I have a friend who has 4 NGK sparkplugs he had bought from Jackson Racing. The numbers on the plugs are ZFR5F 11. Would these be a little too hot for my bolt-on apllication? Isnt the recommened heat range for stock prelude 7? Would it hurt performance if i install these plugs from jackson racing? I could use new spark plugs but i just want to make sure these are only for boosted applications.

 

I would go colder plug, 5 is way too hot

 

6 is the stock heat range. Stick with 6.

 

7 is recommended for very hot climates and continuous high speed driving (long trips I'm guessing)

 

What i want to know is why would Jackson Racing sell 5 heat range plugs for a supercharged aplication? Isnt that suicide?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Revi-Ra &raquo;</TD></TR><TR><TD CLASS="quote">What i want to know is why would Jackson Racing sell 5 heat range plugs for a supercharged aplication? Isnt that suicide?</TD></TR></TABLE>
basically

 

ZFR6F's should do just fine.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Revi-Ra &raquo;</TD></TR><TR><TD CLASS="quote">What i want to know is why would Jackson Racing sell 5 heat range plugs for a supercharged aplication? Isnt that suicide?</TD></TR></TABLE>

ngk #'s higher the colder, as we all know. other companys go down for colder ranges. i bet the guy at jr got it backwards and ordered the wrong plug for him