Wiring in auxiliary water pump
Turbo Mini Forums

Hi

I've bought a bosch auxiliary water pump. I'm also using a uprated mechanical water pump.
Would it be ok to wire the auxiliary pump to come on with the electric fan?
The fan is wired to a permanent live in order to cool the water once engine shut down. Ive also got a overide switch on the dash if I need to cool it down for what ever reason. Or if the thermostat switch fails as it did once parking up at a local classic car show (bit embarrassing)

Would it cause any problems if it comes on while the engine is running? As it has the mechanical pump as the main pump?

Thanks
Josh

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985

I'd have the circuit wired up using a relay, so that it disconnects power to the pump whilst the ignition is on, and switches it to the live feed with ignition off. Easily done with the correct relay.

Could you put a link up Carl?

Much appreciated if you could :)

Cheers
Josh

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985

Just something like this mate, http://www.autoelectricsupplies.co.uk/mobi...174/category/36

85/86 ignition live/earth
30 Fused permanent live feed
87a To water pump/controller
87 leave blank as that will power up when ignition live is on, you could also use 87 for a seperate auxiliary circuit for something when the ignition is on, making the relay dual purpose.

Thanks for that carl very helpful!
I have a relay for my fan already. Would it be possible to wire it in to the permanent live on that? Via a timer switch?

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985

I'd keep the fan seperate, otherwise you'll have the pump running when you turn the fan on, which you might not want if the car is running, although it might be okay I'd rather not risk it myself. You could loop off the fused feed and loop the earth and have the relays side by side, cutting down wiring mess,just make sure the wiring is of adequate size tobrun both the fan and pump.

Thanks carl

Would it be a good idea to use a relay for a heated rear screen as the one I've seen has a 12 minute delay on it. Maybe a bit too long to run the pump without engine on mind you...

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985

Yeah, a timed relay for the rear screen wouldn't be a bad idea, Youd probably only want about 2-3 minutes of water pump time after shutdown at the very most, with the fan on for only as long as it needs to be, id would probably use the switchover relay, implementing a water temp switch to control both the fan and the pump, and possibly also via a timered relay set to a few minutes as a failsafe incase the switch fails closed, draining the battery

Something like this?

http://m.ebay.co.uk/itm/MINI-TIMER-SWITCH-...4155?nav=SEARCH

I could just do it on a manual switch but thst just too easy lol.

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985

Yeah, just as long as 12a is enough to power the pump and fan, or fit two, one per item so long as the fan is less than 12a draw

Excuse my ignorance but what benefit do you think you will get from the additional pump? Depending on position, all i can see is a risk of cavitation in the mechanical pump (my views are simply gut thoughts with no particular science or knowledge to support mind!)

The leccy pump will only be on after engine shut down.
I'm running a gt17 turbo which is water cooled aswell. So in order to prevent the water boiling in the turbo after shutdown the leccy pump will kick in to pump water round the engine.
I think most production water cooled turbos have this system in place to pro long the life of the turbo.

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985

What pump have you gone for? i had a similar idea and got the pump but wasn't sure if it'd be man enough to work.

double post..

Edited by jamestar on 24th Feb, 2016.

That makes sense

It wouldn't be difficult to wire this up so that the pump runs when the fan runs, but only when the ignition is off.

What model pump is it? Are you mounting it inline with the mechanical pump or in parallel?

Edited by PhilR on 25th Feb, 2016.

http://m.ebay.co.uk/itm/BOSCH-universal-au...d=1486045550018

That's the one I got. And I'm planning on plumbing it in between the heater take off on the head, and back in at the bottom hose.
I'm not running a heater at the moment. I might fit one later.
I'm also dry deck.

Josh

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985

Circulating water in that way means that it wouldn't pass through the radiator, id try and take from the engine and put back into the top of the radiator or the thermostat housing with a sandwich plate.

Maybe this is a necessary precaution on a Mini, but on my car I have only once had the water boil in the turbo and that was after 6/7 laps of Cadwell.Convection usually takes care of it but maybe I shut down too early.

I do normally allow the engine to idle for a while before switching off.

As Dave says I normally let the engine idle after running and then let the fan run to it turns off.

Never had any problems with it, my turbo is water cooled also.

I have started posting on Instagram also my name on there is turbomk1golf

Nothing is impossible it just costs more and takes longer.

[quote=Carlzilla,25th Feb, 2016]Circulating water in that way means that it wouldn't pass through the radiator, id try and take from the engine and put back into the top of the radiator or the thermostat housing with a sandwich plate.[/quote

So only the water in that part of the engine will be moving when the pump is on? Surely not!?

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985