STS Turbo with Wideband
On The Tree
Joined: Aug 2005
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From: houston
I too have had a problem..98 A4 C5 Coupe STS TT w/ 100shot with AEm wideband. I am not familiar with turbocharging and have the car done for not long. What I have experienced is that under full throttle, i get a flat line on my AEM UEGO on the rich side and stays there, even when I spray a 100 wet shot. I am just a little nervous that I am washing the oil away, or I am not gettting an accurate reading and the car is actually running lean. I put the O2 sensor 5 inches away from H pipe as instructed.
Can anyone help me resolve my tentativeness regarding this issue. Tune set at 11.5
thanks
andy
Can anyone help me resolve my tentativeness regarding this issue. Tune set at 11.5
thanks
andy
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Joined: Nov 2002
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When you say the tune is set for 11.5, have you been able to verify this with any wideband yet?
My car's a/f was running in the high 9s with the target tune set to 11.0. You may be running very rich. I had to lean mine out considerable (software wise) to get it to 11.5.
Tommy
My car's a/f was running in the high 9s with the target tune set to 11.0. You may be running very rich. I had to lean mine out considerable (software wise) to get it to 11.5.
Tommy
On The Tree
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From: houston
Originally Posted by TaTommyWS6
When you say the tune is set for 11.5, have you been able to verify this with any wideband yet?
My car's a/f was running in the high 9s with the target tune set to 11.0. You may be running very rich. I had to lean mine out considerable (software wise) to get it to 11.5.
Tommy
My car's a/f was running in the high 9s with the target tune set to 11.0. You may be running very rich. I had to lean mine out considerable (software wise) to get it to 11.5.
Tommy
My Wideband goes completely flat on the rich side on the AEM UEGO, (no numbers at all with wide open throttle and 100 wet shot of gas). I want to make sure that I am not going to blow the thing up before I make it to San Antonio to have Allen tune this thing on the dyno.
Is placing the O2 sensor after H-pipe OK?
thanks
andy
turtle and the hare
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I placed my wideband AFTER the turbo, which is only about 18inches from the exhaust tip. It seems accurate. 14.7 exactly at idle and part throttle. and about 11.5 at WOT.
I think putting the wideband BEFORE the turbo will yield inaccurate results, as the pressure buildup in the exhaust system throws off the wideband since it is calibrated for "normal" barometric pressure.
I would try moving the wideband back, behind the turbo, and see what results you get.
Good luck!
Tommy
I think putting the wideband BEFORE the turbo will yield inaccurate results, as the pressure buildup in the exhaust system throws off the wideband since it is calibrated for "normal" barometric pressure.
I would try moving the wideband back, behind the turbo, and see what results you get.
Good luck!
Tommy
Launching!
Joined: Jan 2002
Posts: 299
Likes: 41
From: Detroit, Murder City
Andy, please see my original reply to this thread on page #1! The wideband output will be skewed if it's subjected to higher pressure (in between the engine and turbine). What the sensor is telling you is "off the charts rich" may not actually be. You REALLY need to verify your actual lambda before you break something by trying to "fix the rich condition" with a 100 shot.
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I had to install Cat replacement pipes that removed them from the system (Cant use cats if you have a 2-Step). So are we saying withought cats... its ok to put the wideband pre-turbo?
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Originally Posted by longrange4u
I had to install Cat replacement pipes that removed them from the system (Cant use cats if you have a 2-Step). So are we saying withought cats... its ok to put the wideband pre-turbo?
The pressure build-up in the exhaust system is what throws off the readings.
The wideband should go after the turbos, and with no Cats, its perfect. Just like a normal turbo car: Turbo then Sensor (then Optional Cats)
Tommy
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Yeah, my sensor is only about 5 inches from the turbo, and 12-18 inches from the exhaust tip. It works fine there with the expection of it overheating once on a two hour trip that I was averaging about 100mph... Once it cooled down, and I restarted the car, it started to work again. I am going to add a piece of copper and make a heat sink which should help in hot conditions.
Tommy
Tommy
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From: houston
Originally Posted by turbolx
Andy, please see my original reply to this thread on page #1! The wideband output will be skewed if it's subjected to higher pressure (in between the engine and turbine). What the sensor is telling you is "off the charts rich" may not actually be. You REALLY need to verify your actual lambda before you break something by trying to "fix the rich condition" with a 100 shot.
andy
turtle and the hare
On The Tree
Joined: Aug 2005
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From: houston
Originally Posted by TaTommyWS6
I placed my wideband AFTER the turbo, which is only about 18inches from the exhaust tip. It seems accurate. 14.7 exactly at idle and part throttle. and about 11.5 at WOT.
I think putting the wideband BEFORE the turbo will yield inaccurate results, as the pressure buildup in the exhaust system throws off the wideband since it is calibrated for "normal" barometric pressure.
I would try moving the wideband back, behind the turbo, and see what results you get.
Good luck!
Tommy
I think putting the wideband BEFORE the turbo will yield inaccurate results, as the pressure buildup in the exhaust system throws off the wideband since it is calibrated for "normal" barometric pressure.
I would try moving the wideband back, behind the turbo, and see what results you get.
Good luck!
Tommy
andy
turtle and the hare
