All posts by Jeff

Misc.

Weighing In and Straightening Out

One of the important elements to calculating accurate information from a FATS pull is to know the vehicle weight.  For my baseline weight I fill the gas tank and ensure the typical items I carry around in the car are onboard.  My S4 weighed in at 3600 lbs.

Audi B5 S4 Vehicle Weight Sheet
Audi B5 S4 Vehicle Weight Sheet
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Another thing I took care of today was having an alignment performed.  Since having the Stern adjustable upper control arms returned from being rebuilt I have not had the car properly aligned.

Audi B5 S4 Alignment Spec Sheet
Alignment Spec Sheet
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And lastly, a photo of the current state of wiring partially occupying the passenger footwell area.

Audi B5 S4 sensor wire bundle

Testing

K03 Modifying Boost Results

The following charts show how three different tunes drive output results with the BorgWarner K03 Turbochargers.  The tunes consist of a stock, Lo, tune, a mid boost tune, Mid, and a high boost tune, Hi.

All results were recorded with ambient temperatures at 70 degrees Fahrenheit.  It should be pointed out that how the car was driven prior to each collect was similar, but not exactly the same, which could influence some of the temperature results, though that does not appear to be the case.

High vs Low Boost
High vs Low Boost
Manifold vs Pre-Turbine Exhaust Pressure
Manifold vs Pre-Turbine Exhaust Pressure
Pre-Turbine Exhaust Pressure vs Mas Airflow
Pre-Turbine Exhaust Pressure vs Mass Airflow
Post-Turbocharger Compressor Temperature
Post-Turbocharger Compressor Temperature

These are the boost profiles of the three tunes used for the data collection.

K03 Boost Profiles
K03 Boost Profiles
K03 Tune AFR Comparison
K03 Tune AFR Comparison

Results below were collected with the S4 on a dyno:

K03 Tunes Compared
K03 Tunes Compared