Masterworks skrev:Jag har bytt tändstift på min C5 1999!
Det satt AC 41-952 i och dom stift jag satte i
var AC 41-985, då undrar man vad skillnaden är
på dessa stift, motorn går fint iallafall!
Lite info från amerikanarna
What I will say to you will not be popular, however, the following is FACT.
I will share the basics with you. The biggest reason, is ignition timing.
Theory follows.
If you look at the spark plug center electrode, it projects a certain amount from the base of the threads. That is called electrode protrusion. What alot of people do NOT understand, is that there were 3 different plug designs on c5. And each one had a different electrode protrusion. 97 had 41-931 plugs, 98-00 carried the 41-952 plugs, and 01-04 carries a new design plug, PTJ16R15.
As you can see, differences abound, that people do NOT like to talk about.
Now, the reason that the electrode protrusion has such a bearing on ignition timing, is that the protrusion is the starting point of the flame front, as it burns the fuel across the combustions chamber. This changes the amount of time that the fuel takes to burn. HOWEVER, HERE IS THE REASON THAT ITS SO IMPORTANT.
The engine control computer does NOT know that the plugs were changed, and the timing program is for the original plugs that were in there. So, it will advance or retard the timing, based on the original equipment spark plugs. This timing program may NOT be ideal for power production with the different plugs. And obviously, there is differences in the spark plugs, you will have a different running engine when you change the plugs.
Some aftermarket plugs do not protrude as far into the combustion chamber, so this actually retards ignition timing, because the flame has farther to travel across the chamber. This is the reason that so many people report no engine detonation when they change plugs, when they heard the detonation before.
Se även
http://www.globaldenso.com/PLUG/cross_r ... 01_01.html
du får fem uppsättningar NGK TR55 för samma pris. 