Interesting ignition observation
Posted: Wed Aug 06, 2014 4:45 pm
Granted, it's a rotary, but internal combustion is internal combustion:
http://www.rx7club.com/single-turbo-rx- ... n-1068028/
Relevant quotes:
"I modified my ignition with a Crane Hi-6 and LX-92 coil per leading coil about a decade ago (ed. note: this means one ignition box per spark plug!) when I had misdiagnosed a power cut out as poor ignition. It turned out to be two separate things, fuel pressure dropping out under boost creep and BOV popping open.
However, when I dyno tune my set up I find it is unlike most people rotaries that make power by "leaning" out the air fuel mixtures. I believe leaning out the AFRs to make power is often a bandaid for poor ignition strength on a rotary."
"1) The tuner was amazed that my engine wanted LESS timing to make peak power at many load points compared to the Haltech conservative base map I use. Less timing= more manifold burn= more boost."
"We found the motor made the most power with the AFRs flatlined below the 10:1AFRs that the 02 sensor could accurately register once the wastegate was open.
Lowering the AFRs had the added benifit of eliminating the boost drop at peak torque and so raising overall power."
"These findings were consistent with my earlier dynapack dyno tuning session where the tuner found no power leaning out the mixture from my street tuned 9-10AFRs except in the 7-8,000rpm range where 10.5:1 made slightly more power."
And finally:
"MSD 6AL: 135 millijoules/spark
Crane Hi-6: 1200 millijoules/spark"
http://www.rx7club.com/single-turbo-rx- ... n-1068028/
Relevant quotes:
"I modified my ignition with a Crane Hi-6 and LX-92 coil per leading coil about a decade ago (ed. note: this means one ignition box per spark plug!) when I had misdiagnosed a power cut out as poor ignition. It turned out to be two separate things, fuel pressure dropping out under boost creep and BOV popping open.
However, when I dyno tune my set up I find it is unlike most people rotaries that make power by "leaning" out the air fuel mixtures. I believe leaning out the AFRs to make power is often a bandaid for poor ignition strength on a rotary."
"1) The tuner was amazed that my engine wanted LESS timing to make peak power at many load points compared to the Haltech conservative base map I use. Less timing= more manifold burn= more boost."
"We found the motor made the most power with the AFRs flatlined below the 10:1AFRs that the 02 sensor could accurately register once the wastegate was open.
Lowering the AFRs had the added benifit of eliminating the boost drop at peak torque and so raising overall power."
"These findings were consistent with my earlier dynapack dyno tuning session where the tuner found no power leaning out the mixture from my street tuned 9-10AFRs except in the 7-8,000rpm range where 10.5:1 made slightly more power."
And finally:
"MSD 6AL: 135 millijoules/spark
Crane Hi-6: 1200 millijoules/spark"