Electric Water Pump?
Le Mans Master
Joined: Oct 2000
Posts: 7,831
Likes: 5
From: Austin TX
the thing that is forgotten is that the alternator is putting out that 12V at xxxamps when ever the engine is running...the car does not use all that amperage...that is why there is a HP gain droping the extra pulley,,, the Alt isn't working harder, you are just using more of what it makes
Race Director
Joined: Nov 1999
Posts: 10,643
Likes: 8
From: Foxfield CO 1970 Convertible
Your English is great! In fact, it's better than 35 million people living in the US.
What the engine needs at WOT is more cooling. Maybe it needs more water flow and maybe not. The water might be hotter at idle because the car is not moving, the stock water pump is spinning slowly, and the air is not flowing as much through the radiator. In this case, it will need more water at idle than at WOT. Besides, WOT is usually only for a few seconds. Many times, idling is done for long periods when we are stuck in traffic.
Think about this case: you floor it and go WOT with a stock water pump, you hit 150 mph (
) then decide to slow back down when you hit a traffic jam. When the engine was WOT the water pump was pumping fast for only a few seconds. Now when you slow back down, the heat begins to build up but the water pump isn't pumping fast anymore. If you had an electric, it would still be pumping rapidly - even if the car was sitting at idle.
Over here, in the Summer, cooling Vette engines while in traffic is a bigger problem than cooling the engines while moving on the highway - at least that is what most people complain about.
You need more water at wot than at idle..... of course!
The EWP pump the same flow at idle than at WOT...... this is not a good thing.
The EWP pump the same flow at idle than at WOT...... this is not a good thing.
Think about this case: you floor it and go WOT with a stock water pump, you hit 150 mph (
) then decide to slow back down when you hit a traffic jam. When the engine was WOT the water pump was pumping fast for only a few seconds. Now when you slow back down, the heat begins to build up but the water pump isn't pumping fast anymore. If you had an electric, it would still be pumping rapidly - even if the car was sitting at idle.Over here, in the Summer, cooling Vette engines while in traffic is a bigger problem than cooling the engines while moving on the highway - at least that is what most people complain about.
Racer
Joined: Mar 2006
Posts: 276
Likes: 1
From: Pistoia PT (ITALY)
Think about this case: you floor it and go WOT with a stock water pump, you hit 150 mph ( ) then decide to slow back down when you hit a traffic jam. When the engine was WOT the water pump was pumping fast for only a few seconds. Now when you slow back down, the heat begins to build up but the water pump isn't pumping fast anymore. If you had an electric, it would still be pumping rapidly - even if the car was sitting at idle.
) then decide to slow back down when you hit a traffic jam. When the engine was WOT the water pump was pumping fast for only a few seconds. Now when you slow back down, the heat begins to build up but the water pump isn't pumping fast anymore. If you had an electric, it would still be pumping rapidly - even if the car was sitting at idle.OK..... I guess that a clever man must be able to change idea...... but not so much!!!!
I have to agree with you in the case you sed..... but (there is ALLWAYS a "but".....) for the "energy" theme I stay with me!!!
If you need 0.3 Hp to move the water you need..... at least, you will drag the same power in both cases.
Moreover you have to consider that the efficency of the alternator is in the range of 85-90%...... so, with an electric water pump, you will drag 10-15% more power from the engine.
...... unless you like to discharge your battery!
Safety Car
Joined: Dec 2004
Posts: 4,071
Likes: 0
From: San Diego CA
Personally my feeling on ALL pumps is to keep em mechanical, for cars. Water AND fuel. Racepumps.com obviously makes a mechanical pump that can keep up with electric fuel pumps on pressure and mechanical water pumps obviously still work well to this day. Now here's what I look at, for the water pump, if for some reason you lose coolant... that pump is dead. The same goes for your fuel pump, run the tank dry and bye bye fuel pump. Now on mechanical ones you'll obviously notice your temperature going up or the engine idles rough and stalls (fuel starvation.)
My point? It's harder to kill mechanical pumps, than electric ones. They're also USUALLY cheaper. (If you're running a carb the mech. fuel pumps are dirt cheap as are water pumps.) Nuff said?
My point? It's harder to kill mechanical pumps, than electric ones. They're also USUALLY cheaper. (If you're running a carb the mech. fuel pumps are dirt cheap as are water pumps.) Nuff said?
Instructor
Joined: Sep 2006
Posts: 142
Likes: 1
I disagree with one of your points. Not needing better flow at idle. Let's be serious here, you don't need an electric pump on a stock motor. We should be talking about modified, high hp motors. A lot of these problems can have some of their most damage at idle sitting in traffic. Unless you are road racing you aren't going to see WOT for very long periods but you are going to see idle, if driven on the street, a lot. So, at least to me, having more flow (hence, better cooling) at idle where there is air being pulled through the radiator only by a fan is very beneficial.
It's been I long time since I've been anywhere close to overheating now that the temperatures have cooled down, but sitting at a light is when my water temp reaches it's max and I'm using an electric markVIII fan.Out of curiousity, does would a 70amp alternator pull the same or less out of the motor that say a.... 130 amp? I need to upgrade mine to handle that fan as well as the multiport fuel injection of my inprogress motor and possibly an electric water pump.
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