ruled out spark blowout so what is the best plug gap ?

68_GT · April 10, 2014, 01:17:40 PM

initially I was told my tuning hesitation was or coulds be spark blow out.

So I regapped my plugs to .28 becasue my hesitaion was pretty bad on occasion so I figured that would really do it but I don't recall noticing any dramatic improvement by closing the gaps down.

Tuning revisions have now eliminated any hesitations so now I wonder what gap to open them back up to ?

Seems like the larger the gap you can run the better the combustion which equals more power and more mpg right ?

So is everyone gapped at .30 ? anyone try .32 ??

68_GT · April 14, 2014, 11:37:18 AM

no takers ?

also my plugs have the markings CYFS12YT3 / LTR6CI-8 on them. Is that the newer SP345 plugs ?

FracaSHO · April 14, 2014, 11:46:44 AM

I gapped my NGK plugs to 0.030 and the car runs great. My stock plugs were probably 0.035 to 0.038 but I didn't measure them. From what I've seen, 0.030 seems to be the sweet spot.

Brad
2010 SHO with PP
170* T-Stat
NGK LTR7IX plugs, gap at 0.030
BOV VTA
MyCal LMS Stage 4+
Sent from my iPhone

68_GT · April 14, 2014, 11:50:27 AM

were you running rough with the larger gaps ? I mean a larger gap should give any car more power and more MPG.

I might try .32 and see how it goes. Closing the gap to my knowledge has always been to smooth out the idle, and misfires. I don't think with my latest tunr revision I will need a smaller gap ??

FracaSHO · April 14, 2014, 12:16:32 PM

Car ran fine with stock plugs and gap. There are performance benefits to colder plugs and smaller gap when tuning and modding our SHO's. There is some good info somewhere on this forum that I can't find right now. I'll look again when I have some time. Or maybe someone else can chime in.

Brad
2010 SHO with PP
170* T-Stat
NGK LTR7IX plugs, gap at 0.030
BOV VTA
MyCal LMS Stage 4+
Sent from my iPhone

68_GT · April 14, 2014, 01:22:55 PM

well I just gapped mine to .32 and it runs perfectly. I'm going on a road trip so I'll see if I get a MPG inproovement. I couldn't tell any performance difference. I wonder about the colder plugs if there's really anything to that on these cars.

Needmoreboost · April 14, 2014, 01:39:11 PM

Quote from: 68_GT on April 14, 2014, 01:22:55 PM
well I just gapped mine to .32 and it runs perfectly. I'm going on a road trip so I'll see if I get a MPG inproovement. I couldn't tell any performance difference. I wonder about the colder plugs if there's really anything to that on these cars.

If you live in Houston the .032 is probably fine. Colder climates in colder weather .030 is probably the best.

black99lightning · April 14, 2014, 06:25:39 PM

With forced induction vehicles you want a tight gap. I ran my old 09 GT500 at around .28. On the SHO I'm at .30. What may happen under boost is the sparkplug "flame" may blow out. I would regap them to .30.

MeanKS · May 16, 2014, 09:24:49 AM

i'm noticing a slight hesitation at idle and decrease in MPG since i had the SP534 plugs gapped at .030 installed.

obviously i'm not liking this and don't get why its happening. i'm going to have the car looked at to see if theres some issue...

Tuner Boost · May 16, 2014, 10:01:53 AM

Quote from: 68_GT on April 10, 2014, 01:17:40 PM
initially I was told my tuning hesitation was or coulds be spark blow out.

So I regapped my plugs to .28 becasue my hesitaion was pretty bad on occasion so I figured that would really do it but I don't recall noticing any dramatic improvement by closing the gaps down.

Tuning revisions have now eliminated any hesitations so now I wonder what gap to open them back up to ?

Seems like the larger the gap you can run the better the combustion which equals more power and more mpg right ?

So is everyone gapped at .30 ? anyone try .32 ??

Have you tried installing the RX system to see if that cures it?

SHOdded · May 16, 2014, 10:24:50 AM

Quote from: DRII on May 16, 2014, 09:24:49 AM
i'm noticing a slight hesitation at idle and decrease in MPG since i had the SP534 plugs gapped at .030 installed.

obviously i'm not liking this and don't get why its happening. i'm going to have the car looked at to see if theres some issue...

I forget, is your MKS tuned? If not, then you want 0.033-0.037 gap.

MeanKS · May 16, 2014, 10:52:06 AM

Quote from: SHOdded on May 16, 2014, 10:24:50 AM
Quote from: DRII on May 16, 2014, 09:24:49 AM
i'm noticing a slight hesitation at idle and decrease in MPG since i had the SP534 plugs gapped at .030 installed.

obviously i'm not liking this and don't get why its happening. i'm going to have the car looked at to see if theres some issue...
I forget, is your MKS tuned? If not, then you want 0.033-0.037 gap.

no its not tuned yet. i have everything just haven't got around to loading the tunes from Torrie.

i assume thats the problem, its meant for a tuned car. but, i remember a few people saying that when the first installed the .030 gapped plugs their engine ran smoother even before the tune. i'll bring it in and see what the dealer service says, just to make sure...