Spark Plugs and Ignition

[Jays07MS3]

I was wondering why the factory plugs wouldn't be colder too. I know there's always a compromise with the decisions made on factory cars, largely to keep costs down and efficiency up, while still making the best product they can... but I can't figure out how this applies to sparkplugs.

While we're at it, is there any drawback to an ignition amplifier, such as increased heat or draw on the ... alternator maybe?

The downside of a colder plug is that it may foul quicker since it might not burn off the deposits as well as a hotter plug. This is probably why the car comes with hotter plugs since they'll last longer and still perform decently.

While a hotter plug may last longer, it will also be prone to pre-ignition (knock).

To have the best of both worlds, you would want the hottest plug you can run without having knock at max boost/WOT conditions.

I also plan on running a colder plug soon as I'm starting to see more knock at WOT.

 

[Gmac03]

how do y0u tell if your knocking, iv always wanted to know this.. haha

No you don't. Once you hear it you'll wish you didn't or it didn't happen.

Gmac

 

[bacarl]

Wow, that sounds fantastic and I am 99% sold on new plugs, but then I have to ask (because this time around I am being ANALLY discerning about what I throw on my car) if there are benefits without drawbacks, why wouldn't the come stock on our cars?

Because our cars don't come stock with boost controllers, CAIs and 3" downpipes...

 

[AutoXRacer]

You basically need colder plugs when you increase boost. The higher the boost, the higher the cylinder temps will be, so you need a colder plug to reduce the cylinder temps.

The only way you can monitor knock is with a data logger like DashHawk or something similar.

 

[scatt nasty]

Alright.. due to my current mods and my knock readings I've decided to go with the colder plugs.. I'm going to go with the Denso ITV24's. Couple questions though.. What are these pre gapped at ? What do they need to be gapped to if they need to be gapped at all ? and has anyone done the install themselves ? Install time/tools/any tips ?

 

[AutoXRacer]

They come pre gapped... Iridium plugs are not recommended to be gapped since the tip is very brittle and will be damaged if gapped.

Denso is the only Iridium plug that I know comes already pre-gapped.
The ITV24s I think come with .28" or .30" which is with in stock specs.

Just bolt them up...install time is roughly 30-45mins depending on your experience.

 

[scatt nasty]

awesome..thanks

 

[coyfish]

Good info here. But will the colder plugs make a noticable difference with light bolt ons? They are only 12 bucks so I should just buy em. Just weird that they are so cheap yet not too many people have them.

 

[OJ Bartley]

I was under the impression that the ITV22 was gapped close to what our factory plugs are, and are one step colder...

Denso Iridium Power ITV27 gap 0.8mm (0.0315") three steps colder HIGH HEAT RANGE

Denso Iridium Power ITV24 gap 0.8mm (0.0315") two steps colder

Denso Iridium Power ITV22 gap 0.8mm (0.0315") one step colder

Denso Iridium Power ITV20 gap 1.1mm (0.0433") Mazda heat range

Denso Iridium Power ITV16 gap 1.1mm (0.0433") one step hotter LOW HEAT RANGE

Again, lots of info if you check the top thread in this google search: Plug Info

 

[mspeed3420]

So am I going to be fine running NGK 1 Step Colder Spark Plugs even tho they are not pre-gapped? I am pretty new to this stuff and I already ordered the NGKs, how should I take it from here?

NVM guess Im returning them lol

 

[PCspeed3]

All you need to get is a spark plug gapping tool.

http://www.expertvillage.com/video/6078_spark-plugs-gap.htm

But I would suggest you just buy Denso's in the first place to make it easier.

 

[OJ Bartley]

if you've already ordered the plugs you can probably gap them, but be careful with the iridium ones, because I think they can lose the coating, and also if you have to adjust them too far, they end up not parallel, and the spark loses surface area to jump to.... |_| turns into /_| sort of.

 

[IKE=MS3 08.5]

any reason why u couldnt use the 2 step colder on a mild bolt on set up?

+1

 

[mattj3636]

so pretty much, get the Denso's?

 

[AutoXRacer]

All you need to get is a spark plug gapping tool.

http://www.expertvillage.com/video/6078_spark-plugs-gap.htm

But I would suggest you just buy Denso's in the first place to make it easier.

(shocked)(braindead Definitely NOT the way to gap Iridium plugs!!!!

By tapping the spark plug you risk the chance to come in contact with the Iridium tip causing it to fracture or break.
Iridium tips are very very brittle and will break with the slightest contact. In addition, the coating on the tip and electrode will crack and flake off.

They sell a tool that is made to properly gap spark plugs without having to tap them...

 

[AutoXRacer]

so pretty much, get the Denso's?

If you can, stick with Denso since they are already pre-gapped.
HKS might also come pre-gapped as well.

 

[IKE=MS3 08.5]

I know that everyone is saying that the NGK spark plugs don't come pre-gapped but what about the NGK ILTR6A-8G, it is listed as having a .032 gap. I saw these on SU website and was curious about these. They are almost twice the price as the Denso but I think this gap falls under what we need.(correct me if I'm wrong) Any thoughts about these? Why are they so much more?

 

[AutoXRacer]

Those are the Lazer models. NGK for some reason offers a Lazer Iridium and a IX Iridium line. I always though the IX line was more expensive... Hmmm...

Weird...

NGK info:
http://www.ngksparkplugs.com/products/spark_plugs/index.asp?mode=nml

 

[IKE=MS3 08.5]

So I guess I should stick with the denso plugs? Are they good quality I have heard of NGK but never denso until I started looking for plugs for my speed3?

 

[IKE=MS3 08.5]

Ah stupid me, that is the Denso logo that is on the F1 Toyota car. Nevermind, if its good enough for F1 it will be good enough for me.