Only fitted the originals PFR6B about 2k ago and from reading and that now running more power than standard fitted some PFR7B and what a difference, smoother idle and more aggressive on boost, why would spark plugs make sutch a difference?
Know the 7's are colder plug would like to understand this.
Done the same on pals car and has reported back the same result.

 

Shouldn't really feel much difference. Placebo effect? Did you re-set the gap to 0.65mm on the new plugs? Prefered if you are running above standard boost level.

JohnD

 

Set to 0.70mm which is in the middle from the research done, some say .65 some say .75 so went for in between, the plugs out of the box was .80 and .75

 

From what I understand...
The colder plugs help prevent pre spark (det) especially at higher boost and power levels when combustion temp tend to get rather high.

Definately made a difference in the higher rev range of mine, (seemed stronger somehow.) It went bang 300 miles later...

 

Cheers Dan, hope this does not put a curse on mine!
How is yours coming along?

 

It's about time Dan did a project thread / general update!

 

Project thread:

Bought car, it went bang, repaired it, it went bang...

 

That summarised that very well

 

It's the .... part we want to know about!