I'm considering new plugs

Paradigm_Guy · #1 (**permalink**) 07-13-2007, 04:06 PM

I'm considering new plugs. I have always ran BKR7E's with good results. I just gap them down a bit and they work great. But I have to change them pretty often because the gap opens. I figure for a $1 and change per plug, I may as well just put new ones in each time. But I'm looking for some new ones, I found these...

NGK PFR7B's - for $11+ each, they're about $10 more per plug than what I currently run. But these come pre-gapped at .25", so I should be able to run that without changing anything. I also think that I could run them for longer, maybe 20K miles instead of 3K miles.

They're OE plugs for the early-mid 90's A4's, and TT Z32's. Anyone ever try them?

Highboosted · #2 (**permalink**) 07-13-2007, 04:58 PM

They're OK, I ran a similar plug (but colder), and didn't get spark blowout like I was with Denso plugs (I blew apart a Denso IK27 plug and switched back to NGK-R's).

Before using coppers the last time, I was using PFR-11J's or something like that, I'll have to check the numbers. No blowout for at least 15K miles (all under boost), I'm running coppers in anticipation of melting something. :::evil laugh:::

Paradigm_Guy · #3 (**permalink**) 07-13-2007, 06:33 PM

11's? 27's? Holy crap. I just put these BKR7E's in yesterday, but maybe next month I'll try the PFR7B's.

UrineMachine · #4 (**permalink**) 07-15-2007, 12:25 PM

Quote:

Originally Posted by Paradigm_Guy

11's? 27's? Holy crap. I just put these BKR7E's in yesterday, but maybe next month I'll try the PFR7B's.

The reason the gap is opening is because the plug is too hot. Switching to an iridium or pregapped plug is not going to help - at your power level 7's are plainly too hot, you should prob be running at LEAST 8's.

Paradigm_Guy · #5 (**permalink**) 07-15-2007, 03:10 PM

Quote:

Originally Posted by UrineMachine

The reason the gap is opening is because the plug is too hot. Switching to an iridium or pregapped plug is not going to help - at your power level 7's are plainly too hot, you should prob be running at LEAST 8's.

Hmm, you might be right. I'll check out what the big HP Supra guys are running.

Highboosted · #6 (**permalink**) 07-15-2007, 08:43 PM

I'll save you the trouble: Surface gap plugs.

Temp range depends on HP. You need colder plugs than I run.

[edit]: Stock for my car was 7, BPU cars usually run 8 (400 HP or less), I run 9's since my car is built more for driving than high HP, The 550-600HP and up guys run IK27's to IK31's depending on the amount of boost.

You need to pick up something in the IK27 range or colder.