Poszperałem trochę w necie i znalazłem coś takiego na temat świec BKR5E-11 i ZFR5F-11.
http://www.mazdas247.com/forum/showthread.php?123631485-FP-DE-FS-DE-alternate-OEM-spark-plug-recommendationFP-DE/FS-DE alternate OEM spark plug recommendation
REPOSTED FROM CLUBPROTEGE. ORIGINALLY POSTED ON 1/24/2004.
To make a long story short, I was researching spark plug application compatibility for my friend's 240SX (between the ones used on mazdas and his car because I can get plugs cheaper than he can). Turns out none are compatible... but anyway... I stumbled upon the recommended spark plugs used for the Japanese spec FP-DE, FS-DE, and FS-ZE. They are very different than the ones used on the US spec FP and FS engines.
Most of the US spec engines (other than the MSP's) use BKR5E-11 plugs from the factory. They use the heat range level "5", which is very common for a NA engine. The Japanese spec engines still use the same heat range but use ZFR5F-11 plugs from the factory. I was curious what the differences between these two types of plugs were because the engine is basically the same. Turns out that the "Z" plugs are "long reach", meaning the base of the plug (where the 2 electrodes are) are longer, protruding into the combustion chamber more. Now realize that all of the Japanese spec engines I've mentioned already have higher compression than the US spec ones, so that puts "the plug will kiss the piston" out of the question.
I decided to throw down the few bucks to experiment and see how the engine responds (since my engine is now hybrid spec). The BKR5E-11s I took out have about 9000 miles on them, there is very little wear on them... they look practically new other than some carbon build up. First initial observation from the new ZFR5F-11 plugs was, when I was slipping the clutch to back out of the driveway... I normally just use the engine idle speed to "roll" it out... what's different now is, the engine no longer hessitates/stumbles/almost stall when clutch let off too much.... it smoothly and powerfully just goes.... a slight free rev before launching from a stand still is much more smoother and effortless than before.... I was thinking that I must be smoking crack that this is happening.... plugs normally don't do shit! But driving around the block, the engine seemed more eager to rev and didn't seem to bounce as much as it used to when shifting... it seemed to get to redline much faster and smoother before too... at the last 500rpm, the engine seemed to be making more power than before... and when I was just cruising through a parking lot, the engine bucked even less than before... it's nearly non-existant now combined with the mazdaspeed #3 engine mount I'm using
After that, I did some a quick search and found this:
http://www.fizzindi.demon.co.uk/longreach.htm It makes sense from what it says, as I previously thought that the longer reaching plugs did change how the flame front would work. As it says there, the ignition timing is also theoretically increased very slightly. I also believe that because the plug protrudes into the combustion chamber slightly more, there is a very minute increase in compression ratio. But regardless of all the technicalities, this does work well with my engine.
I'm thinking Mazda chose not to use these plugs in the US because they want to make sure that their engine will 99% run on crappy gas all of the time. Because these longer plugs protrude into the combustion chamber more, there is always the possibilities of increased hot spots which will lead to detonation. With the use of better gas in Japan, the use of these plugs there is not a real issue. What I HAVE noticed with these longer reach plugs is on cold starts, the engine doesn't seem to run as rich anymore... indicating that the mixture is being burned better/more fully than before (my cold start emissions are crappy anyway because I don't have VTCS anyore)... and if the combustion process is more complete, then more power, better fuel economy, and better emissions is the result
I recommend these plugs to everyone who have a NA FP or FS engine... they're cheap copper NGK V-Power plugs that serves a purpose... Don't buy into that iridium or platinum bullshit... all they do is increase service life... it takes more energy to arc those type of fancy plugs than the conventional good ol' stuff. I will still say spark plugs and wires don't make a difference in performance (I know this for a fact because when I changed the wires and put in the BKR5E plugs months ago, the engine performed no different than before)... but these do because they are physically different... the plug itself goes deeper into the combustion chamber, therefore repositioning the spark point... on other engines it may not make a difference/hurt it... but on our engines, it seems to be the "sweet spot"... remember using these MAY increase the possibility of pinging, so be prepared to use mid-grade or better gas
you can get these plugs anywhere and at the dealer if you want... the Mazda part # is 0000-18-F287
I don't know the real indepth technical workings of the combustion process, Jesse seems to know better... so that input will be appreciated
Jutro zmienię na ZFR5F-11 i zobaczę czy będzie jakaś różnica...
Napisane: 9 wrz 2011, 13:09
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