = 8800 ohms, N = 65,
L(primary) = 12 mH, L(secondary) = 50 H, ~ 30 mjoules @ 6K RPM - 6 cylinders TCI
Bosch CDI (small black) - R(primary) = .30 ohms, R(secondary) = 700 ohms, N = 78,
L(primary) = .20 mH, L(secondary) = 1.2 H
Bosch CDI (small silver) - R(primary) = .70 ohms, R(secondary) = 720 ohms, N = 63,
L(primary) = .40 mH, L(secondary) = 1.6 H
Bosch TCI (Porsche 993) - R(primary) = .70 ohms, R(secondary) = 8200 ohms, N = 90,
L(primary) = 3.1 mH, L(secondary) = 25.3 H
MSD Blaster (8222) - R(primary) = 1.1 ohms, R(secondary) = 4700 ohms, N = 95,
L(primary) = 4.2 mH, L(secondary) = 38 H
Perma-Tune - R(primary) = .90 ohms, R(secondary) = 10000 ohms, N = 125,
L(primary) = 4.7 mH, L(secondary) = 74 H
As can be seen from the above which were linked to in an earlier post,
the MSD 8222 (MSD's CDI coil) has basically the identical spec to most
all the TCI coils. So using the 8222 coil should not be a problem for the
Bosch CDI, as would be the case when using most any TCI coil.
04-04-2013, 01:33 PM
#43
Drifting
Still waiting for you to short your CDI coil and your link to YouTube to show actual the results.
I have assumed that when you repaired my CDI the SCR was upgraded to more modern technology, 2010 vs 1976. Higher breakdown voltage, hfe, DV/DT, IC, etc. If that was not the case then advise me of such and the test you suggest would be appropreate.
More mis-information posted on the 'Dark Side'.
Change of subject matter...why.....you lost...??
With one of three stator windings shorted the VR would be forced to "pump up" the voltage output of the remaining 2 windings in order to reach an average of the correct voltage across the battery posts."
http://forums.pelicanparts.com/porsc...sues-87-a.html
- wwest -
An alternator regulator regulates the alternator's peak output voltage via the D+ and NOT its average voltage.
Taken from...
http://www.pelicanparts.com/techarti...oubleshoot.htm
Forth paragraph..
Loren, you need to do more than just "parrot" stuff you find on the internet, you really need to try and understand the overall subject matter more competely. Absent a possible difference, MINOR difference, in B+ diode vs D+ diode forward bias voltage, the D+ PEAK voltage will be EXACTY equal to the B+ AVERAGE voltage.
[B]Apples vs Orangesargument...
In the oranges case you make (open B+ diode, "parallel" D+ diode still intact) you are correct.
But in the apples case I stated, neither the B+ and D+ diodes would EVER be forwarded biased, and I would be correct.
And by-the-by. With all components fully operational the PEAK (flat-topped "sinewave") voltage on the D+ terminal will be EXACTLY equal to the DC (battery "filtered") level on the B+ terminal.[B]
So an alternator will not output a higher voltage than its regulator is set for to compensate for a bad winding,
"..compensate for a bad winding.." But, your example makes use of the case of having an open B+ diode, not the bad winding case I stated.
assuming the regulator is functioning O.K.
If that were the case, then all the car's electronics could be damaged, as most alternators can easily output 25 - 30 peak volts.
In point of fact, open or shorted stator winding, ALL of the cars electronics WILL be compromised due to excessive battery charge voltages.
Some electronic components only suffer temporary "latch up" (brake warning light, rev-limiting circuit.) some suffer permanent damage (battery, light filaments, the CDI you repaired for me).
And that's why an alternator light glows when there's a bad winding and/or connection in the alternator. If the regulator regulated the average voltage as mis-stated, then there would be no glowing light.
"..there would be no glowimng light.." Exactly, correct. Has anyone EVER seen a glowing light as a result of encountering the infamous battery overcharging failure?
NO! (I feel comfortable speaking for yawl in this case.)
"Intermittent shorting of alternator stator windings (when you hit bump in the road??) causes HUGE magnetic field (RFI/EMI)which couples into the magnetic pickup wihin the distributor. That, in turn, results in multiple false firing of the CDI (or even otherwise). Tach "hits" the rev-limit, rev-limit shuts the fuel pump down."
http://forums.pelicanparts.com/porsc...questions.html
- wwest -
The magnetic pickup input from the distributor to the CDI ('87 930 or 911SC) is shielded
and would not 'see' any RFI from the alternator. Remember, the pickup is in the distributor
where it's 'seeing' 15-20KV sparks as the spark jumps from the rotor to the cap and there's
no problem.
Then what is your alternative explanation for the tach jumping when the battery is being overcharged....??
I first thought it was DV/DT effects, or CDI inverter supply voltage being to high on the SCR, but you and I ended up agreeing that could not be the case. Something seems to be sending spurious signals to the tach, and since that signal comes from the CDI, and untimately from the ignition magnetic pickup......
I have assumed that when you repaired my CDI the SCR was upgraded to more modern technology, 2010 vs 1976. Higher breakdown voltage, hfe, DV/DT, IC, etc. If that was not the case then advise me of such and the test you suggest would be appropreate.
More mis-information posted on the 'Dark Side'.
Change of subject matter...why.....you lost...??
With one of three stator windings shorted the VR would be forced to "pump up" the voltage output of the remaining 2 windings in order to reach an average of the correct voltage across the battery posts."
http://forums.pelicanparts.com/porsc...sues-87-a.html
- wwest -
An alternator regulator regulates the alternator's peak output voltage via the D+ and NOT its average voltage.
Taken from...
http://www.pelicanparts.com/techarti...oubleshoot.htm
Forth paragraph..
Loren, you need to do more than just "parrot" stuff you find on the internet, you really need to try and understand the overall subject matter more competely. Absent a possible difference, MINOR difference, in B+ diode vs D+ diode forward bias voltage, the D+ PEAK voltage will be EXACTY equal to the B+ AVERAGE voltage.
[B]Apples vs Orangesargument...
In the oranges case you make (open B+ diode, "parallel" D+ diode still intact) you are correct.
But in the apples case I stated, neither the B+ and D+ diodes would EVER be forwarded biased, and I would be correct.
And by-the-by. With all components fully operational the PEAK (flat-topped "sinewave") voltage on the D+ terminal will be EXACTLY equal to the DC (battery "filtered") level on the B+ terminal.
[B]So an alternator will not output a higher voltage than its regulator is set for to compensate for a bad winding,
"..compensate for a bad winding.." But, your example makes use of the case of having an open B+ diode, not the bad winding case I stated.
assuming the regulator is functioning O.K.
If that were the case, then all the car's electronics could be damaged, as most alternators can easily output 25 - 30 peak volts.
In point of fact, open or shorted stator winding, ALL of the cars electronics WILL be compromised due to excessive battery charge voltages.
Some electronic components only suffer temporary "latch up" (brake warning light, rev-limiting circuit.) some suffer permanent damage (battery, light filaments, the CDI you repaired for me).
And that's why an alternator light glows when there's a bad winding and/or connection in the alternator. If the regulator regulated the average voltage as mis-stated, then there would be no glowing light.
"..there would be no glowimng light.." Exactly, correct. Has anyone EVER seen a glowing light as a result of encountering the infamous battery overcharging failure?
NO! (I feel comfortable speaking for yawl in this case.)
"Intermittent shorting of alternator stator windings (when you hit bump in the road??) causes HUGE magnetic field (RFI/EMI)which couples into the magnetic pickup wihin the distributor. That, in turn, results in multiple false firing of the CDI (or even otherwise). Tach "hits" the rev-limit, rev-limit shuts the fuel pump down."
http://forums.pelicanparts.com/porsc...questions.html
- wwest -
The magnetic pickup input from the distributor to the CDI ('87 930 or 911SC) is shielded
and would not 'see' any RFI from the alternator. Remember, the pickup is in the distributor
where it's 'seeing' 15-20KV sparks as the spark jumps from the rotor to the cap and there's
no problem.
Then what is your alternative explanation for the tach jumping when the battery is being overcharged....??
I first thought it was DV/DT effects, or CDI inverter supply voltage being to high on the SCR, but you and I ended up agreeing that could not be the case. Something seems to be sending spurious signals to the tach, and since that signal comes from the CDI, and untimately from the ignition magnetic pickup......
Last edited by wwest; 04-04-2013 at 02:40 PM.
04-04-2013, 02:20 PM
#44
Team Owner
Thread Starter
Bosch TCI (black/silver) - R(primary) = .70 ohms, R(secondary) = 6200 ohms, N = 90,
L(primary) = 3.6 mH, L(secondary) = 30 H, ~ 60 mjoules @ 6K RPM - 6 cylinders TCI
Bosch Blue Coil - R(primary) = 3.5 ohms, R(secondary) = 8800 ohms, N = 65,
L(primary) = 12 mH, L(secondary) = 50 H, ~ 30 mjoules @ 6K RPM - 6 cylinders TCI
Bosch CDI (small black) - R(primary) = .30 ohms, R(secondary) = 700 ohms, N = 78,
L(primary) = .20 mH, L(secondary) = 1.2 H
Bosch CDI (small silver) - R(primary) = .70 ohms, R(secondary) = 720 ohms, N = 63,
L(primary) = .40 mH, L(secondary) = 1.6 H
Bosch TCI (Porsche 993) - R(primary) = .70 ohms, R(secondary) = 8200 ohms, N = 90,
L(primary) = 3.1 mH, L(secondary) = 25.3 H
MSD Blaster (8222) - R(primary) = 1.1 ohms, R(secondary) = 4700 ohms, N = 95,
L(primary) = 4.2 mH, L(secondary) = 38 H
Perma-Tune - R(primary) = .90 ohms, R(secondary) = 10000 ohms, N = 125,
L(primary) = 4.7 mH, L(secondary) = 74 H
As can be seen from the above which were linked to in an earlier post,
the MSD 8222 (MSD's CDI coil) has basically the identical spec to most
all the TCI coils. So using the 8222 coil should not be a problem for the
Bosch CDI, as would be the case when using most any TCI coil.
L(primary) = 3.6 mH, L(secondary) = 30 H, ~ 60 mjoules @ 6K RPM - 6 cylinders TCI
Bosch Blue Coil - R(primary) = 3.5 ohms, R(secondary) = 8800 ohms, N = 65,
L(primary) = 12 mH, L(secondary) = 50 H, ~ 30 mjoules @ 6K RPM - 6 cylinders TCI
Bosch CDI (small black) - R(primary) = .30 ohms, R(secondary) = 700 ohms, N = 78,
L(primary) = .20 mH, L(secondary) = 1.2 H
Bosch CDI (small silver) - R(primary) = .70 ohms, R(secondary) = 720 ohms, N = 63,
L(primary) = .40 mH, L(secondary) = 1.6 H
Bosch TCI (Porsche 993) - R(primary) = .70 ohms, R(secondary) = 8200 ohms, N = 90,
L(primary) = 3.1 mH, L(secondary) = 25.3 H
MSD Blaster (8222) - R(primary) = 1.1 ohms, R(secondary) = 4700 ohms, N = 95,
L(primary) = 4.2 mH, L(secondary) = 38 H
Perma-Tune - R(primary) = .90 ohms, R(secondary) = 10000 ohms, N = 125,
L(primary) = 4.7 mH, L(secondary) = 74 H
As can be seen from the above which were linked to in an earlier post,
the MSD 8222 (MSD's CDI coil) has basically the identical spec to most
all the TCI coils. So using the 8222 coil should not be a problem for the
Bosch CDI, as would be the case when using most any TCI coil.
Reiver no worries .. it s black
.. or at least it will will be once i peel off that gawd awful tacky sticker
04-04-2013, 02:51 PM
#45
Drifting
"If it goes south then just put an MSD unit in place with their coil"
Another 'performance' joke! Read here:
https://rennlist.com/forums/911-foru...n-exposed.html
But then again, you'll be all set for that Chevy engine install (like NASCAR) as both will
match with their nice red paint!
Another 'performance' joke! Read here:
https://rennlist.com/forums/911-foru...n-exposed.html
But then again, you'll be all set for that Chevy engine install (like NASCAR) as both will
match with their nice red paint!