The 75/25 ratio is a sound bet if you are trying to simply do a cost analysis for fuel savings. However, keep in mind that dual plugs are not there for redundancy- they're there to allow the flame front to get all the way across the piston face. The only way to do that is to start at opposite sides and meet in the middle, thereby effectively halving the distance. This only works if both plugs fire at the same time. Hard to put a cost on this aspect, but significantly mis timed plug firing is "wrong" from a design standpoint.
The 75/25 ratio is a sound bet if you are trying to simply do a cost analysis for fuel savings. However, keep in mind that dual plugs are not there for redundancy- they're there to allow the flame front to get all the way across the piston face. The only way to do that is to start at opposite sides and meet in the middle, thereby effectively halving the distance. This only works if both plugs fire at the same time. Hard to put a cost on this aspect, but significantly mis timed plug firing is "wrong" from a design standpoint.
The 75/25 ratio is a sound bet if you are trying to simply do a cost analysis for fuel savings. However, keep in mind that dual plugs are not there for redundancy- they're there to allow the flame front to get all the way across the piston face. The only way to do that is to start at opposite sides and meet in the middle, thereby effectively halving the distance. This only works if both plugs fire at the same time. Hard to put a cost on this aspect, but significantly mis timed plug firing is "wrong" from a design standpoint.
Bill,Mike makes a good point. Most of our cylinders are 5-1/8" in diameter and it does take a while for the flame front to propagate. However, as he stated in his next post, there is little evidence that two mags firing at different times is causing harm.
When asked, I tell people to put in one P-mags and keep their traditional mag. After a year they will install a second P-mag.