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View Full Version : 11.6 AFR in an STI OK?

criz
10-23-2005, 10:48 PM
I was hitting 11.6 AFR tonight while in 4th gear @ WOT... when it was warmer I was hitting 11.3 and I was cool with that.

Just wanted to get your opinions so I can sleep tonight.

thanks
slavetothemuzic
10-23-2005, 10:59 PM
I'm not a Subie guy, but I'd say that anything 11.5:1 - 12:5 or so is fine. Generally speaking, 11.5:1 or lower is getting pretty damn rich.
TROLL
10-23-2005, 11:06 PM
the cooler air is denser and as a result we're seeing more air (and higher boost) as a result. i would assume that your AP will adjust over the next week or so to the cooler temps and your AFR will go back down a little bit. 11.6 is nothing to get crazy about, but its a bit higher than I think a tuner would aim for on an STi at least.
bryan
criz
10-23-2005, 11:47 PM
i'll do some logging tomorrow and try tuning it down a bit

thanks guys
igo4bmx
10-23-2005, 11:50 PM
thats fine
TROLL
10-23-2005, 11:55 PM
the AP adjusts even with the tuner right? if so i wouldnt tune it... just let it adjust itself... i have a feeling it'll kick back to what you're used to. maybe check the cobb forums for how it adapts, etc.
bryan
99SL2_Modder
10-23-2005, 11:56 PM
I'm not a Subie guy, but I'd say that anything 11.5:1 - 12:5 or so is fine. Generally speaking, 11.5:1 or lower is getting pretty damn rich.

Subie's love the 10.5-11.7, I believe. Anything higher is destructination for their engines. Turbo, that is.
teh DIRT
10-23-2005, 11:57 PM
i wouldnt let it get any higher than that. Have you experienced any knock? i think that it should be fine with the colder weather.
slavetothemuzic
10-24-2005, 12:01 AM
Subie's love the 10.5-11.7, I believe. Anything higher is destructination for their engines. Turbo, that is.
Damn. Just goes to show how different engines react. Mitsus are generally not quite that rich. Course I know that S/C applications also don't require as much because they don't get as hot as turbos, so mine is a little unique in that respect.
99SL2_Modder
10-24-2005, 12:35 AM
Damn. Just goes to show how different engines react. Mitsus are generally not quite that rich. Course I know that S/C applications also don't require as much because they don't get as hot as turbos, so mine is a little unique in that respect.

Nah, most engines generally don't want below 11's. The opposing 4's that subies have are really strange in tuning. I know on my engine, I'd start washing rings at around 10.7. Below 11 is VERY bad on my car, as it is on most cars.
teh DIRT
10-24-2005, 12:38 AM
yeah subies are unique. while people think that 10.8 is pig rich. Its really just a safe tune.
wgknestrick
10-25-2005, 05:48 PM
Most tunes will end up around 11.2-11.5 on turbos with small hotsides (esp stock turbos). If you have a larger hotside/turbo, most tunes end up around 12.0-12.3 on WOT runs. The better your entire exhaust flows, the leaner you can go. This reduces in-cylinder pressures giving you more headroom under your knock threshold.

first is dyno of my car with a "smaller" hotside:



2nd is dyno of my car with larger hotside: