Iridium plug gapping

[Peaven]

Just picked up a set of TR55IX plugs....NGK has them gapped at .059 and says to leave them there...LT5 specs of course say .050, so....which one is right?

Anybody that has theses plugs got any insight....Uly?

Thanks for the help gang.

[blackjack]

im sure the ngk big boss doesnt know what a zr-1 is....the gm service manual says .035...the wider the gap,the harder it is for the coil to fire the plug,to the point of misfire,specially the newer plugs with so-called precious metal,which is good for long life,buut not so good for conductivity...i gap my ngk at .040,no mo'
blackjack
91/1735

[guinnessdood]

Originally Posted by Peaven

Just picked up a set of TR55IX plugs....NGK has them gapped at .059 and says to leave them there...LT5 specs of course say .050, so....which one is right?

Anybody that has theses plugs got any insight....Uly?

Thanks for the help gang.

I have the same plugs but cannot remember for the life of me the correct gap. Call Corey Henderson and he will tell you... 210-867-6286. If you are running the stock coils and the original or stock wires I would gap them at no more than .045. If you have better wires and/or coild you could go out to .055-.060....so my research tells me...

[Peaven]

Thanks guys ....I think the 90-92 LT5's spec gap is .035 but the 93-95's get the gap spec'd at .050, no?

I'll either call Corey or Marc Haibeck tomorrow, thanks for the phone# Uly.