Toyota Corolla Water Pump (what capacity for electric version?)

[oil pan 4]

Originally Posted by jeff88

Were both of these conversions for cars in New Mexico, or at least somewhere that is similarly hot? I wonder if the fan is on a lot in a hot climate, then electric and belt-driven pumps won't have many efficiency differences, whereas here in the Bay Area, in a milder climate, one could benefit from the switching on and off of the pump.

Just a thought, what do you think?

The suburban got electric fans back in 2007 and electric water pump in 2011.
The electric fans helped fuel economy quite a bit.

In the camaro I did the electric fan conversion ane electric water pump at the same time, didn't see any difference in FE.

[Honda100]

For reference, an LT1 water pump is around 32-36 GPM.

The thing is though, yes I understand the intrigue, but it's not really worth it. At full tilt, a 36 GPM water pump is using maybe 1 hp, and that's for a 5.3 liter V8. Let's say the Corolla is the same though (I have a Corolla and I know the pump is considerably small than an LT1, but let's just say). Anyway, I have a 400 GPM water pump at my farm and it uses an 11 hp motor to drive it. Assuming the diesel isn't 100% efficient, it's probably using just 8 hp to crank a 400 GPM water pump. So that's less than 1 hp per 40 GPM. If the Corolla had a 40 GPM pump (which it doesn't), then at most it is using 1 hp to drive it at full throttle. That's less than 1% of it's available power at full throttle. At idle, it's significantly less obviously, so you're likely looking at a tenth or even half of a tenth of a horsepower most of the time.

So, in essence, it's not going to gain you anything.

Also to note, in Cambodia (where it's always 90 plus degrees, sometimes 100), my Hyundai runs with the A/C on full blast in the city at idle (stop and go traffic all the time) and it never goes over 190 F. I just use distilled water and water wetter with a 20% antifreeze mix. Never had an issue with the heat, so I wouldn't worry about it.

[jere]

BAH HUMBUG to the naysayers!

The davis craig is the way to go, you can control when the pump comes on, and keep your motor nice and hot and not worry about going too hot. (Make sure you get a coolant temp gauge and note where the temps are pre swap) The controller will reduce power consumption, unlike most other e-water pumps out there (that it looks like most here are talking about) You can ditch the lag of a belt, and cavitation that belt driven pumps run into at higher RPM (if that even applies here).

Make sure to take out the T-stat and the old bladed pump or you can hurt the pump.

You could always go with a cheaper bilge pump ( bilge being kinda risky longevity wise, or maybe just a meizere or something) and the davis PWMC

[echo-francis]

Originally Posted by jeff88

Thanks for the link! I've seen thid thread in the list, but for some reason have failed to read through it. Weird considering how similar our cars are.

Can you tell me more about the davies craig? I was looking at that one, but wasn't sure if it would work for me. Have you found it to work for your car, or is it a little overkill? I assume with the similarities of our cars, that I can pretty much match up to yours without any major problems.

What size engine do you have? I did a side-by-side comparison of our cars and they are both 1.8 I4, but you mention in your thread a different size, so I was confused.

Is all the work you done with the coroplast from the same trip out searching for it, or have you made multiple trips? (You only mention one time of going out and getting some.)

Also, great job on the work you have done.

my engine is 1.5l but the pump is to power full thats why I reduce its power by wiring 4 diodes.

I get my coroplast in 3 differents trips

[jeff88]

Originally Posted by echo-francis

my engine is 1.5l but the pump is to power full thats why I reduce its power by wiring 4 diodes.

Can you explain this further? I wasn't sure how those diodes reduced the pump's power. Where are they connected to? Is it based on engine speed, coolant temp, or something else?

Thanks for the help!

[echo-francis]

the speed of the waterpump is based on the coolant sensor that replace the thermostat (electric water pump= no thermostat) but because I do a lot of p&g and my engine is small for the waterpump I use 4 diodes to slow down the waterpump when I want (1 diode reduce the voltage of 0.5v-0.7v

[jeff88]

Oh got it! So you are just lowering the voltage to the pump so it doesn't get as much power = slower turning. Does that mean it is always turning slower than the rated amount or do you have a switch and on the absolute worst day in the worse circumstances, you can have it running full blast?

Did you test it to see how many diodes, experimenting with a couple then adding more as needed, or was there a way for you to figure out exactly how many diodes you needed?

Thanks for the help!

[echo-francis]

I use the diodes every time I drive but I switch them when my engine is at about 85C (if that happen ) initially i was using 5 diodes but when my engine is cold my ewp system make it turn on only 6v and 5 diodes lower the voltage from 6v to 3.5v-2.5v and it was to low for the pump. by just removing 1 diodes the voltage was lowered to 3.2v-4v and i think thats the minimun to make it turn

[jeff88]

Originally Posted by echo-francis

I use the diodes every time I drive but I switch them when my engine is at about 85C (if that happen ) initially i was using 5 diodes but when my engine is cold my ewp system make it turn on only 6v and 5 diodes lower the voltage from 6v to 3.5v-2.5v and it was to low for the pump. by just removing 1 diodes the voltage was lowered to 3.2v-4v and i think thats the minimun to make it turn

So you have it as a driver operated switch? Have you considered making it automatic based on various factors (specifically coolant temp, RPMs, etc.)?

What goes in the spot where the thermostat was, the coolant sensor, or does the radiator hose connect to the engine block directly? With no thermostat, how does the EMS know what the temp of the coolant is and how does it not throw a code/CEL?

At 85C, when you turn the pump on, what does the temp go down to (roughly)? Shouldn't the temp be right at 85C?

Sorry for all the questions, just trying to learn

[jere]

The T-stat is mechanical and doesn't talk to the ECM. It is usually just mounted in a housing that is completely separate. You can just leave the housing and take the T-stat out.

It isn't good for the life of the EWP to be switched on and off, that is why the pulse width modulation controller should be used.