OldFogey99
Newbie
- Joined
- Sep 22, 2024
- Points
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-thankful to each of you for this forum and the community it provides!
I'm new to an S52 M Roadster, and I've been going through a punchlist. On that list are coils and spark plugs.
Bosch FGR8KQE were in it when I got it -4 prong, known as the following:
Bosch Super Plus Copper Spark Plug 7405
After perusing a glut of forums, I heard a lot of folks eschew the 4 prong design... as an economy or "durability" choice by BMW.
I installed Bav Auto "HP" coils, and NGKBKR6EIX (6418) plugs. The car was incredibly smooth, but really lacked low end torque. (I also suspect vacuum leaks)
ok... so to suss this out, I ordered a spark plug tester and ... whether this is valid observational data or not,... I was blown away by the findings. In the following photo, you will see following:
LEFT - used, "OEM spec" Bosch 7405, 4 prong plug
MIDDLE - new, NGK BKR6E Copper (gapped to 1mm or .039)
RIGHT - reference new, Autolite 104 (gapped to .043 - this is for a 5.8L Ford 351... just a large gap for reference on the other two.
ok, what do you see!?
Next Steps will be to go back to the Bosch Coils (new boots) and new Bosch 7405 plugs... and repeat a few 0-60 runs on the same stretch I did for the Irridium NGKs and BavAuto coils.
I'm new to an S52 M Roadster, and I've been going through a punchlist. On that list are coils and spark plugs.
Bosch FGR8KQE were in it when I got it -4 prong, known as the following:
Bosch Super Plus Copper Spark Plug 7405
After perusing a glut of forums, I heard a lot of folks eschew the 4 prong design... as an economy or "durability" choice by BMW.
I installed Bav Auto "HP" coils, and NGKBKR6EIX (6418) plugs. The car was incredibly smooth, but really lacked low end torque. (I also suspect vacuum leaks)
ok... so to suss this out, I ordered a spark plug tester and ... whether this is valid observational data or not,... I was blown away by the findings. In the following photo, you will see following:
LEFT - used, "OEM spec" Bosch 7405, 4 prong plug
MIDDLE - new, NGK BKR6E Copper (gapped to 1mm or .039)
RIGHT - reference new, Autolite 104 (gapped to .043 - this is for a 5.8L Ford 351... just a large gap for reference on the other two.
ok, what do you see!?
Next Steps will be to go back to the Bosch Coils (new boots) and new Bosch 7405 plugs... and repeat a few 0-60 runs on the same stretch I did for the Irridium NGKs and BavAuto coils.
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