Spark Plug Gapping
Thread Starter
Staging Lane
Joined: Oct 2006
Posts: 83
Likes: 0
From: Iowa
Spark Plug Gapping I replaced my plugs and wires over the weekend and am not sure if they were gapped correctly. I followed a guide and what it said that the gap should be on the plugs for the LS1's.
It said that anything from .055 to .060 was good for our motors. In the guide, he said that his factory plugs were gapped at .060.
I installed NGK TR55's and they were all gapped about .057/.058 so I left them alone and installed them in the vehicle at that gapping. When I was pulling out the stock plugs, they were gapped WAY closer than .055-.060. I think on many of them it was closer to .048 or so. This made me very nervous.
I fired up the car and there are no problems whatsoever, but am still curious what I should be listening for if they are not gapped correctly. So my plugs are gapped at .058, is that ok?
Also, the stock plugs were in there TIGHT AS HELL. My hands are scraped and bleeding in many spots trying to break them loose. I tightened them back fairly tight, but I know for sure they aren't as tight right now as the stock plugs were. What are your thoughts on this as well?
It said that anything from .055 to .060 was good for our motors. In the guide, he said that his factory plugs were gapped at .060.
I installed NGK TR55's and they were all gapped about .057/.058 so I left them alone and installed them in the vehicle at that gapping. When I was pulling out the stock plugs, they were gapped WAY closer than .055-.060. I think on many of them it was closer to .048 or so. This made me very nervous.
I fired up the car and there are no problems whatsoever, but am still curious what I should be listening for if they are not gapped correctly. So my plugs are gapped at .058, is that ok?
Also, the stock plugs were in there TIGHT AS HELL. My hands are scraped and bleeding in many spots trying to break them loose. I tightened them back fairly tight, but I know for sure they aren't as tight right now as the stock plugs were. What are your thoughts on this as well?
On The Tree
Joined: Dec 2004
Posts: 114
Likes: 0
From: Vancouver, WA.
Your plugs should only be tightened to 11 ft lbs (factory spec) and that's after giving them a little dab of anti seeze on each one. I've run the TR55 plug at the same gap you used on and off the track without any problems. Lately I've been gapping them at .050 and they seem to do a little better (sounds better) in my track car. No real difference in power.
I also just changed my plugs and they were the original plugs the car came with from the factory. They were gaped at 75 and they were ac 41-952. I installed NGK tr55s also and gaped mine at 50. I also had another 99 trans am that I bought new back in 99. When that car had 6000 miles on it I installed tr6s in it for a dry shot of nos it had on it. I gaped those at 45 and never had a problem. I was also wondering what I needed to gap my tr55s at. I didn't even think about it back when I had my first 99 Trans am I just gaped them the way I had on my other small blocks.
"My hands are scraped and bleeding in many spots trying to break them loose."
Buy mechanics gloves at Autozone, awesome tool and good investment.
Regarding the gap, I do TR6's at .042. But the TR55's at .058 you did will be fine.
Buy mechanics gloves at Autozone, awesome tool and good investment.
Regarding the gap, I do TR6's at .042. But the TR55's at .058 you did will be fine.
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Thread Starter
Staging Lane
Joined: Oct 2006
Posts: 83
Likes: 0
From: Iowa
Yes, of course. Normally I would agree with you on that, but I don't know anyone could possibly fit in the tight spaces required to change the plugs/wires when they are wearing the gloves. It was hard enough with just my bare hands...and I'm a skinny guy!!
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Verdad Gallardo On The Tree
Joined: Dec 2004
Posts: 114
Likes: 0
From: Vancouver, WA.
Nice to see Vancouver on here. 
NGK TR6's is a cold spark plug(i.e.nitrous) and should be gapped at .35-.40 for max performance. and the NGK TR55's are a hot plug, for n/a applications and should be gapped at .50-.60. Just call a performance shop. but make sure its a known performance shop, even if you have to call out of town like to MTI or such. they should be able to tell you.
