Difference between BP8ES and BR8ES

[hecyan]

What is the difference between this two. The BP8ES or BPR8ES is what we normally run and has a longer insulator and the BR8ES without the P has a flat look on the tip of the spark plug.
Any performance diference between these two.
Thanks

 

[markGSX]

dunno if this helps any (probably not)
http://www.ngksparkplugs.com/techinfo/spark_plugs/partnumberkey.pdf

 

[dedlewamp]

The difference between the BPR8ES and the BP8ES is the resistor. The BP8ES does not use one.

Spark plugs use resistors to suppress the emitted electrical "noise" from ignition systems. We must do this to comply with government regulations on the amount of electrical noise allowed by ignition systems. Stock plugs are resistor type, so use of a non-resistor plug and YMMV.

B Thread diameter = 14 mm
P Construction = Projected Insulator Type
R Construction = Resistor Type
8 Heat Rating Number = Hot -> Cold
E Thread Reach = 12.7 mm
S Firing End Construction = Standard 2.6 mm diameter center electrode

 

[Defiant]

The P, with the projected tip, will tend to run cleaner and cooler.

The information about the R was correct, just dyslexic. Lost of pleolpe hvae taht prolbem.

 

[Black95TSIawd]

I've been told numerous times and by shop owners that a non projected tip will help reduce knock. Accurate? I've yet to try it out myself yet.

 

[dedlewamp]

I've been told numerous times and by shop owners that a non projected tip will help reduce knock. Accurate? I've yet to try it out myself yet.

The non-projected type of plugs are said to reduce compression ever so slightly, as well as start the flame closer to the top of the cylinder head. I noticed no difference though in my setup when switching from projected to non-projected plugs.

 

[Defiant]

If you're running too hot a plug with a projected tip, it will retain heat and become a compression-ignition source. The compression difference couldn't be measured. Due to their exposed nature -the very feature that makes them so well-suited for street use- projected tips are more subject to the violence of the combustion chamber. For full-race use, they may be more liable to be damaged than non-projected tips.
In the real world, you want to run projected tips if the engine will accomodate them.

Odd we've not had a plug indexing thread around here.

 

[Kevin Jewer]

I had chronic problems with breaking/burning side electrodes off. Those would then go through and ruin the pistons, head, and turbo.

When I went to nitrous on the EVO, I decided to finally try the non projected plugs. I initially started with 8s to give me some fudge factor as I tuned the nitrous in. Due to some mishaps and oversights on my part, I made two full passes down the quarter mile at 13.5:1, with the boost line pulled off the wastegate (max boost), full timing advance that I usually run, with a 75 shot, in the heat of summer, on totally seperate occassions. Both times the motor not only survived, but the plugs showed now signs of overheating on the side electrodes. Since then I have been convinced that I am better off with non-projected plugs and I'm calling it cheap insurance. Of course I still brought AFR back down to ~12:1

After a few weeks I would have some cold idle misfires on the 8s, so I switched to 7s (still non-projected). I have had similar succuss with them, and they are now my standard plug choice. I think anyone that is pushing the limits, especially for high boost pump gas daily drivers, should try them. I should have tried it a couple motors ago in the GSX.

 

[ikickuintheball]

To clear this up, you were using the BR8ES (and BR7ES later on), Kevin?

 

[Kevin Jewer]

That is correct. I also tried some BPR8ESs, but didn't get much data on them since I didn't have any "mishaps." But I honestly feel that the shorter side electrode is worth more than the colder heat range, and can be implemented without fouling issues as in the case of the BR7ES.