electric water pump on the street

[sen2two]

Every now and again I want to drive my car on the street to meets and shows. It's legal and with the muffler it's not that loud, but I have a smaller radiator and electric water pump. anyone ever have any problems driving on the street with a similar set up? Motor is a stock un-ported 13b with stock turbo.

[Monkman33]

my weekend warrior/autocross car will have an ewp setup. I am also going to have a warning system in stages if my water temps start rising too high to let me know of a water pump failure.

[730RWHP12A]

what kind of pump is it?

[sen2two]

Meziere inline pump. I believe it flows at 20 GPM and I am using -16 hose and AN fittings.

[Mazdabater]

Correct me if I'm wrong but isnt the main point of an ewp to keep the flow constant at its most efficient point? As opposed to a belt driven pump that varies at rpm, I would have thought it would be better on the street as your pumping more fluid at idle.

[Monkman33]

http://www.stewartcomponents.net/Merchant2/merchant.mvc?Screen=PROD&Product_Code=E389A&Category_Code=ElectPump

This is the one I have on order. It has a controller on it so it varies the flow based on current temperature.

Also, I want to be able to run the pump after the engine is off for even cooldown.

Plus, this has a max flow rate the should exceed the max needed flow.

[sen2two]

Correct me if I'm wrong but isnt the main point of an ewp to keep the flow constant at its most efficient point? As opposed to a belt driven pump that varies at rpm, I would have thought it would be better on the street as your pumping more fluid at idle.


Not really. Its to reduce friction on the crank to gain more a few more HP. Especially in the top end of NA cars.

[Pete_89T2]

^These are both valid advantages for an E-water pump. Being able to control flow rate independent of RPM helps to optimize the efficiency of the cooling system, all other things being the same, and switching to an EWP should get you a net reduction in parasitic loads at the crank. I say "net reduction" because the electrical power needed to run an EWP isn't free - the alternator will have to work harder (more drag on the crank) to produce that power. The question is does the increase in parasitic drag from the alternator get offset by a larger decrease in parasitic drag from the mechanical water pump?

[My5ABaby]

^These are both valid advantages for an E-water pump. Being able to control flow rate independent of RPM helps to optimize the efficiency of the cooling system, all other things being the same, and switching to an EWP should get you a net reduction in parasitic loads at the crank. I say "net reduction" because the electrical power needed to run an EWP isn't free - the alternator will have to work harder (more drag on the crank) to produce that power. The question is does the increase in parasitic drag from the alternator get offset by a larger decrease in parasitic drag from the mechanical water pump?
And to expand on it, is the offset even worth it?

[sen2two]

Dynos have proven to give up to 20 whp when switching to an electric water pump at the top end of high rpm engines like PP 12a's and 13b's.

So yes, its worth it.

[My5ABaby]

Dynos have proven to give up to 20 whp when switching to an electric water pump at the top end of high rpm engines like PP 12a's and 13b's.

So yes, its worth it.

Whut... My waterpump is using 10% of my HP?

[Pete_89T2]

Whut... My waterpump is using 10% of my HP?

That does seem like a lot of power just to run a water pump... Sen2two, were the quoted dyno figures from a before & after test, where the only thing they changed between the two runs was the water pump?

[Kentetsu]

More importantly, was the pump actually running when they checked the dyno results? Maybe 20hp is what you get simply by removing the water pump from the equation altogether...




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[sen2two]

This was not done on my car. I've seen it done on various cars throughout the years. Rotary and piston alike.

There's a reason that almost all serious drag cars use them. My question is not if it works, my question is if a combination of a smaller radiator and the electric pump is enough to keep the car cool on the street.

I guess ill just take it for a drive and find out.

Also, a lot of drag racers have the electric pump hooked up to a switch along with the fan. This way you can do the pass and after you cross the line, you turn your fan and pump back on. Reducing the pull from the alternator during the radiator.

[Rx-7fetish]

So how exactly do you install one of these, it can't just go in one of the radiator lines cause of the thermostat right? And how do you deal with deleting the belt driven pump?

[730RWHP12A]

Meziere inline pump. I believe it flows at 20 GPM and I am using -16 hose and AN fittings.

you will be fine :)