MS3 and Electric Water Pump

[arran]

Hi, is there any reason that I would not be able to control an Electric Water Pump with Megasquirt? I have MS3 and MS3X

I have had a look around the settings displayed in Tuner Studio and it looks possible. I've had a search and I can see a few old posts a year or two or three ago using MS2 where others have asked.

Can I use one of the Generic closed loop outputs?

[Matt Cramer]

Usually I've seen them run as an on/off output.

[TheSilverBuick]

I set mine to one of the generic ON/OFF outputs. Comes on at 190*F and off at 180*F or at throttle above 60% (reverse flow cooling, try and chill the head at higher loads).

[mill383]

SilverBuick,

Just to clarify,
Are you turning on the WP if throttle is above 60% regardless of CLT temp?

[masterx81]

Look at the bmw unit. Command via pwm or 1 wire serial with feedback on actual pump speed

[arran]

Being able to control the speed of the pump is a key advantage to using an EWP, I'd really prefer that if I am going to install an EMP that it be variable speed.

Thoughts on generic pwm or generic closed loop?

[elaw]

Thoughts on generic pwm or generic closed loop?

Both would be doable, but generic PWM would be a heck of a lot easier.

Choose an output, set "variable" mode, pick a frequency, set Y axis to "CLT", make sure RPM (X axis) bins in the table are sensible, put in CLT (Y axis) bins, and fill the table with PWM values.

The toughest part might be finding a suitable driver for the pump motor... assuming it doesn't have one built in.

[slow_hemi6]

These things are popular amongst my non efi muscle car friends down this way. They run these and the ally bodied 115 pumps on hard to cool big block cars.
http://www.daviescraig.com.au/Controlle ... tails.aspx
With the right driver ms3 should be able to do the same but at a fraction of the cost.

[dontz125]

I am in the process of building a prototype PWM fuel pump controller, a licensed rugged version of Madhu's design. It seems to me that modifying the firmware to drive the pump according to temperature instead of pressure shouldn't be too hard, but I'm a solder-spreader, not a key tapper.

What sort of range / thresholds would you like to see?

[masterx81]

The bmw unit has internal drivers all it need is the pwm 5v signal. Would be nice a specific output, maybe when it se a wot can increase immediately the water pump speed, or interfacing with the 1wire interface cam be useful to read the actual speed for flash a cel.
This was my request long time ago: http://www.msextra.com/forums/viewtopic.php?t=51373

[nuk1ear]

Thought the best way would be to control the pump via PWM through a solid state relay. Surely the MS3/MSx can do this with one of its PWM outputs. Use CLT and RPM on the y/x axis of the map. You would want to run low speed for low CLT (or off) to promote quick warm up, the map should give very good control of the water temperature control.

[slow_hemi6]

One of the major benefits of an EWP is divorcing the pump flow from engine speed. Just the other day I went up a local range and rpm stayed the same but due to load alone the temp climbed about 7 degrees C. Mechanical fan and mechanical pump so neither of those were in the equation. Some more water flow at that rpm might have dropped the temp or might not have. You have to keep in mind with a lot of set ups the most efficient water flow for thermal transfer is not going to be pumping flat out. The coolant needs to be exposed to the radiator for the correct time to get the best thermal transfer which of course also varies due to airflow. If you keep ramping up water speed you can actually go backwards if your pump is good enough. Especially if you run into cavitation. This is why some intelligent temperature targeting would be a good strategy.
Going back to cooling basics the old method was if your car was fine on the highway but got too hot waiting at traffic lights you had an airflow problem. If your car got hot on the highway you had a surface area problem with your radiator. It was blocked or too small. Thermo fans could help the traffic light issue by divorcing airflow from engine speed. Fan/s could run flat out with engine idling. None of that took into account water flow which was always tied to engine speed. Anyway there are many ways to skin a cat and every system is different but this was just some thinking aloud. My heap is happy with the right sized radiator, fan shroud and mechanical fan and pump. My next engine however, is going to be around 11:1 and I expect it will be much more of a pain to keep in a good temperature range.

[arran]

Some good discussion.

I started thinking about an EWP because of an after boil problem that persists for no good reason. The engine is a rotary 13b turbo, the water temp when running is perfectly fine usually around 86 to 90 Celsius under normal driving. I have been looking at an E&J ewp, pics here (not my car!):
http://www.ausrotary.com/viewtopic.php? ... 24&start=0

It saves space and allows the water pump housing to be retained which mounts the alternator and has a bunch or ports for sensors

[masterx81]

http://people.bath.ac.uk/enscjb/airtex.pdf

interesting when they analize that the wax thermostatic valve is too slow.... in fact cars equipped with ewp (bmw and mercedes) have an electric valve...
In this sheet they speak about 1 up to more that 2 lpm per kw. Wow, on big power engines that's a lot of flow that no ewp can do. the biggest that i've seen is 150lpm (and must be checked that the pump is able to to deliver that flow on a specific engine due to internal restrictions), can be used only on an engine of 75 to 150kw? so a 300kw engine need 300 to 600lpm?

[TheSilverBuick]

SilverBuick,

Just to clarify,
Are you turning on the WP if throttle is above 60% regardless of CLT temp?

Yes, I use the "OR" command. I am using the assumption the engine is going to be loaded up and generating some heat (going up a hill, racing, etc) and may as well give the cooling system a head start as the heat starts coming in. Plus, as I mentioned on my car I have used the electric pump to make it reverse flow cooling, so when I get a turbo on the engine the head gets chilled as boost comes on (which I may have to switch the TPS to a MAP setting at that point, maybe...)