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I have the wideband 02 with the laptop and did my hight throttle setting keeping my a/f ratio around 11.6 now what am i exactly doing to get my a/f ratio correct on my low throttle. What would be the best process to get it correct.
 

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during low throttle (just cruising) there is no "set" AFR to be running. The AFR's fluctuate all over the place for a balance of fuel consumption and safety. Thats why regular Air/Fuel gauges do that back and forth sweeping.

Assuming you have bigger injectors, you'll need to trim them back a little just so they appear as regular injectors to the PCM, but then the PCM will be able to correct as needed to get that sweeping effect.

The AFR's will swing high to save fuel and then swing low to cool down the engine due to the previous high AFR's and then repeat. During low throttle there isn't much load on the engine, so the fluctuating AFR's do not hurt the engine.
 

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Low throttle settings are usually set by fuel trims. If you have an OBDII reader you will be able to read short term & long term fuel trims. Your goal is to set the low throttle settings to get as close as possible to 0% correction. In reality if you can keep it between +/-8% you are doing fine. I was able to fine tune my low throttle steetings to obtain steady -2% long term fuel trims on my Eclipse.
 

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heavyD said:
Low throttle settings are usually set by fuel trims. If you have an OBDII reader you will be able to read short term & long term fuel trims. Your goal is to set the low throttle settings to get as close as possible to 0% correction. In reality if you can keep it between +/-8% you are doing fine. I was able to fine tune my low throttle steetings to obtain steady -2% long term fuel trims on my Eclipse.
I agree 100%.
 

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Either while driving the car or on the dyno. With no load and at various rpms.

On my old STG1 ECU w/STG2 injector setup in Lo on my SAFCII It pulled from 14-18% thru the rpm range. This was done on the dyno by a tuning shop. They just drove the car gently on the dyno up and down thru the rpm range.

The car went from hard starts, stalling, rough idle to just like stock with plenty of HP up top.

FYI,

Marion
 

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50 trim, stage2, 650's.....

It took a little while for me to figure out a good daily driver configuration. I ended up with 50trim, stage2, safc2, rc650's, and fuel return. I have all the low settings on the safc set to 0. This lets the stage 2 pcm handle normal driving. The 650's seem to be close enough to the stage2 injectors that it runs smooth and drives like stock. I did need to up fuel pressure slightly on the return line to achieve stock idle. It also helped adjusting the high/low settings on safc to dial things in. I drive with manual boost set at 20lbs on 91 octane. My wide band has wot at 11.2-11.5 afr's to 6200rpms. I have other mods, but the ones listed apply to the tuning question. The car is my daily driver and has run flawless for the last year/9,000 miles.
 

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I have 750cc injectors, on a S2 computer. And I have the bad stumble, I have a return and a check on the vac line, pressure at 44psi. I can adjust the high settings. But I dont know how to do the Lo settings. It seems you need a scan tool to see the correction factor and try to dial it in. Unlike the high settings where I can use the wide band and nail 11.5-12.00afr.



Rickrockr said:
It took a little while for me to figure out a good daily driver configuration. I ended up with 50trim, stage2, safc2, rc650's, and fuel return. I have all the low settings on the safc set to 0. This lets the stage 2 pcm handle normal driving. The 650's seem to be close enough to the stage2 injectors that it runs smooth and drives like stock. I did need to up fuel pressure slightly on the return line to achieve stock idle. It also helped adjusting the high/low settings on safc to dial things in. I drive with manual boost set at 20lbs on 91 octane. My wide band has wot at 11.2-11.5 afr's to 6200rpms. I have other mods, but the ones listed apply to the tuning question. The car is my daily driver and has run flawless for the last year/9,000 miles.
 
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