Spark Plugs Difference, advantages etc

[Adamal]

I think its to do with any kind of modding really.
When you do something to your car and hop in to take it for a spin, it always feels like it goes a bit better
I kinda feel like that after an oil change!

[fangsport]

yeah , it's like saying i've put some 'rinky-do' tyres on to replace a set that were on the wires and bleating about how much better Rinky-Do tyres corner and stick to the road.

[sergei]

BTW I've scored some iridiums for $54 (mates rates) from Partmaster, so they are not very expensive and last longer then $22 copper ones... thats the reason I went to iridiums, otherwise I would keep the platinum splitfires...
In my opinion colder sparkplugs produce more power because they tend not to preigninte the mixtue

[ROBODISCO_20v]

tell me then ROBODISCO_20v, how do different spark plugs cause a car to perform differently?... If the air/fuel mixture is ignitied by both a 'good' plug and a 'bad' plug how does the 'good' plug differ?

Well if a plug is worn out the electrodes normally wear down and the gap opens further making your igntion system work harder and does not produce as bigger spark as it could causing the car to run poorly. You will notice it more at higher revs. It's simple the bigger the spark you have the easier the gas is going to ignite. The less effort the ignition sysem has to make to produce that spark the longer it will last.
I work in a parts shop so i have access to dirt cheap spark plugs so i tryed a few different styles, like slit fire, twin electrode ngk, champions and found that Iridiums give the best increase over standard plugs. I have sold thousands of NGK iridiums to trade customers & i have only heard good things back from them, most of them run them in there own
personal cars.
Half you guy would know the first thing about cars, you just drive them! You don't understand the details that are an igniton system, by reading some of the replys. Spark plug can & do make a difference to the running of a vehicle.

[sergei]

They do difference, but it is very small
take a brand new copper plug and iridium plug, try them on same car, you will not feel that difference, even if you take it to dyno, the results will be almost same maybe with small variation, but those variations happen anyway - temp increased, etc... ass dyno is +/- 50% accurate take a car and reduce power by 50% (leaving the power curve the same shape) people just wont feel much difference because they are not using that power all time, especially if the car is an average performer;
I bet no one can feel 1kw difference in 100Kw car...

[celica_tommo]

You have no arguement ROBODISCO_20v.

All you have said is that a worn plug (when really the discussion is expensive plugs vs. cheap plugs) puts more strain on the ignition system. How does this extra effort impact on combustion?

What does it matter how long a spark lasts?... surely as soon as the mixture is ignited the flame front will move from the plug through the mixture regardless of wether there is still spark present or not

working in a parts shop does not make you an authority on spark plug perfomance that we should believe regardless of the fact that you have no evidence to substantiate your claims or any theoretical basis for your arguments

[TWSTD]

What does it matter how long a spark lasts?... surely as soon as the mixture is ignited the flame front will move from the plug through the mixture regardless of wether there is still spark present or not

Not true. Look at an MSD ignition for example - these put out MULTIPLE sparks on each stroke providing better compustion hence more power.

[Al]

I even doubt wether an MSD ignition system would make any more power on a stock motor than all new toyota factory ignition components.

[strap-on]

sorry if this has been said, but someone told me once with iridium spark plugs, u are just always gaurenteed a spark.

but this came from someone whos dad races triumphs

[Wildcard]

sorry if this has been said, but someone told me once with iridium spark plugs, u are just always gaurenteed a spark.

'Guaranteed' ? So if it doesn't spark on one revolution you can take them back to the shop?

[Snoozin]

Well heres my 2c on the matter.

Having spent a lot of time around race cars, engine builders etc etc. and a lot of the very knowledgable people around the Alfa club, I have never really come across anyone who would vouch for an iridium/splitfire/etc plug being superior to another.

The general consensus was, that as long as the correct heat range was chosen, and the gap was correct, a regular plug would perform just as well as any.

I used Splitfire Platinum plugs for a spell.... mainly because I had access to them cheaply, and when I changed to a standard NGK plug (same heat range, $6 each rrp) I noticed absolutely no difference... except for the fact it was much better on cold starts!

Another story I heard regarding Splitfire or other multi electrode/split electrode plugs, was that if the electrodes are not an equal distance apart, the spark will travel to the closest only, resulting in effectively a smaller spark.

So-called performance leads are a load of bollocks as well.... 10mm racing leads, what a crock, why not use a set of proper old-school copper-core leads, unless of course you are concerned about interference with yours and other peoples radios!

[sergei]

Agreed to SnoozinEuro,
copper leads are different story, if the system is designed with resistive leads it will perform better/will have less stress with them...
but diameter is just BS,it is just amount of insulation, anyway there no need in fat wires because the current is so small (mA range), if 5mm doesnt arc then there is no point of having 7,8 or 10mm

[TRD Man]

Interesting topic this.

Shortly after TRD released Iridium plugs I travelled with them to that year's Longbeach Motorshow.
DENSO had a stand there where they were replicating a firing cycle using a platinum plug and an iridium plug side by side under an electro-microscope. The action was displayed on a large computer screen.
What was crystal clear was that whilst the spark from the platinum plug was erratic in both it's brightness and direction, the spark from the iridium plug was consistent in both it's brightness & direction. The spark from the iridium plug was noticeably brighter, and possibly larger, than the platinum.
This was due largely to the thickness of the electrode (0.4mm), I was told. It seemingly takes less power to deliver a stronger spark.

For those who don't know, Iridium is the hardest metal ever discovered. It is taken from a meteorite which fell into the gulf of Mexico evidently. Iridium is used to harden platinum plugs. It is the hardness of iridium which allows the electrode to be so thin.

All this means diddly squat if they don't produce a gain. The technical guy I was talking to claimed that his racing Mini produced around 4 to 5 hp gain with these plugs. There were no dyno sheets to verify this.

We tried them in our rally car. Problem was the car runs quite rich on start up & the thin electrode was easily fouled if the car didn't fire immediatedly. We discarded them in favour of platinum plugs, purely because of this.

Personally, I would believe that a standard road car off the showroom floor would likely show some gains with the iridium plugs.
However, as with the fitting of any component designed to create a relatively small gain, these can often be offset by age, condition and existing modifications to a vehicle which is a few years old.

[TWSTD]

as I said earlier, its more the shape and size of the electrode that is giving a better spark with an IX plug over a standard plug, and as i also said earlier you cannot replicate this tiny electrode in a copper plug as it just wouldnt last.

[EVLGTZ]

We tried them in our rally car. Problem was the car runs quite rich on start up & the thin electrode was easily fouled if the car didn't fire immediatedly. We discarded them in favour of platinum plugs, purely because of this.

Thats basically how it was for me when I used them. And also why I use std old NGKs rather than the platinums, i prefer to change them very regularly.

[sergei]

Hardest metal???
not true according to this:
http://www.bartleby.com/65/me/metal-ent.html


"...The hardest elemental metal is chromium..."