Electric water pump RB25 and Extreme

[KennyJ]

i plan on using this kit:

https://boostdoc.com.au/collections/outlets/products/ewp-electric-water-pump-kit-for-rb?variant=41265114382492

i would prefer to not use that controller  , can i control this pump via my Extreme ecu ? what hardware is needed and whats the control strategy

[DerekAE86]

I've not done it myself but it looks pretty easy to do. Some other threads I found on the subject:
 

[KennyJ]

i was more looking to PWM it to get some variable speed , but then i would need a pwm ss relay i assume
so i'm looking for advise on that
also i would really need some automotive stuff , not the house stuff

[Adamw]

To do variable speed you will need a solidstate relay as Derek suggested.  More commonly they just pulse them on/off at different intervals which only requires a standard relay.   I have no idea how much current the various davis craig pumps use so dont have any suggestions for the relay.  There are also the Pierburg ones some of which have the solid state controller for PWM input built-in.  

From a thermodynamics perspective the water flow rate has no influence on the heat transfer so you will likely see little difference either way - as long as there is flow.  

[koracing]

My engineering school memory (20+ years ago now) says that the convective heat transfer coefficient is directly proportional to velocity - so flow rate I think *could* have an affect on heat transfer - theoretically.  Practically, however, most cooling systems I've worked with seem to be more air side limited on heat transfer than water side (assuming all is operating at nominal efficiency) so measured differences may be relatively small.