Category Archives: Sensors

Boost Manager Profile Analysis

With the Boost Manager operating and Aquamist’s Flow Sensor recording I logged my S4 to see how the pump duty cycle map that I had created worked out.

Boost Manager Water Methanol Injection System Profile Analysis

I’m attributing the jumpiness in the water/methanol flow to sensor noise which I hope to minimize in the future.

The water/methanol pump duty cycle map is based upon engine speed and manifold pressure (MAP).  As is shown by the left line with arrows, activation of the pump takes place around 2000 rpm once MAP reaches about 6 psi of boost pressure.

At 10% duty cycle the pump is essentially still off with respect to the flow volume, this was first shown when I conducted a calibration session with the water/methanol injection system.  I have the pump at such low duty cycle to get things moving in anticipation of the system injecting a measurable quantity of fluid shortly thereafter.

When engine rpm reaches 2500 and MAP passes 11 psi the pump duty cycle increases and the flow rate increases quickly.  The flow rate tracks with the increasing rpm, though I have some refinement to do in order to match engine speed better.

A couple of other parameters that would be useful to look into are airflow, via the MAF reading, Fuel Injector Duty Cycle, and intake air temperature.

At the right side of the chart the flow rate drops, despite engine speed increasing, because the MAP is dropping and then lowers the pump duty cycle.  This is another area of the chart that will get some attention to refine the pump duty cycle and better manage the fluid flow rate.

 

 

BoostManager Flow Calibration

After some troubleshooting with the folks from Aquamist to figure out how to record the voltage from their sensor on my LM-1 I set out to calibrate the Aquamist flow sensor in conjunction with the BoostManager water-methanol injection system.

aquamist 806-428 flow sensor
Aquamist Flow Sensor (806-428H)

The Aquamist sensor has three output ranges that can be set depending on how much water flow is expected to be generated by the system.  As it turned out my system was right on the edge between the middle setting, good for around 1200 mL/min., and the upper setting that can handle approximately 2500 mL/min.

Aquamist Water Injection Nozzle
Aquamist 1mm Nozzle with Integrated checkvalve

The decision was whether to get a full range reading, with less resolution, or lose the very top end but have better granularity over the rest of the detection range.

I decided to go with the middle setting that gave better resolution.  I don’t know how much affect spraying into the charge air will have on the flow rate, but I expect it to drop the rate some, which should serve to minimize the negative aspect of the range I chose.  Also I know I can simply set a maximum duty cycle for the pump lower than what it is capable of if I want to keep the flow readings within the reporting range of the sensor.

Snow Performance Tank and CoolingMist Pump
Snow Performance 2.5 gal. tank & Coolingmist Pump

I set up the BoostManager software to test the flow rate.  It has a handy feature that allows the pump to activate with just a ‘press of the button’ on the software.  The pump duty cycle can also be set from 0 to 100 in this ‘test state’ in order to check the flow rate at the different duty cycle settings.

Along with the BoostManager software the data display software for the LM-1 was open to allow me to record the output voltage from the Aquamist flow sensor.

BoostManager & Logworks Screens
BoostManager & Logworks Screens

To capture the water from the nozzles I removed the nozzles from the APR bipipe, tied them together, and placed them in a measuring container with a piece of aluminum foil over the top to contain water mist or splashes.

Flow calibration setup
Flow calibration setup

Here’s a picture of the nozzles directed into the container with the splash cover removed.

Aquamist nozzles into liquid container
Aquamist nozzles into liquid container

With the setup complete I ran the pump at several different duty cycles and recorded the output voltage for each test point.

The pump duty cycle versus flow rate is shown below.

Coolingmist Pump Duty Cycle Chart
Coolingmist Pump Duty Cycle Chart

Shown below is the flow sensor output voltage for the various flow rates.

Aquamist flow sensor output voltage
Aquamist flow sensor output voltage

With the sensor calibration table created and the flexibility of the BoostManager software to allow for the pump duty cycle to be varied based upon inputs from the boost pressure sensor and RPM, I will be able to create a tailored w/m injection rate table.

Eurodyne Boost Manager Water-Methanol Duty Cycle Table
Boost Manager W/M Table

Knowing how much fluid is being injected will help in building a table that is well matched to the amount of fuel that is being injected into the engine.