What do you guys think of 12.5 AFR @ WOT on a Radixed L33 5.3?
Mods are only a Corsa and CAI.
Boost is just touching 7 psi.

Thanks

 

too lean IMO... I'm sure it makes great power there but It would be much safer in the high 11's... ideal WOT N/A AFR is around 12.7 if that tells you anything...

 

OK, I just had a reputable tuner set me up and he knows it's a FI motor. He said it would be fine. But I read different here, this being why I asked.

How do I confirm? What are trouble signs? Detonation?
Is there a spark plug check procedure?

In your opinion is 12.5 an absolute NO! NO!

Remember only 6.9 - 7 psi. 93 Octane.

I drove it in @ 10.5 and detonating. He pulled some timing and did the AFR and more I do not understand.

 

You need a wideband in it... That's the only real way to confirm...

I'm not saying he doesn't know what he's doing, but I personally wouldn't run one that lean...

 

You need to be about 11.2 afr.

 

For your boost level 11.7-11.8


Anything between 11.3 and 11.8 IMO, I absolutely wouldnt run it at 12.5AFR

 

I have a PLX wide band.

The truck is running better than it ever has and in the 98-degree heat. Not a hint of detonation.

And then there is the great and much respected input I get from all of you guys here.
Not to forget the tuner whom is very well known for tuning boosted applications.

So here I am all tight in the gut about the differences of opinions and concern about my motor. Heh! If I go back to the tuner and tell him to make it richer it will not be pretty.

Is there any way I can monitor or check for danger? I do have a live diagnostics feature in a hand held.

 

dont you have the stock exhaust? Where is your wideband sensor in the exhaust? If it's post-cat that will read leaner than it actually is.

 

I have stock manifolds with a Corsa catback. I have the o2-sensor installed pre-cat via a welded in bung.

 

If your tuner has a problem tuning the vehicle how you want it then you should go somewhere else anyway IMO. It doesn't belong ti him, so in turn he should respect your wishes... What's the timing set to??

Like I said, I'm sure it flys, but with these weak *** stock pistons all it takes is the first drop of bad fuel or the slightest hint of knock due to increased load or heat then you'll be researching a new shortblock... Ask me how I know