I admit it's my fault.
From that site you posted:
Red = lean
Yellow = in the zone no more mods
Green = a little rich
Blue = rich
The problem is you don’t know what that device’s interpretation is. Turbo charged rotaries HAVE to run rich at WOT to prevent detonation. A conservative tune is high 10’s low 11’s across the powerband, which is pig rich for an NA piston car… Given that particular AFR gauge is a general purpose device it begs the question on what it actually detects in the green? Low 12’s, 11’s Don’t know..
^ yeah I agree ... so I wont know for sure until I have the wide band and a dyno run. at least the lights look cool at night. the colors represent a voltage range, I think that site mentioned something.
well I hope the op had a good read anyway...
well I hope the op had a good read anyway...
A narrowband is completely useless in knowing whether you are safe or not as it tells you nothing. It's only real use is in closed loop control at keeping AFR at stoic for "best" fuel economy and emissions. It serves no other purpose, especially on our cars. A wideband is the only way for usable data.
Look at the comparison... Beyond 14 AFR and your "rich". Um... How rich is rich? Get how useless it is?
vs...
As for the Pettit ECU, its tuned pretty conservative. When I bought my car many moons ago i ran 12.5 PSi and later turned it up to 14 PSi with both intake and exhaust (no cat). Never ran into any issues. A stock motor, stock twins, has enough fuel for 16 psi (not that you want to run the twins there) assuming everything is in good shape. However, given the fact that our cars are 15+ years old, a pettit ECU is a fixed tune ment for like new compenents, and given the fact that injectors do clog over time its best to verify that your actually getting the safe AFR's with a wideband since its not tuned specifically to your setup.
I tuned a car a year ago with a stock motor and stock non-sequential twins. It was hitting 90+ duty cycle @ 11 PSi which didn't make sense. I suggested to have the injectors cleaned and we could try again. When I got the car back I had to remove 20-25% of fuel across the whole boost range and then upped the boost to 13 psi. Now imagine if you ran a pre-tuned ECU with your injectors in this state, you would be 20-25% leaner in fuel and your motor would go kaboom at some point. You probably wouldn't know the difference until its too late as your car would be feeling like a rocketship and if you take it to the dyno it would give you great rwhp numbers. "They run best before they blow."
Of course we're not even getting into things like fuel pump wiring being inadequate, fuel pump filter getting clogged, fuel pump dying, and any other number of things that can go wrong.
thewird
Look at the comparison... Beyond 14 AFR and your "rich". Um... How rich is rich? Get how useless it is?
vs...
As for the Pettit ECU, its tuned pretty conservative. When I bought my car many moons ago i ran 12.5 PSi and later turned it up to 14 PSi with both intake and exhaust (no cat). Never ran into any issues. A stock motor, stock twins, has enough fuel for 16 psi (not that you want to run the twins there) assuming everything is in good shape. However, given the fact that our cars are 15+ years old, a pettit ECU is a fixed tune ment for like new compenents, and given the fact that injectors do clog over time its best to verify that your actually getting the safe AFR's with a wideband since its not tuned specifically to your setup.
I tuned a car a year ago with a stock motor and stock non-sequential twins. It was hitting 90+ duty cycle @ 11 PSi which didn't make sense. I suggested to have the injectors cleaned and we could try again. When I got the car back I had to remove 20-25% of fuel across the whole boost range and then upped the boost to 13 psi. Now imagine if you ran a pre-tuned ECU with your injectors in this state, you would be 20-25% leaner in fuel and your motor would go kaboom at some point. You probably wouldn't know the difference until its too late as your car would be feeling like a rocketship and if you take it to the dyno it would give you great rwhp numbers. "They run best before they blow."
Of course we're not even getting into things like fuel pump wiring being inadequate, fuel pump filter getting clogged, fuel pump dying, and any other number of things that can go wrong.
thewird
green is rich and blue is really rich, that's where you want to be, at least thats how all the narrowbands I've seen are. Read a little further, stoich is 14.7:1 for gasoline mixtures, WAY to lean for WOT
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