NGK BPR6ES-11 vs. NGK BPR6ES-8

[_Madman_]

I'm starting this thread because I couldn't find any info on NGK plug last digit (gap size in millimeters * 10) and different revisions of the plugs in this forum or Google. So I hope someone can benefit from this discussion.

I replaced the spark plugs today, unfortunately, the only ones available were BPR6ES-11 (V-line), which are gaped at 1.1mm or 0.0433".

What are the bad effects that I could run into with such a wide gap? I hope the pistons are not reaching the plug? WTF

Mechanic told that re-gaping NGKs 11 to 8s is not recommended, so I guess I will order the BPR6ES-8, but for now, should I expect any problems with these plugs?

Form what I gather, 11 might not be able to produce the spark at high boost levels, but bigger spark should be better for idling and cruising.

I didn't felt any stuttering at high boost 16psi so far. But then again, car was stuttering at 16psi with old plugs, so maybe it can run even better.

 

[ramsack]

why did you start another thread about this? factory gap recommendations are 0.028-0.031". the last number (say 11) on a ngk is just the gap it comes set at. it's always recommend you check the gap anyway. you may want to get a heat range colder too. bpr7es. your car will run like crap on a .043" gap. your pistons are nowhere near touching the plugs.

 

[Damills]

ALWAYS gap your own plugs and like mentioned above I second that you might be better over with BPR7's rather than 6's. Some people prefer non projected tip over projected as well, I would also look into that

 

[Backinajiffy12]

+3 on gapping and a colder plug...a DSM with even a few mods with foul the 6's out real quick

 

[_Madman_]

Sorry, for dual thread setup (see. http://www.dsmtuners.com/forums/newbie-forum/368844-rough-response-hesitation-near-peak-boost.html), but the last one was about hesitation which I managed to fix, and it turned into spark plug thread.

I created this one to discuss spark plug issues, and only because I was searching for like 2 hours today and couldn't find any info on NGK plugs with extra gaping index in them (search with NGK BPR6ES-11 comes up empty).

My mods in profile are up to date and I was wondering about BPR7ES setup as well. As far as I understood, the 6s are just fine for T25ed car (http://www.dsmtuners.com/forums/frequently-answered-dsm-questions/233421-spark-plug-faq.html), but since I drive the car hard, I was thinking that 7s might be even better.

If you say that T25@16psi is fine with 7s, I'll definitely switch to them.

So it turns out larger gap creates a weaker spark?

 

[ramsack]

So it turns out larger gap creates a weaker spark?

correct. also with a t-25 pushing 16 psi, i would get the colder plugs. they don't actually create less spark, they just have thicker metal area where it bolts to the head to get rid of heat quicker, to help avoid knock. unless you do something like a CDI with huge voltage or run really high boost, you should stay in the stock gap range.

 

[_Madman_]

This would definitely help, as the car seem to pick up some knock in EvoScan logs after some driving. T25 seem to heat up the air quite badly.

 

[knochgoon24]

The T25 is a hairdryer past 15psi.

I'd just gap the plugs down to .028" and go from there. I'm surprised the car isn't stuttering with a gap that large. I know my car started to miss under full boost anytime the gap got larger than .040".

 

[DSM1G90]

"11's" were for the NT motors that had a set compression. the others needed to have that short gap due to the higher compression coming from an forced induction source like a turbo or supercharger.