DukesOfHazard

Everyone talks about the NGK brand spark plugs. I actually bought a set the other day from the ws6store.com with a set of MSD wires. My question is, what is the difference between NGK 555 and NGK TR55? Those are the most common two that I have seen that will work for my application (low bolt ons, no FI or spray). Is there any major difference?

I ended up going with the ngk TR55's since it was either those or tr6's and I've heard those work better for FI or more power. But my next question is that the ws6store says they are pre-gapped at .060, will this gap work for a DD or will I need a lower gap?

Erik@Lashway

iTrader: (14)

That gap is a bit much for my taste. For most N/A applications, we gap our plugs right around .045". That seems to work well. The biggest diff between NGK plugs are their heat ranges and electrode/insulator shape/size. The TR6 is a cooler running plug and has a smaller electrode insulator than that of a TR5 or 55. That makes them ideal for boost and higher hp as detonation does not become an issue.

DukesOfHazard

Ah ok. I understand that you can re-gap a spark plug by basically tapping the cap or whatever you call it on a table and re-measuring. I've heard this can actually cause the plug to become brittle at the tip.

Can you explain what having a larger or smaller gap does? Smaller gap = better ignition or what? I basically just want something perfect for my DD. I've heard either .050 or .055 is good.

Sales2@Texas-speed

iTrader: (5)

You want as wide of a gap as you can run without the spark being blown out. The wider gap will make for a better an cleaner burn! People gap them down on higher compression engines and power-adder engines because they have to, otherwise the spark will get blown out. We gap the standard NA street/strip stuff to about .050" or so as a starting place.

RPM WS6

iTrader: (3)

Excellent advice, and I agree.

I've usually gapped my stock LS1s (with TR55s) at about .055".

DukesOfHazard

Excellent, the TR55's came from the WS6 store pre-gapped at .055 even though their site states .060, so I'm happy. Probably gunna throw these in this weekend (not looking forward to this lol). Just wasn't sure if I should re-gap them down to .050 or so. Even had a suggestion to go down to .040 or .045 and that just didn't sound right.

RPM WS6

iTrader: (3)

There is no reason to do this on a stock LS1. The factory ignition system is powerful enough to handle a bigger gap, and as Matt stated above, a bigger gap is better (in the stock heat range) so long as you're not blowing the spark out.

On a stock motor you should be fine anywhere from .050 to .060, but I like to split the difference and use .055. Always worked well for me (and many others on this site).

Georgio281

iTrader: (1)

This. There's no purpose to going with such a small gap on a bolt-on NA LS1.