Honestly, it really depends on the year. Normally, they do NOT go far enough into the chamber.
I had a hunch that was it but, because I've never actually tried the TR55 in a Gen 3, I didn't know if it was too much or too little.
It's always been interesting to me that you can fuss with timing just a little by swapping around amongst plugs with slightly different center electrode lengths.
This is why the people who put them in, claim no more spark knock retard, and increase power.
Interesting. When you say "no more spark knock", you must mean at light throttle, because detonation at WOT should be addressed by knock retard. As for more power....as we both know, those people are imagining the increased power as a result of an effective decrease in spark advance.
I cannot tell you all how many aftermarket plugs I have removed because of poor performance over time, and drivability concerns.
Yeah, you can tell me.
I know exactly what you are saying. A great number of aftermarket plugs are marketed to consumers with flim-flam (Split Fire, Bosch Platinum, esp. Plus-2 and Plus-4, Champion Truck Plugs) and cause power losses and driveability quirks. Not many aftermarket plugs have any useful engineering behind them.
What's been your experience with Denso's Iridium product in Gen3s?
On the other hand, my biggest complaint with ACDelco's OE stuff is the lack of colder heat ranges for racing or very aggressive street driving.
What do you recommend in situations like that, particularly C5s with nitrous oxide injection or superchargers?