mykim72

how can you tell? does the motor go out right away? are there any signs before youre in trouble?

tx_zstang

Without a air-fuel gauge or datalogging, you wouldn't know. Then it's too late.
Get a wideband air/fuel sensor and gauge in asap!!!

mygt500

when you lean out most likely (if your lucky) the motor will have denotation....look up what it sounds like and preferably with a S197 stang. Most never have the chance to save the car when WOT and a lean condition happens cause a rod will give way and destroy the motor.

You can have signs but usually it is too late.....do you have gauges? Boost and A/F ratio and fuel pressure? those can help diagnose a problem before its too late.

mykim72

i have a wideband...which is why im asking...since the AFR keeps changing under boost i cant look at the gauge and keep an eye on the rpm...im really more just curious what happens when it leans out...call me paranoid because when i see those red dots and get scared

mygt500

understandable but the red lights will come on with decel etc.....best thing would be to datalog and get them to a tuner that tunes turbos and set it and forget it. 9 out of 10 the motor will blow before you even read the gauge....sucks I know but you want to play you usually have to pay....R U forged? and what psi you running now?

mykim72

the car was tuned but i had this huge electrical problem and everything was just in a horrible state...when i finally got things under wraps i dont remember if my wideband was always showing that many red dots all the time...so i re-loaded the tune but was worried there too because ive never done that before...so then i was worried i uploaded the wrong tune...

the tuner wouldnt have put it anywhere else other than custom tunes in the diablo would they? sorry paranoid...cant afford a new motor...or a new anything these days...

mykim72

im running about 6-6.5 psi...i see a lot of 13s on the wideband...

mygt500

it should be in the custom tunes of that tuner...I cant see him putting it any other place.
You might need to set the parameters again for the A/F gauge...have you tried that?

Sp3kter

If you run to lean you'll detonate and/or melt a piston due to the temp skyrocketing in the combustion chamber. Your A/F should be around 11.5 no higher than 12 during wot. If your running race fuel you can lean it out to 13 during wot due to the slower burn of the high octane fuel. I dont know to much about the mustang pcm but on my srt the pcm used to retard timing if detonation was detected to safe the engine. If the mustang pcm has a safty net like that than I would assume only prolonged acceleration with a too lean A/F would blow your engine up.

rford426

off topic but op your car is absolutley sick....nicely done more info on hp boost...etc