All posts by Jeff

Avant Engine Out

This afternoon I removed the engine from the Avant.  This time it took a bit longer than it has in the past, partly attributable to being a car that I’ve not worked on before and having some components that are not as removal friendly as ones on my Silver S4.

Audi B5 S4 Avant Engine Pull

With the engine out of the car I began removing items from the engine in preparation for detaching the transmission.  My plan is to use the transmission with a lower mileage engine, and to sell the Avant’s engine.

Avant Engine Pull Checklist Complete

All preparations are complete in readying the Avant’s engine for removal.

Audi B5 S4 Avant
Audi B5 S4 Avant

A little extra fun with this motor on account of the Oil Cooler that needed to be removed before the AC compressor could be lowered.

In other news, the rear differential is now in the hands of ET Tuning for the installation of an MFactory Helical Limited Slip Differential.

RS6 Turbocharger Flowbench Test

All of the turbochargers I have had my hands on lately have been put on the flowbench to have the airflow through the turbine housing recorded.

The most recent B5 S4 suitable turbocharger to show up is a pair of the Audi RS6 K04 turbo’s.  Because in OEM form these will not fit on the 2.7T engine this pair has been modified to work with B5 S4 components.

Audi RS6/K04 Turbocharger mounted to Flowbench
Audi RS6/K04 Turbocharger mounted to Flowbench

Unlike with the TTE turbo’s that also showed up with turbo to downpipe studs firmly stuck in the turbine housing, I chose not to pay a shop to remove the studs out of the RS6 turbo’s turbine housing.  Instead I’ve modified the adapter used to attach the turbocharger to the flowbench to accommodate the studs.

Following alteration of the adapter I went through the normal process of testing an article on the flowbench, beginning with a calibration test.   Results of the flow test are shown below:

Audi RS6/K04 Turbocharger Flow Test
Audi RS6/K04 Turbocharger Flow Test

It is clear that the airflow through the RS6 turbine housing is substantially greater than of that through the RS4 K04 and FrankenTurbo F21 turbochargers.  (The F21, TTE550, and TC Stg1 flowed approximately the same so I have omitted the TTE550 and TC Stg1 data from the chart to make following the lines easier.)

I have found the results on the flow bench to correlate with the exhaust back-pressure readings that I have made on my S4.  That the RS6 K04 turbocharger is able to flow higher than RS4 K04’s comes as no surprise, the magnitude of the increase is the most noteworthy finding from this test.