yes!

 

Yes! don't know about how long term will be... but I will let you know!!!

 

Andy happens to be right - if you guys want, we can do a dyno next week with new OEM plugs vs new Iridiums - I don't expect a difference of more than one or 2 HP.

If you are still NA even with the basic mods, don't get one step colder - absolutely no need whatsoever. In fact, one step hotter might be the better route to go to actually lean the mixture out a bit (would have to see the A?F scale on a good wideband with proper placement of the sensor to know for sure - anyone have this sort of info)? I guess if all else fails I can hook my Horiba up to my car and see, though I honestly have no idea where it is

 

I didn't saw how many HP but if you say around 2 hp that is enougth to saw that are better than the stock ones... I believe that the IKH16 are not colder than the stock ones... all I know is that Iridium works better than the platinum!
my friend G35C have 12.5 A/F mix, he have the same mod that I have except plenum... I think I'm a little rich that him, he have better flow because of the plenum... but I have to see what is my mix for sure!

 

when buying new iridium plugs, is one step colder plug better for N.A.?

I am about to buy IKH16, but I see some people are using IKH20 for their n.a. application, why is that?

thanks.

 

found my answer:

quote from fellow member, ForceInduction:

The heat range of the spark plug determines how much heat the spark plug is capable of removing from the combustion chamber. The heat range of the plug does not increase or decrease HP. It changes the temperature that the tip of the plug produces. If the plugs heat range is too hot, detonation can occur. If the plug is too cold, the deposits will not burn off the tip and the plug will foul and may misfire. This will not hurt the engine. So running a colder plug will not hurt your engine, but there may be chances that you might not get full potential out of your plugs. If your vehicle is stock or close to stock you do not need to go with a colder plug.

If you only have a cone filter you should go with the IKH16, those will work perfectly.

 

Yes goto the dyno, I think andy is right too. You got these kids driving hondas with 100,000+ miles on the car, change out old spark plugs and say they gained 20hp.

 

One more thing. If they really give you 2hp (possible I suppose) there is no way you could FEEL that. So even if the dyno shows 2hp the people who "feel the increase" are still imagining it. I don't think a professional driver could feel a change that small.

 

yep

 

That is correct sir, but if you put them on, and what it used to be a close race before with another car, suddenly you spank his *** without any other modification, and have the same results after a couple of weeks of driving, you get a feeling that those spark plugs had to do something with it! And maybe, just maybe, they are worth a little more than 2hp... dont you think!

My brother and I raced every time we did something to our Z's until it got pretty close. He installed the Iridiums, and he started to pull a car lenght on me. Take it or leave it. That was our experience. Not trying to sell something, just sharing our experience with other fellow members...

In case anyone wonders, we had around 5k to 6k miles on the odometer each.

 

Its kinda like arguing which brand of match makes a better fire =)


Fire is Fire.

X

 

Found some info here..

http://www.densoiridium.com/heatranges.htm

What range are the stock ones does anyone know??

 

i have the denso irridium's 2 step colder plugs, but i will be running over a 100 shot of nitrous among other mods.

you dont need colder plugs for stock cars. waste of money. apexi350z is right. the only difference is the colder step plugs is their ability to dissapate heat.

colder plugs dissapate heat faster then stock plugs. the colder the plug rating over stock the faster it dissapates heat. the ONLY reason you need colder plugs or where they would be usefull, is when you have cases where you will have higher cyclinder pressures. this meaning that you are running some sort of FI or N2O, cams etc.

higher cylinder pressure create more heat then otherwise would, for this reason you'll need a plug that can get rid of extra heat, and faster to prevent detonation.

so getting colder plugs will NOT free any otherwise locked up hp, they're more of a safety precaution. HOWEVER, the type of plug is a different story. as you kow, different metals conduct better then others. copper is the BEST conductor of electricty. this is followed by irridium and then platinum. this is also probably y copper wears out the fastest followed by irridium and then we have platinum lasting a long time. being a good conductor of electricity also means that a plug can make a spark in higher cylinder pressures because of their ability to conduct electricity better. when heavily modding your car, you need plugs that conduct electricty very well. stronger spark burns fuel more efficiently. i havent seen anyone that makes 2 step colder plugs for the z in copper, but ngk makes them 1step colder in copper. then you have denso with 1 or 2 step colder plugs in irridium. another big factor is gapping your plugs. gapping the tip and prong too close together, or too far apart plays a role as well. and this is where im stuck.

just emailed denso to c what my plugs should be gapped at in n2o applications.

having said that, i dont think power gains would be anywhere near to where you would notice it.
hope that helped. peace

oh and...

Denso irridum plugs: (thanks mjedens)
Stock: IKH16
1step colder: IKH20
2step colder: IKH22

NGK copper plugs: (thanks mysunset350z)
Stock: LFR5A-11
1step colder: LFR6A-11

 

just installed the IKH16 tonight, at first, I didn't feel anything different.. but after driving around town for about 20+ miles, it seems to have better reponse and pulls better after 4000 rpm?

it's definitely a keeper

 

I keep seeing ads for new NGK Irradium's anyone seen these for sale yet, one step colder for my FI kit?

 

I might suggest you look at clubplug.net

 

thanks, I didn't even know they were out because know one is talking about them, guess I need to go visit this seeminglu infamous website. Is their a part # anyone knows off hand for one step cooler NGK Irrad's? Guess I will go find out. Last time I looked for NGK cooler plugs it was ridicoulous, ended up being Marine plugs lol

Edit add, yeah just like I thought nothing but numbers to me gobble gook.

I know I need 11's and I know PL is Plat and FR is Copper
and I think I want 5's?

Am I close?

IFR5G11 $12.69

Think it's that one or what?

 

J/W if you had to gap them or did they come out of the box within specs? Thanks

 

no need to gap them, they are pre-gapped. Just install and drive! it was kind of tough to get to all the plugs, you have to remove the stb, air box, etc..

do the driver side first, since it's the hardest

 

5's are stock, 6's are 1 degree colder, 4's are 1 degree hotter!!!