Miscellaneous Experiments

This page contains links to various test experiments that I’ve conducted that don’t fit into one of the general test categories.


Pre-Turbocharger Pressure Drop: Comparison of pre-turbocharger pressure drop of S4 and RS4 intake components.

Exhaust System Back Pressure: Measurement of 034 Motorsport single 3.5″ exhaust system back pressure on a K03 equipped B5 S4 on the street.

Exhaust System Back Pressure: Checking out the 034 Motorsport Exhaust System back pressure at idle.

Blocked Exhaust System: Measuring back-pressure and boost onset with a partially blocked exhaust pipe.

K04 Turbocharger Turbine: Measuring back pressure of a K04 turbocharger turbine on the flow bench.

Exhaust Manifold Runner vs K04 Turbine Housing shows how the pressure drop through each of these compare.

Turbine Inlet Pressure: Initial attempt to record turbine inlet pressure on the B5 S4 when equipped with K03 turbochargers.

Stock boost TIP: Recording the pre-turbo pressure of the exhaust gasses using K03’s on the stock tune.

K03 high boost TIP: Recording the pre-turbo exhaust gas pressure using K03’s with a higher boosting tune.

K04 Stg3 TIP: Recording the pre-turbo exhaust pressure with K04’s and a moderate Stage 3 tune.

K03 and K04: Compressor housing pressure.

Composite pressure drop: Various components glommed together.

N75 Valve Adjustments: Tweaking the settings of the N75 valve to see what affect this has on boost onset.


Exhaust Manifold Surface Temperature: Measuring the exhaust manifold surface temperature with an IR sensor during engine start up.

More Exhaust Manifold Temperature Testing: Checking the exhaust manifold surface temperature after applying Swaintech coating.

Exhaust Manifold Temperature Driving: Recording the variation of near surface temperatures in the vicinity of the stock B5 S4 exhaust manifold.

Low Temperature Thermo Switch: Results of replacing the stock after run coolant temperature sensor with a low temperature sensor.

Windshield Washer Reservoir Temperatures: An assessment of how the washer fluid reservoir temperature changes under different driving conditions.

Fog Light Removal: Test to determine if removal of the fog lights has an affect on intake air temperatures.

Downside of the Darintake Mod: Showing how the temperature inside the stock airbox changes before and after performing a ‘Darintake’ modification.

More Darintake Testing: Inside the airbox temperatures with and without additional hole in the side of the airbox.

Inside the airbox temperatures: Recording the temperature inside a stock B5 S4 airbox while driving.

EGT Readings: After installing a pair of RS6 EGT sensors I am able to record full range exhaust gas temperature readings.

Post Turbo Temperatures: Recording of the temperature out of the turbo during routine driving conditions.

More Post Turbo Temps: Recording the temperature rise through the turbocharger while commuting.

W/M Injection vs High Octane: Comparing the results of a tune using water-methanol injection and a 100 octane fuel tune.

Turbocharger Blanket: Assessing the impact that a turbocharger blanket has on K03 turbocharger spool up.

Stock S4 vs IPP IC’s:  Comparing the stock S4 intercoolers with the IPP aftermarket product.

Stock S4 vs Stock RS4 IC’s:  Comparing the S4’s stock intercoolers to those of the Audi B5 RS4.

Foil Wrapping the Airbox: Initial drives to check if foil wrapping the airbox makes a difference to intake air temperatures.

Foil Wrapped Airbox Summary:  Determining if intake temperatures change after applying reflective foil to the stock airbox.

Hot Air Intake: A look at how hot the air under the hood near the airbox gets.

Hot Air Intake – Part 2: Continued investigation into under hood temperatures.

Wrapped Y-Pipe: Intake air temperatures with the Y-pipe wrapped in duct insulation.

Wrapped MAF Housing: Putting Gold Foil on the MAF housing to see if intake air temperatures are lowered.

Wrapped Turbo Inlet Pipe – Part 2: Checking the effectiveness of Gold Foil Wrap


Exhaust Manifold + Turbine Housing: Attaching the ehxaust manifold to the K04 turbine housing and measuring airflow through the components.

K03 Turbine Housing Airflow: BorgWarner K03 turbocharger turbine housing flow tested on the flow bench.

Turbine Airflow Versus Wastegate: Flow testing a turbocharger turbine and housing with the wastegate flapper open and closed.

Gradually opening wastegate: Incrementally opening the wastegate flapper door to see if airflow jumps at any point.

Turbine Airflow with wastegate open or closed: Checking the airflow through the turbine housing with the wastegate door closed and then open.

Turbine Fixed vs Free: Airflow testing of a K04 turbine housing on the flow bench with the turbine wheel fixed and with it free to rotate.

Recorded and table MAF values: Comparing the MAF voltages obtained on the flow bench versus the predicted value from teh MLHFM table.

Larger pipes on intercoolers: Flow testing of a set of Silly Rabbit Motorsport side mount intercoolers with larger RS4 sized inlet and outlet pipes.

MAF Screen: Flow bench test of a part with and without a MAF screen in place.

RS4 MAF without Screen: Removing the screen from an RS4 MAF to measure airflow.  Also tested with a K&N cone filter.

AWE S-Flo Intake: A preliminary look at the AWE-Tuning S-Flo intake for the B5 S4.


Ramp safety: Assessing how easy it would be for the S4 to roll off a pair of Rhino ramps.

Brake Bias: Comparing the stopping distance using S4 versus RS4 bias settings along with the StopTech ST-40 Front Big Brake Kit.

Audi B5 S4 Information and Testing