Iridium Plugs

Little Guys + NGK Iridium

Mike8675309 said:
Unless you're running 22psi of boost, it's highly unlikely that you need them.
Maybe us Little Guys @ +10% would like to learn Why these plugs help at 22 psi Boost!

Is there any harm in Little Guys using that spark plug?

68COUGAR
 
There have been a couple guys running 350 rwhp engines that have gotten buy just fine with the stock double platinum autolites. I can recall XR7 Dave posting that he had been running the standard autolites for quite a while. If I recall one of his posts it wasn't until his latest tuning round on his autorotor car where he was seeing spark blowout as RPM's increased and boost pressure was hitting over 21psi. Maybe he can comment more on this if he gets a chance.

For the cost, the stock double platinum autolites are just a killer spark plug that seems to work really..really well in our cars. Our ignition system is a bit of a twitch unit. We're getting good spark, good combustion at 12psi -15psi, where folks with vortechs and such running anything over 6psi get spark blowout on their 4.6 motors unless they run an iridium plug. I don't know that anyone has figured out why this is.

There certainly isn't any harm in using the irridium plugs. The only down side that I've seen is that since our system is a wasted spark system. The plug will see energy flow both directions through it. That's why stock is a double platinum tipped plug, so that both the tip and the ground electrode don't wear away. The Irridium plugs I've seen from anyone but the new AutoLite irridium, don't use irridium or platinum on the ground conductor. Thus in our ignition system you might see some excessive wear on the ground conductor with a standard irridium plug.
 
Last edited:
I used swiched to Autolite 103's gapped at .045 after running the NGK iridiums. I was getting a miss at upper rpms @19psi. The car seems to run better since the switch but the cold idle needs a little more tuning yet, runs a little rough. Do a search on autolite 103 and you will run across some good threads on them. The only downside is you will have to change them more often, but you can get 6 autolites for the price of 1 iridium plug
 
rzimmerl said:
you can get 6 autolites for the price of 1 iridium plug
Who ever is interested, I went to Kragen today to get some Autolite plugs, they were out of stock but they had the NGK Iridium for $1.00 less than the double platinum. Go figure... I bought a set of Iridiums. Changed out the driver side in 90 minutes (spent 1 hour trying to fish out my socket which fell in between the motor mount and its bracket. Thank God for wire hangers. I need to go invest in a magnetic retriever. Darkness prevailed so I could not do 2 and 1 yet.

John
 
Back
Top