Hey guys, I'm in the process of changing plugs on my g.. Fully built TT looking for help with the gapping..Ngk 1step colder #lfr7axi. I was told by tuner. 028. Does this sound rt? I'm reading in people running gaps that are all over the place.. Looking for a good solid number so I can be confident in gapping them right... ANY help would be great... Thxs

 

I like Kyle / IPP and my last set I bought from him were pre-gapped ...

http://www.importpartspro.com/ngkvqirsppl.html

but I'm interested to see what others say...

 

.028 to .032 up to about 20-25psi

The higher the boost, the smaller the gap.

I use an iridium plug gapped at .032, and I make 18-20psi

If the motor breaks up @ WOT in the upper RPM with a new plug, then you likely have spark blow out and need to reduce the gap.

You want the largest gap you can get away with, so better off starting on the big side and move down from their.

Hope this helps.

 

^good stuff OldManZ - thanks for your input -

 

FWIW, with .035 gap ~17psi spike to ~15psi taper down higher up in the rpm I could hear it getting blow out during a tuning session, knock count was clean. Gotta gap it lower and redo tuning with more boost. Gonna probably go .028. What would be the issue if I went say .022 as you alluded OMZ with you recommending to go with the largest gap you can get away with?

On a side note, I really dislike actuators. Even the turbosmart actuators have wobbly boost control and allow big spikes 2-3psi initial. Need to eventually switch this ex-GTM kit over to external waste gates -_-

 

I was using one step colder iridium @ .035. had spark issues around 10 psi (9:1 cr motor aps twins). regapped to .017 and have been good. when I change plugs I am going to go with 2 step colder and the smaller gap. my car is 500-550 @ 15 or so PSI

 

Thanks everyone, I gapped at .028. Car seems to be running 100 times better. Running 19psi. Car was hesitating at wot with old plugs. All the old plugs seem to be at .026 other then cyl 1. cyl 1 was like .035. I thought that was kinda odd. Needless to say I changed and like I said gapped at .028 and car is running strong again.