NGK LTR7IX-11 (6510) / GAP Question

[Pucklord]

Hi everyone,

I'm looking for guidance on the proper spark plug gap for them NGK 6510 spark plugs on my '17 GT. My current setup includes:

VMP Level 1 tune - Roush Cold Air Intake - Ported throttle body

I've come across various recommendations on this site—some folks suggest 0.048", others 0.050", and a some insist that 0.040" is ideal and the best for NA setup. After reading multiple threads, I’m more confused than ever.

Can anyone with experience on a similar setup clarify what gap would be optimal for performance and reliability?

Thanks in advance for your help!

Sponsored

 

[GregO]

I'm looking for guidance on the proper spark plug gap for them NGK 6510

The 11 in NGK LTR7IX-11 nomenclature stands for 1.1mm air gap which equals .043”.
NGK has a recommended limit on the acceptable limit of bending the ground strap. Some people disregard the limits set by NGK and bend the strap well beyond the limit. I prefer not to deviate past the NGK factory set gap. In your case setting the gap between .040-.045 is optimal.
As far as any performance gains there really isn’t any. Just for reference the GT500 Supercharged is factory set at .040” and then there’s supporting documents from Roush recommending .039-.040 air gap on their supercharger kits.
At the end of the day check the NGK gap for consistency at .043”, install the plugs and sleep well at night knowing you haven’t arbitrarily placed undue stress on the spark plug grounding strap weld by over bending and fatiguing the weld zone.

 

[cbrtrx]

6510s in an NA car work great at .040 gap. Out of the box at .044 is fine as well.

 

[Pucklord]

You’ve all been incredibly helpful—thank you so much, I truly appreciate it.

I’ll go ahead and leave it as is, then.

Sponsored