Iridium Spark Plugs kill Fuel Economy?

[turboc87gn]

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[gczarny]

Dutweller went from a regular plug to iridium in a blown Fxxx & picked up over 200 hp, years ago.
I'm interested in iridium & this is the first Buick thread I've seen with iridium plugs. I do have a set in my toolbox, however, the ur5 plugs in the TR now have been doing fine.

I have tried iridium plugs after reading same post looking for HP gain , in my Buick iridium plug test they killed power ,on the dyno car made 434 RWHP I could feel blown spark efect at at top of the dyno pull , it happend that next guy up for the dyno test was turbo imports guru ,once he find out I was running iridium he said take them out and use Autolites instead , power went up to 523 RWHP ( the test was done on my other Buick -not the one in signature -had similar engine build with GN1 heads and 67GTQ turbo 93 octane & alky at 22 psi ) so in my case they did not work :frown:

 

[V6UnderPressure]

I have tried iridium plugs after reading same post looking for HP gain , in my Buick iridium plug test they killed power ,on the dyno car made 434 RWHP I could feel blown spark efect at at top of the dyno pull , it happend that next guy up for the dyno test was turbo imports guru ,once he find out I was running iridium he said take them out and use Autolites instead , power went up to 523 RWHP ( the test was done on my other Buick -not the one in signature -had similar engine build with GN1 heads and 67GTQ turbo 93 octane & alky at 22 psi ) so in my case they did not work :frown:

Some cars like em, some cars hate em. Imports are well known to like them. As was stated before, I'm sold on the whole reverse spark thing is the reasoning.

 

[muddin'metal]

I use UR6IXs

I ran only a .28 gap and knocked at anything above 12lbs... and Ur4s are just too damn hot, BE CAREFUL!!!

 

[GNeric]

I run UR5's and with 83# injectors, I get 25mpg's on the highway. Got the ME-R (mafless) on the car and that is as good as I can get the mileage. In town I haven't checked as my foot is in it a 'few times' while driving.

 

[muddin'metal]

What gap and ignition?

 

[Turbo6Smackdown]

FTR, that is completely not true. If boost of any sorts never went well with iridium plugs, then they wouldn't work on EVO's pushing 30psi. And thats their FACTORY plugs. Do you know how many people running boosted cars are running iridium plugs!!!??? It may not work in the buick world, but it sure as hell works everywhere else. Different things can come into play such as placement of the plug in the head etc. etc. etc. Need to check that common knowledge.

DR BOOST is also mistaken. The plugs are not firing backwards. Because I am faster than DR BOOST, it just seems like hes going backwards. All kidding aside, I surprisingly believe DR BOOST is right? Three fire from the center electrode to the outer, and the other three from the outter to the center, correct? The outter to the center firing would have a tough time with such a small electrode. Maybe someone can chime in here and clarify, but I believe this has something to do with the whole "waste spark" thing? I believe RJC was working on a set of two coil packs working in conjunction with each other in order to eliminate waste spark, and I believe this would have cured the problem, and allowed us to use the Iridium plugs. At any rate, you would think with this issue that AC delco would have made a plug for our cars with the same size center and outer electrode.

"Smallest tip diameter available Iridium / Platinum surfaces ensure slow wear rate providing stable idle, superior anti fouling, improved fuel efficiency and lower emissions"<-----With this sales pitch, I don't blame TABuickMike for giving them a try.

The waste spark system is the ENTIRE REASON you SHOULD be using precious metal plugs lol. Do a little research on iridium plugs, and see what you turn up.

 

[GNVYUS 1]

If you're still up for trying out new plugs, try the E3's before you bail on your MPG test. I'm going back to these next year as they are definitely better with E85 vs AC42's. I was firing off 25psi with the E3's and those are a set gap at .040 so consider them.

 

[Nick Micale]

Back in the late 80's, platinum plugs became the rage, and it was discovered quickly that that were not well suited for turbo applications.

Years later when the iridium plugs were becoming available, a Denso rep discussed with me about how great these were. They furnished me with a large selection of their plugs to test since I was skeptical.

On my first pass they were not working well, and even after trying a few different heat ranges it was still a no-go. Tried them in street GN's also, and the same issue. I just recently "disposed" of the remainder of those plugs.

I have worked on MANY of Kenny's engines and never have seen a platinum or iridium plug that he ran in a turbo Buick application, an Autolite racing plug was his norm.

Since the basic Buick turbo V-6 was designed before most owners were born, adapting new technology does not always work out with them.

I am always amazed at the parts counter "experts" ability to up-sell products like designer plugs and synthetic oil because it is the latest and greatest based upon their sales training, instead of actual experience and application. :biggrin:

 

[Dabigguy]

really dumb question, but why did 3 plugs break when you were removing them? Do you think you may have broken one when reinstalling them?

 

[Raist103]

an Autolite racing plug was his norm.

i dont remember the part number for the gn but on my typhoon i gained 14-17rwhp "front shaft removed" by switching to these from ngk tr6's. same gap, same boost, same tune, same day "with in 10min of the last pull" so yes i think snake oil on plugs is NOT bs some DO work better then others.

Do you happen to have the part number for the racing gn ones?

 

[machinegun]

Super this Duper that douple special the other thing.

Sometimes the simplest of items work the best.

As Nick has stated I too have tried all kinds of plugs, platinum, irridium super unobtanium

None of them seemed to have worked as well in our cars as the plain old CR42TS, CR43TS and autolite 23's
These may be plain and boring and uneventful at the crusein car show or street gathering but as far as reliability and performance I have found none better

sometimes KISS is the way to go.

 

[chopped39]

The biggest reason manufactures are using iridium plugs is they can take alot higher temps and last 100k.
Some cars like nissan with throw codes if wrong plugs are used. Some gms also.They watch the resistence across the plugs. back in 87 they didnt know this technology. I bet you install a proefi with coil on plug and run iridium plugs you will see the differance. The waist spark system that gm uses just fires on exhaust stroke as well. emission strategy but it take power from firing on power cylinders. The best coils are microprocessed like most german cars where they have their own ignition module built right in the coils. you get way better spark and control . Someone on here made a system where they got rid of the waist spark and made I think 15 or 20 horsepower.
Stick with delco or ngk plugs and leave the iridium plugs for the lexus and infinity owners unless you do major upgrades to your ignition system.
Technology sucks dont it. The GTR uses iridium plugs and I believe it turbocharged:biggrin:

 

[TABuickMike]

really dumb question, but why did 3 plugs break when you were removing them? Do you think you may have broken one when reinstalling them?

The old plugs broke when I was taking them out, probably because I didnt keep the spark plug socket straight while trying to break them loose; just ended up putting pressure on the side and cracking the ceramic.