Electric water pump

[California98Civic]

My set up would powered off the grid, which for me means wind power. I don't run the alternator much, (except during DFCO and very long drives). So an electric pump means reducing the carbon footprint of the car, overall.

[oil pan 4]

The engine still needs coolant circulation even when the thermostat is closed.

[serialk11r]

Originally Posted by t vago

As you know, the trouble is that the water pump load will change only as a direct result of engine speed. At that point, it becomes a debate whether to continue to mechanically drive the pump at a 1% loss due to the drivebelt, or electrically drive the pump at anywhere between a 30% to 45% loss from conversion from mechanical energy to electricity, but gain a net 1% to 3% increase in fuel efficiency at the same time.

This Hot Rod magazine article has a rather interesting take on electric water pumps.

Baseline Testing - Do Water Pumps Suck Power? - Hot Rod Magazine

I gathered, from reading the article, that it might be best just to get an underdrive pulley.

Worth remembering that at high rpm, the eddy current losses of the alternator are very high and the efficiency is usually under 50%, so that cuts the peak power saving down a bit.

At idle the mechanical pump is almost certainly more efficient than the electrical pump. However 50% greater pump speed = 1.5^3 = 3.375x as much power, so any time the engine is more than just barely above idle you're saving power with the electric pump.

[KrautBurner]

I had a Meziere EWP on my GTO for a few years
loved how I could cool down the engine between races (didn't like how it killed my battery a few times)

as well as the 16RWHP it added (checked by dyno)

but it failed after about 3 years (25K miles)

they don't seem to be a great idea for street applications

[echo-francis]

i have my davies craig water pump since nearly 4 years and about 35kmiles. i had no problems so far

[Sunaj]

Originally Posted by echo-francis

i have my davies craig water pump since nearly 4 years and about 35kmiles. i had no problems so far

How's it setup?

[California98Civic]

Originally Posted by Sunaj

How's it setup?

He has one of the greatest mod threads on this site, and if you read post number one you'll find he has indexed everything. Click "thanks" on his posts and show some love... echo-francis is one of our best diy engineers on this site. Check out his thread: http://ecomodder.com/forum/showthrea...tml#post264300

Thumbs-up! Way up!!

[serialk11r]

Originally Posted by KrautBurner

I had a Meziere EWP on my GTO for a few years
loved how I could cool down the engine between races (didn't like how it killed my battery a few times)

as well as the 16RWHP it added (checked by dyno)

but it failed after about 3 years (25K miles)

they don't seem to be a great idea for street applications

A belt-driven water pump is mechanically the same thing as an electric pump, minus the electric motor. There are plenty of reliable electric motors, so there's no reason it can't be a good idea for a street car.

Your Mezier pump may have failed, and BMW N54 pumps may have sucked, but millions of Priuses use an electric pump that is quite reliable, and all the new VW/MB/BMW cars are using electric pumps.

[California98Civic]

So, studying echo-francis's fuel log and EWP install shows it was associated with improved fuel economy. But it is hard to tell how much of the improvement was due to the new pump because he did a bunch of mods at once. The EWP was installed Sept 2012. In March 2012 he had recorded 58.59 MPG (US) and in October he recorded just over 63 mpg. But there were a few mods in between, like wheel skirts for one. So maybe it was worth anything from 1-3mpg in highway driving conditions? BTW, the install was a bear. Here is the install post: http://ecomodder.com/forum/showthrea...tml#post328930

[t vago]

I can also say that when I put a 25% UDP on my Dakota's engine back in 2011, I did not notice any real difference in fuel economy.

Then again, I did not (and do not) really rev the engine that much past 2000 RPM for any real length of time.