I am looking at buying some spark plug's, they come with a 0.8mm gap, is this correct for a 1999 uk turbo, lightly modified with a decat, induction kit & dump valve. Searching the forum gap's used see to range from 0.6-0.8mm.

Cheer's.

 

If you still run the OEM boost, then gap to 0.7mm... if running 0.2bar/3psi above that, then 0.65mm... if 0.4bar+/6psi+ above std, then gap to 0.6mm.

It's the extra boost pressure that could literally blow the spark out if the gap is too 'wide' (i.e. spark has a greater distance, therefore time, to travel from one electrode other - thus increasing its chances of getting blown out by the hurricane-like charge of air!...)

 

Thank's for the info, is it ok to re-gap iridium plug's with feeler gauge's?

 

yes fine,and 0.7 will do nicely

 

Using a feeler gauge is the only 'proper' way of doing it. I don't think the fact they're iridium means you can't, can it? Are they soft or something and therefore will break easily

Anyway, best plugs for your car are:

NGK PFR6B (if standard/std boost/mild mods like air filter/exhaust)
NGK PFR7B (if upped boost/decat/remap or more...)

When you gap, the correct gap is when you feel an ever so slight drag or resistance against the feeler gauge. If it's 'stiff', and reluctant to pull/push, then it's too tight and you need to open the electrode out a miniscule amount...

 

I am looking at a set of ngk PFR6B that I can pick up cheap, these are gapped to 0.8 as standard, I am running a full decat/stainless, k&n induction kit & forge dump valve so guess I should be gapping to 0.7? Or should I pay the extra & get the NGK PFR7B?

Desicion's desicion's!!!

 

Get the 7Bs and gap to 0.7mm...

 

Cheer's chap, will have to stump up a few more readies then!!!

 

That's the beauty of the 7s over the 6s - they're all but the same price! Check on eBay - should be able to get 4 brand new boxed jobbies for a tad over £30 delivered.......

 

I looked these up PFR78 4853, are these the right one's or are they just for the sti/wrx, seem's to be a bit of confusion when asked?

Sorry about all the question's!!!

 

You sure that's an 8 and not a B after the 7?

If it's not a B then they're not the ones we're discussing. Defo PFR7B...

 

Yes they are a b, having a funny 5 minute's, think it was your avatar putting me off!!!

 

I have a wrx 53 plate. just bought new plugs pfr6b 's . someone told me that the plugs can be changed from underneath. is that nonsense, as there is a vid on You tube of some one taking off the wiper washer bottle and the air filter box, then changing from above!
Could someone advise me please!! Also, what is the gap size, it is a standard 2.0 wrx turbo

Many Thanks

Nick

 

Yeah change them from above

 

lol at the time elapsed 'twixt Q and A!

 

Still a useful thread though - i changed my plugs this afternoon on a 55 plate WRX.
The Subaru manual says NGK6G (not 6B) so i used those gapped to 0.7mm.

Took me 2 hours - i took off the battery and washer bottle on passenger side, then air filter box on the driver side.

A great set of instructions (with pics) is here:
http://www.subaru-impreza.org/forum/...s-classic.html

The Youtube vid is here:
http://www.youtube.com/watch?v=DgwA2BdLJwA

Carl

 

What is the spark plug gap on a 1.8 impreza cheers

 

4 inches... lol joke

 

Hahaha very funny if you don't no the answer don't dick about it might only be a 1.8 but its still a scooby and needs the plugs changing so if anybody can help with out Being a dick please do

 

It was a joke, I'll say what I want mate.. can anyone please help Mr. Serious here?

 

Why don't you try and Google OEM impreza plugs look up the info or just type impreza 1.8 plug gap??? Lol I bet I could find you the answer in seconds but am on a mobile atm so can't...

 

Iv tried google and it says 0.044 but that's on American sites iv got a full set of feeler gauges and it hasn't got a 0.044

 

thats imperial measurements, im assuming you have a metric set, so just convert it

 

As Gambit says, it's imperial i.e. "thou" (thousandths of an inch).

For the metric equivalent:-

0.044" (or 4 thou) = 1.12mm.


Wow, that's large lol