NGK Iridium IX Spark Plugs? Are these good plugs for the NSX?

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13 December 2003
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73
NGK IRIDIUM IX Spark Plugs...

Ive been informed that NGK are the best choice for the NSX. Is NGK the way to go?
I can get 6 new for $40.

Advertised for....
*Acura NSX 1991 to 2004 C30A1, C32B1
*Acura Legend 1991 to 1993 C32A1
*Acura Legend "L", "LS","SE" 1991 to 1995 C32A1
*100% new.
*Retail Price over $110.00
*NGK Iridium IX
Part # BKR6EIX-11
Stock # 3764
6 Spark Plugs
 
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- no -
 
I think the same rule applies here that applies to oil filters. I don't believe many owners use Fram filters, even though they fit right and do what they're supposed to. I have yet to see proof of any performance benefit of iridium over platinum on spark plugs. Iridium plugs are marketed as better because iridium is harder than plat and has a higher melting temp. Has anyone ever had a platinum plug fail on its own because it was too soft or because it melted?

The key design difference between the OEM platinum plugs and the NGK IX plugs is that the plat plugs have dual platinum electrodes (both tip and ground), whereas the iridium plugs have a single iridium tip, and a steel ground. The exotic coatings over the steel substrates are what allow plugs to last 100k miles. Is a steel ground with an iridium tip good enough? I don't know. I do know that I have 4 cars with OEM platinums, 2 of which went over 100k on their originals, and I don't want to take a chance with anything else. I know my old plat plugs looked pretty good and all were within .002 of factory gap when they were removed. Where can we find observations of IX plugs after 100k?

On a $/mile basis, OEM spark plugs are about the cheapest thing to maintain. Cheaper than gas, tires, clutch, belts, brakes, oil, fluids, insurance, registration, etc. And they're not entirely easy to swap out. My preference is to use the factory-recommended plug and have peace of mind rather than try to save ~$30 every 100k.
 
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Oem plugs are about $17/each. ~$102/set
Those IX plugs were mentioned at $40/set

$60 difference. As for performance difference, they may or may not be better. All I know is in my truck, I've ran 3 different set of platinum plugs through a period of 5 years and it ran the same. But when I swapped to the hyped up Bosch Platinum 4 plugs (4 grounding straps), the difference was huge. Prior it would have a hard time revving to redline, now it runs smooth all the way up. Not a placebo effect, since I wouldn't goto redline before because it would have such a hard time doing so, now I can and I do. So my answer would be, yeah plugs can and do make a difference.

The question is, how much of a difference will the iridium make? I say, if it's cheaper and it offers a minimum of equal performance and quality, then why not?

I'm certain that sparkplug technology has evolved in 18 years. If father honda knew best, there wouldn't be a factory tape deck in a 2005 nsx. We're not comparing Fram to Oem oil filters, it's NGK oem platinum vs NGK Iridium IX. Obviously it's going to be good quality.

Here's a little thing I found, check out question#4
http://www.nbmeiya.com/engfaq.htm
It says "standard plug to Iridium plug", but doesn't say if it includes the oem platinum.
 
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Oem plugs are about $17/each. ~$102/set
Those IX plugs were mentioned at $40/set

$60 difference.


well... i've bought the OEM ones (NGK in Honda red boxes) from Dali Racing, and they were only $55... so much for the difference...and my opinion, for what it's worth, is that for an stock engine you use OEM sparks..i believe some FI applications require different ignition.
 
I have the IX plugs in my car. I don't know the mileage on them as they were in there when I bought it 4k miles ago. My car has 65k miles now, so I doubt they are very old.

In any event, the engine runs smooth and has no ignition problems that I can feel or see.

<img src="http://www.nsxprime.com/photopost/data/1087/medium/DSCF0093.jpg" />

David
 
I have changed a zillion spark plugs in my life and never seen any noticeable seat of the pant's HP gains ever. It's kinda like people changing brands of oil and claiming to feel a jump in power. Realistically I don't think thats possible. Just my .02.
 
Right, thanks for the info and thoughts in the mater.

I do not mind spending the extra money on the recommended OEM's. I just felt that if Platinum’s and Iridium’s are both from NGK then I could be safe. I want to do what is best for my NSX and try not to cut corners. I have considered buying Bosch Platinum 4s (and do have a feeling they could be better than the average plug out there) but I keep hearing that NGK were intended for NSX. So I just wanted your opinions to make my final decision. Overall my goal is to do what is most healthy for the engine.

Thanks again for the help.
 
I had a 1997 Nissan Maxima a while back and I swapped out the original old oem plugs for a set of another brand, I think Bosch. The car immediately developed a misfire at idle. I thought maybe I had damaged a coil pack from taking them out and reinstalling, so I took the car to the dealer. They said it was the a/m plugs I had installed. They installed the factory model NGK plugs, which cured the misfire.

The dealer stated to me the oem plugs are "indexed" for that engine. Now my understanding of indexing a plug involves trial and error in trying to line up the electrode a certain way to the valves. It depends on the position of the electrode in relation to the spark plug's threads. You just keep trying different plugs until you get it where you want it. Then you mark that plug for that cylinder.

I doubt that's what the dealer was referring to, but anyway the oem plugs did seem to fix the problem.
 
I would say stay away from those. That's one where I have read about cases where the tips have broken off in the combustion chamber.

Those are the plugs I was referring to in my truck. I got AMAZING results from those.

Have only a year on them though. I'll run them the full 60k or 100k or whatever the interval is for them to see what happens. I'm sure they'll out live my truck because I've got 190k miles on my truck now.
 
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You built/put together your Smart car in your dinning room! Freaking awesome! How did you get it out of the house?

+1 :eek:

As far as the plugs. Local Acura dealership recommend the NGK Plat. plugs to me instead of the OEM Honda (which are actually made by NGK) and when buying the plugs... the irid. and plat. were the exact same price (or not much dif at all) so I went with the irid. in my car. Well here I am about a month or so later and the car is running great!
 
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I don't recommend for nor against Iridium spark plugs.

I use NGK Iridium on my NSX for nearly 6 years. No problem, no complaints, swapped out the old and went 1 heat range colder immediately after installing CTSC (BKR7E-IX). I did so not for cost saving. I ran the same NGK Iridium BKR7E-ix in my Supra. The cooper BKR7E (6097) works great too, but I used to changed out the cooper spark plugs with every oil change prior to switching to Iridiums.

Most people on Supra forums running higher boost don't run Platinum spark plugs. Iridium is 6 times harder, 8 times stronger, and has a melting point 1200 degrees higher than platinum. A lot of Supercharged S2K owners also run Iridum spark plugs.
 
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I have been using the NGK Iridium BKR6EIX-11 for the past 2 years. I just changed them last week after 30000 miles. They have been running smoothly for me.
 
The Irridium plugs in 1 step cold are advised for forced induction.
I just put them in my CTSC last week.
I don't know why for forced induction they are advised over platinums though.
 
I had a 1997 Nissan Maxima a while back and I swapped out the original old oem plugs for a set of another brand, I think Bosch. The car immediately developed a misfire at idle. I thought maybe I had damaged a coil pack from taking them out and reinstalling, so I took the car to the dealer. They said it was the a/m plugs I had installed. They installed the factory model NGK plugs, which cured the misfire.

The dealer stated to me the oem plugs are "indexed" for that engine. Now my understanding of indexing a plug involves trial and error in trying to line up the electrode a certain way to the valves. It depends on the position of the electrode in relation to the spark plug's threads. You just keep trying different plugs until you get it where you want it. Then you mark that plug for that cylinder.

I doubt that's what the dealer was referring to, but anyway the oem plugs did seem to fix the problem.

Not sure what your dealer was referring to.....but "indexing" your plugs is something anyone can do when installing new plugs. While the spark plug is removed, you put a mark on the top of insulation that is lined up with the opening of the electrode of the plug. This is so you can tell which direction the opening of the electrode is facing when you install the plug. Next you install the plug and align the opening of the electrode with the intake (intake valves) of your engine. This is rumored to be good for a one horsepower gain in any engine.:wink: Good luck proving that one.

My advise on sparkplugs for your NSX is this:

I have raced Japanese motorcycles for twenty five years and tried everything at one time or another. Stay away from Bosch and Champion spark plugs. Stick with either ND (NipponDenso) or NGK. Both Irridium and Platnum will suit your needs. Get which ever one you can get a better deal on.
 
According to ngk's website:

BKR6EIX-11 stock #3764 for all years

http://www.ngksparkplugs.com/part_finder/car_truck_suv/default.asp

So their website says yes unless someone else knows why not....

Standard BKR6ES-11 5553 .044 - $1.99 at Autozone = $12/set
V-Power BKR6E-11 2756 .044
G-Power BKR6EGP 7092 .044
Laser Platinum PFR6G-11 5555 .044
OE Laser Iridium IFR6E11 6741 .044
Iridium IX BKR6EIX-11 3764 .044

I just went with the standard copper BKR6ES-11. $12/set at Autozone. Good enough for 600whp+ its good enough for me. I have no problem replacing my plugs every year since they are that cheap and not hard to replace.

0.02
 
Those are the plugs I was referring to in my truck. I got AMAZING results from those.

Have only a year on them though. I'll run them the full 60k or 100k or whatever the interval is for them to see what happens. I'm sure they'll out live my truck because I've got 190k miles on my truck now.

i have had similar results. basically the plugs provide additional flame initiation points and in vehicles with less-than-ideal combustion they are guaranteed to help. as far as nsx goes, the difference may be negligible as it has a very good combustion chamber design.
 
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