crazzy said:
Hmm.. icic.. do you have any cable plug for sale there bro?
Wahh.. "R" spark plug? hehe What brand? er.. borsh? :)
R = resistor
As expected, the voltage at the cable (before any resistor) rises at the same rate regardless of resistance until the point of firing. Thereafter however the picture changes.
The coil generates a certain amount of energy. This energy wants to go somewhere. At a voltage of about 7KV the plug fires (irrespective of resistance). Until that happens NO CURRENT FLOWS. Whether you have resistance or not does not matter. A paltry 5KOhms does not do anything when compared to the nearly infinite resistance of the gap itself (until the plug fires that is).
Once the plug fires the resistance comes into being. The coil cannot get rid of its energy in the shortest possible time due to the resistance.
This reduces current flow in the spark and it takes quite a bit longer until the energy in the coil has expelled itself via resistor and spark gap. This results in a longer spark. However the spark is weaker due to energy loss in the resistor.
The scope shows this very nicely and it also gives reason why the resistor helps to suppress RF. With the resistor changes in the rate of current flow are much less resulting in "flatter" edges on the voltage vs. time curve that the scope shows you. This implies less high frequency components of the signal in the cable feeding the spark plugs.
Conclusion: It is quite safe to insert a resistor. It will not stop the plug from firing at all. High values will however lead to a weaker spark -but it is going to spark, no matter what
NGK bpr7es, bosch super 4 (r)... bla bla bla... as long as get resistor...
Grand
Torismo cannot use spark plug without 'R'... hope this can help u bro