Looking for recommendations on a plug for my LS2.
Mods:
1-7/8" LT Kooks to 3" collector.
3" X pipe no cats
3" B&B
Vararam
MSD wires

Looking for a recommended "Proven" plug with gap recommendation.
currently running stock.
No issues, just curious.. I am looking to change soon.

 

I prefer NGK TR55 plugs, gapped somewhere between .035 and .045 I believe?

 

The factory fill. Just cuz you got headers doesn't change anything.

 

until you bump compression and someother mods it will be a waste of money and could cause problems.

 

I guess i should just clarify and say I am just seeking the best option for the car in this trim. Not looking for gains, or consider my mods to have given me alot. Just looking for a very efficient burning plug that works without throwing codes.

 

The stock plug works very efficiently. Why mess with it if it's not broken. Are you getting any CELs, if not, leave it alone.

 

Per NGK engineering, TR55 should be gapped at .055" - .060" while the TR5's gapped between .035" and .040". They admitted their website was wrong. This information has been posted before.

After trying NGK plugs, I switched to back to the AC Delco Iridiums. Other than price, I don't see a reason to use non-Iridium plugs. They wear out fast.

 

I (as well as many others who have gone quite fast on the track with these cars) don't use them due to costs, I use them for conductivity reasons. The stock AC Delco plugs are platinum, the NGKs (NGK also makes an Iridium plug as well by the way) are copper.

 

Part number on my AC Delco plugs, 41-110, are an iridium plug and are the factory fill.

And honestly, the resistance of copper to iridium, in an ignition system, is trivial, simply being, in a stock setup, the coil will fire what it needs and nothing more, regardless of copper or iridium, that's the way they are designed, up to a point. Besides, the iridium is only at the tip, it does not extend into the plug. The basic plug materials are the same. I have seen stock COP/CNP ignitions run with .060 gap. MSD and other aftermarket ignitions being the exception.

We also know that using copper plugs have caused some problems with the charging system setting a low charge indicator.

Per Denso http://www.globaldenso.com/en/produc.../features.html

"IRIDIUM POWER has a low required voltage and a high ignitability, resulting in less misfiring and no spark, the outcome being a dramatic improvement in combustion. Engine output is thus increased. The findings of a bench test using a motorcycle engine to show the improved combustion from IRIDIUM POWER is shown on the below. Compared to normal plugs, a 0.5ps (1.4%) improvement is seen in output at 110km/h."


This statement gives a better reason to why copper plugs reduce spark knock. This is also from Denso

"Electrodes have a quenching (cooling) affect (where the heat of the ignited flame kernel is taken away by the electrode). This cooling affect is greater with larger electrodes,"

So, if you look at the tip of the copper Vs iridium ......

 

On this part we can definitely agree, in a stock/nearly stock application it really won't make much of a difference (if any) at all.
I did go fast with factory (AC Delco) plugs and I also went even faster with the NGK TR55s in there...but there were other minor changes made to the car and the weather conditions that were far greater contributing factors than merely the spark plug change itself.

 

i use the cooper ngk due to cost as i change often and the ability to try different plug gaps.

 

I run TR6 plugs gapped at .036" in my LS2 which has ported TB, ported Fast 102, K&N intake, MSD Wires, and AR 1 3/4 Headers. The TR6's solved detonation and timing pull issues seen on the dyno while tuning with the stock AC plugs.

 

All good stuff, thanks gentleman.

 

i'm running very similar to what you have and installed new stock plugs
since compression/cam/other things really didn't change much i didn't see a need to change, nor has the tuner mentioned the need to change plugs
only changes i have from you are ported intake, TB and SLP blackwing and 160 stat and complete tune

 

Any numbers (hp) on your combo. My intention is fast 102 and NW 102 with 160 and programming..

 

Forget the 160° thermostat.

All a 160° 'stat does is open sooner which cause the coolant temp to decrease to 180° range during cruise. But as soon as you slow down, the temp goes right back up to the 198° - 207° range. You can pull it down by cranking up the fan duty cycle but that can burn out the fan connector or the fan itself. So the net result is the 160° 'stat increases the coolant temp range during normal driving, which is not good.

The real HP increase comes from keeping the IAT as low as possible not from low coolant and oil temps.

I recently removed my 160° 'stat and put in a 186° 'stat made by Stant and set my fan duty cycle back to stock. Now my coolant stays in a very narrow range of 198°-207° range. Oil temp stays in the 215°-224° range which is perfect.

 

I run a 180 tstat and a fan cycle that when needed keeps coolant temp in range 192 - 196. Oil temps generally run 210 or less.