: Iridium Spark plugs



1997BlackETC
11-24-06, 12:03 AM
Anybody tried the new AC Delco Iridium plugs in their Northstar, I know they are working out very well in my chevy colorado, thinking about trying them in my northstar. The idle is much smoother, better fuel economy too, longer life. The Iridiums just came not too long ago, I hear they are better than the platinums.

1badcaddy
11-24-06, 12:11 AM
I'm running the NGK Iridiums in my North* and it seems to like them just fine.

Blown Z
11-24-06, 01:07 AM
I am interested in the feedback as well as I am getting ready to do a tuneup on my N*. Thanks in advance!

Ranger
11-24-06, 01:46 AM
My wifes '96 Bonneville (3800) is speced for and has Iridium plugs. Not quite sure what the difference is but I'd stick with what is spec'd.

dkozloski
11-25-06, 06:50 PM
What about Splitfire http://www.ftc.gov/os/1997/05/c3737cmp.htm; and Blue Crown plugs.

AlBundy
11-25-06, 06:58 PM
Great read, dkozloski were do you find this stuff?

dkozloski
11-25-06, 07:13 PM
You ought to see the one the FTC put out about STP and Andy Granatelli. It resulted in the biggest consumer fraud fine in history; something like $668,000.

1997BlackETC
11-25-06, 07:38 PM
The Iridium plugs do work great in my colorado, it idles smoother. They last even longer than the platinums too as they are even harder metal. Expensive though @# 11.00 per plug.

eldorado1
11-25-06, 08:06 PM
The NGK Iridium spark plugs were recommended to me by the northstar guru...

He knows I'm into performance, and he's the one who recommended running plugs 2 ranges colder...

Splitfire is a joke, and so are the Bosch +2's 4's etc... Iridiums are NOT in the same league, or zip code, or world really... Iridiums have all the benefits of platinum spark plugs, which are stock on northstars - but - they have a finer electrode tip. This makes it easier for the spark to jump the gap. Comparing them to split fires is ignorant. You will never see split fires used in an OEM application. Iridiums are used in OEM GM applications. When the Chevrolet team designed the 500hp Z06 Vette, what plugs do you think they used? Iridium. 'Nuff said.

dkozloski
11-25-06, 09:06 PM
Because iridium plugs have finer electrodes, the combustion gases can swirl around the insulator and keep the plug clean. They last longer but they aren't going to increase performance over another plug unless you are replacing worn out ones.

1997BlackETC
11-25-06, 09:30 PM
A lot of people are saying on the Colorado forums that they notice their headlights are brighter after switching to the Iridiums, I am finding the same thing myself as crazy as it sounds. The Colorados have 5 coils, one over each plug and the Iridiums take less voltage to fire, therefore less of power drain, therefore brighter headlights.

dkozloski
11-25-06, 10:09 PM
A lot of people are saying on the Colorado forums that they notice their headlights are brighter after switching to the Iridiums, I am finding the same thing myself as crazy as it sounds. The Colorados have 5 coils, one over each plug and the Iridiums take less voltage to fire, therefore less of power drain, therefore brighter headlights.
That's the most rediculous godamn thing I ever heard in my life. You'd have a better chance of making the Northern Lights look brighter by standing in the back yard waving bed sheets at them.

Ranger
11-26-06, 01:52 AM
:histeric:
Don't hold back Koz. Tell us how you really feel, but I have to agree with you.

dkozloski
11-26-06, 03:26 AM
:histeric:
Don't hold back Koz. Tell us how you really feel, but I have to agree with you.
What's ironic is that if the theory were true the spark plugs would draw more current and the headlights would dim. Nixon was right; the public will believe any damn thing you tell them.

turbojimmy
11-26-06, 08:00 AM
I haven't put the iridiums in my Northstar but I have them in the GN. I'm not sure they'd be necessary in the Northstar, frankly. I only started having trouble with the Delco plugs in the GN when I started to tighten the gap well beyond stock so that I could run much higher timing and boost. The car wouldn't idle right but at WOT it was fine. The iridiums fixed that by exposing more of the fire to the intake charge with a tight gap. The car idles like stock, has really snappy throttle response and I can run it at the track without having to re-gap the plugs. I can't remember the last time I've had the plugs out of the car, actually. When I do pull the iridiums out, they look like the day I put them in. I guess that's the only reason - longevity - that I'd put them in the Northstar. But with the platinums going 100k miles, what more do you want? The iridiums are almost twice as much as the platinums, aren't they?

Jim

dp102288
11-26-06, 09:34 AM
I will be switching to Denso or Delco Iridums when I actually decide to change the plugs on my car. I haven't heard anything bad about them, as opposed to the Bosch platnium series! :histeric:

turbojimmy
11-26-06, 09:40 AM
I will be switching to Denso or Delco Iridums when I actually decide to change the plugs on my car. I haven't heard anything bad about them, as opposed to the Bosch platnium series! :histeric:

I have the Bosch platinums in my Cadillac. I got them because at the time I rebuilt the car I didn't know any better. It idles crappily and sometimes breaks up at WOT. I have a set of stock Delco plugs for it - today might be a good day to pop 'em in. Anyone know off hand what the gap should be? Are they good out of the box?

Jim

eldorado1
11-26-06, 09:56 AM
Because iridium plugs have finer electrodes, the combustion gases can swirl around the insulator and keep the plug clean. They last longer but they aren't going to increase performance over another plug unless you are replacing worn out ones.

They can increase performance, but not in our applications. GN's and Lightnings are using them and have been able to get away with an extra degree of timing... Which can literally mean 20 or more hp.

1997BlackETC
11-26-06, 10:03 AM
That's the most rediculous godamn thing I ever heard in my life. You'd have a better chance of making the Northern Lights look brighter by standing in the back yard waving bed sheets at them.

Why is that such a hard concept to understand, I am a electronic engineer. Did you ever take any electronic classes? My digital voltmeter reads 13.9 volts at 2000 rpms with the platinum plugs, it reads 14.2 volts with the iridiums, more voltage, brighter headlights. I have two power amps in the back cab of the truck, when I crank up the stereo the amps suck up voltage, volts go from 14.2 down to as low as 13.5 headlights get dimmer. With some music such as disco, the headlights flicker, are you getting it yet?

eldorado1
11-26-06, 10:48 AM
Probably a coincidence... The coils don't draw much more than 8 amps. If your voltage was dipping low because of that, you probably had other electrical problems that "fixed themselves".

codewize
11-26-06, 10:59 AM
I use AC Delco Rapid Fire in my 4.5 STS Actually I think I used them in the Brougham last time too. I like them they last a long time.


What about Splitfire http://www.ftc.gov/os/1997/05/c3737cmp.htm; and Blue Crown plugs.

codewize
11-26-06, 11:09 AM
I agree, that is pretty ridiculous. First of all spark plugs don't draw anything. They're feed with whatever the coil-pack is loaded with at the time of firing. The coil isn't going to draw any more or less because you changed the plugs.

As you know current is measured in amperage. in order for the amperage to change the resistance or power has to change, and that hasn't happened unless you put a less resistive coil-pack on.

The stereo is another system all together. High power amps CAN draw enough current to strain the alternator, which is why you see the drop. The coils don't have that ability. You're talking apples and oranges and you should get a higher output alternator if that's happening.

Ranger
11-26-06, 11:52 AM
I have the Bosch platinums in my Cadillac. I got them because at the time I rebuilt the car I didn't know any better. It idles crappily and sometimes breaks up at WOT. I have a set of stock Delco plugs for it - today might be a good day to pop 'em in. Anyone know off hand what the gap should be? Are they good out of the box?

Jim
.050
Probably set out of the box but always check them.

dkozloski
11-26-06, 03:20 PM
Why is that such a hard concept to understand, I am a electronic engineer. Did you ever take any electronic classes? My digital voltmeter reads 13.9 volts at 2000 rpms with the platinum plugs, it reads 14.2 volts with the iridiums, more voltage, brighter headlights. I have two power amps in the back cab of the truck, when I crank up the stereo the amps suck up voltage, volts go from 14.2 down to as low as 13.5 headlights get dimmer. With some music such as disco, the headlights flicker, are you getting it yet?
I have over 45 years experience and training with military and industrial electronics ranging from surface to air missiles to main frame computer systems with every type of aircraft and automobile electronic system in between. Battery charging/system voltages vary with system load, ambient temperature, and the state of charge of the battery let alone engine RPM and ghetto blaster sound systems. To say that the current draw at the spark plugs is going to reflect all the way to the charging system voltmeter in a measurable and definitive way indicates an appalling lack of practical experience. You better hope your coworkers don't hear about this discussion and laugh you out of town.

Submariner409
11-26-06, 05:34 PM
It was a nice day near the Chesapeake Bay. I changed the oil and filter in my '70 Olds 455-powered workboat/cruiser. This setup runs NGK XR-VI iridium electrode plugs fired by a Delco/Pertronix distributor fed by an Accel coil, with Accel 8mm-500 ohm/foot cables and a 1.25 ohm ballast.The whole rig is out in the open, once you remove the surrounding engine box. For grins, I temporarily installed a series precision Fluke ammeter and parallel voltage circuit in the coil feed. At 2500 RPM in neutral, 14.3V at alternator tap, the iridium setup drew 4.6 amps, 10.2 volts (ballast, remember?). I changed to stock NGK XR-5 common ordinary plugs (onboard spares) and the values were identical. Hmmmmm....I put in a set of non-resistor AC plugs, and same results. (When you can sit on a bucket and have the plugs at eye level, all this is easy).....I now conclude that coil draw in a properly wired ignition setup, whether points, magnetic, or electronic trigger, is a non-issue. If I'm not mistaken, MSD says you need a potential amp feed of 6-8 amps to run a 6A trigger system. A lot less than the headlights or a ghetto blaster in a Hounda. :rolleyes:

dkozloski
11-26-06, 06:15 PM
It was a nice day near the Chesapeake Bay. I changed the oil and filter in my '70 Olds 455-powered workboat/cruiser. This setup runs NGK XR-VI iridium electrode plugs fired by a Delco/Pertronix distributor fed by an Accel coil, with Accel 8mm-500 ohm/foot cables and a 1.25 ohm ballast.The whole rig is out in the open, once you remove the surrounding engine box. For grins, I temporarily installed a series precision Fluke ammeter and parallel voltage circuit in the coil feed. At 2500 RPM in neutral, 14.3V at alternator tap, the iridium setup drew 4.6 amps, 10.2 volts (ballast, remember?). I changed to stock NGK XR-5 common ordinary plugs (onboard spares) and the values were identical. Hmmmmm....I put in a set of non-resistor AC plugs, and same results. (When you can sit on a bucket and have the plugs at eye level, all this is easy).....I now conclude that coil draw in a properly wired ignition setup, whether points, magnetic, or electronic trigger, is a non-issue. If I'm not mistaken, MSD says you need a potential amp feed of 6-8 amps to run a 6A trigger system. A lot less than the headlights or a ghetto blaster in a Hounda. :rolleyes:
Holiday greetings from an old tin can sailor to a submariner. A little welcome illumination can come from a careful experiment. Thanks for passing on the results. Mythbusters would approve.

GreenMachine
11-26-06, 10:40 PM
I heard that after using the Iridium plugs sometimes the northstar glows green, and if your not careful any spark plug tool or ratchet that touched them could too!

Ok couldn't resist.

dp102288
11-27-06, 09:28 AM
^^ Huh :confused:

Which brand is the right one? Denso or Delco? I still can't figure it out.

EcSTSatic
11-27-06, 09:44 AM
In all fairness to the claims and discussion here, Iridiums do take less voltage than normal plugs, mainly due to the thin electrode. IMHO though, I can't see how the change in load would be noticable to the driver in terms of brighter headlghts etc.
They sound like great plugs. I think the 100K miles life expectancy on AC Delco is a better return on your money though.

Submariner409
11-27-06, 10:23 AM
DKOZ.....One of my sisters graduated from UA/Fairbanks. Lives west of Juneau. Yep, I spent 25 years in subs...diesels, nuke fast attacks, and missile boats. Was a navigator, Chief of The Boat, Diving Officer.

EcSTS...Yep, iridium plugs require less average voltage to establish a flame kernel, but, as we know, that's [I]secondary[I]or high voltage, generated by coil breakdown, not coil saturation current draw, which is where the load on the vehicle electrical system comes from. The two coils in an ignition coil case, whatever shape they're in, are apples and oranges in the same box.

dkozloski
11-27-06, 11:00 AM
The problem with the theory is that if the plugs fire more easily with the reduced resistance of the smaller electrodes, the increased current flow would reduce system voltage and make the headlights dim. It's a great theory, too bad it doesn't work.

EcSTSatic
11-27-06, 11:08 AM
DKOZ.....One of my sisters graduated from UA/Fairbanks. Lives west of Juneau. Yep, I spent 25 years in subs...diesels, nuke fast attacks, and missile boats. Was a navigator, Chief of The Boat, Diving Officer.

EcSTS...Yep, iridium plugs require less average voltage to establish a flame kernel, but, as we know, that's [i]secondary[i]or high voltage, generated by coil breakdown, not coil saturation current draw, which is where the load on the vehicle electrical system comes from. The two coils in an ignition coil case, whatever shape they're in, are apples and oranges in the same box.

I understand what you a saying. I oversimplified my response :thumbsup:
I have an electronics background as well. I worked the avionics on RF4-Bs in the Marines and Cessna Citations. I also have an FCC radiotelephone license.

dkozloski
11-27-06, 01:33 PM
I understand what you a saying. I oversimplified my response :thumbsup:
I have an electronics background as well. I worked the avionics on RF4-Bs in the Marines and Cessna Citations. I also have an FCC radiotelephone license.
Greetings to another vet. I spent 4 years as a SAM missile tech doing depot/component level maintenance and aboard a DDG during the Viet Nam era. A&P and pilots tickets plus FCC broadcast engineers license. About every ten years I changed careers. Retired as facilities manager of a regional airline. Taught A&P mechanics to Army helicopter mechs so they could get a civilian ticket. Semper Fi.

EcSTSatic
11-27-06, 01:50 PM
Greetings to another vet. I spent 4 years as a SAM missile tech doing depot/component level maintenance and aboard a DDG during the Viet Nam era. A&P and pilots tickets plus FCC broadcast engineers license. About every ten years I changed careers. Retired as facilities manager of a regional airline. Taught A&P mechanics to Army helicopter mechs so they could get a civilian ticket. Semper Fi.

Greetings dkozloski ! I only caught the evacuation of Viet Nam in '75.
My past sounds similar to yours. i've had an interesting lifetime but mainly a horizontal move in terms of professional advancement. Many of my acquaintences are higher on the food chain because they stuck with one field instead of gaining broader experience. Of course some don't know one end of a screwdriver from the other but they can afford to checkbook everything.

I digress.....

codewize
11-27-06, 08:49 PM
as we know, that's [i]secondary[i]or high voltage, generated by coil breakdown, not coil saturation current draw, which is where the load on the vehicle electrical system comes from. The two coils in an ignition coil case, whatever shape they're in, are apples and oranges in the same box.

I think I said that a few posts ago.

mtflight
11-30-06, 03:50 PM
Some awesome people in here. No kidding that Mythbusters would approve. Thumbs up!

1997BlackETC
11-30-06, 07:56 PM
I notice too the cd player is running a little faster, Barry Whites voice now sounds like Alana Morrisette ::) Ok, you guys got me :) I tried though even though I could not convince you.

Submariner409
12-01-06, 09:54 PM
1997BlackETC......One of the great things about a series of forums such as these is that people can exchange ideas and learn from the process, as long as we respect the other person's question or experience. The whole idea of learning from others' achievements or mistakes goes back to way before Grandma (or great-Grandma) and is the basis for knowledge. We all have our own soapboxes; how we stack 'em is anyone's guess........Howzzat, Iametarq?

dp102288
12-01-06, 10:20 PM
^^ Damn nice post man...sums up the purpose of the board pretty well. :thumbsup: