I just finished installing my Hahn stage two and every thing is running perfectly except for the A/F gauge. I have nothing in my catch can, no signs on knock or detniation. The idle pressure is set at 50 psi. My idle exhaust temp is 900 and 1100 while driving. I havent taken it past 4000 rpm or 4 pounds of boost because I am worried about the A/F gauge. It reads stoich for about a min. then bounces back and fourth like crazy. Tommrow I am going to install the corbins A/F gauge. What kind of readings should I look for on the corbins A/F gauge. I have the A/F gauge tapped in to wire #31(?) white with black stripe.
1998 Eclipse GS,
Hahn Stage 2 Turbo Kit w/missing link
and Vortech SFMU,
Corbins Digital A/F Gage,
Apex N1 Exhaust,
NeuSpeed Short Shifter,
Autometer Boost, A/F and Exhaust Temp Gauges,

Put in the Corbin gauge, the blinkly lights are useless for proper tuning.

You should be seeing numbers in the .900 and above range at full throttle on the corbin gauge.


________________________________________________________________________________________
Car Sold


http://hometown.aol.com/ohshootuhh/
www.Fast420A.com

The A/F gauge you have is supposed to do that. When the motor is in closed loop, ( 80% or less throttle), the o2 sensor is controlling your air/fuel ratio. The ECU is monitoring the o2 many times a second, which is what you are seeing on the gauge. The voltage goes up and down very quickly, and you see this on the gauge. Now, when you go WOT with 80% or more gas pedal, the ECU goes into open loop mode, and then refers to its pre-programmed fuel maps, and the o2 sensor is not controlling the air/fuel mixture anymore, it just outputs a voltage relavant to the ratio of air/to fuel. This is how you know if you are lean or rich. At WOT, you should be in the very last green LED on the gauge. You want to run pretty rich. If you were to connect a voltmeter to the o2 sensor wire, you want o2 WOT readings of around .93 to .95, in 4th gear (if you are manual) Watch your EGT's and never go over 1600 degrees, as detonation can result too. I like to keep EGT's around 1550 max at WOT

13.5 @108 MPH-2.2 60ft(stupid FWD!)
S16G @ 18 PSI/FMIC/Running on MegaSquirt II (Now with sequential
fuel injection)
My webpage: http://eclipsed4evr.home.comcast.net
-1998 Mitsubishi Eclipse RS-T- "Toy"
-1992 Plymouth Laser Turbo AWD(SOLD)
-2000 Honda CR-V(daily)

Thanks. I feel alot better knowing that is how it is supposed to act.
1998 Eclipse GS,
Hahn Stage 2 Turbo Kit w/missing link
and Vortech SFMU,
Corbins Digital A/F Gage,
Apex N1 Exhaust,
NeuSpeed Short Shifter,
Autometer Boost, A/F and Exhaust Temp Gauges,

Hmm.. .94 is pretty damn rich, thats what you run from the factory I think. If you want to make powah, you should shoot for .92, and .88 as the lowest possible voltage. I think .92 translates to 2 green lights on the blinky gauge but I don't have one so I dunno.

Just being pedantic, but I didn't think there was such term as "open loop", I think "static mode" is more accurate. But google says 1,600 people use it so I guess I'm wrong.

"Most ECUs seem to operate in two modes. In one mode, the ECU is monitoring as many engine sensors as possible, trying to get the best fuel economy. This mode is normally referred to as "closed loop" because it is a closed feedback system. In the other mode, the ECU is generally trying to achieve the greatest level of performance possible. This mode is normally called "open loop" because it does not continuously monitor sensors and compute fuel correction: simpler routines are used. It's difficult to change the exact behavior of the ECU under closed loop conditions because it requires an understanding and possibly a re-write of that portion of the code running the ECU. Open loop conditions are generally stored in the form of a table where the ECU "looks up" fuel and timing values using a relatively simple algorithm. In most cases, the open loop tables also serve as values to use as a base for fuel correction routines. Modifying these tables is the most basic way to retune a car, however it bears remembering that the ECU will be making adjustments to whatever fuel/timing information it has."

>Hmm.. .94 is pretty damn rich, thats what you run from the
>factory I think. If you want to make powah, you should shoot
>for .92, and .88 as the lowest possible voltage. I think .92
>translates to 2 green lights on the blinky gauge but I don't
>have one so I dunno.
>

Tune for less than .92 and you will get detonation and very high EGT's under WOT full boost. Trust me. If you were N/A tuning, then .92 would be considered pretty rich. But when we add boost pressure into the equasion, then we NEED to run rich, esp when we start to go past 8 or 9 psi, to help keep things cool, and to avoid detonation. In second gear at WOT, i get amost 1 volt of o2 voltage. The car pulls damn hard, even with this high voltage. When i go though the gear, the load increases on the engine, and the o2 voltages will come down, and i end up with about .94 in 4th gear at WOT @ 8 or 9 psi. NO big streams of black smoke out the exaust either. The car pulls very well like this. YOu tune for .88 volts at 8 psi, you will melt your motor..either by detonation or extremly high
egt's.

13.5 @108 MPH-2.2 60ft(stupid FWD!)
S16G @ 18 PSI/FMIC/Running on MegaSquirt II (Now with sequential
fuel injection)
My webpage: http://eclipsed4evr.home.comcast.net
-1998 Mitsubishi Eclipse RS-T- "Toy"
-1992 Plymouth Laser Turbo AWD(SOLD)
-2000 Honda CR-V(daily)

If you run .88 A/F ration with your stock injectors, you will blow your motor within a month of boosting a lot. with stock internals, tunr for .92, the perfect middle ground for safety and power. 5hp isnt worth blowing your motor for. also, when you hook up the corbin gauge, the displayed numbers will jump around like crazy in closed loop just like your blinky light did, its normal.

www.TeamKLR.com
1997 Silver RS
12.3@118mph,20psi, race gas(drag radials)
Wiseco 10.5 Pistons
Eagle Rods
T3/T4 Turbo
Custom FMIC
Greddy Exhaust
440's

I am running about 4 to 5 lights in the green at WOT in fourth right now. I am going to leave it a little rich right now until it warms up. Rich is better than lean any day. Thanks for everybodys hel !