RMilla17

which are the best set if so? thanks

jackmott

conductor wires?

thetorch

Are you referring to Nology plug wires???

Power Shifter

IMO on C5's there is no gain. Our wires are so short there is very little resistance if there in good working order. Ric

ZO6Les

:iagree:

Les

CAPN17

Just because you have a short wire do not assume the rest of use do!! :jester

jackmott

its my undnerstanding that with coil on plug ignition you dont have plug wires at all

CAPN17

Wrong!

SWCDuke

The coils are on the valve covers, so there are short wires to the plugs.

Here are some basics on ignition - all from published SAE papers. Once you have sufficient ignition energy to consistently ignite the mixture adding more ignition energy will not improve performance or emissions. (Note that I am talking about ignition ENERGY, not voltage. Big advertised open circuit voltage numbers don't mean anything. Actual breadown voltage is rarely above 15 Kvolts and that's all the system will see.) More ignition energy means longer spark duration, and long spark duration is necessary to provide reliable igntion at idle and light load. This is why OEM igntions are inductive rather than capacitive. CD ignitions can have high energy, but spark duration is short. This is fine for a racing engine running a rich mixture, but lean, low density mixtures typical of idle and low speed driving need a long duration spark to assure consistent igntion.

Old point ignitions would degrade and misfire, which is why GM installed the HEI system in '75 corresponding with the nearly universal use of catalytic converters. The reason was to improve emissions by reducing misfires and to keep the catalyitic converter from overheating due to severe misfires. The HEI usually works perfectly or not at all, and the HEI system provided double the per spark energy as the old single point. A HEI will fire a plug with a gap that you have to measure with a ruler.

I don't have any specific data, but modern individual coil systems have even more ignition energy than the HEI because a much longer time interval is available to saturate the coil with full steady state current since they only have to fire once every other revolution instead of eight times in two revolutions.

Absolute reliable ignition is required for emissions and fuel ecomony, and of couse, this will maximize power. Modern OBD II systems actually count misfires - usually with a crank sensor that can detect the torsional fluctuation caused by misfires, and if they exceed a certain and very low threshold, you get a check engine light and code.

Bottom line: Modern OEM ignition systems are very powerful and reliable, and the aftermarket cannot improve on their performance. Installing wires that are not properly RFI shielded or non-resistor plugs might increase energy to the plug, but the energy level is already so high and misfires so rare, more energy is not going to make any difference; but if the wires/plugs are not properly shielded they can interfere with the high frequency digital data that is running in the harnesses and cause dropped bits and other problems that can foul the electonics and cause operational problems.

Duke

Power Shifter

[QUOTE]The coils are on the valve covers, so there are short wires to the plugs.

Here are some basics on ignition - all from published SAE papers. Once you have sufficient ignition energy to consistently ignite the mixture adding more ignition energy will not improve performance or emissions. (Note that I am talking about ignition ENERGY, not voltage. Big advertised open circuit voltage numbers don't mean anything. Actual breadown voltage is rarely above 15 Kvolts and that's all the system will see.) More ignition energy means longer spark duration, and long spark duration is necessary to provide reliable igntion at idle and light load. This is why OEM igntions are inductive rather than capacitive. CD ignitions can have high energy, but spark duration is short. This is fine for a racing engine running a rich mixture, but lean, low density mixtures typical of idle and low speed driving need a long duration spark to assure consistent igntion.

Old point ignitions would degrade and misfire, which is why GM installed the HEI system in '75 corresponding with the nearly universal use of catalytic converters. The reason was to improve emissions by reducing misfires and to keep the catalyitic converter from overheating due to severe misfires. The HEI usually works perfectly or not at all, and the HEI system provided double the per spark energy as the old single point. A HEI will fire a plug with a gap that you have to measure with a ruler.

I don't have any specific data, but modern individual coil systems have even more ignition energy than the HEI because a much longer time interval is available to saturate the coil with full steady state current since they only have to fire once every other revolution instead of eight times in two revolutions.

Absolute reliable ignition is required for emissions and fuel ecomony, and of couse, this will maximize power. Modern OBD II systems actually count misfires - usually with a crank sensor that can detect the torsional fluctuation caused by misfires, and if they exceed a certain and very low threshold, you get a check engine light and code.

Bottom line: Modern OEM ignition systems are very powerful and reliable, and the aftermarket cannot improve on their performance. Installing wires that are not properly RFI shielded or non-resistor plugs might increase energy to the plug, but the energy level is already so high and misfires so rare, more energy is not going to make any difference; but if the wires/plugs are not properly shielded they can interfere with the high frequency digital data that is running in the harnesses and cause dropped bits and other problems that can foul the electonics and cause operational problems.

Duke, Great post!! If you get time, explaneing why less ignition timeing is desirable, if you have very eficient combustion event would illustrative in the way you do so well!! Thanks, Ric

SWCDuke

Okay, but I'm going to start another thread as this may be interesting to some others.

Duke