When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Well, no luck on my end for the BPR7EY, guess they are no longer available here in the states. I tried the 1144 number as well. What I did find plenty of was the BPR6EY stock number 6427. I can live with this only one step hotter plug. They are cheap by the way, only $1.89 at O'Reilly's.
This is quite a good explanation I just found on the ole interweb:
Many times, we've talked to customers who have had "misses" or "sputtering" that they have attributed to many things, but the obvious: spark plugs and ignition wires. If you ever have misses or sputtering, usually at higher RPMs, your first target for a culprit will be wires and plugs, assuming nothing else serious is going on, like a lean condition. The NGK BPR-6ES and BPR-7ES plugs are by far the most common and by all means the cheapest at $1.99 each in most auto parts stores. So which ones should you use? In most respects, your car will let you know when you've made a mistake in heat range selection.
Heat range is the plug's ability to remove heat from the cylinders. Colder plugs (higher numbers, ie. 7 is colder than 6) mean the plugs will remove more heat from the cylinders. Immediately, those who know a vague amount about tuning might think that sticking the coldest plugs they can get their hands on will reduce cylinder temps the most, which will help avoid knock, and that they can run unlimited boost or a super-lean mixture. Those who don't know a thing about it, may actually switch to a colder plug as some kind of a "performance mod". This, however, is not true and if you go to a colder plug too soon, you could actually impair your performance. Let's take a look at heat ranges for a minute.
Off the bat, it is generally never a good idea to go with a hotter plug than stock so our discussion here will be with going to a colder plug. Click the image to open in full size.As we have said, the higher the heat range number, the more it will cool the combustion chamber. How exactly does that work? As you might expect, heat is pulled from the combustion chamber through the plug, into the insulator where it is then transferred into the cooling passages. As you can see, a "7" plug has much less area exposed to the combustion heat and has much more of an insulator than a "5" does . Translation: it will conduct heat more quickly and have a cooler tip (excellent for avoiding pre-ignition). How much more heat will it remove? For every step colder, approximately 160°F-210°F of heat will be removed.
In addition, a "projected" tip plug will run approximately 50°F-70°F hotter than non-projected tip plugs. So going from a BPR-6ES to a BPR-7ES plug will remove 160-210°F, while going to a BR-7ES (note no "P") will remove 210-280°F.
The difficult part is determining which plug to use and when. According to NGK, a plug one step colder should be used per 75-100HP that you add to your engine. By "adding HP", what we are really targeting is the associated increase in cylinder pressures and their related temperatures...and that is the key to choosing the right plug.
Spark plugs need to operate in their "self-cleaning" heat range (500°-850°C) to function properly. Colder than 500°C and they will not be able to burn off carbon/fuel and will foul...hotter than 850°C and they will overheat. As you can see, that is a pretty wide gap to operate in and there is room to work within each heat range. All of our 400-500 wheel HP DSMs are running BPR-7ES or BR-7ES plugs, well above the "1 heat range per 100HP" rule. If you are using nitrous, that's another ball of wax entirely.
The BPR-6ES plugs have worked well on all DSMs we've seen in the 275-375 wheel HP range. At any point, you are welcome to try a 7, but you may end up with more sputtering and misses than you care to deal with. That is exactly what we meant when we said if you pick the wrong heat range, your car will let you know. That missing will probably be associated with the plug being too cold and not making its minimum operating temperature. If you try a 7 and simply cannot run them yet, don't forget that you may also go for a non-projected BP-6ES to help remove some heat, but without being so cold as a 7.
What gap? That will depend on your mod level, how much boost you run, and any ignition modifications you may have, but generally, .028" is pretty much a set it and forget it gap. That works well on just about any turbo and we've run that gap on big turbos up to 30psi without a hiccup.
I guess the proof is in the pudding. I had to go out and pull a couple plugs. These are the BPR6EY's. I have had them in about 10 months and 7,000 miles. The car runs great and they look pretty damn good to me. For $1.89 these might just be the ticket!
When your spark plugs are worn, you may want to give the BPR6EIX a shot, which are theoretically better suited to E85. NGK doesn't produce the V-Groove and Platinum VX anymore, their current top-of-the-line offering is the Iridium IX.
The smaller electrode leaves more space for the flame kernel to grow so that it gets less easily extinguished and grows faster ("quenching") which comes in handy during cold start, and it also lowers the required voltage to jump the spark gap ("hotter spark").
And they last ~50k miles as iridium is more resistant to spark erosion.
Another option is the PGR6A, which instead of the Iridium electrode has a fine platinum electrode, a small platinum chip laser welded to the ground strap and lasts ~80k miles. For $4.49, they're basicalling giving these away.
Maybe a stupid question; but is there any difference in the 8v or 16v spark plugs? Else i'll get the BPR7EY's from the local parts store here (yeah they do have them here..)
I have been running the iridium plugs for about 3 years now. I found them at SEMA where NGK had a booth. I spoke with an NGK engineer about my setup and that was his recommendation. They have worked well for me. One step colder. I also like the small electrode tip. Running 22psi, I feel it is less of a hot spot for detonation. My EGT's run typ between 1250 to 1450.
05-31-2014, 05:28 PM
They are cheap by the way, only $1.89 at O'Reilly's.
