Bracket Talk
BMW CWA 200 water pump

This topic can be found at:
https://drr.infopop.cc/eve/forums/a/tpc/f/80760912/m/9117053186

July 07, 2018, 06:13 PM
Curly1
BMW CWA 200 water pump
I have bought a BMW water pump CWA200 and I can not get it working right. Not sure what I am doing wrong so any help is appreciated.

https://www.tecomotive.com/en/products/CWA200.html

Here is a link to the pump and there is a download link with more information. If I can get it to work I think it would be much better than all the other pumps we are using on our race cars. It is designed to last for 100,000 miles or more and run at 220* or more. It also is supposed to move up to 43 GPM on high speed. I have it wired 12v+ to 1. Switch power to 2, and 3 and 4 are ground.


https://postimg.cc/gallery/np3zpruo/
"Dunning-Kruger Effect"
-a type of Cognitive bias where people with little expertise or ability assume they have superior expertise or ability. This overestimation occurs as a result of the fact that they do not have enough knowledge to know they don't have enough knowledge.

Before you argue with someone ask yourself, "Is this person mentally mature enough to grasp the concept of a different perspective?" If not there is no point to argue.

4X NE2 CHAMPION. 2020 TDRA NE2 Champion
July 07, 2018, 08:13 PM
rusty
bruce #3 is a signal ground have you tried switching it also.i dont see why it would matter though


honesty is the best policy,insanity is a better deffense
1.036, 6.16@ 224

July 07, 2018, 08:28 PM
rusty
another thought is the motor stuck,do you have an amp probe ,or look for spark to see if it is drawing amps


honesty is the best policy,insanity is a better deffense
1.036, 6.16@ 224

July 07, 2018, 08:39 PM
rusty
pm bruce


honesty is the best policy,insanity is a better deffense
1.036, 6.16@ 224

July 07, 2018, 10:16 PM
rusty
https://www.tecomotive.com/dow...d/manual_tinyCWA.pdf


honesty is the best policy,insanity is a better deffense
1.036, 6.16@ 224

July 07, 2018, 10:54 PM
Curly1
Motor is not stuck, it will rotate just slowly. Amp draw is not very high and motor is not getting hot or anything unusual. I could get that controller but I prefer to manually control the pump and fan.


https://postimg.cc/gallery/np3zpruo/
"Dunning-Kruger Effect"
-a type of Cognitive bias where people with little expertise or ability assume they have superior expertise or ability. This overestimation occurs as a result of the fact that they do not have enough knowledge to know they don't have enough knowledge.

Before you argue with someone ask yourself, "Is this person mentally mature enough to grasp the concept of a different perspective?" If not there is no point to argue.

4X NE2 CHAMPION. 2020 TDRA NE2 Champion
July 07, 2018, 10:55 PM
rusty
i am not sure it will work without the controller,but if it will i think 2&3 will be jumped.there is some good info in the instructions i found


honesty is the best policy,insanity is a better deffense
1.036, 6.16@ 224

July 08, 2018, 01:14 PM
rusty
es, I have two .pdf's that will make your life easy: A description of each of the 4 pins and what each needs to see in order to control the pump speed. I can email them to you. Cliff notes:

Pin 1 is battery voltage
Pin 2 is PWM signal
Pin 3 is a test/BSD signal
Pin 4 is Ground

Supplying +12volts to Pin 1 AND pin 2 (and grounding pin 4) should make it run full speed after a 'timeout' period of about 3-10 seconds. To vary speed based on PWM input on Pin 2, you need at least 3ms of an inturrupted high pulse in order for it to awake the pump. Keep that in mind when you decide on the PWM frequency and/or your duty cycle percents.

PM me your email address or email me at timmafod at gmail.
bruce leave #3 ungrouded and power to 1 and 2


honesty is the best policy,insanity is a better deffense
1.036, 6.16@ 224

July 08, 2018, 05:26 PM
Curly1
quote:
Originally posted by rusty:
es, I have two .pdf's that will make your life easy: A description of each of the 4 pins and what each needs to see in order to control the pump speed. I can email them to you. Cliff notes:

Pin 1 is battery voltage
Pin 2 is PWM signal
Pin 3 is a test/BSD signal
Pin 4 is Ground

Supplying +12volts to Pin 1 AND pin 2 (and grounding pin 4) should make it run full speed after a 'timeout' period of about 3-10 seconds. To vary speed based on PWM input on Pin 2, you need at least 3ms of an inturrupted high pulse in order for it to awake the pump. Keep that in mind when you decide on the PWM frequency and/or your duty cycle percents.

PM me your email address or email me at timmafod at gmail.
bruce leave #3 ungrouded and power to 1 and 2

And that did it but I am tired of messing with it and going back to the old Maziere. I found out they recommend putting pump with no restriction on inlet and to pump it through the radiator and engine. I am not going to change the system all around.


https://postimg.cc/gallery/np3zpruo/
"Dunning-Kruger Effect"
-a type of Cognitive bias where people with little expertise or ability assume they have superior expertise or ability. This overestimation occurs as a result of the fact that they do not have enough knowledge to know they don't have enough knowledge.

Before you argue with someone ask yourself, "Is this person mentally mature enough to grasp the concept of a different perspective?" If not there is no point to argue.

4X NE2 CHAMPION. 2020 TDRA NE2 Champion
July 09, 2018, 12:35 PM
rusty
looks like a good pump bruce,not sure why it would not work on your system as is.if need to run slower a resistor on numbe 2 might work.athough not sure on that it may use freqency to slow it.


honesty is the best policy,insanity is a better deffense
1.036, 6.16@ 224

July 09, 2018, 05:19 PM
Magnethead
I finally heard back from Tobias...(Owner of Tecomotive)

quote:
I tested one of the knockoff pumps, too.

With the same results. It would not really work ... And I tried everything.

I don't think they have the same interface as the genuine Pierburg ones, or their control circuitry is so inferior that it is unable to be self aware of the shaft speed.

I remember a warning from Pierburg that those copies are not able to deliver the same flow at a given pressure.
So yes those things seams to be a bit weaker than the genuine ones.

We are using one on a Time Attack car (SR20) and it is not even using its full current capability's.

The original CWA200 with the most compact mounting points is the "11517586925", there is also a "11517586929".

The currently "normal" aftermarket CWA400 version is the BMW number "11517604027".

11517586925: https://www.turnermotorsport.c...4-30-n51-n52-engine/

11517604027: https://www.turnermotorsport.c...-f10-x1-f25-f26-e89/



----

Here's a couple articles that explain that centrifugal charge pumps do not create a vacuum on the inlet, and must be gravity fed at all times (gravity or otherwise primed). This is why BMW mounts the pump down low next the oil pan sump. [Note to those unaware, on the BMW N50, N52 N54 engines, only the AC and alternator are belt driven. power steering and water pump are both electric].

Because the pump cannot have a dry input, it lends itself to a reverse flow system: If the engine is low on coolant, the upper hose may go dry, causing the pump to potentially go dry. As a result, the coolant must be drawn from the lowest point in the cooling system so that the inlet is always submerged, even when the engine is low on coolant.

https://www.waterworld.com/art...al-pump-priming.html

quote:
Centrifugal pumps are designed to pump liquids not gases. Any centrifugal pump (even a self-priming pump) will not start pumping unless at least the first stage (such as in a multistage vertical pump) is full of liquid. When pumping a liquid with an excessive amount of entrained air, the air/gas tends to be centrifuged inward towards the eye of the impeller, eventually blocking any liquid flow through the pump (air binding it). If this only happens occasionally, the pump has a positive suction pressure (flooded suction), and the flow stoppage can be quickly detected, stopping and restarting the pump can clear up the air binding.


http://www.stevenbrownassociat...ifugal-pump-priming/

quote:
L/FM fire pumps require what is commonly called a “flooded suction,” or a positive suction pressure prior to starting. The concept is that the water supply source must arrive at the pump impeller on its own, without the aid of the pump. This will guarantee that the pump is properly primed and ready for operation. With many centrifugal pumps, as little as 3% air in the casing can be enough to prevent the proper operation of the pump. So it is important to maintain a positive pressure on the pump prior to starting.

But even a pump with a proper suction supply can have air in it, or not be fully primed. We are often asked about how to prime pumps when first installed, or how to prime pumps that are used with a water level source below the elevation level of the pump (not flooded suction).

Unless you have a self-priming centrifugal pump (liquid primed, compressed air primed, or vacuum primed), you will need to manually prime it anytime it might become filled with air or gases. Priming a centrifugal pump is essential if you want it to function properly, otherwise the suction pressure created will not be sufficient enough to lift water, and this can cause issues such as overheating and pump failure. Unfortunately this isn’t too uncommon since the valves can leak, but the good news is that this process isn’t difficult to perform!




This message has been edited. Last edited by: Magnethead,