Well i just bought a 2006 MCS, and i ordered an alta intake and an alta 17% pulley. I have searched high and low and have not seen any definitive reasons to get colder plugs. My climate is typically 80's during summer, and well really cold in the winter. Its august and temps shouldnt get about 85 outside, so are the colder plugs really needed?

 

The added boost pressure from the pulley creates higher combustion chamber temps. Thus the reason for going to the colder plugs. I suggest trying the Brisk Racing 4 prong plug.(also known as the "Lambo" plug). Do a search here on "Brisk spark plugs". Plenty of good info.

Good Luck!
Jim

 

I have seen both you must get colder plugs and it is not necessary.
I have a 15% pulley and decided it would not hurt. I went with JCW plugs but the Brisk is what Jan at RMW recommends so I will put them in the next time.
Better safe than sorry.

 

15% here. They are commonly recommended. However, in my application my car did not like the JCW plugs (ngk BRK7EQUP i think) as I developed a significant hesitation when on boost. Even though it might have been defective plugs, in my case stock range plugs have worked perfectly troughout 30k mile. I'm eventually going to try the BRISK lambo plugs to see if my car likes them or not.

 

I recommend colder plugs with every pulley install. Been running the JCW plugs in my cars even the race car without any problem ever.

 

JCW oem plugs.

 

hmm ok, i went an ordered the bkr7eix from napa. i needed them by friday. lets hope they work!

 

The operating temperature of a spark plug is the actual physical temperature at the tip of the spark plug within the running engine, not the outside temperature