80TexasC3

As with most everyone else on this forum...my hobby has turned into an obsession and now an addition. Seems that I'm always looking for the next project to take on or way to add more horsepower to my Vette.

Have been reading about the Iridium spark plugs and doing research... Impressive, but these things can be quite expensive. So, I placed a search on ebay and just let it run for the past several months. Well, I finally won an auction that didn't cost a fortune...

They arrived today... am going to borrow a friend's Gtek and see if they make an objective difference in acceleration/hp. Will probably put these in next week over the holiday.

Glassbowtie77

page62

80TexasC3

Baseline complete... with NKG T5s

337 hp 387 tq

To start with...I'm pretty impressed with this GTek... thought it would be really off of what the rear wheel dyno recorded a few months ago... only the Hp was off by one with the dyno recording 338 hp.

Will do the spark plug switch sometime this next week.

Twin_Turbo

if your standard plugs are in good condition your power increase will be around 0% or so, all these hyped spark plugs, I don't buy it. Regular delcos for me, I side gap them myself...cheaper than all those hyperzidiumconfuctorwhatevers

If there's 1 spark plug that I would buy at high cost, it'd be the champion plugs w/ thermocouplers inside, a direct probe to combustion temperature...I don't know if they are available on the market yet but some race classes have used or are using them.

Mike Ward

Now is that +0% or -0% difference?

Glad to see there's somebody else that can see past the marketing hype.

For this test to be truly objective, the baseline plugs will also need to fresh out of the box too. If there is going to be any field trials, the driver must not know which plugs are installed and you'll have to normalize all readings (baro/temperature/humidity/traction index) back to standard conditions. Have fun

zwede

Iridiums are great for their intended application: OEM installation where the first scheduled maintenance is at 100K miles. Platinums turned out to be marginal going that far so Iridium was introduced (better wear).

Can't see how they could make more power. Either the mixture ignites or it does not. There is no try.

The thinner tip of iridium takes less voltage to throw a spark so it will help if the ignition system is marginal. Copper plugs will do the same as iridium as long as the ignition system is healthy.

Corey_68

They lasted ONE DAY in my Big Block before they fouled out.

Hope you have better luck

80TexasC3

Exactly why I'm "trying" them... Bottom line is that I'm an objective "show me the numbers" guy. Am sick of all of the hype and opinions that these being good or bad...neutral at best. Will let you know what I find...

BTW... the NGKs have about 70 miles on them...should be pretty fresh but I'll assure there aren't any issues when I pull them.

comp

fauxrs2

Sounds like an interesting test.. however I'm in the -0% to +0% gain camp myself....the only real benefit these can probably offer is durability..or the ability to operate when the ignition system is faulty....

Beyond that spark is spark...you ignite the mixture or you dont...and a certain air/fuel mixture shouldnt burn hotter or provide greater pressures in the cylinder because of a spark plug....

marketing....

80TexasC3

Same camp I've been in and am currently... am just one to want to see facts...Can't find any in all of the research I've done, so...I'll do a test myself.

Ironcross

All thats really needed for any engine is the proper heat range plugs for the combination and usage. Fancy high dollar pie in the sky plugs are not any better than the proper OEM or equilavant ones. If it wont run on a stock brand it will not run on any other brand.

flood

Actually ....In a Cessna 152 with a dual ignition setup you test both systems by turning one or the other off.

when you turn 1 of the systems off you get about a 100rpm decrease. Spark is not spark. If it was just setting the mixture on fire there would be no difference between 1 spark plug or 2.

Also in a turbo charged motor the voltage required to ignite the mixture increases.

fauxrs2

See now that is somethign I didnt know and is quite interesting....I wonder what it is you are seeing there....

Yes increased cylinder pressures will have that effect...question is all things being equal... the only difference there would be the resistance inherant in the plug itself... yes?

zwede

In a twin plug cylinder you create 2 flame fronts, thus the entire charge completes the burn earlier. The quicker you complete the burn, the more energy is converted into turning the crank (a force pushing on the piston when it's already down doesn't do you any good).

So that's why you see the rpm drop. Spark is just spark... but 2 sparks in different locations can be better than one.

Mike Ward

That's entirely true. For additional proof and to carry out my own investigation I tried lighting my grill, at one end with a wooden match, and the other with a Binford 9500 CD electronic zoomy spark lighter.

Guess what? It singed my eyebrows on both sides absolutely EQUALLY!