Accuracy of a wideband with dumped wastegate exhaust???

[turbolarry]

I read this question from another forum and it didn't get any replies and I'm curious too. Would a dumped wastegate effect the accuracy of a wideband down stream?

 

[GRAVEDIGGER]

As far as I know, no it wouldn't. The exhaust gasses are just bypassing the turbine. There is still going to be a certain amount going through the turbine and it will all have the same content so it will provide the same readings to the o2 sensor regardless of being dumped or not.

 

[92tsiawdguy]

It will be just as accurate as a non dumped gate. This is because you are expelling exhaust gases under pressure which isnt allowing air to enter the exhaust system. So as long as air isnt entering the exhaust system under boost, the a/f reading will be dead on.

 

[delta448]

Actually, yes it can affect it. But I doubt it will affect it a lot if you already have a 3" TBE without a cat convertor.

The reason is that pressure skews the readings of a wideband sensor as long as the controller does not take the local exhaust pressure into account in it's calculations. High exhaust pressure makes lean/rich readings fall further away from the stoich point the more they stray from stoich and the more pressure increases.

 

[ramsack]

I'd say yes, just based off the fact that a tiny exhaust leak before a stock narrowband sensor can make the car run like crap and get crap gas mileage.

 

[GRAVEDIGGER]

I'd say yes, just based off the fact that a tiny exhaust leak before a stock narrowband sensor can make the car run like crap and get crap gas mileage.

A pre-sensor exhaust leak and an atmosphere dumped wastegate are two completely different things.

 

[knochgoon24]

The dumped exhaust is kept completely separate from the exhaust that the wbo2 will be reading. It's not like air is going to flow back up through the dumptube (as long as it's not stupid short). It will read fine.