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Why is the GS recommendation for NGK different than L or LS?

1976 Views 15 Replies 11 Participants Last post by  Merlin the Wrench
2
What's the difference? Is it just heat range? Since the GS uses the same motor as the 94-95 L/LS Coupes, wouldn't the recommendation for L/LS Coupes be the same as the GS?

Take a look at these two images:

NGK PART NUMBER: PZFR6F-11 [ recommended for GS Sedans ]


NGK PART NUMBER: PFR6G-11 [ recommended for L/LS Sdn/Cpes]
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yo! I'm doing the dreaded 90k service next week and figured that I should put in new spark plugs and spark plug wires.

WHERE CAN I GET THESE NGK SPARK PLUGS? (Also, how about 8mm spark plug wires?
u can just go to the ngk main website and order them, i got them recently for 77.90 for laser platinums after delivery which took about 4-5 days. wires i dont think we need them for legends......find out from someone who knows for sure tho
NGK

HAHA I just payed the same exact amount and just got mine yesterday. I have a 94 Legend Sedan. Cant wait to put them in my car has been dragging some serious azz lately. Havent changed plugs in over a year! Im such a slacker! As far as wires. i think only generation 1 has them. All we have is electronic ignition coils , no wires.
asianlegend,

The only thing I can come up with as far as the different part numbers is that at the NGK website, it doesn't specify the L/LS as being coupe or sedan. My guess is that those are listed for the L/LS sedans rather than coupe. And if indeed the GS uses that different part number, the Type II coupes would use the part number that the GS uses.
Re: NGK

KINGFABIAN said:
HAHA I just payed the same exact amount and just got mine yesterday. I have a 94 Legend Sedan. Cant wait to put them in my car has been dragging some serious azz lately. Havent changed plugs in over a year! Im such a slacker! As far as wires. i think only generation 1 has them. All we have is electronic ignition coils , no wires.
notice any difference?
I bought my Legend from original buyer who bought it new. It had 83K. Just completed my 90K service. Last thing I did was install new Denso Iridium IK20. The NGK R's that came out had a nice tan color but man they looked OOOOOLDDD! So I put in the Denso took for a test to see if I could feel any difference. Man! :D did I need new plugs. It made a huge difference in the engine response all the way from bottom to top!!!
Thanks :cool:. I created a monster thread when I started this one... asked a single question... got many answers, none of which answered what I wanted, and then comes LegendGS, a respected member of this board, to come and save the day! ;) :D

LegendGS said:
The only thing I can come up with as far as the different part numbers is that at the NGK website, it doesn't specify the L/LS as being coupe or sedan. My guess is that those are listed for the L/LS sedans rather than coupe. And if indeed the GS uses that different part number, the Type II coupes would use the part number that the GS uses.
I just stumbled over this thread trying to figure out the same thing. Why there is the difference between Type1 and Type2 spark plugs. I found this document on NGK website:
DOCUMENT

According to this chart, in addition to being Premium Platinum plug just as for Type1, Type2 spark plug has an "Inductive Resistor"(Z in the part number). It also has a different firing end construction (F in GS compared to G in L/LS)

Could somebody clarify what advantage difference this can make?

Should I just blindly follow the specification for GS or there is not that much difference?
slightly OT -

NGK platium plugs are changed every 60k miles- so a 90k service
does not required this replacement.

Guessed if you are unsure whether it got changed previously, might as well do it.

You may want to settle this issue w/ your dealer or whoever doing the service first.
hey, shahavchik.....

what kelvin temperature rating are your HID bulbs? they look soooo purplish. and where did you got it from? thanks.
imports_only1 said:
hey, shahavchik.....

what kelvin temperature rating are your HID bulbs? they look soooo purplish. and where did you got it from? thanks.
you gotta love photoshop LOL :D those aren't HIDs :)
So does anybody know the answer? What would be the difference if I use PFR6G-11 instead of PZFR6F-11 on a GS?
http://www.ngksparkplugs.com/techinfo/spark_plugs/partnumberkey.pdf

Geez, the guy asked for specs and all that has been said is babble. specs at NGK.

P=platnium
F=14mm
R=resistor (cuts noise in radio)
6=heat range (2-hot -> 11=cold)
G= fine wire nickel alloy center electrode
11=factory wide gap = 1.1 mm / .44 inch gap

xxxxxxxxxx

P=platnium
Z=extended gap
F=14mm
R=resistor
6=heat range
F=tapered seat at firing end construction
11=factory wide gap = 1.1 mm / .44 inch gap

What I see is this but a call to ngK might reaveal more. Both are platinum, 14mm. both are resistor and have the same heat range. The GS one has a shorter insulator with a tip that probably allows room for the glue when it bubbles out at temp. Gap is the same. My guess is that NGK expects the GS plug to tolerate being run at higher RPMs than the L and LS and have suggested to Acura that by using the shorter insulator and center insulator gap they can conduct off the heat generated at contantly higher RPM's without changing the overall heat range of the plug. You'd literally have to talk to a NGK technician to get the fine points. I doubt if I would use a GS plug in an L or LS and vice-versa as there would not be a horsepower gain, this looks like more of a life expectancy issue for the plugs based upon gearing. The L and LS won't spend as much of their life in higher RPMS like the 6 speed gearbox will. That is my opinion. Legends have a pretty good history with plugs. I've read mine a few times and they looked pretty good. If you were going to run at the track on a 200 mile race you might want a colder plug by one but doing so on the street would start it fouling maybe. I would stay with the recomended plug. Too hot a plug and one would start detonation as it would act like a glow plug. Stay with the factory chosen NGK's. Acura has already done the ignition homework by giving us one coil for each cyl. That cut the coil saturation issue most igntions have to deal with.

I don't know if this helps or not but here is an analogy. Early 911's. Porsche went to a colder plug to provide the best plug when racing around or at high speed. Great but it had a tendancy to foul at lower PRM's so all the Porsche 911 owners were driving around in 3rd gear to keep the PRM's up to keep the plugs from fouling around town. Put in a hotter plug and the fouling went away but other problems surfaced at higher RPM. If you look at the two NGK Acura plugs you will see that while both are the same heat range - designed to run at the same temp, the GS one is shorter. My opinion is that this tries to compensate for the PRM issue - ie, the GS engine runs up and down more each time it shifts than the automatic does. As a result, the GS plug is designed to handle a broader environment rather than get into a situation like the 911 which had to reduce the envirnoment by running around in 3rd gear when in town. Putting a GS plug in an LS won't do a thing for performance and putting a LS plug in a GS might cause some overheating and detonation at the highend, especially in states where the octane ratings are lower. When I went to FL I noticed I could buy 93 octane in many states but in states like here in CA, 91 is all we see at the pump anymore and sometimes 90. Legends run a pretty high compression ratio for a stock engine so I'd stay with the factory NGK plugs.
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Thanks a lot for your input. I took one of the plugs out last night to see what I have. It turned out to be Denso PK20PR-L11 (the L,LS) kind. Good thing about it is that I know that the spark plugs on my car were changed at least once (my car has 79K on it). Bad thing is that they are not factory recomended ones for GS. I don't have any problems with my car but after what you've said I might just go out and buy some GS spec plugs.

Thanks a lot

Merlin the Wrench said:
http://www.ngksparkplugs.com/techinfo/spark_plugs/partnumberkey.pdf

Geez, the guy asked for specs and all that has been said is babble. specs at NGK.

P=platnium
F=14mm
R=resistor (cuts noise in radio)
6=heat range (2-hot -> 11=cold)
G= fine wire nickel alloy center electrode
11=factory wide gap = 1.1 mm / .44 inch gap

xxxxxxxxxx

P=platnium
Z=extended gap
F=14mm
R=resistor
6=heat range
F=tapered seat at firing end construction
11=factory wide gap = 1.1 mm / .44 inch gap

What I see is this but a call to ngK might reaveal more. Both are platinum, 14mm. both are resistor and have the same heat range. The GS one has a shorter insulator with a tip that probably allows room for the glue when it bubbles out at temp. Gap is the same. My guess is that NGK expects the GS plug to tolerate being run at higher RPMs than the L and LS and have suggested to Acura that by using the shorter insulator and center insulator gap they can conduct off the heat generated at contantly higher RPM's without changing the overall heat range of the plug. You'd literally have to talk to a NGK technician to get the fine points. I doubt if I would use a GS plug in an L or LS and vice-versa as there would not be a horsepower gain, this looks like more of a life expectancy issue for the plugs based upon gearing. The L and LS won't spend as much of their life in higher RPMS like the 6 speed gearbox will. That is my opinion. Legends have a pretty good history with plugs. I've read mine a few times and they looked pretty good. If you were going to run at the track on a 200 mile race you might want a colder plug by one but doing so on the street would start it fouling maybe. I would stay with the recomended plug. Too hot a plug and one would start detonation as it would act like a glow plug. Stay with the factory chosen NGK's. Acura has already done the ignition homework by giving us one coil for each cyl. That cut the coil saturation issue most igntions have to deal with.

I don't know if this helps or not but here is an analogy. Early 911's. Porsche went to a colder plug to provide the best plug when racing around or at high speed. Great but it had a tendancy to foul at lower PRM's so all the Porsche 911 owners were driving around in 3rd gear to keep the PRM's up to keep the plugs from fouling around town. Put in a hotter plug and the fouling went away but other problems surfaced at higher RPM. If you look at the two NGK Acura plugs you will see that while both are the same heat range - designed to run at the same temp, the GS one is shorter. My opinion is that this tries to compensate for the PRM issue - ie, the GS engine runs up and down more each time it shifts than the automatic does. As a result, the GS plug is designed to handle a broader environment rather than get into a situation like the 911 which had to reduce the envirnoment by running around in 3rd gear when in town. Putting a GS plug in an LS won't do a thing for performance and putting a LS plug in a GS might cause some overheating and detonation at the highend, especially in states where the octane ratings are lower. When I went to FL I noticed I could buy 93 octane in many states but in states like here in CA, 91 is all we see at the pump anymore and sometimes 90. Legends run a pretty high compression ratio for a stock engine so I'd stay with the factory NGK plugs.
on their site Denso only shows one plug for all Acuras L, LS or GS. I seem to remember one time buying plugs from Acura and getting Denso instead of NGK. There might have been a time period where NGK was on strike or their supplier was. Personally I like Champion products but I use the NGK in my Legend. Either are fine plugs. We used Champion in racing for years and they had very good quality control. We used to use the plugs as a means of tuning the engine so it was critical they were consistant. One leaned up until the glue just began to bubble around the center electrode and then that was it - assuming the correct plug was used to begin with. The Champion Spark plug guys could almost tell you which way the wind was blowing from by reading the plugs. It is an art form. I trust NGK and Champion although years ago when NGK was new to the American market I did get a set that went bad at about 1500 miles. Drove us nuts trying to find the misfire until we put the old plugs back in and the problem went away. It was the whole set because the mis was moving around making it look like a mixture issue or general ignition issue.
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