Roojai

turbo 2.0 WRX - Platinum PFR6B
turbo 2.0 WRX - Iridium BKR6EIX
modded WRX/STI - Platinum PFR7B

http://www.spark-plugs.co.uk/cars/subaru.htm

Which you would you recommend for a slightly modded scoob (running about 15psi).
I'm currently getting some misfire at high boost.

Also I heard that a 0.7mm gap instead of 0.8 might be good. Any comments?

Falkirk.scoob

[most people recomend NGK double platinum mate]

yoza

Ive just had fitted 4 x NGK PFR6B's, Part code 03A060 at 10.47 each.

My 01WRX had a flat spot/hesitancy, and these I believe sorted it out.

It had a full service too....

Fitting them was not easy, off with the washer bottle assy, for the offside bank, and away with the airbox assy for the nearside bank.

We needed an oddball sized 1/2" extention bar to do the job, and there wasnt much room between the inner wing and the cylinder heads to work.

The off side bank being the more difficult to get at.

Note: When we took the original plugs out, the tops (opposite ends to the electrode end) were solid, not screwed on.

The new ones supplied by Subaru were screw on tops. So what I thought.

Until my mechanic friend showed me the coil pack/plug cap assy, and inside the rubber cap was a small spring which made the contact to the plug top.

Now on the originals you could see the mark on the plug cap were the spring had mad contact with the plug top. But on the new ones there was a threaded hole, were the plug top was screwed in.

So I phoned Subaru and was assured this was OK, they only fit these plugs to this car, and have done since year DOT.

They seem fine........

The plugs had a different last letter, originals were D, and the new ones B.

Anyway, I digress.......

Later Yoza

yoza

Thanks for the reply.

Hey, dont mention it.

Roojai

Err. yeah thanks for the reply.
My thanks would have been quicker but I don't have internet connection at work. I'll try harder next time.
Got the spark plugs today and will put on car now. I have done it before so it shouldn't take long. And it should be a lot easier than changing the turbo which is the lasy job I did.

yoza

WREXY

So what are the "laser" platinum NGK PFR7B, stock number 4853 then? Anyone heard of them? Are they better than the platinum PFR7B?

Cheers,

George.

Roojai

I just fitted the "laser" platinum NGK PFR7B so I'll tell you tomorrow if they have made a difference. I was on Denso platinum's previously.

Scooby-Mike

I was told that the pfr7b's are a slightly hotter plug? not too sure what this means. I stuck with the 6's

Bob Rawle

grade six is hotter than grade seven, you should fit sevens when applying any mod to the car, the six's tend to allow pre-ignition.

So my advice would be to always fit the PFR7B's, far better plug for these cars.

Whatever is before or after as a descrption a PFR7B is always a PFR7B btw.

cheers

bob

Nathan L

Another vote for PFR7B's here.

Bob has mapped 2 of my cars now. Both ran better and smoother with the 7's.

Mine are gapped to 0.7mm running 24 ish PSI

Nathan..

WREXY

I couldn't find the platinum NGK PFR7Bs here in Greece and one of the dealers came up with the "laser" platinum jobbies (7s). He charged me an arm and a leg for them, hence my question above, as to whether they are supposed to be any better than the "plain" platinum (7s) plugs.

Looking forward to your report Roojai.

Cheers,

George.

Abbylad

iTrader: (4)

Got 8`s in mine

Bob Rawle

Laser or plain they are all the same plug

bob

Roojai

The car is running loads better on the new PFR7B's. I have them gapped at 0.7mm.

It idles better and I have lost the tiny bit of hesitation I was getting at high boost. Engines revs a lot more smoothly.

The denso platinums I took out looked quite knackered. Very brown. Weird as I only put them in 3000 miles ago. I don't know why they got knackered so quickly. I have been using octane booster. Anyway I put a chip in the other day that should change the AF ratio and also make octane boost unnecessary so I'll have to see how I go with that.

Cheers

They were 11 quid each so not cheap though.

JohnD

iTrader: (5)

Would appreciate some advice from BobR if you're still there?
What would be your preference, assuming same heat grade and cost not an issue - NGK PFR7B or equivalent iridium, e.g. HKS S35i, Blitz T7340B-7 (which is NGK) etc. Are there any advantages of one over the other?
JohnD

Bob Rawle

John, there is nothing wrong with the Denso plugs (ie the HKS which are all Denso at source) however I would suggest using the NGK's. I have found the insulators/electrodes of the Denso type plug (Iridiums) just a bit too small for aggressive use, not a problem on a car with no mods of course.

bob

JohnD

iTrader: (5)

Bob
When you suggest the NGKs I assume you were referring to the PFR7B and not the Blitz (NGK)? I have a set of the Blitz to go in my 03STi PPP (as you know, the standard NGK PFR6B's are left in) Would you agree that these are OK and a safer bet than leaving the originals in? Value your knowledge on this!
JohnD

VinPlate

I have just removed a set of NGK BK6EIX due to a misfire at full boost, enough to cause the engine management to shut the engine down...

Visually they are perfect and the mixture is spot on too.

Anyway, replaced with NGK PFR7B and now she's back to "how scared do you want to be!" on WOT!

Luke Morgan

Hi all.

Hope your all well. Is it worth putting pfr7b spark plugs in a standard wrx just got upgraded air filter -bov and straight pipe from centre to rear?
Thanks luke

JDM_Stig

iTrader: (3)

Not really.

Luke Morgan

Ok thanks is it worth putting the ngk laser platinum pfr6bs in?

1509joe

iTrader: (2)

Standard will do fine.