Hi,

I followed the threads according the leaning out problems for months, so I wanted to make my own picture of this topic and wanted to find out what my car is doing while driving on the street.

O.K., with the help of my tuner we have found out it runs perfectly on the road, just the way we wanted.

We installed an extreme accurate wideband from my tuner (exhaust temperature corrected!) right after the engine with no cats in between! (I have no first Catalytic converter). We also watched the Knock Detection on each Cylinder with Star Diag in real time while we were driving on the road up to approx. 180 MPH on the Autobahn. After the first run we richened the mixture a little bit to a healthy 11,9 A/F, to even further minimize knock activity. Now only on one Cylinder there is insignificant knock activity at redline.
On another test ride I measured my fuel pressure while driving up to approx. 180 MPH on the street in 5th gear. No fluttering of the pressure, as we expected with the SL55Fuel Pump. Pressure is right in the specs.

My conclusion:

I will only speak for my car, every car is different. Different boost, different IATs, different intake. Even different boost-level when you start tuning...My car is NOT running lean with the SL55 Pump (which I installed 2 years ago),the regular fuel pressure regulator, and the correct tune for the car. It runs perfect even during real High-Speed runs. My boost-pressure is 19-19,5 PSI and IATs never go above 130 degrees F. This helps the car a lot...

Attached you find two pictures. Preparing the car for test drive on the road with Lambda-AFR-Meter and Star Diag. And Fuel pressure testing while driving on the way to the Autobahn...