exhaust soot revisited esp. for gradyex and mmd
I guarantee you could spend one hundred years and never figure out why a number of 997S's show more soot in driver's side exhaust. I had a compression leak down test...completely normal, code check all OK, didn't burn oil..etc, etc...
Then I installed a wide band O2 sensor to see if there was a difference in A/F ratios left vs. right bank....seemed there was a slight (.1) difference favoring richer on right bank...I also noted that under accel. it seemed the right bank's A/F's dropped quicker....still no definitive answer.
I even let car idle for 40 mins and checked with no difference in soot left to right....AND THEN I noticed something very odd....I had a fan directly in middle of the front of the car blowing towards the rear....believe it or not the car's underside aerodynamics are skewed!!!! The driver's side of the engine and exhaust manifold is literally bathed in rapidly flowing air, HOWEVER, not so the passenger's side. I suspect the soot issue is a result of the uneveness of air cooling the underside of the engine and exhaust...the driver's side getting fresh cool air and the passenger's very little...resulting in the difference.
Try out the experiment....put a fan on the ground in the front of the car dead center and go around to the back and feel the diffence.....
I would love to here this explained....
Then I installed a wide band O2 sensor to see if there was a difference in A/F ratios left vs. right bank....seemed there was a slight (.1) difference favoring richer on right bank...I also noted that under accel. it seemed the right bank's A/F's dropped quicker....still no definitive answer.
I even let car idle for 40 mins and checked with no difference in soot left to right....AND THEN I noticed something very odd....I had a fan directly in middle of the front of the car blowing towards the rear....believe it or not the car's underside aerodynamics are skewed!!!! The driver's side of the engine and exhaust manifold is literally bathed in rapidly flowing air, HOWEVER, not so the passenger's side. I suspect the soot issue is a result of the uneveness of air cooling the underside of the engine and exhaust...the driver's side getting fresh cool air and the passenger's very little...resulting in the difference.
Try out the experiment....put a fan on the ground in the front of the car dead center and go around to the back and feel the diffence.....
I would love to here this explained....
).
