spark plugs

[quickbrick]

what is the difference between the ac delco 42ts,43ts,and44ts. which is the factory recommended? i took 44s out of mine and put the 43s and it seems slower now. i dont know if its just me or if it is actually slower.

 

[kenmosher]

Heat range ... from hotter to colder:

44 Stock
43 One step colder
42 Two steps colder

Heat range won't make it faster or slower .. a colder plug just helps control detonation at higher boost levels. Make sure you gap them correctly (a tight 0.035" works well for most).

 

[wicked6]

For a pump/alky car for a low 12 /high11 car which plugs should be used?

 

[kenmosher]

43s should work well ...

 

[BlackBeauty]

Originally posted by kenmosher
Heat range ... from hotter to colder:

44 Stock
43 One step colder
42 Two steps colder

Heat range won't make it faster or slower .. a colder plug just helps control detonation at higher boost levels. Make sure you gap them correctly (a tight 0.035" works well for most).

If the heat range makes no difference, besides colder = less chance of detonation, then shouldn't everyone just go with the 42's to be on the safe side? I am interested in knowing what plugs to get too, I should be in the 12's (and I'm using alky). I'm getting a little knock still, that's why I'm looking towards the plugs now.
Unless someone can idetify my current plugs.... they say "AC" (AC Delco I assume) on one side, and on the other side, just a "3".

 

[kenmosher]

Heat range affects driveability ... too cold a plug and you may get fouling (some folks do with 42s ... 43s seem to be a good compromise).

 

[DonnieShort]

What does the NGK UR5's equal too?




Donnie