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Electric Water Pump?
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
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
My alternator works differently.
Pro
Joined: Feb 2006
Posts: 718
Likes: 7
From: Jacksonville , NC
Hey send me a list of the parts you want me to put aside for you. Bob
As for the loss of HP and GPM of mech water pump Form the stewart web site:
Stewart Stage 4 pumps are the cutting edge in performance water pump technology. The Stage 4 pump utilizes the Stewart Components DRV-8 impeller. This exclusive 8 vane impeller is fully CNC machined from 6061-T6 billet aluminum. It's special design flows up to 160 GPM, while consuming less than 3 horsepower at 4,500 pump RPM. Stewart Stage 4 pumps are the ULTIMATE water pump for any application!
Not knocking any electric or endorsing any mechanical but if your talking 3 hp difference I think you can choose either and feel comfortable that you arent giving up much in performance.
Semper Fi Bob
Last edited by rclinton; Oct 13, 2007 at 08:09 AM. Reason: additional information
Melting Slicks
Joined: Nov 2001
Posts: 2,659
Likes: 7
From: Katy (Houston) TX
CI 7-8 Veteran
True only if you're using an electric fan. If mechanical fan is attached it's gonna suck more hp. Electric pump necessitates an electric fan so that's where some of the inflated numbers come from.
Racer
Joined: May 2005
Posts: 436
Likes: 0
From: Stavanger
I see you also are using serpentine belt. Where is the place to buy those for our cars.???
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Instructor
Joined: Nov 2004
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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
I believe you can only have current if something is drawing it (notice I said current, not voltage, since you don't "draw" voltage)...meaning there's no such thing as "unused" amperage that an EWP can take advantage of.I think the only way you'd see a HP increase is if the EWP is more efficient than the stock pump it replaces, and it may not be a safe assumption to think that it's more efficient simply because it's not (directly) belt-driven. I agree with the other posters that the biggest advantage of an EWP is that you can pump water independent of engine speed and it might look nicer...
Thread Starter
Instructor
Joined: Sep 2007
Posts: 109
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From: Woodstock Ga
Le Mans Master
Joined: Jan 2006
Posts: 6,506
Likes: 139
From: Butler Pa
Hmmm...that doesn't sound quite right I believe you can only have current if something is drawing it (notice I said current, not voltage, since you don't "draw" voltage)...meaning there's no such thing as "unused" amperage that an EWP can take advantage of.
I think the only way you'd see a HP increase is if the EWP is more efficient than the stock pump it replaces, and it may not be a safe assumption to think that it's more efficient simply because it's not (directly) belt-driven. I agree with the other posters that the biggest advantage of an EWP is that you can pump water independent of engine speed and it might look nicer...
I believe you can only have current if something is drawing it (notice I said current, not voltage, since you don't "draw" voltage)...meaning there's no such thing as "unused" amperage that an EWP can take advantage of.I think the only way you'd see a HP increase is if the EWP is more efficient than the stock pump it replaces, and it may not be a safe assumption to think that it's more efficient simply because it's not (directly) belt-driven. I agree with the other posters that the biggest advantage of an EWP is that you can pump water independent of engine speed and it might look nicer...
If the alternator produces more current, it will take more hp to turn the alternator.I once saw an alternator mounted to a 3 hp lawnmower engine. If you loaded the alternator enough, it would stall the engine.
Burning Brakes
Joined: Nov 2004
Posts: 899
Likes: 1
From: Kansas
Race Director
Joined: Nov 1999
Posts: 10,643
Likes: 8
From: Foxfield CO 1970 Convertible
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.
Stock pumps should be sufficient on stock motors. The reason I went with an EWP and electric fan have more to do with providing more room in front of the engine. I want to install a spreader bar eventually. Also, with EFI and a computer, I can control both the fan and pump with the computer.The big improvement comes when you are idling or only moving slightly in heavy traffic. It's more noticeable with a hotter engine.
Yes, but the regulator unloads the alternator if nothing is drawing current and the battery is charged.
Race Director
Joined: Dec 1999
Posts: 11,096
Likes: 990
From: Sierra Foothills CA
It is a universal law. Nothing is free. That pump gets it's power from a battery or alternator which takes some power from the engine which gets its power from the gas which gets its power from a dead T-Rex 100 million years ago who got it's power from another dinosaur the T-Rex ate which got it's power from eating some green leaves which got it's power from the sun which got it's power from gravity which got it's power from the big bang theory, which got it's power from god somewhere down the road. .................Our cars are powered by God! I never knew that. Thats why they're so special! 
Race Director
Joined: Nov 1999
Posts: 10,643
Likes: 8
From: Foxfield CO 1970 Convertible
I'm saying that the regulator doesn't allow any "excess" current production that is wasted. "If the alternator produces more current, it will take more hp to turn the alternator" is true only when accessories are demanding power. For example, my 140 amp alternator won't put out 140 amps if the electric equipment is only "requesting" 50 amps.
I was trying to point out that high powered alternators don't take more power to spin them under low load conditions. It sounded like some folks think that the alternator is always putting out full power whenever it is spinning, even to the point of generating "excess".
I was trying to point out that high powered alternators don't take more power to spin them under low load conditions. It sounded like some folks think that the alternator is always putting out full power whenever it is spinning, even to the point of generating "excess".
Le Mans Master
Joined: Jan 2006
Posts: 6,506
Likes: 139
From: Butler Pa
I'm saying that the regulator doesn't allow any "excess" current production that is wasted. "If the alternator produces more current, it will take more hp to turn the alternator" is true only when accessories are demanding power. For example, my 140 amp alternator won't put out 140 amps if the electric equipment is only "requesting" 50 amps.
I was trying to point out that high powered alternators don't take more power to spin them under low load conditions. It sounded like some folks think that the alternator is always putting out full power whenever it is spinning, even to the point of generating "excess".
I was trying to point out that high powered alternators don't take more power to spin them under low load conditions. It sounded like some folks think that the alternator is always putting out full power whenever it is spinning, even to the point of generating "excess".
My point was it takes hp to generate all that electricity and people think it all comes free.
Racer
Joined: Mar 2006
Posts: 276
Likes: 1
From: Pistoia PT (ITALY)
Energy
May the problem is that my english is quite bad.....!
I never sed that at idle you need lot of wather flow.... my intention was to say the opposite!
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.
Note that when the engine is producing very low horses, it wil produce consequentely less heat to be dissipated and the thermostat will reduce the flow of water in order to keep the right temperature.
I'm conviced that there is no reason to use an EWP unless you have a race only car.
Regarding the energy...... an alternator will drag power proportionally to the current you are pulling from the battery.
I never sed that at idle you need lot of wather flow.... my intention was to say the opposite!
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.
Note that when the engine is producing very low horses, it wil produce consequentely less heat to be dissipated and the thermostat will reduce the flow of water in order to keep the right temperature.
I'm conviced that there is no reason to use an EWP unless you have a race only car.
Regarding the energy...... an alternator will drag power proportionally to the current you are pulling from the battery.