well I had to change the sparkplug gap from .040 to .065. Replaced the Acdelco iridiums with some NGK Vseries TR5. Truck felt strong on the bottom end, got on the highway and my top end was gone, truck pulled short after 3k rpms. I knew something was wrong off the bat. I regapped the plugs to .065 this afternoon. As my sticker even says .060. I am aware of the new tsb and new plugs are .040. But what a lack of performance IMO. With the new gap the VMAX has tons of power now, just got back from a lil ride, and the dubs are still burning.

 

Why did you gap at .065 instead of the .060 your label states?

 

The new plugs are .040 because they are iridium which is a harder metal and requires a smaller gap for the spark to jump. Platinum is softer than iridium, and copper is even softer yet. I've been running my NGK TR55's at .055 which is where they were at out of the box IIRC, and it has been working well for me.

 

i recheck all of my NGK plugs out of the box. ive seen some pretty big variances.

 

same here. i checked the gap and they were at 55 when i put them in. working good so far

 

I should have done .060, but since Im a hard head, and I was already doing the plugs for the 2nd time, I decided to give it a lil extra to see what direction it was going to go. I know the cooper is less the platinum and the gap is for platinum plugs (.060)

Im glad I did too. Not too glad, cause yesterday rubber chucks came off the back tire. Need a new tire soon.

All I know is that a .040 gap ngk-v was terrible on the vmax, felt like a 5.3. But now it feels tremendously better with the regap, quicker, more throttle response, and crazy fast acceleration. My tires hate me now. Feels tons better than the iridums I replaced, thats for sure. So in the future, I may get some delco iridiums, and still re-gap them from .040, to a .050 or so to see some results.

 

I didn't know spark plugs made that big of a difference, good to know though.

 

Yea, my Vmax feels like a MAX should. Its stupid fast on top end, as well as the bottom. Love the .065 gaps too. Minded my VMAX was street tuned by Alvin from PCM4less in person. And it has tons of timing and is tuned for 93 octane. SO it really likes to spark, and that small gap was killing it for some reason. It may not affect a stock as drastic, but still on my previous engines, Ive always leaned to the bigger gap on NA engines.

 

ok pulled the V power plugs out today, they looked new, but i replaced them with the iridium AC delco plugs, and gaped the iridium plugs to .060 like the stock sticker says. All I have to say is JESUS its 10x better than the Vplugs, and Im sure more better than the .040 gap as well. Engine feels nothing like before.

Search about gaping the iridium and everyone says NO, thats because they are wearily of people damaging the tip of the plug, gaping them the traditional way. Just use some needle nose pliers and I was good to go.

Just want people to gap their plugs to what the sticker under their hood says... and yes, even if you have iridium I would regap them. Seems like performance is WAY up.

 

Maybe i should change trade out my .035 gapped ngk tr6's for some stock ac delco iridiums gapped at what, .060? Might get some more out the old girl. I was going to run nos but decided not to so the tr6's are not required any longer. Plus after reading this, seems like this might be one of my "not so fast" issues.