im getting an aem wideband O2 sensor and was wondering what would be a good air/fuel ratio to go for...any ideas?

 

disregard

 

We're talking about an Evo, right? 12.5 is way way way too lean for pump gas. Low 11s is really conservative. Mid 11s is about right for most people. High 11s to 12.0 is marginally lean for pump gas. Above 12 should be reserved for race gas.

If you are doing part throttle tuning with larger injectors, you should be seeing around 14.7 at cruise with light throttle and you need to monitor the ECU's fuel trims so that corrections are at a minimum.

If you do a search on my username, you'll find a post that I did a little earlier this year about tuning my SAFC with a portable wideband.

 

I suppose 11.2-11.4 would be safe. 12.5 is dangerous.

 

Opps.
EVO8LTW and Dr. Fob are right. I refernced an old article in Turbo Mag, but didn't consider octane.

 

would you recommend getting a dynoflash and then making small adjustments with the safc?

 

If you have a wideband, yes. You can probably pick up another 8-10 hp on average.

 

If you have a dynoflash custom tune, then AFC won't do you much good since Al will extract the last bit of power out of your car. If you opt for the "Through The Mail" tune, then I suppose there is room for leaning out, cuz the A/F ratio will likely be at the 11.0 range.

 

My through-the-mail flash went into the 10s.

 

10.7 to be exact from what i measured. Pretty freakin rich. But al tunes very conservatively so your engine doesn't blow up.

 

so should i just sell my safc and go with just the dynoflash, im not doing anything big on my car, i have the hks rs intake and a cat-back, and im not planning anything major

 

After Dynoflash, my A/F graph shows a lean 12.4 ratio in low rpm, and progressively richens to about 11.0 by 4000rpm. I now use the S-AFC to sustain 11.4 from 4000rpm to redline.

 

thanks for the info guys