plug gap for BPU

[JohnA]

I've seen here that people tend to run 0.7mm on BPUs

 

Yesterday I fitted a new set of iridium NGKs, BKR7EIX-11.

Now these came pregapped at 1.1mm, which is funny because I'm sure I had bought a couple of sets before and they were gapped at around 0.7mm (they didn't have the "-11" suffix obviously, must be a new fruit)

 

I decided to follow their advice and not gap them myself (although I've gapped iridium plugs in the past with no problems)

 

The question is: has anyone here used plugs of this heatrange (one step colder than stock) at 17-18psi and still kept the 1.1mm gap?

 

Cheers guys

[normore1]

1.1 mm is guaranteed to result in missfire at high rpms at that boost level. Standard Denso Iridiums (IK 22) are 0.8 mm (0.032") which works fine for your boost levels. 1.1mm is the stock gap for stock boost levels.

 

derek

[JohnA]

1.1 mm is guaranteed to result in missfire at high rpms at that boost level.

what sort of guarantee is that then?

 

If mine doesn't misfire, do I get my money back?

 

I know it's the stock gap for stock plugs mate. I've also ran stock plugs at the same boost level and it didn't feel any worse either, despite the heat range being different.

 

If the plugs came gapped at 0.8 or so, I would have left them alone, but now that they are preset at 1.1mm I don't want to fiddle with them if there is no reason to believe that the gap is indeed too large. The thickness of the iridium coating is the main reason.

[Alex]

The NGK Iridium's are largely untested...but you'd be a fool to try and regap them as you'll probably knacker the iridium.

 

Try them...see if they work at 1.1mm if they do we'll add them to the FAQ.

[normore1]

what sort of guarantee is that then?

 

If mine doesn't misfire, do I get my money back?

 

I know it's the stock gap for stock plugs mate. I've also ran stock plugs at the same boost level and it didn't feel any worse either, despite the heat range being different.

 

If the plugs came gapped at 0.8 or so, I would have left them alone, but now that they are preset at 1.1mm I don't want to fiddle with them if there is no reason to believe that the gap is indeed too large. The thickness of the iridium coating is the main reason.

 

No guarantees here mate on anything especially advice Hey if they don't misfire and your stock plugs didn't misfire at 1.1 mm, why ask the question. Put them in and don't worry about it. It's just hard to believe that you ran stock platinums at 1.1 and didn't have any misfire at 18 psi but anything is possible. Just about everyone I know who ran the stock gap on high boost experienced misfire. I agree, gapping iridiums is not recommended.

 

derek