Monthly Archives: December 2016

Turbo Concepts

Turbo Concepts Stg1 Temperature Rise

A pair of readings that I often take when logging the car are the air temperature going into the turbocharger compressor, and that when it comes out.

Auber pressure sensor installed in intake pipe

Shown above with the arrow is the location where the temperature reading is taken of the air entering the turbocharger compressor.  The sensor in the picture is not a temperature probe.

Auber Instruments Air Intake Temperature Sensor
Auber Air Temperature Sensor installed in charge pipe joining turbo and intercooler

Above is the location of the temperature reading for the air exiting the turbocharger compressor.  This is the hardpipe that joins the compressor outlet to the intercooler inlet endtank.  I believe this temperature reading is somewhat lower than what exits the compressor due to cooling that takes place in the hard pipe prior to reaching the probe tip.  Since this same location is used for each setup I have tested, even though the measurement is probably not an accurate reading of the compressor outlet temperature, the relative performance between different turbochargers should be correct.

I have found that even without any boost (compressing the air) taking place the mere passage of the air through the housing and compressor wheel causes the air temperature to rise around 25 degrees Fahrenheit.

Shown below is a boost profile that I am operating the Turbo Concepts Stage 1 turbochargers at:

Turbo Concepts Stage 1 Boost and IAT @ 48F
Turbo Concepts Stage 1 Boost and IAT @ 48F

These readings were taken when the ambient temperature was 48 degF.  Also shown is the intake air temperature as recorded with the car’s charge air temperature sensor.

The rise in air temperature through the Turbo Concepts turbocharger when operated at the boost level shown above is displayed in the chart below:

Turbo Concepts charge air temperature rise
Turbo Concepts charge air temperature rise

This is showing how much difference there was in the air temperature leaving the turbocharger compared to the temperature upon entry.  Note that even though the boost pressure drops over the course of the pull that the air temperature is rising.  The compressor housing acts like a heat sink, absorbing energy from the air when it is compressed.  Over the time span of the pull the capacity of the housing to absorb energy declines, and the energy remains in the air, leading to the temperature rise.

It’s important to keep in mind that this chart is showing relative temperatures, the temperature of the air entering the turbocharger is approximately 60 degF in the case with the lowest starting temperature.  By the time the air is compressed, in each case it leaves the turbochargers above 200 degF.  As was pointed out, the location of the outlet probe results in a lower reading than is the true outlet temperature.  It’s likely the true outlet temperature could be 25-50 degrees hotter than what is being recorded.

Another interesting aspect of this data is the IAT compared to the compressor outlet temperature.  After the charge air passes through the cross flow heat exchanger (Silly Rabbit Motorsport Intercooler), and is hit with a squirt from the 4mm Aquamist nozzles I use with a water-methanol injection setup, the temperature is dropped from over 200 degrees to between 78-92, not too far above ambient temperate.

Next up I’ll be comparing these results with some of the other turbochargers that I have measured.

Turbo Concepts, Turbo Selection

Turbo Concepts Stg1 Backpressure

With the tune for the Turbo Concepts Stage 1 turbochargers now tapering in a manner similar to what I had with the BW K04’s it’s a good time to measure the pre-turbine exhaust back pressure.

The results for three pulls are shown below:

Turbo Concepts Stg1 Manifold and Pre-Turbine Pressure
Turbo Concepts Stg1 Manifold and Pre-Turbine Pressure

Compared to the BorgWarner K04’s readings:

TC vs BW Manifold and Pre-Turbine Pressure

These results put the Turbo Concepts product in the same range as the other K04-hybrids I have measured, the FrankenTurbo F21 and Turbo Engineers TTE550.

The ratio of exhaust back pressure to manifold pressure for the different turbo’s around 6500-6600 rpm is shown below:

  • BW K04 – 1.56:1
  • TTE550 – 1.70:1
  • TC S1 – 1.85:1
  • F21 – 1.80:1

 

Maintenance

ECS Jack Pad Kit

I decided to make an effort to save the pinch welds on the Avant.  With the S4 routinely being jacked up I want to use something better than a piece of 2×4 to blunt the contact between the jack and the car.

The ECS Tuning Jack Pad kit looked like something that would help with protecting the car.  I installed the grommet’s and the companion snubber’s.

ecs_jack_pad_adapter_front

There are four locations underneath the vehicle for installing these pieces.

ecs_jack_pad_grommet_rear

The jack pad adapter seats in the center of the snubber, although I’ve found the adapter isn’t needed with my floor jack.

ecs_jack_pad_kit

ecs_jack_pad_adapter

I’ve used the jack pad kit a few times now and have found it easy to use and successful at achieving it’s purpose of safely lifting the car while protecting the underbody.

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The instructions ECS Tuning supplies states to put the snubber into the grommet and then push into place.  I don’t recommend following these procedures as it’s more likely that the snubber will be pushed into the grommet BEFORE the grommet is seated in the hole it’s to fit into.  If that happens it becomes more difficult to get the parts into place.

I found it worked better to use a wide socket along with the floor jack to push the grommet into its hole, at least partly, and then to put the snubber into place and use the adapter to push it into its final position.