Plugs, revisited. Options

[natedogg]

This webpage has some good info on spark plugs. Also keep in mind, the colder the plug, the easier it is to foul at normal cruising speeds, but as you said it also better resists detonation.

http://www.ngk.com/sparkplug411.asp?kw=Com...er+chart&mfid=1

[awd4kicks]

Interesting stuff.

Sunday at the cook out, NCGalant and myself attempted to tune the now-running Talon in, burning new data to the EPROM. To our dismay, we found the O2 sensor readings to be untrustworthy and worse yet I had a violent popping when trying to make WOT pulls. The popping changed, but continued through all attempts to richen or lean the mixture and adjut the timing. The popping also seemed to be unrelated to knock for the most part.

I came up with a theory that the problem was at a more basic level that effected all things more equally. I knew my plug gap was good because I purposely narrowed it to .025. I suspected that my NGK BPR7ES's that I had been running for so long were maybe out of their legue with this set-up.

I got a fresh set of 8's locally on Monday. Low and behold 95-98% of the popping was gone instantly! Later that evening Spyguy and I made another test run. This time the popping had come back a bit. Not much, but it was present.

Now I'm wondering if I need to go to 9's or if the 8's I'm using now are already prone to fouling from intown slug driving. The NGK info says a rule of thumb is to go one range colder for every 70-100 HP the engine is upgraded! DAMN! That would put me at something like 10ES's if I truely get to the HP level I'm looking for. I just can't imagine that I wouldn't foul the plugs by normal street driving. I know Nate had some issues with 9's.

[awd4kicks]

At first NC and I thought rich knock, but it was too comon through all levels of tune. It sounds like rich knock no doubt, and it is rich, but I'm not sure it's that rich. Roughly 10.8-11.5 at WOT on the wide band. (Keep in mind this is the initial and conservative tune for the EPROM.)

I can get the popping to go away for a period of time by easing into WOT with a good (leaner) part throttle burn. We will be leaning the tune, but I'm also going to try the 9's.

Compression ratio is roughly 8.5:1. Nothing too excessive.

[wortdog]

If you're down around CU or I'm in Peoria for some reason, I can break out the Ostrich emulator and we can do some real time tuning, unless NC already has one.

[awd4kicks]

Thanks for the offer Eric. I may be willing to make the drive to get the hook-up with your ostrich emulator.

[turbohcar]

Nice info guys! Kicks, congrats on getting the beast running again. Lets see if we can't keep it running for a while this time!?

[Mitsu 77]

I agree great info, I will probly be needing this in a week or so when I start to tune the ems in my car.

Hey Marcus, how do you like that FP3052? When dose it start to spool and how about full boost?