Hi everyone,

I'm running ~15.5 AFR at cruise and something like 12.0 AFR at 120mpa and 11.5 AFR above up to 200mpa which is my max boost target. running a stock 1.6 with FF640cc injectors, BKR7E plugs, MSpnp2, LS coils. The car pulls and runs great but when I pull the plugs out they have a lot of white deposits and look scarily lean. However, according to my wideband (new AEM) the AFR is running pretty safe under load.

Is this normal for a turbo'd engine? I went out and did a WOT pull in 4th gear and immediately turned the car off pulled over and pulled the plugs. They had a bit more of a brown tint but hardly any darker in color. Not the golden brown that I am used to tuning to on my ancient carb'd motorcycles.





Thanks,
Nick

 

Looks nice to me. Don't change a thing.

That golden color comes with the normal burning of a little oil over time so it varies by consumption. Additives can make it more pronounced.

 

I also believe that unleaded gas does not color plugs like we were taught, (at least old guys like me), with leaded gas. Been awhile since I tuned any carbs, but damn, it made more sense to me than CAN/BUS, or laptop fiddling, etc. I'm still looking for that nice, dry brown look.

 

Alright, i'll send it. Thanks for the responses guys.