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Discussion Starter #1
looking to upgrade the plugs??


do we already have irridium tipped plugs??

id like to know (made a difference for me in the past, for sure)

as for now, denso's site has no application listed for the fx....

our OEM plugs have a p/n of::


PLFR5A-11 (STANDARD)
PLFR4A-11 (HOT)
PLFR6A-11 (COLD)

anyone know which of these one can expect to find??? im guessing that 'cold' refers to the climate in which the car is/was sold/driven, etc??

any info would be very helpful!
 

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I dont know much about them... sorry. But I am pretty sure we dont have iridium tipped plugs.
 

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I would be careful going to Denso's. I ran IT-22s in my 03 Cobra and one set that I purchased within 1 week had 3 plugs have complete porcelain tip failures. This is the first plug I have had this problem with. I know several other people who have had the same problem with Cobras and Lightnings, but we are running a lot of boost also.

Here is a pic of two of the plugs that failed.
 

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Cold/hot/ normal usually refers to combustion chamber temp and the need to stay away from preignition/detonation,not external climate...I would guess with a blower you would want cold,because of the higher chamber temp.
There is a huge debate about the new hot firing plugs(plat,irr,etc0 and the damage done elsewhere in the motor and Cat)I heard this first from GM powertrain engineers...stock plugs,change often.I have not stayed current because we changed plugs everytime we raced!
 

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denso iridiums

I've tried the denso irid plugs on my 300zTT, and found that they fouled out within a month. I was not too happy considering that i spent so much on them. My z currently runs at 21psi on pump gas and 25 on race gas so the need for a cooler plug is a must. I've gone the extra mile and decided to use HKS iridiums and so far, its been good.
 

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brnjugfx45 said:
stock plugs, change often.
So, we shouldn't be letting our plugs stay in for the 100K(?) miles speced by Nissan?

When should I change 'em?
 

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I just change the plugs for my '99 Accord V6. OEM plugs are NGK platinum. My local parts store only have 4 in stock, so I went with Denso Iridium plugs. A little pricy @ $12 a pop, but so far I am extremely happy with them. Before I changed the plugs the car was a littlle sluggish. The only modification to the engine is a K&N filter. I noticed now the acceleration is much quicker both from stop and passing. Also the mpg shoot up noticeably. I am talking about at least 20% improvement from my observation. Only time can tell now how long these plugs will last. [-o<
 

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esemes said:
ujmot said:
I dont know much about them... sorry. But I am pretty sure we dont have iridium tipped plugs.

per the SM, we have "platnum tipped"...........



i wanna ditch em for the denso, bosch, or ngk irridium's......
~ FX35's ALSO ~ Anybody else replace the OEM's for these to improve performance/mpg's?
 

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PINITI-FX said:
Anybody else replace the OEM's for these to improve performance/mpg's?
Have you had a chance to check out the discussion in the timing advance topic? It's a '45 discussion, but I'd be surprised if the answers were much different.

Also, I'll bet since you've got a VQ, there's a metric assload of discussion about it in FA's G35/Maxima(?)/Altima(?) sections, and on G35Driver.com .
 
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