How do the heat ranges with the spark plugs work? And how do you know what spark plug has what heat range? And what heat range to use with what application? Thanks

Heat ranges are how well a spark plug can dissapate heat quickly. It deals with the length of the plug, but the advice is to go colder when you have more mods. If you're running a pulley, intake, exhaust, 180 stat, you should have atleast 1 range colder. I think it helps KR more then anything. Correct me if i'm wrong guys.

Close enough

The TR55 is one heat range colder. That would be good for a pulley and intake. I had to go two heat ranges colder very recently. I'm running the TR6 now.

Your auto parts store should be able to show you a chart of the heat ranges and the plugs available.

Found on the web:

The heat range of the spark plug determines how hot the plug will get.
The length and diameter of the insulator tip and the ability of the spark plug to transfer heat into the cooling system determine spark plug heat range.
A hot spark plug has a long insulator tip that prevents heat transfer into the waterjackets. It will also bum off any oil deposits.
This provides a self-cleaning action. A cold spark plug has a shorter insulator tip and operates at a cooler temperature.
The cooler tip helps prevent overheating and preignition. A cold spark plug is used in engines operated at high speeds.
Vehicle manufacturers recommend a specific spark plug heat range for their engines.
The heat range is coded and given as a number on the spark plug insulator.
The larger the number on the plug, the hotter the spark plug tip will operate.
For example, a 54 plug would be hotter than a 44 or 34 plug.
The only time you should change from spark plug heat range specifications is when abnormal engine or operating conditions are encountered.
For instance, if the plug runs too cool, sooty carbon will deposit on the insulator around the center electrode.
This deposit could soon build up enough to short out the plug.
Then high voltage surges would leak across the carbon
instead of producing a spark across the spark plug gap.
Using a hotter plug will bum this carbon deposit away or prevent it from forming.
Spark plug reach is the distance between the end of the spark plug threads and the seat or sealing surface of the plug.
Plug reach determines how far the plug reaches through the cylinder head.
If spark plug reach is too long, the spark plug will protrude too far into the combustion chamber and the piston at TDC may strike the electrode.
However, if the reach is too short, the plug electrode may not extend far enough into the cylinder head and combustion efficiency will be reduced.
A spark plug must reach into the combustion chamber far enough so that the spark gap will be properly positioned in the combustion chamber without interfering with the turbulence of the air-fuel mixture or reducing combustion action.

NGK is opposite from that. Higher numbers are colder heat ranges.

How did you know to go colder?

I still have the original plugs......damn boots.....but I can't tell from performance. Obviously since I haven't had them out, I haven't looked at them so I can't tell if they are burning too hot.

Why did you go to a v-notch type and not the iridium or GM OEM type?

The Vpower works like the splitfire. Two spark paths for a slightly more efficient burn. I've been running them in all my cars for about 5 years now.

I ended up going another heatrange colder, as I was burning the TR55'* up twice as fast as I should have. NGK suggested to me that I step down to the TR6.

Ya, I've been running with splitfires in my Bird and Jeep for over 10 years and wouldn't switch..........but these newer engines seem to command a much more premium plug. If from only the standpoint of not having to slice hands trying to get at the rear ones. A standard electrode, like the v-notch type, should be expected to wear faster than a higher priced iridium plug.

I would have expected that you would be running with a higher end plug.
The factory plugs cost $15. cdn each and the other iridium type cost about the same.
The Vpower plugs must be far less expensive.

I would say for the normal driver/car owner the iridiums would do very well as they will lsat a long time. However, in my case and other car modders cases, My iridiums have less that 4K miles on them and already I need to move down to cooler plugs. Kendra'* car has cheap copper autolites and it runs just as well as my expensive iridiums. If your going to change them once, get the iridiums. If your going to beat the crap out of them and change them often then go copper of your choice.

i think that iridium and platinum are not recommended for SC, right? They burn the metal off or something?