am i right in thinking 6's are standard ish @7's are for more tuned motors?

 

yup

 

so my car is slightly tuned(fmic,air filter,exhaust)will 6's be ok or best go for 7's?

 

Hmm don't really know at which stage your supposed to swap sizes, I'm running around 400 or so and use the PFFR 7's

 

Seeing as you have a FMIC, I assume you've had a remap and are running more boost/power than std.? (I think from 350+ bhp is considered 7s territory...)

Whatever, I'd use 7s - after all, they can only help in alleviating det, because they are a colder plug. The fact that you've started modifying means you'll invariably carry on, so fit the 7s. There's bugger all cost diff between 6s and 7s, so a no brainer...

 

any idea where to get them from?

 

eBay - brand new, boxed for a set of 4 should be no more than £30. I got mine for about £25 inc p&p.

 

time for a look then

 

£29.23 for a set of 4 delivered, from this seller:-

NGK spark plug PFR7B (plugs) PFR7-B trade price 4853 on eBay (end time 26-Jan-10 13:35:26 GMT)

 

i like the way you say invariably carry on modifying !!aint that the truth,the pringle sydrome imy missus calls it,once you pop you cant stop lol!!!

 

You sure she's talking about modding Imprezas?

 

im sure
,cant be anything else haha!!!

 

jdm sti v8 came standard with "7" plugs