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View Full Version : WB A/F gauge is in


Redog
04-18-2011, 06:24 PM
OK It's in and I'm wondering how far I can go, safely.

At idel, after it's all warmed up the numbers hang around 13.9 to 14.2. I've gotten on it and it's dropped to 10, all the rich lights light and then when I let up, 17 and all the lean lights light.

I r confuzed :cry:

[ion] C2
04-18-2011, 06:40 PM
Newb....

It's going to swing around 13-high 15s during cruise, idle, etc. Any time you're in closed loop.. the O2 sensor is switching and your fueling adds/subtracts to keep your AFR around 14.6...

In open loop (heavier throttle)the AFR ramps down to whatever it's tuned to reach. Usually people target 11.5 - 13.0 depending on boost or N/A, compression, etc.

When you let off it's going to swing to the edges pretty severely because some major changes are happening, the throttle plate closed and now there's a ton of fuel and not as much air, so it subtracts fueling, and then it will even itself out. What happens off throttle is not that important. It's the heavy throttle stuff that you want a consistent number between 12-12.5 I assume for your car.

Redog
04-18-2011, 07:33 PM
I've read that 12 to 12.5 is a good number for a NA car with 9.5 : 1 CR (actually I'm at 9.7)

It's probably a safe bet to do the tuning with my CAI, even though I run a WAI on the street :ninja:

[ion] C2
04-18-2011, 07:40 PM
I still don't get why you switch them.. if you're worried about water, that's silly..

mfuller
04-18-2011, 07:43 PM
I think you are missing the point here Ken.
Every car will be different, and whatever mods you have will change things even more.
When I had mine tuned, it flowed a ton of air up top so we needed to add as lot of fuel up top. I think it was somewhere around 12:1 more I went way rich from the CAT over-temp protection. But your car could be different.
If you have HPTuners, you really need to set up your histogram data so you can log your W/B lambda readings, and you can then adjust your tune accordingly. I highly recommend Greg Banish's tuning DVD from Summit Racing.

XanderWiFi
04-18-2011, 10:12 PM
Just thread carousing, but I may need to pick that dvd up myself...

Redog
04-18-2011, 10:18 PM
I think you are missing the point here Ken.
Every car will be different, and whatever mods you have will change things even more.
When I had mine tuned, it flowed a ton of air up top so we needed to add as lot of fuel up top. I think it was somewhere around 12:1 more I went way rich from the CAT over-temp protection. But your car could be different.
If you have HPTuners, you really need to set up your histogram data so you can log your W/B lambda readings, and you can then adjust your tune accordingly. I highly recommend Greg Banish's tuning DVD from Summit Racing.

It is true, I still have a lot to learn about this stuff, it's not like the old days where swapping parts and a little turn of a carb screw was all you have to do