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Discussion Starter · #1 ·
After seeing so many discussions on platinum vs copper ngk plugs and using 6 or 7 heat ranges i decided to look into some of the facts about the various plugs being suggested and this is some of what I've found. First off, here's a link that explains what the letters and numbers mean, I suggest you open it before reading this.

http://www.ngksparkplugs.com/techinfo/spark_plugs/partnumberkey.pdf


The Helm manual says to use the following plugs

H23A1 normal driving: ZFR6F-11
H23A1 high speed driving: ZFR7F-11

H22A1 normal driving: PZFR6F-11
H22A1 high speed driving: PFR7G-11

From looking at NGK's webpage I saw that they don't make a PZFR7F-11 so I imagine Honda figured out that the PFR7G-11 is the closest match to the PZFR6F-11 plug with a heat rating of 7. In case you're wondering what the differences beside the heat ratings between these two plugs are..... the Z means "Extended Gap" and is not an option with a heat rating of 7. After seeing this I tried to see if NGK made a plug with code PFR7F-11 (just got rid of the extended gap option) and saw that they don't make one. This explains why the G is in the part number rather than the F. The G means "Fine wire nickel alloy center electrode". This is a type of tapered seat. The F means "tapered seat". So basically in order to get a platinum plug with a heat rating of 7 you have to use a plug without the extended gap and you have to use a different type of firing end (but it's still a tapered seat plug.

The next thing I looked at was how a zfr6f-11 (or zfr7f-11)compares to a pzfr6f-11. Platinum/copper core and heat ratings aside..... the copper plug has a MUCH different designed firing end than the platinum plug. Look at these two links and you'll see that the copper plug has a firing end shaped like a v and the platinum has a domed shape.

ZFR6f-11: http://www.ngk.com/more_info.asp?AAIA=&pid=3021
PZFR6f-11: http://www.ngk.com/more_info.asp?AAIA=&pid=2530

I don't know enough about spark plug design to comment on what you should take out of this but I'm hoping someone else will. For now I'm going to run the PFR7G-11 in my car though.
 

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interesting.......i am using zfr7f-11 with my nitrous setup. I have read about the much debated copper vs platinum plugs but I don't think anyone pointed out the difference between the shapes and design of the copper vs platinum plugs.

perhaps someone more knowledgable will chime in soon. I'm curious as well.
 

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Discussion Starter · #4 ·
I decided to run a colder plug for multiple reasons
1. I have a jdm h22a which has higher compression (although it does come with the same plugs as a usdm from the factory)
2. Honda suggests it for continuous high speeds driving
3. I plan to run a small shot of nitrous in the near future
4. It seems to have got rid of some problems i was having when using zfr6-11 plugs that only happened after 45 minutes to an hour of driving which i'm guessing was heat related.
 

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Shark...why aren't you using the copper ZFR7F-11? I've never heard of this plug (BCPR7ES-11).

Scott...here are some good discussions about platinum vs. copper
http://www.preludeonline.com/showthread.php?threadid=47800&highlight=platinum
http://www.preludeonline.com/showthread.php?threadid=25362&highlight=platinum

I run copper and change them out often. My orig. platinums appeared burnt/hot after 20k miles, so I went with coppers instead. I've tried both heat ranges and like the colder version (ZFR7F-11) for the same reason you listed (#4 above).
 

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it is interesting how honda uses platinums in the H22 for someone reason but not in the H23. supposedly the platinums are better for high compression, is what is said in one of the links. my only problem is, many people here run the coppers and so does almost every tuner shop or professional racer that you see. if platinums are so much better, than these people would be using them.

$.02
 

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I'm using the ZFR7F-11's right now in my stock H22A1 with just a CAI. I've noticed that the "laggy" feeling I used to get with the 6 heat range plugs after running the car for a while or driving hard never comes back, the motor feels fresher and more peppy. I may try the 7G-11's sometime in the future.
 
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