Clutches, plugs, n other stuff...

[bdw18_123]

Originally Posted by XfireZ51

When it comes plugs let me recommend doing plug cuts and inspecting the ground strap for proper heat range. On my 92, I found the 41-602s to be a bit too hot. I use the NGK BRK6E. A step colder than the 602s . Important to get right heat range especially when tuning for WOT.
How you drive the car will be a factor. If you don't flog it, you'll likely need a hotter plug.

Did you mean BKR6E? Because BRK6E doesn't show up. I'm debating whether to go with the 41-602's or the BKR6E's in my '90 Z (stock other than relocating the IAT sensor and timing the exhaust cams to the 93-95 LT5 stock timing). I will be driving the car harder than the average person would.

What is the difference between hotter and colder plugs and what effects does it have to run the engine with too cold a plug or too hot a plug?

[XfireZ51]

BKR6E.

Spark Plug



Some cars require a hot plug. This type of plug is designed with a ceramic insert that has a smaller contact area with the metal part of the plug. This reduces the heat transfer from the ceramic, making it run hotter and thus burn away more deposits. Cold plugs are designed with more contact area, so they run cooler.


The difference between a "hot" and a "cold" spark plug is in the shape of the ceramic tip.
The carmaker will select the right temperature plug for each car. Some cars with high-performance engines naturally generate more heat, so they need colder plugs. If the spark plug gets too hot, it could ignite the fuel before the spark fires; so it is important to stick with the right type of plug for your car.

Next, we'll learn about the coil that generates the high voltages required to create a spark.