91ls1silverado

Hey what's up guys. I have a cammed ls1 with longtubes and a cold air intake...i have the ngk tr55s at .55 but people say they have there's at .35 what gap should i use? Thanks!

thunderstruck507

iTrader: (18)

I have run mine from .40-.60" with no noticeable changes in how the car runs on the street or track.

Russ K

iTrader: (1)

Wrong plugs, GM has a TSB about revised spark plugs with a .040 gap. I would drop a heat range to TR6 & gap them at .040.

Russ Kemp

JRENIGAR

iTrader: (37)

Does it have any KR when datalogging? I would only go that low if it had a blower or nitrous on it but that would require a colder plug also. I gapped my TR6's at .032 with 8lbs of boost.

Zmg00camaross

iTrader: (11)

Gap mine at factory specs, cam only runs high 10s. You want the wides gap possible without blowing out the spark. Removed plugs out of a escort and were at .085 haha still ran ok.

91ls1silverado

What are yours guys mods with the spark plug gap?

03Sssnake

iTrader: (20)

Running TR6s around .40 on my 99, full bolt-on car with 243 heads, F13 cam and LS6 intake manifold. The heads have had .20 taken off for a little compression bump.

Zmg00camaross

iTrader: (11)

Bolt ons,fast 78 ATI dampner, eps cam. Never been on the dyno. Trap 126 mph. Stock gap.

studderin

iTrader: (28)

tr55 stock gap .055 here

91ls1silverado

I gapped the plugs to .40 and it started to backfire at idle and no power at all, should i gap em back to .55?

fordkilla2000

.55 is a little much I'm almost certain you should gap at .40 .35 is for stock application and will work for mild cams. Talk to Pat G. He's great at anything you throw at him. Patrick@guerragroup.com

jsteele90

iTrader: (13)

same here, been running like that for over 7 years.

thunderstruck507

iTrader: (18)

I have a hard time believing a .010" in gap would cause backfires at idle. Sure you didn't crack the plugs or something?

mjs1012

iTrader: (36)

tr55 at .55 also without any issues.

JRENIGAR

iTrader: (37)

TR6 @.032 Full boltons w/ Vortech @ 8lbs boost. Run 110 miles a day 5 days a week. 40,000 miles later plugs still look good. Made 450RWHP and tuned rich for safety.

Exidous

iTrader: (11)

The tighter ~.030" gaps are for boost. .040"-.050" is just fine for an N/A car.

03Sssnake

iTrader: (20)

I would agree with this...I had a bad back fire after changing plugs and wires (MSD red wires)...turns out the insulator on 3 was just touching the header, it would backfire under light load etc, caused flashing CEL...I would look it over again, maybe run a scanner, it should have a trouble code with a backfire/misfire.

91ls1silverado

Yes I'm sure, i gapped them back to .55 and it runs good, but had to send computer back cause tuning problems
...but when i get it back I'll gap em at.40 and double check everything