Running rich?
02-22-2007, 06:29 PM
#1
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Running rich?
I notice that if I go full throttle, I leave a nice cloud of exhaust/smoke behind me. Granted this may just be a characteristic of the engine, as many high performance engines run rich at WOT. I can also tell because there seems to be a fair amount of residue/debris on my rear bumper and trunk lid that has come from the exhaust.
Just curious if anyone else noticed this. I did a scan and there are no fault codes and everything seems fine....
Just curious if anyone else noticed this. I did a scan and there are no fault codes and everything seems fine....
02-22-2007, 07:09 PM
#3
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It seems to be worst on my car after washing and getting some water in the exhaust.
You try to get all the crap off the tips and end up with it everywhere if you drive at any speed soon after washing. At least on the silver you don't see it so much on the paint. The yellow and white probably show it very well.
02-22-2007, 07:48 PM
#5
At WOT the engine is designed to run 15% rich
If you have VAG-COM, you can see it happen in the recorded lambda. The engine runs in a computer controlled closed loop even at WOT.
The engine is also designed to run rich after startup, to light up the catalytic converter and bring it up to temperature.
The engine is also designed to run rich after startup, to light up the catalytic converter and bring it up to temperature.
02-22-2007, 09:02 PM
#6
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I've made exactly the same observations...
The extra exhaust is really noticeable at night time when gunning it in front of another car...you can see a huge cloud in their headlights. Also, I notice a lot of black soot residue on the rear bumper. I didn't really start noticing it until after the Milltek, but I guess it was always there.
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02-22-2007, 09:59 PM
#8
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Re: At WOT the engine is designed to run 15% rich
Once again, it's not only the RS4 engine that is setup to run rich at WOT. Every engine must do so. Even the old carbureted cars had power jet in the carburetor?...aside from the normal fuel jets?
Also, engines and their control sytems are designed to warm up as quickly as possible for emissions reasons, and it's not just happeneing at the catalytic converter. One of the most important aspects of fast engine warming is the age old, low tech thermostat. And one of the original reason for the use of aluminum heads was also to aid in fast engine warmup(over cast iron) to improve cold drivability and lower overall emissions.
Also, engines and their control sytems are designed to warm up as quickly as possible for emissions reasons, and it's not just happeneing at the catalytic converter. One of the most important aspects of fast engine warming is the age old, low tech thermostat. And one of the original reason for the use of aluminum heads was also to aid in fast engine warmup(over cast iron) to improve cold drivability and lower overall emissions.
