A/F Meter
Thread Starter
Staging Lane
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Joined: Aug 2003
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From: Highlands Ranch, CO
A/F Meter I have the AEM UEGO Wideband installed, and i'm trying to get used to it. After the car is up to temperature, idle, it sits between 13 and 14, then under light acceleration, goes up to around 15-17. Under moderate acceleration (75% throttle, it seems to stay there as well). Under full throttle, the a/f drops to 10.0 (the lowest the gauge will read), then climbs up to around 10.8. There is hestitation when I first stomp on it, and I'm sure that's due to it being too rich.
My question is, is 15-17 normal for most driving circumstances, and where should it read during idle? The car doesn't show any knock.
I have the GMR single kit with the T76 upgrade. When we ordered it, we asked for a 7-8psi wastegate spring and I was only seeing 3.5psi. The 4" elbow that came with their kit sucked -- literally - just reving the motor, you would see the entire elbow suck in and collapse. Anyhow - I switched that to a new elbow from intakehoses.com -- This is the quality I that I originally expected. I moved the wastegate boost line from off the turbo to the new intake elbow, and now the car sees 5psi in every gear. What a shock there. GMR installed the wrong spring. So rather than replacing the spring, I'll just wait until the boost controller is installed. Besides, I haven't changed my fuel pump yet, and I can't imagine going much higher than 5psi without switching it.
My question is, is 15-17 normal for most driving circumstances, and where should it read during idle? The car doesn't show any knock.
I have the GMR single kit with the T76 upgrade. When we ordered it, we asked for a 7-8psi wastegate spring and I was only seeing 3.5psi. The 4" elbow that came with their kit sucked -- literally - just reving the motor, you would see the entire elbow suck in and collapse. Anyhow - I switched that to a new elbow from intakehoses.com -- This is the quality I that I originally expected. I moved the wastegate boost line from off the turbo to the new intake elbow, and now the car sees 5psi in every gear. What a shock there. GMR installed the wrong spring. So rather than replacing the spring, I'll just wait until the boost controller is installed. Besides, I haven't changed my fuel pump yet, and I can't imagine going much higher than 5psi without switching it.
I'm not sure why the O2 sensor, if it's after the turbo, would have to be moved to after the cats. Wouldn't you want the AFR to read before the cat?
Anyway, I'm seeing 14.25 around idle, 15.5 at light cruise, in the high 10's when accelerating hard (due to acceleration enrichment, which is about done by 4K rpms) and above 4K at WOT, in the 11.8-12.2 range.
Light accel should be in the 13 range, IMO.
You should only see 16.5+ if you have fuel cutoff on deccel, or if the fuel is set to go pretty lean on deccel. You shouldn't see that range in normal, steady state driving.
Jim
Anyway, I'm seeing 14.25 around idle, 15.5 at light cruise, in the high 10's when accelerating hard (due to acceleration enrichment, which is about done by 4K rpms) and above 4K at WOT, in the 11.8-12.2 range.
Light accel should be in the 13 range, IMO.
You should only see 16.5+ if you have fuel cutoff on deccel, or if the fuel is set to go pretty lean on deccel. You shouldn't see that range in normal, steady state driving.
Jim
Joined: Jun 2004
Posts: 1,501
Likes: 7
From: Ft. Irwin, California (But Virginia is home)
Originally Posted by MaverickWH
I have the AEM UEGO Wideband installed, and i'm trying to get used to it. After the car is up to temperature, idle, it sits between 13 and 14, then under light acceleration, goes up to around 15-17. Under moderate acceleration (75% throttle, it seems to stay there as well). Under full throttle, the a/f drops to 10.0 (the lowest the gauge will read), then climbs up to around 10.8. There is hestitation when I first stomp on it, and I'm sure that's due to it being too rich.
My question is, is 15-17 normal for most driving circumstances, and where should it read during idle? The car doesn't show any knock.
I have the GMR single kit with the T76 upgrade. When we ordered it, we asked for a 7-8psi wastegate spring and I was only seeing 3.5psi. The 4" elbow that came with their kit sucked -- literally - just reving the motor, you would see the entire elbow suck in and collapse. Anyhow - I switched that to a new elbow from intakehoses.com -- This is the quality I that I originally expected. I moved the wastegate boost line from off the turbo to the new intake elbow, and now the car sees 5psi in every gear. What a shock there. GMR installed the wrong spring. So rather than replacing the spring, I'll just wait until the boost controller is installed. Besides, I haven't changed my fuel pump yet, and I can't imagine going much higher than 5psi without switching it.
My question is, is 15-17 normal for most driving circumstances, and where should it read during idle? The car doesn't show any knock.
I have the GMR single kit with the T76 upgrade. When we ordered it, we asked for a 7-8psi wastegate spring and I was only seeing 3.5psi. The 4" elbow that came with their kit sucked -- literally - just reving the motor, you would see the entire elbow suck in and collapse. Anyhow - I switched that to a new elbow from intakehoses.com -- This is the quality I that I originally expected. I moved the wastegate boost line from off the turbo to the new intake elbow, and now the car sees 5psi in every gear. What a shock there. GMR installed the wrong spring. So rather than replacing the spring, I'll just wait until the boost controller is installed. Besides, I haven't changed my fuel pump yet, and I can't imagine going much higher than 5psi without switching it.
. Anyhow, after the freaking air pump shuts off, idle is 14.3-15.1 Anything under the "perfect 14.7" average for idle is a bit rich. With normal driving I'm looking at the 14-16 range all day long, more so in the 15 range. This is normal. I had the gauge hooked up a week BEFORE installing my turbo and the car ran the same N/A. WOT I KNOW I'm running rich. I also hit 10.0 at first and then it creeps to about 10.6. Hesitation means you are running even richer than 10.0 to 1. I had a bad hesitation when I first began tuning my setup. The freaking A/F was actually about 8.7 to 1! My friend leaned this out...and what a difference. Even 10.6 (or 10.8 in your case) is rich. I have mine rich so I can up the boost and still be good. I'm lazy like that.
A "perfect" ratio would be around 11.5 to 1 WOT. Also, if you have a M6 you will see the gauge peg out lean between shifts. This is normal too.
Last, but not least. Make sure the O2 bung is in the right place. It should be BEFORE the cats. Mine is actually in the header collector on the passanger side.
Hope this helps.
your numbers sound normal for a safe tune, especially 10-11 at WOT. i have mine set at 14-15 at idle and under slight accel. cruising it stays in same range, at WOT its in the 10-11 range , on the safe side for more boost later, just as lazy as SHANTIN.
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Thread Starter
Staging Lane
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Joined: Aug 2003
Posts: 70
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From: Highlands Ranch, CO
I think I've seen two problems so far. Under 70-80% throttle, it'll sit around 15-16, and I get some hesitation there. That tells me that i need to richen that up a bit. Then when I go full throttle, it's too rich for a split second.
I have the O2 bung about 4 feet behind the turbo - remember - this is a front mount turbo hanging off the header, so after the exhaust routes back along the header, it's placed about 1-2' behind the stock front o2 sensor. When I add the cat, I'll add it about 2-3' behind my wideband o2.
Thanks for the feedback. The only other time I've ever seen my a/f logged was on the dyno, so I never really knew what it does under normal driving.
I have the O2 bung about 4 feet behind the turbo - remember - this is a front mount turbo hanging off the header, so after the exhaust routes back along the header, it's placed about 1-2' behind the stock front o2 sensor. When I add the cat, I'll add it about 2-3' behind my wideband o2.
Thanks for the feedback. The only other time I've ever seen my a/f logged was on the dyno, so I never really knew what it does under normal driving.
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