We've had great success with the "Let's Talk Nitrous" thread, so I thought we'd start a couple of new ones that diverge from your general mod discussions.

Let's Ignition & Spark:
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High-boost forced induction, increased horsepower, or nitrous oxide demands more fuel, and subsequently demand fool proof ignition and spark systems that deliver higher better than OEM. So let's look at what the products are out there, hear from those that have taken the plunge, and perhaps even come up with the best system(s) for our modded G's.

Items in this discussion will include:
* Ignition Controls
* Spark Plug Wires
* Ignition Coils
* Spark Plugs
* High Capacity Alternators
* Other tips and tricks


Please make sure to be concise in your discussion, descriptions and include pixes & Links where possible.

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'03.5 Sedan 5a: BS/G, Prem, Aero/Body, Sport, Nav
Click for MODS - www.teamtransport.org/forums

 

let's start with an easy one... spark plugs.

What's all this "Hot" and "Cold" talk?
A "hot plug" has a long insulator nose which exposes more surface area to the combustion gases. This keeps the plug temperature higher overall which is ideal for stop-start city driving conditions.



A "cold plug" has a shorter insulator nose, which minimizes the amount of surface area exposed to the combustion gases. Cold plugs are typically used in racing conditions because of its ability to transfer heat out of the cylinder chamber quickly. Most turbo, supercharged and nitrous oxide applications use this type of plug because of the tremendous heat they generate. A colder plug can also minimize the risk of pre-ignition and detonation, however if the plug is too cold, there is risk of fouling during extended periods of idling and low-speed operation.



For most brands, the heat range number located on the insulator indicates the temperature range of each spark plug. The lower the number, the hotter the plug; the higher the number, the colder the plug.

Heat Dissipation in a spark plug
Of the 100% heat generated from the combustion, 20% is absorbed by fresh air from the intake of the following stroke. 58% of the heat is absorbed by the walls of the cylinder head which hold the spark plug in place. Twenty percent is absorbed by the insulator and side walls of the plug, the remaining 2% being absorbed by the spark plug wires.



What's so special about Iridium?
Iridium is a precious, silver-white metal and one of the densest materials found on earth. The natural properties of Iridium offer the opportunity to create one of the world's finest spark plugs. The result are spark plugs that require less voltage to spark, burns fuel more efficiently, sparks at leaner air/fuel mixtures, and delivers higher horsepower and better gas mileage.




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For NGK's, you will need LFR5AIX-11 (Stock), LFR6AIX-11 (1 step colder) they run around $9.95 to 13.95 ea

There are also Denso plugs (which I have been told are a little better): IKH16 (stock), IKH20 (1 step colder), IKH22 (2 steps colder). They run around $9.95 to 10.95 online.


lastly, there are Greddy plugs (iridium)
that run about $18 ea. Part numbers are Iridium 6 (stock?), Iridium7 (1step colder) and Iridium8 (2 steps colder).

These sparks are available online or at your local Kragen. Just do a search on the part numbers. Don't forget that these are priced individually and you will need 6 total.

Cheers, Ted

(Note: some text was copied/edited from mfgr websites. I love you all, but don't have the time to create verbiage for everything. So if you see content somewhere else, I never claimed to have created it!)


'03.5 Sedan 5a: BS/G, Prem, Aero/Body, Sport, Nav
Click for MODS - www.teamtransport.org/forums

 

ted: what would the benefit of goin 2 steps colder opposed to just one step colder? less chance of pre-igniting? would you just want to use 2 steps colder on a car that is used more for racing, due to the fact that if you use it for street use your car will be idling more and have more fouling? i guess the more boost you are making the colder you want your plug to be?

Daniel

screw the GTC's. Maya RT5's now!!!

 

Daniel:

what would the benefit of goin 2 steps colder opposed to just one step colder? less chance of pre-igniting?

>>>Less chance of pre-igniting and detonation... but for high boost or for nitrous shots over 125

would you just want to use 2 steps colder on a car that is used more for racing, due to the fact that if you use it for street use your car will be idling more and have more fouling?

>>That is correct

i guess the more boost you are making the colder you want your plug to be?

>>>Correct, but be careful if it is a daily driver and you will be in a lot of low speed or long idle situations. You may have to change your plugs more often due to foluling.


'03.5 Sedan 5a: BS/G, Prem, Aero/Body, Sport, Nav
Click for MODS - www.teamtransport.org/forums

 

thanks for the info. maybe you can help me out again.

so would it be benefical to go to a one step colder plug on a stock motor? or should one just wait till they go FI or nitrous before gettin the colder plugs?

would goin to a colder plug give you more performance on a NA motor? or would it not be as beneficial because it would lead to more fouling and having to change them out sooner?

Daniel

screw the GTC's. Maya RT5's now!!!

 

There's no reason to go one step colder on a stock engine. The stock plugs are already pretty well matched to the application. There's just no benefit to going colder. At the same time, for the reason you mentioned, fouling at low speeds/idle would result.

(No Benefit) + (Fouled Plugs) = (Don't do it.)

'03 G35s 5AT, Garnet Fire/Willow
Staggered 18" SSR GT1/Bridgestone PP S03
Eibach Springs/Sways, Stillen 2-pc BBK
Stillen Intake & SS Cat-Back Dual Exhaust