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11-05-2005, 07:27 PM
#1
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Join Date: Nov 2005
Posts: 4
My 1979 GS is still waiting for me to sew the new upholstery and door panels. 
I have a 1985 electronic distributor to swap onto my '79 in place of the dual points distributor. I have an Accel GM type coil with two high tention outlets to use for a direct fire ignition on the leading plugs.
It looks like if I extend the mount in the distributor up about 3/4 of and inch (20 mm) I could mount two pickups above the level of the stock reluctor and 90 degrees apart. I would then add an additional two lobe reluctor to fire the trailing plugs alternately through the stock two coils remounted to the drivers side strut tower. This should give me direct fire on all plugs with less than a foot ( 30 cm) long plug wires. I hope the result will be that all spark energy will be expended at the plug gap.
Any discussion is welcome.
I have a 1985 electronic distributor to swap onto my '79 in place of the dual points distributor. I have an Accel GM type coil with two high tention outlets to use for a direct fire ignition on the leading plugs.
It looks like if I extend the mount in the distributor up about 3/4 of and inch (20 mm) I could mount two pickups above the level of the stock reluctor and 90 degrees apart. I would then add an additional two lobe reluctor to fire the trailing plugs alternately through the stock two coils remounted to the drivers side strut tower. This should give me direct fire on all plugs with less than a foot ( 30 cm) long plug wires. I hope the result will be that all spark energy will be expended at the plug gap.
Any discussion is welcome.
11-08-2005, 08:47 AM
#4
Senior Member
Join Date: Oct 2003
Location: Boston Ma.
Posts: 1,420
That seems like a harder way of doing it. Check this out DLIDFIS
I wont pretend to have a great knowledge of coils, but when i tried to use FC coils with the electronic dizzy i got a real weak spark. I think some ECU controled coils dont work well with those pickups.
I wont pretend to have a great knowledge of coils, but when i tried to use FC coils with the electronic dizzy i got a real weak spark. I think some ECU controled coils dont work well with those pickups.
11-08-2005, 10:30 AM
#5
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Join Date: Nov 2005
Posts: 4
The DLIDFIS results in the leading plugs being fed by a short wire direct from the coils to the plugs.
This is accomplished for the leading with the "wasted spark" accel coil that I have.
I am working on a scheme to make the trailing direct fire as well.
Because the trailing timing is later I can not use a wasted spark system like the leading.
The trailing needs to be fired alternately by one coil per plug. That is why I need two pickups in the distributor for the trailing coils (plus the one to fire the leading coil) The goal is direct fire on all plugs. Since the Accel coil may flow higer amps than the stock coils I am thinking of rumming it off a GM HEI ignitor module and useing the two J109's to fire the coils for the trailing plugs.
I am concerned that the magnet for the pickup coils may be damaged by heat if I weld the bracket to the distributor plate. I may need to find a way to attach the pickups without welding (possibly rivit) or use a heat sink to protect them. Also I have not yet found a source for the two lobe reluctor. Anyone know if the older Subarus would have this?
What did you go to for the weak spark issue?
That seems like a harder way of doing it. Check this out DLIDFIS
I wont pretend to have a great knowledge of coils, but when i tried to use FC coils with the electronic dizzy i got a real weak spark. I think some ECU controled coils dont work well with those pickups.
This is accomplished for the leading with the "wasted spark" accel coil that I have.
I am working on a scheme to make the trailing direct fire as well.
Because the trailing timing is later I can not use a wasted spark system like the leading.
The trailing needs to be fired alternately by one coil per plug. That is why I need two pickups in the distributor for the trailing coils (plus the one to fire the leading coil) The goal is direct fire on all plugs. Since the Accel coil may flow higer amps than the stock coils I am thinking of rumming it off a GM HEI ignitor module and useing the two J109's to fire the coils for the trailing plugs.
I am concerned that the magnet for the pickup coils may be damaged by heat if I weld the bracket to the distributor plate. I may need to find a way to attach the pickups without welding (possibly rivit) or use a heat sink to protect them. Also I have not yet found a source for the two lobe reluctor. Anyone know if the older Subarus would have this?
What did you go to for the weak spark issue?
Originally Posted by RONIN FC' post='776558' date='Nov 8 2005, 06:47 AM
That seems like a harder way of doing it. Check this out DLIDFIS
I wont pretend to have a great knowledge of coils, but when i tried to use FC coils with the electronic dizzy i got a real weak spark. I think some ECU controled coils dont work well with those pickups.
11-08-2005, 01:11 PM
#7
Junior Member
Thread Starter
Join Date: Nov 2005
Posts: 4
Ronin:
The reliability of DFIS is one advantage. I also think that the factory went to DFIS for a reason. Possibly less emmissions & better fuel efficiency. I suspect there may be a little power there too, but surely not much compared to a good spark on the leading. I am going to the 2gen fues link box and electronic distributor in part to clean up the engine bay, but I expect reliability and power to be improved as well. With the leading on DFIS I can move the trailing to the "L" positions on the distributor cap to eliminate one gap in the high voltage path to the trailing plugs which should help, but I am trying to get to all DFIS to eliminate as much of the resistance as possible in the secondary circuits. I am hopeing it may reduce the poping in the exhaust on decelleration as well as improve tractability. I know it will not be as smooth as the EFI system, but it should be close.
For the weak spark i just went with Accell Super Stock coils.
I see your dillema with the trailing side. But whats the goal behind it? Simplify the engine bay, less wiring?
The reliability of DFIS is one advantage. I also think that the factory went to DFIS for a reason. Possibly less emmissions & better fuel efficiency. I suspect there may be a little power there too, but surely not much compared to a good spark on the leading. I am going to the 2gen fues link box and electronic distributor in part to clean up the engine bay, but I expect reliability and power to be improved as well. With the leading on DFIS I can move the trailing to the "L" positions on the distributor cap to eliminate one gap in the high voltage path to the trailing plugs which should help, but I am trying to get to all DFIS to eliminate as much of the resistance as possible in the secondary circuits. I am hopeing it may reduce the poping in the exhaust on decelleration as well as improve tractability. I know it will not be as smooth as the EFI system, but it should be close.
Originally Posted by RONIN FC' post='776589' date='Nov 8 2005, 09:14 AM
For the weak spark i just went with Accell Super Stock coils.
I see your dillema with the trailing side. But whats the goal behind it? Simplify the engine bay, less wiring?
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