Plug Recommendation
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From: Palm Harbor, FL
Plug Recommendation Running a stock shortblock LT1 with 230/242 111LSA cam and Impala gaskets, which plug should I run: NGK TR55 or TR6? And also what gap do you think?
I bought a set of TR55s because thats what Everyone says run on here!!! The S10 was loadin up & they fouled out... Checked the gap & they were like .065 No wonder everyone Bitches about the Opti LoL So I cross referenced the A/C Delco plugs that came stock... They crossed to an A/C Delco R44LTs & that crosses to an NGK TR5 not TR55!!! The TR5 is gapped at .035 so gappin those to like .040 or .045 is better than tryin to pull down a plug from .065 in My opinion!!! I put the R44LTS plugs in My junk gapped to .040 Once I get the other PCM back from Moe the way Fat condition will clear up!!! I guess the Trans Am PCM has a tune because I changed Plugs , Coil & ICM tryin to eliminate **** LoL Put the Caddy PCM in & bam fired up Faster than it ever did but it needs VATS & emission crap deleted!!! Hope My Ramblin helps!!! Oh the reason I didnt go with TR5 plugs is because they were screw on caps not solid ones...
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Verdad Gallardo Are the 104's slightly hotter or colder than a TR6? I read somewhere the 104's aren't quite a full heat range colder which makes them a little better for a slight bump in compression like a gasket change or milled heads. True or not? just curious.
On The Tree
Joined: Jun 2015
Posts: 182
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From: Portland OR
The only time I would consider a colder plug is if I was using a power adder.
And then only if I was seeing signs of plug overheating.
Often just switching to a non-extended tip plug is enough for a power adder.
Unless you are going gonzo batshit crazy with the boost.....
And then only if I was seeing signs of plug overheating.
Often just switching to a non-extended tip plug is enough for a power adder.
Unless you are going gonzo batshit crazy with the boost.....
. My EXPERIENCE is that 104 or TR6 are right and run better in a heads/cam motor over 11:1, TR5/TR55 had funky idle completely cleared up with TR6 or 104 and that was recommended to me by someone else who had found the same thing. In more aggressive setups even still NA 103s are warranted, again based on experience.
I've been running Autolite 104's for N/A use in my h/c motor. 12:1 CR, 500+ crank hp. I tried 103's once; had no trouble with them, but they didn't look as clean as the 104's when I pulled them after one season.
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Joined: Aug 2008
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From: Nebraska
I'll second the TR6 for bumped compression motors. Although an LS, my friends camaro with a 11.8:1 compression 370 kept fowling out plugs within a few hundred miles. They were TR55s. We swapped them for TR6s and never had a problem again. Starts better, runs better, and doesn't fowl them out. As for my cam only car with stock compression, the TR55 is working just fine with a 0.040 gap.