JDM28

I'm looking at changing my plugs and need pfr6g but the ones i've seen on ebay all have -11 or -13 on the end. DOes this number refer to the gap?

would these be ok to buy and then gap them myslef or do them numbers refer to something else.
Whats the correct gap size for a jdm 04 running 300bhp+ ?

thanks

scoobymoz

iTrader: (53)

i would go for PFR7G plugs as they are cooler running i have them in my 99 type R and my bugeye JDM STI

PeeVee

iTrader: (1)

For that sort of bhp I would be going for the slightly cooler running 7g as opposed to the std fitment 6g.

Yes the -?? is the plug gap set when it was made, it will be fine to adjust this yourself but I would go for the -11 to minimise the adjustment you have to make.

You should gap them to 0.6-0.7mm

DIPSY

Did you not get a Japanese owners manual with your car .I did with the 05 Jdm STi i have and it says for sti/sti spec c PFR7G thats what i took out when changing plugs the gaps were 0.70mm.It says above for wrx PFR6G .I could not get PFR7G local so bought PFR7B the gap they were set was 0.70mm and plug gap is 0.7mm to 0.8mm that what it says in manual.I don't know what the difference is between PFR7B and PFR7G plug .

PeeVee

iTrader: (1)

The difference, is the material that the cntr electrode is made out of... On some early Import classics that had g's fitted from the factory, it was noted that if you fitted a "B" instead of a "G" it would induce a missfire under load, a refittment of g's sorted the problem.

The lower powered Uk cars between 95 & 2001 ran b's with no problem, but at the launch of the new age car the factory started fitting g's to both the import & uk cars.

Edited to add, if you are running 300 bhp+ then I would recommend the 7 over the 6 as it runs a bit cooler. if you are also running more boost than std then reduce the plug gap to 0.6-0.70 as this prevents the extra boost from "blowing" the spark out and causing a hessitation/missfire.

DIPSY

NGK spark plugs symbol code .I did look at this in the NGK spark plug book