Spark Plugs: Denso vs NGK

[EdgeAutosport.com]

Hey guys just wanted to clear the air on some slight misinformation concerning spark plugs.

We get a lot of request for Denso ITV22's because people seem to think they are pre-gapped. I'm not sure where this rumor started (it has been around for as long as I can remember) but the ITV22's are not pre-gapped. They coincidentally come with a gap range of .030 to .032 which is good for the stock heat range plug, but when going with a colder plug you also typically need to reduce the gap. It is recommended to run a spark plug gap of .026 to .028 when you are operating at higher boost levels that require colder plugs.

The following is from Cobb's Website.

Our data has shown that the factory spark plug temperature range (6) and gap (~.034”) are sufficient for stock boost levels and normal driving conditions. Although, operating the car with higher than stock boost levels or with the calibrations that are loaded on the AccessPORT, require that a spark plug gap of .026” - .028” (6.6 – 7.1mm) be used on a 1-step colder temperature plug. Denso currently offers this spark plug as part # ITV22 (please be sure to verify each plug is properly gaped before installing them). Our experience has shown that operating your turbocharged engine at higher than stock boost levels requires that your spark plugs be replaced at around 12,000-15,000 mile intervals.

NGK also offers a One Step Colder Plug comparable to the Denso ITV22. The NGK (LTR7IX-11) Iridium IX Spark Plug. The gap on these is typically between .035 and .037. Even though the gap is further from the ideal gap with the NGK's, it does not mean that it is harder to achieve the appropriate gap with these plugs.

From a performance stand point, with both sets of plugs gapped properly, you will not be able to tell a difference between the two. I hear stories from die hard believers on both sides about how terrible the other plug is but most of those guys have not had experience with both plugs. They just know a guy or have an uncle who says one thing or the other.

This brings us to availability. Denso ITV22's are currently on a galactic back order. We have had several hundred sets on order since December of 2012. Twice since then we got a shipment of four or five sets in and they sold out immediately. There is no ETA on when the next batch will come in nor how many it will include. However, we do have plenty of NGK Iridium IX's in stock and ready to ship.

So when trying to decide between the two, you don't need to worry so much about which one to get. Instead, just make sure that which ever one you get is properly gapped because they both require proper gapping.

Let me know if you have any questions and I'll be happy to help you out!

[Nitr0EngiE]

Originally Posted by EdgeAutosport.com Hey guys just wanted to clear the air on some slight misinformation concerning spark plugs. We get a lot of request for Denso ITV22's because people seem to think they are pre-gapped. I'm not sure where this rumor started (it has been around for as long as I can remember) but the ITV22's are not pre-gapped. They coincidentally come with a gap range of .030 to .032 which is good for the stock heat range plug, but when going with a colder plug you also typically need to reduce the gap. It is recommended to run a spark plug gap of .026 to .028 when you are operating at higher boost levels that require colder plugs. The following is from Cobb's Website. NGK also offers a One Step Colder Plug comparable to the Denso ITV22. The NGK (LTR7IX-11) Iridium IX Spark Plug. The gap on these is typically between .035 and .037. Even though the gap is further from the ideal gap with the NGK's, it does not mean that it is harder to achieve the appropriate gap with these plugs. From a performance stand point, with both sets of plugs gapped properly, you will not be able to tell a difference between the two. I hear stories from die hard believers on both sides about how terrible the other plug is but most of those guys have not had experience with both plugs. They just know a guy or have an uncle who says one thing or the other. This brings us to availability. Denso ITV22's are currently on a galactic back order. We have had several hundred sets on order since December of 2012. Twice since then we got a shipment of four or five sets in and they sold out immediately. There is no ETA on when the next batch will come in nor how many it will include. However, we do have plenty of NGK Iridium IX's in stock and ready to ship. So when trying to decide between the two, you don't need to worry so much about which one to get. Instead, just make sure that which ever one you get is properly gapped because they both require proper gapping. Let me know if you have any questions and I'll be happy to help you out!

on the denso and higher boost applications if you dont make the gap like .25 you will get blowout and it will foul out the plug, this happened to me several times in my tuning history

[EdgeAutosport.com]

Originally Posted by Nitr0EngiE on the denso and higher boost applications if you dont make the gap like .25 you will get blowout and it will foul out the plug, this happened to me several times in my tuning history

Thanks for the heads up on that! I was speaking more towards factory turbo with higher boost. But with a bigger turbo and higher boost .025-.026 will be necessary.

[speed_freak91]

My NGK's had insane gap when I got them from you guys. Seriously thought I was going to break the strap off trying to get it down to .028. If I remember correctly, they were over .04. They have been working great since I installed them though...

[Sam4]

Originally Posted by speed_freak91 My NGK's had insane gap when I got them from you guys. Seriously thought I was going to break the strap off trying to get it down to .028. If I remember correctly, they were over .04. They have been working great since I installed them though...

From an old import parts guy - the "11" refers to 1.1 mm factory gap setting or ".044 in"

[El_Diablo]

Originally Posted by Sam4 From an old import parts guy - the "11" refers to 1.1 mm factory gap setting or ".044 in"

You are correct sir.

http://www.ngksparkplugs.com/techinf...tnumberkey.pdf

[breakfstincluded]

great write up, much better than having had to sift through threads in search of a concensus in the past for this topic lol

[shamie]

Originally Posted by breakfstincluded great write up, much better than having had to sift through threads in search of a concensus in the past for this topic lol

Yes - thanks for the consolodation and clarification.

[sl33py24]

Amazon has Denso ITV22.. Thats where I bought mine. I had to wait 3 months to get them shipped.

[Keko]

Does anyone know why the Denso's have been on backorder for so long? Just curious

[silvapain]

There have been multiple cases of the ceramic insulation on the Denso plugs separating and either dropping down on to the ground strap, or disappearing altogether.

[atvfreek]

After running both sets on my car and tuning several cars on both, I prefer the NGK's. Once you start getting up there in power, the denso's seem to cause blow-out no matter the gap.

The denso's do seem to run a tad smoother at idle, but thats it.

Originally Posted by silvapain There have been multiple cases of the ceramic insulation on the Denso plugs separating and either dropping down on to the ground strap, or disappearing altogether.

Then you have this situation, which makes them a liability.

[BigRedSpecial]

My NGKs were ~.042 when I got them but they've been trouble free since

[anavrinIV]

I've regapped a few sets of NGKs without issue, the main thing is to get it right the first time. Small taps on the back of a vice (flat spot) or heavy work bench seem to work well and check often so you don't overshoot. All the ones I've seen have been .04-.042 but I've gotten them down to .026-.028 without any problems.

[EdgeAutosport.com]

I went out and measured a few to get that gap range for the NGK's, but I supposed it could be bigger. I didn't spend a lot of time on it because all that really matters is that they are gapped properly when you install them.

[The Nut]

I've heard plenty of fail stories with both brands. Fact is, sometimes you just get a bad set. Or a bad 1 or 2 in a batch that will make your car run like shit cause it only takes one plug to accomplish this fail. That being said, and like every one has said above and in many other threads...Don't put any plugs, no matter what the claim of being "pre-gapped", without checking it first. OEM recommended, 1, 2, or 24 steps colder. CHECK THE GAP BEFORE PUTTING ANY SPARK PLUGS IN YOUR CAR. That way if something is wrong, you know its not cause you didn't...CHECK THE GAP.

[breakfstincluded]

Does edge recommend use of any di-electric grease when installing spark plugs

[silvapain]

Originally Posted by breakfstincluded Does edge recommend use of any di-electric grease when installing spark plugs

NO; at least with NGKs:

http://www.ngksparkplugs.com/pdf/dyk_5points.pdf

[breakfstincluded]

Originally Posted by silvapain NO; at least with NGKs: http://www.ngksparkplugs.com/pdf/dyk_5points.pdf

Perfect, thanks (:

[El_Diablo]

Originally Posted by silvapain NO; at least with NGKs: http://www.ngksparkplugs.com/pdf/dyk_5points.pdf

I see a mention of anti-seize but no mention of dielectric grease.

[CWP_MS3]

Originally Posted by silvapain NO; at least with NGKs: http://www.ngksparkplugs.com/pdf/dyk_5points.pdf

That's interesting. Did you not use anti-seize when installing them?

[silvapain]

Originally Posted by CWP_MS3 That's interesting. Did you not use anti-seize when installing them?

No; I used to, but stopped using anti-seize after reading that pdf.

Originally Posted by El_Diablo I see a mention of anti-seize but no mention of dielectric grease.

Sorry, thought you said anti-seize. Because the plugs on our engines sit down so far in the head, any dielectric grease used in the COP boots will get hot enough to turn into a dry, crumbly mess. I don't use that stuff either.

[El_Diablo]

Originally Posted by silvapain No; I used to, but stopped using anti-seize after reading that pdf. Sorry, thought you said anti-seize. Because the plugs on our engines sit down so far in the head, any dielectric grease used in the COP boots will get hot enough to turn into a dry, crumbly mess. I don't use that stuff either.

I use permatex dielectric grease and I've never had it dry up on anything other than my old Jeep that doesn't get driven much. Most of that seems to occure just due to age but this car is my DD and sees about 17-18k miles a year so my plugs get swapped once or twice each year so no problems there either.

[The Nut]

Can using it when not recommended be bad?

[silvapain]

Originally Posted by The Nut Can using i when not recommended be bad?

See the PDF link I posted above.

[The Nut]

Originally Posted by silvapain See the PDF link I posted above.

Thanks so much duder! Learn something new every day.

[NCspecV81]

for some reason my stock plugs came gapped at .024" from mazda.

[The Nut]

Originally Posted by NCspecV81 for some reason my stock plugs came gapped at .024" from mazda.

Cause fucktards at the factory don't check the gap before installing. My OEM plugs each had a different gap.

[The Nut]

@silvapain (Hard keeping track between this thread and the BPV one) I notice with all the talk and info you provided about NGK & Denso, you still choose to use Autolite plugs. Are those their 1 step colders? And was it an availability thing with those or price or something else?

[silvapain]

Originally Posted by The Nut @silvapain (Hard keeping track between this thread and the BPV one) I notice with all the talk and info you provided about NGK & Denso, you still choose to use Autolite plugs. Are those their 1 step colders? And was it an availability thing with those or price or something else?

Haha, I need to update my signature. I switched to NGKs after having issues with closing the huge gaps on the Autolites. They come pregapped at some ridiculously high value; in the 0.040 - 0.050" range. Closing them down to 0.026" caused the ground strap not to be perpendicular to the electrode at all, causing wear and performance issues.

[The Nut]

Originally Posted by silvapain Haha, I need to update my signature. I switched to NGKs after having issues with closing the huge gaps on the Autolites. They come pregapped at some ridiculously high value; in the 0.040 - 0.050" range. Closing them down to 0.026" caused the ground strap not to be perpendicular to the electrode at all, causing wear and performance issues.

That info should be a sticky.

[x09MS3GT]

Originally Posted by silvapain Haha, I need to update my signature. I switched to NGKs after having issues with closing the huge gaps on the Autolites. They come pregapped at some ridiculously high value; in the 0.040 - 0.050" range. Closing them down to 0.026" caused the ground strap not to be perpendicular to the electrode at all, causing wear and performance issues.

Originally Posted by The Nut That info should be a sticky.

I concur. I was just about to ask silva about these plugs , seeing as how he had been running them for quite a while, and they are readily available here...

[Lakespeed6]

I had half of the ceramic on one of my Denso plugs disintegrate and the plug started arching all over the place.
Now using NGKs

[SFWD 1934]

Yea I have never used anything but NGK plugs on and of the import stuff. I have never used anti-seize either. Just use between 13-15 ft/lbs of torque at the most since these are just aluminum heads.

Jason

[2012FailWheelDrive]

NGK definitely seem smoother with higher boost. My car felt hesitant with the denso

[EdgeAutosport.com]

There is some great info coming through this thread so feel free to post up your experiences with either plug to keep it coming. Also what methods do you guys use to gap your plugs?

Mine may be a bit barbaric, but I use a the "lightly tap the ground strap with the handle of a screwdriver until it slowly closes to the desired gap" trick.

[SFWD 1934]

Originally Posted by EdgeAutosport.com There is some great info coming through this thread so feel free to post up your experiences with either plug to keep it coming. Also what methods do you guys use to gap your plugs? Mine may be a bit barbaric, but I use a the "lightly tap the ground strap with the handle of a screwdriver until it slowly closes to the desired gap" trick.

Sounds about like me. Typically just use the stainless top on my Snap-On box. I've been doing it so long I know how many times I need to do it as well as how hard to tap. One little trick you can use is if you have a feeler gauge set where the feeler gauges can be removed, take the desired feeler gauge out, and as you tap keep it under the strap so you cannot go too far on pinching the gap down.

Jason

[El_Diablo]

I either use the tap method or I have a gapping tool that has a little piece of metal that grabs the strap so that you can bend it in either direction. Gapping pliers are nice too.

[atvfreek]

Originally Posted by El_Diablo I either use the tap method or I have a gapping tool that has a little piece of metal that grabs the strap so that you can bend it in either direction. Gapping pliers are nice too.

I use the same gapping tool that hooks onto the electrode. Works mint.

[p057]

i've been using the slightest amount of antiseize on the NGKs for the last 3 sets.
dielectric grease up and around the boot. no corrosion, but it also seems pretty useless.
torquing, i've gotten a feel for it, it almost sits in at the last turn and feels secure. never had a problem with it.
gapping, i'll tap it on smooth concrete next to the car. seriously. just light taps, slowly, use blade gauges until .026 and good.