HR on stock plugs

[Dr. D]

hey this is a quick thread and thanks in advance for the help. what is the stock heat range on the OE plugs on the MZR? and which plugs are everybody running? right know i have the OE lazer iridiums from NGK but it is def. time to go 1 step colder but dunno which ones are best NGK or DENSO.
thanks guys.

 

[Blendercloud]

There are a bunch of threads on the site (MS3 and MS6) that talk about this. I found a couple just by searching "Denso" or "spark plug". Nevertheless, I'll throw some in to contribute to your thread and answer your question.

I'm running the Cobb Stage2 93 +TMIC map. I swapped out the OEM FoMoCo plugs for the Denso ITV22's (1 step colder) and my KR went from 3.5-4.2 down to .35-.7. As of a few weeks ago it started to get really hot here in St. Louis (97 degrees with 95% humidity) and I began noticing a little more KR by both feeling and datalogs. The KR had risen to 1.5 on ocassion. So I ordered the ITV24's (2 steps colder than stock). The car during acceleration feels like it never has before. It fees incredible!

The Denso plugs will come gapped at .028-.030 out of the box. It goes without saying that you should check the gaps out of the box, but be careful not to compromise the Iridium tips. The ideal gap would be .028.

The NGK plugs that are one step colder come out of the box at .044. There are certain tolerances that you must respect when regapping a spark plug. You should never manipulate the gap more than .012 from the 'out of the box' gap. Essentially, the closest gap you should be using with the NGK -1's is .032 without potentially compromising the performance and reliability of the plug.

People do use these for the MZR DISI turbo, but people who know what they're doing strongly recommend against it because of the very wide gap out of the box. I'm sure there will be one or two people who will pipe up here saying they use the NGK -1's and have had no problems. The thing you'll have to ask yourself is... "is it really worth the risk?".

 

[tunersteve]

Denso ITV22s all the way. Chris explained it best. I thought that with iridium plugs that the gap range was plus/minus 0.08. Either way, the NGKs aren't designed remotely close for the gap we need to run.

 

[Super Shredder]

my itv22s will arrive today, i'll let everyone know how they are on stock ecu and minor mods.

 

[tunersteve]

my itv22s will arrive today, i'll let everyone know how they are on stock ecu and minor mods.

I've got very similar mods to you and they are great, you'll enjoy them. The car definitely seems to idle smoother and it seems a bit more responsive on the throttle as well. I'm currently running without the AP installed on my car.

 

[Blendercloud]

I've got very similar mods to you and they are great, you'll enjoy them. The car definitely seems to idle smoother and it seems a bit more responsive on the throttle as well. I'm currently running without the AP installed on my car.

Steve, on a side note - since you're running without your Cobb AP do you notice any difference in fuel economy?

 

[tunersteve]

Steve, on a side note - since you're running without your Cobb AP do you notice any difference in fuel economy?

Yes, unfortunately my mileage went down without the AP installed. I'm driving the exact same route and frequency, but I got a much lower average since I took the AP off.

 

[USAFVMI08]

Sorry for the hijack....

But that's good news that the Cobb gives better mileage! I ordered mine last night

 

[Dr. D]

guys thanks for the advice and what not but i was also asking what the stock plug's HR was...? im not worried about my knock (took me two days to dial in my map perfectly) just know that it time to go 1 step colder any more would be a waste. thank you.

 

[Blendercloud]

guys thanks for the advice and what not but i was also asking what the stock plug's HR was...? im not worried about my knock (took me two days to dial in my map perfectly) just know that it time to go 1 step colder any more would be a waste. thank you.

I've been trying to track down the stock spark plug heat range but can't find anything.

I do know that the Denso ITV20's are the same heat value as the OEM plugs. The Denso ITV22's are one step colder. The ITV24's are two steps colder.

Hope this helps!

 

[Dr. D]

it does b/c if the ITV22's have a heat rating of 7 and they r u step colder than the OE plugs are 6's (HR 6). thank you.

 

[Super Shredder]

am changing my gap on the ITV22s from the stock gap to .28 after i have been experiencing stutter and jerking between 2500 and 3300 rpm at very light throttle and cruise control and i was told this gap along with the AP will make the car run much smoother. the only other solution i've heard to this problem is changing the load maps on ATR but i haven't learned to make adjustments in ATR yet.

 

[tunersteve]

am changing my gap on the ITV22s from the stock gap to .28 after i have been experiencing stutter and jerking between 2500 and 3300 rpm at very light throttle and cruise control and i was told this gap along with the AP will make the car run much smoother. the only other solution i've heard to this problem is changing the load maps on ATR but i haven't learned to make adjustments in ATR yet.

Did you check the gap before you installed them? Mine out of the box were .29-.30 and I just matched them all up to .29 and put them in.

You're definitely doing the right thing, changing load maps in ATR is more involved and poses some disastrous results if not done right.

 

[Super Shredder]

i did not check the gap, because i synced the sparkplug install with a 30k service where i opted to switch out my plugs, so mazda handled it for me. this was before my tool ownership and 10mm and 12mm deep socket skills lol. i am running on the rough side of all the jerky threads i've read, it happens everyday when im on the highway or going downhill, and i am getting up to 5.0 KR on partial throttle, only for a second, but still, i feel it definitely is the reason.

as for the ATR, i am saving for 3 things right now, the corksport racepipe, my catback, and a protune in south jersey, so that should cover it, if the load maps are the problem.

 

[Blendercloud]

I had an issue with the new maps and causing this. For me, the jerk was power loss from knock retard. I changed maps from the Stage2 93 TIHSF + TMIC to the old Stage2 93 TMIC map and don't have the jerk anymore.

 

[tunersteve]

I have also had power loss from high KR. I believe anything above 3 will cut fuel.

 

[jracer]

i have the one step colder denzos.. i am in florida.. very hot.. wondering if two step cold would help.. i get very little knock.. .3-.7

 

[Blendercloud]

In the hottest conditions in Florida if you are only seeing .3 and .7 KR, you should stick with the ITV22's. You will always experience some degree of KR because the ECU is forever trying to advance timing just a tad bit more and hits a wall here and there.