PFR6B, 7B or 8B SPARK PLUGS???
25 January 2008, 03:52 PM
#1
PFR6B, 7B or 8B SPARK PLUGS???
I have a MY 1993 WRX with a Polar Performance's stage-1 non-mappable chipped ECU. This mod raises the standard 0.79bar of boost to 1.1bar for an increase of circa 30-50bhp, so that's 237 + 30 or 50, so let's say the engine is pushing anything between 260 - 290bhp (I also have a Green panel filter, and 3" de-cat centre-pipe & backbox)...
By the way, I have a new engine in, which has covered an alleged less-than 25,000 miles. Also my coil-packs are working fine e.g. no misfires, flat spots, etc...
My question is simply this: which would be the most suitable plug for a WRX engine in this spec - PFR6B, 7B or 8B - and what would the appropriate gap be?
Any helpful advice will be appreciated.
By the way, I have a new engine in, which has covered an alleged less-than 25,000 miles. Also my coil-packs are working fine e.g. no misfires, flat spots, etc...
My question is simply this: which would be the most suitable plug for a WRX engine in this spec - PFR6B, 7B or 8B - and what would the appropriate gap be?
Any helpful advice will be appreciated.
Last edited by joz8968; 25 January 2008 at 08:02 PM.
25 January 2008, 04:17 PM
#3
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I have a MY 1993 WRX with a Polar Performance's stage-1 non-mappable chipped ECU. This mod raises the standard 0.79bar of boost to 1.1bar for an increase of circa 30-50bhp, so that's 237 + 30 or 50, so let's say the engine is pushing anything between 260 - 290bhp (I also have a Green panel filter, and 3" de-cat centre-pipe & backbox)...
By the way, I have a new engine in, which has covered an alleged less-than 25,000 miles. Also my coil-packs are working fine e.g. no misfires, flat spots, etc...
My question is simply this: which would be the most suitable plug for a WRX engine in this spec - PFR6B, 7B or 8B - and what would the appropriate gap be?
Any helpful advice will be appreciated.
By the way, I have a new engine in, which has covered an alleged less-than 25,000 miles. Also my coil-packs are working fine e.g. no misfires, flat spots, etc...
My question is simply this: which would be the most suitable plug for a WRX engine in this spec - PFR6B, 7B or 8B - and what would the appropriate gap be?
Any helpful advice will be appreciated.
there is no way the car is putting out near 290bhp even 260bhp is a push
25 January 2008, 04:23 PM
#5
.I've yet to have it rolling roaded to get a ballpark figure.
For the record, subjectively it really only feels quicker from about 4 - 4.5k rpm till the redline. Even then, the difference doesn't feel that great, just holds boost rather than tailing off...
25 January 2008, 04:39 PM
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I'd go for 7s too, but you could always check with Scott for his opinion. He's probably in the best position to advise 
25 January 2008, 05:17 PM
#11
Get hold of a feeler-gauge from a mate (or buy a cheap one off ebay, etc)... Pull out the blade that has 0.6 or 0.7mm on it... Place it in the gap between the two electrodes... Bend the outer J-shaped earth electrode (either in or out with controlled, slow force) just enough, so that there's light drag on the feeler's blade as you slide it in and out between the electrodes 
Last edited by joz8968; 25 January 2008 at 07:09 PM.
25 January 2008, 07:54 PM
#12
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pfr6b are original equipment so for standard tune engine
pfr7b would be most suitable (lightly modded engine) 8's etc are for highly modded engine
im doing a service myself tomorrow, new pfr6b plugs (standard 260bhp engine) fuel filter , oil and filter,
pfr7b would be most suitable (lightly modded engine) 8's etc are for highly modded engine
im doing a service myself tomorrow, new pfr6b plugs (standard 260bhp engine) fuel filter , oil and filter,
25 January 2008, 08:01 PM
#13
"...The recommended plug is either NGK PFR6B or NGK PFR7B (slightly better for higher boost). Gap these to around 0.65-0.70mm..."
So definitely PFR7B's for me
...
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