Does a Wastegate Dump Effect Wideband Readings?

[Dark_Horse]

Was reading another forum today and someone stated that dumping the wastegate could have a bearing on wideband readings. Does anyone know if this is true?

EDIT - answered my own question. It has no effect on wideband readings at all.

 

[wondersb]

I would really like if someone could elaborate on that. I was wondering the same thing.

 

[viperlp01]

Well dumping the wastegate is releasing gases, but those gases are the exact same as the rest of the exhaust that is flowing through the downpipe.. As long as no oxygen is getting in then the mixture will be the same.. Id imagine at most .1-.2 points different but like i said the exhaust gases so it should still be the same dumped or recirced.

 

[GTOJohnny67]

I question this too, because I just picked up an open dump today from a friend who said he didn't like how loud it was. He told me he didn't notice much difference when he put the open dump on, but when he took it back off he claimed he had to pull some fuel out of the AFC because the wide band was running richer under boost. So does this mean he had a bad gasket letting oxygen in? Or had the "parts or molecules per square inch of exhaust been affected" Any way I hope I'm making some kind of sense. OR could it have been that the exhaust gasses where able to escape faster with the open dump causing the motor to lean out some?????

 

[MakeIt2BreakIt]

if it is far enough from the dump you will be okay

 

[Dark_Horse]

When I was thinking about this even more, I had 2 thoughts.

1. If the wastegate is pulling off just 1 runner (like the Turbonetics manifold does), could it theoretically alter the wideband reading?

2. If the wastegate is plumbed in after the merge collector, or at the merge collector (like the ERL manifold) there should be no difference in wideband readings regardless of if the WG is dumped or recirculated back into the downpipe.

Think of #2 like this: You have a river. At a certain point, the river forks. Is the water in the right fork the same as the water in the left fork? Yes

 

[viperlp01]

I question this too, because I just picked up an open dump today from a friend who said he didn't like how loud it was. He told me he didn't notice much difference when he put the open dump on, but when he took it back off he claimed he had to pull some fuel out of the AFC because the wide band was running richer under boost. So does this mean he had a bad gasket letting oxygen in? Or had the "parts or molecules per square inch of exhaust been affected" Any way I hope I'm making some kind of sense. OR could it have been that the exhaust gasses where able to escape faster with the open dump causing the motor to lean out some?????

Well the o2 sensor under WOT doesn't mean anything to the ecu.. All it cares about is the airflow and it compensates that way.. He really shouldn't have to touch anything considering nothing changed but the WBo2 reading which should have changed by much...

 

[sax_man]

Think of #2 like this: You have a river. At a certain point, the river forks. Is the water in the right fork the same as the water in the left fork? Yes

Great analogy.

 

[viperlp01]

Well dumping the wastegate is releasing gases, but those gases are the exact same as the rest of the exhaust that is flowing through the downpipe.. As long as no oxygen is getting in then the mixture will be the same.

I guess no one even reads my posts..