open dump for stock turbo
i had a question for you people that are running the epm dump pipe, from my understanding, the exhaust gasses are only going to be routed through the dump pipe when under boost ~15 pounds.. after i installed it, i noticed that exhaust gasses are constantly flowing through it even at idle.. wanted to know if this was normal, or if exhaust gasses are sneaking their way out the dump pipe because i ended up using the o2 gasket provided by the 9 install kit
i had a question for you people that are running the epm dump pipe, from my understanding, the exhaust gasses are only going to be routed through the dump pipe when under boost ~15 pounds.. after i installed it, i noticed that exhaust gasses are constantly flowing through it even at idle.. wanted to know if this was normal, or if exhaust gasses are sneaking their way out the dump pipe because i ended up using the o2 gasket provided by the 9 install kit
Go with EPM : http://evopowermods.com/ I have one that is about to go on my Red.
any ill effect if i didnt use the one provided (minus the lightheadedness when driving haha) now to think about it i shouldnt be loosing any extra ponies or anything like that, maybe just have less backpressure causing a later spool?
Q,
With WBO2 installed several feet downstream the main exhaust portion of the O2 dump, have you seen any reports of skewed AFR readings when WG opens? What about drawing O2 in the dump back up through WG and out the scrolls at cruise showing higher than normal O2?
I expect a leaning event compared to w/o dump from lower pressures behind turbine, just wondering what to expect otherwise.
This is a part I'm really considering.
Thank you
With WBO2 installed several feet downstream the main exhaust portion of the O2 dump, have you seen any reports of skewed AFR readings when WG opens? What about drawing O2 in the dump back up through WG and out the scrolls at cruise showing higher than normal O2?
I expect a leaning event compared to w/o dump from lower pressures behind turbine, just wondering what to expect otherwise.
This is a part I'm really considering.
Thank you
The O2 sensor (stock and WB) measure O2 content, not volume. O2 content in the exhaust flow isn't affected with the dump open ... the volume is simply reduced (split). I have seen no changes in readings. The front O2 responds normally in closed loop and the WB matches it.
AFRs didn't change much for me after the install. Maybe a max of .2 difference up top in a small range, but I was also in a different load cell so that's inconclusive. It was dead on my previous logs under 6000. I run ECU boost control, so the boost response was constant before and after the install which gave us a nice AFR comparison.
At a cruise state the WG actuator sees vacuum and the puck is closed. There should be no notable amount of ambient air entering the exhaust flow if the correct gasket is used. If the WG sees enough pressure to open, then ambient air isn't being pulled in to the turbo ... it's being pushed out. Again, front O2 readings are normal and fuel trims are in check.
I hope that answers your questions.
AFRs didn't change much for me after the install. Maybe a max of .2 difference up top in a small range, but I was also in a different load cell so that's inconclusive. It was dead on my previous logs under 6000. I run ECU boost control, so the boost response was constant before and after the install which gave us a nice AFR comparison.
At a cruise state the WG actuator sees vacuum and the puck is closed. There should be no notable amount of ambient air entering the exhaust flow if the correct gasket is used. If the WG sees enough pressure to open, then ambient air isn't being pulled in to the turbo ... it's being pushed out. Again, front O2 readings are normal and fuel trims are in check.
I hope that answers your questions.
Last edited by TouringBubble; Feb 6, 2009 at 02:00 PM.
See above. At cruise, the front O2 could see an artificially lean mix and add fuel, reducing fuel economy. I haven't tested it though ... just a possibility.
mike@AWD Motorsports has them.
http://www.awdmotorsports.com/
http://www.awdmotorsports.com/
The O2 sensor (stock and WB) measure O2 content, not volume. O2 content in the exhaust flow isn't affected with the dump open ... the volume is simply reduced (split). I have seen no changes in readings. The front O2 responds normally in closed loop and the WB matches it.
AFRs didn't change much for me after the install. Maybe a max of .2 difference up top in a small range, but I was also in a different load cell so that's inconclusive. It was dead on my previous logs under 6000. I run ECU boost control, so the boost response was constant before and after the install which gave us a nice AFR comparison.
At a cruise state the WG actuator sees vacuum and the puck is closed. There should be no notable amount of ambient air entering the exhaust flow if the correct gasket is used. If the WG sees enough pressure to open, then ambient air isn't being pulled in to the turbo ... it's being pushed out. Again, front O2 readings are normal and fuel trims are in check.
I hope that answers your questions.
AFRs didn't change much for me after the install. Maybe a max of .2 difference up top in a small range, but I was also in a different load cell so that's inconclusive. It was dead on my previous logs under 6000. I run ECU boost control, so the boost response was constant before and after the install which gave us a nice AFR comparison.
At a cruise state the WG actuator sees vacuum and the puck is closed. There should be no notable amount of ambient air entering the exhaust flow if the correct gasket is used. If the WG sees enough pressure to open, then ambient air isn't being pulled in to the turbo ... it's being pushed out. Again, front O2 readings are normal and fuel trims are in check.
I hope that answers your questions.
WBO2 is very sensitive to partial pressure, thats how it measures how rich it is from the amount of O2 it has to pump toat partial psi of stoich, when the WG opens the pressure on the sensor would drop.
Last edited by C6C6CH3vo; Feb 6, 2009 at 06:44 PM.
mike@AWD Motorsports has them.
http://www.awdmotorsports.com/
http://www.awdmotorsports.com/
-E
