electric fans and water pump?
09-19-2008, 06:41 PM
#1
Racer
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electric fans and water pump?
anyone running electric fan and water pump? if so could you show pics and possible combo that work ? im fresh out of spots on my fuse panel so have to juggle something. this is my effort to squeeze any extra ponies out of engine,thank you
09-20-2008, 01:10 AM
#2
Drifting
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First of all, I don't have an electric pump because they are not intended for a street driven car so you may want to consider that. As for the fans, I have wiring instructions that I copied off the forum. I believe Sixfooter posted them. Do a search but if that doesn't work for you I can fax them if you pm me.
09-20-2008, 09:46 AM
#5
Le Mans Master
can an electric water pump work? sure - if you get the right one, and you work enough with all the supporting hardware but the question really is on a street driven car is it really practical?
Most electric pumps are designed for racing applications. Most importantly that means that they are typically designed for their maximum fluid flow at high RPM's - usually sustained rpm's over 4000rpm. Below that level they are less efficient and do not flow as well as a standard belt-driven pump. What's going to happen if you are cruising below 4,000rpm, or just sitting idling at a traffic light, or stuck in traffic? Are you prepared to watch your temp gauge keep climbing higher and higher.....
Lets look at the flow specs:
A STOCK SB water pump is spec'd to flow 55gpm
A STOCK BB water pump is spec'd to flow 82gpm
electric water pumps range, depending on make and model, from 19gpm up to 55gpm. Even the most efficient Epump flows less than a standard stock SB water pump, and again the flow rates listed for the Epumps are are their highest flow rate which is at higher RPM's - they are less at lower rpm speeds.
So, right there you would be replacing a stock belt-driven pump for something with less flow rate, especially at lower rpm's.
Second, as already mentioned, nothing is free. You may gain a few horsepower with an Epump vs a belt-driven pump but Epumps are notorious for their power consumption. Where is that power going to come from? You will need to upgrade your alternator. Alternators use power from the motor..... some of your "gain" you will lose because of the required additional electrical requirements.
Super Chevy did a nice A/B comparison test on a SB chevy motor using a standard belt-driven water pump and than swapped it out for a Epump to see what, if any, real gains in HP there was. The average HP gains with the Epump were 2-3HP. Is that small amount really worth the hassle, expense, and less efficient flow and cooling at lower RPM's??
Personally, if you are really looking for more power for your car and willing to just throw money at it to achieve that additional power there are much better changes you can make that will get you the gain you are seeking without the downsides to trying to put an electric water pump on a street driven car.
Most electric pumps are designed for racing applications. Most importantly that means that they are typically designed for their maximum fluid flow at high RPM's - usually sustained rpm's over 4000rpm. Below that level they are less efficient and do not flow as well as a standard belt-driven pump. What's going to happen if you are cruising below 4,000rpm, or just sitting idling at a traffic light, or stuck in traffic? Are you prepared to watch your temp gauge keep climbing higher and higher.....
Lets look at the flow specs:
A STOCK SB water pump is spec'd to flow 55gpm
A STOCK BB water pump is spec'd to flow 82gpm
electric water pumps range, depending on make and model, from 19gpm up to 55gpm. Even the most efficient Epump flows less than a standard stock SB water pump, and again the flow rates listed for the Epumps are are their highest flow rate which is at higher RPM's - they are less at lower rpm speeds.
So, right there you would be replacing a stock belt-driven pump for something with less flow rate, especially at lower rpm's.
Second, as already mentioned, nothing is free. You may gain a few horsepower with an Epump vs a belt-driven pump but Epumps are notorious for their power consumption. Where is that power going to come from? You will need to upgrade your alternator. Alternators use power from the motor..... some of your "gain" you will lose because of the required additional electrical requirements.
Super Chevy did a nice A/B comparison test on a SB chevy motor using a standard belt-driven water pump and than swapped it out for a Epump to see what, if any, real gains in HP there was. The average HP gains with the Epump were 2-3HP. Is that small amount really worth the hassle, expense, and less efficient flow and cooling at lower RPM's??
Personally, if you are really looking for more power for your car and willing to just throw money at it to achieve that additional power there are much better changes you can make that will get you the gain you are seeking without the downsides to trying to put an electric water pump on a street driven car.
09-20-2008, 09:53 AM
#6
Second, as already mentioned, nothing is free. You may gain a few horsepower with an Epump vs a belt-driven pump but Epumps are notorious for their power consumption. Where is that power going to come from? You will need to upgrade your alternator. Alternators use power from the motor..... some of your "gain" you will lose because of the required additional electrical requirements.
Super Chevy did a nice A/B comparison test on a SB chevy motor using a standard belt-driven water pump and than swapped it out for a Epump to see what, if any, real gains in HP there was. The average HP gains with the Epump were 2-3HP. Is that small amount really worth the hassle, expense, and less efficient flow and cooling at lower RPM's??
Gotta run. I'm sure chefart has posted more nonsense that needs 'comment'.
Super Chevy did a nice A/B comparison test on a SB chevy motor using a standard belt-driven water pump and than swapped it out for a Epump to see what, if any, real gains in HP there was. The average HP gains with the Epump were 2-3HP. Is that small amount really worth the hassle, expense, and less efficient flow and cooling at lower RPM's??
Gotta run. I'm sure chefart has posted more nonsense that needs 'comment'.
I question the credibility of the magazine test you mentioned. A stock pump as installed only consumes 1-2HP so it's impossible to recover more than that value. I doubt also that the magazine considered the additional load put on the alternator to power the pump.
At best it would be a wash. Same with the fans.
09-20-2008, 09:53 AM
#7
Drifting
I'd consider the electric fan option, as it has immediate results and consistent reviews.
I think I'd wait and review a little more on the electric water pump based on your application/use.
Just my two cents....
I think I'd wait and review a little more on the electric water pump based on your application/use.
Just my two cents....
09-20-2008, 11:25 AM
#9
Le Mans Master
Barry,
I question the credibility of the magazine test you mentioned. A stock pump as installed only consumes 1-2HP so it's impossible to recover more than that value. I doubt also that the magazine considered the additional load put on the alternator to power the pump.
At best it would be a wash. Same with the fans.
I question the credibility of the magazine test you mentioned. A stock pump as installed only consumes 1-2HP so it's impossible to recover more than that value. I doubt also that the magazine considered the additional load put on the alternator to power the pump.
At best it would be a wash. Same with the fans.
you very well may be correct. All i can do is report the published results.
They actually tested the standard belt-driven pump two ways - 27% overdriven and 14% underdriven vs the Epump.
Their results averaged to a 3hp gain based on their chart of dyno results.
regardless of whether it was an average 3HP gain or a complete wash I'd still say my point was made - the expense and hassle of an electric waterpump doesn't really gain anything worthwhile. Even IF there really was a 3HP average gain I'd say that isn't anywhere near enough to justify changing to an Epump.
BTW, if you have any interest at all, here is the article - just so you know I didn't just make it up and pull the numbers out of my a**:
http://www.superchevy.com/technical/...ump/index.html
09-20-2008, 01:25 PM
#10
Team Owner
Member Since: Mar 2003
Location: Greenville, Indiana
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[QUOTE=BarryK;1567177966]Mike
you very well may be correct. All i can do is report the published results.
I didn't just make it up and pull the numbers out of my a**:
[
Sometimes, it's better to leave the books on the shelf and spend a little more time under the hood.
you very well may be correct. All i can do is report the published results.
I didn't just make it up and pull the numbers out of my a**:
[
Sometimes, it's better to leave the books on the shelf and spend a little more time under the hood.
09-20-2008, 01:31 PM
#11
I went and read the test. What a crock of sh*t. There was no alternator on the engine so they have not measured how much power it takes to run it- you know, the thing that makes the power to run the pump?
They also stated the following " An electric motor, on the other hand, does not cost horsepower to run...."
Wow, now I'm really impressed with their basic knowledge of mechanics and the laws of physics . Where do I get me a subscription to this priceless rag? Ka-barf!
Last edited by Mike Ward; 09-20-2008 at 01:45 PM. Reason: had to stop lauging first
09-20-2008, 01:45 PM
#12
Race Director
09-20-2008, 01:46 PM
#13
Le Mans Master
[QUOTE=MikeM;1567178996]spent enough time doing just that this week already working on my own water pump, thanks, as you well know!!
09-20-2008, 01:49 PM
#14
Le Mans Master
That's what we have chefart for, isn't it?
I went and read the test. What a crock of sh*t. There was no alternator on the engine so they have not measured how much power it takes to run it- you know, the thing that makes the power to run the pump?
They also stated the following " An electric motor, on the other hand, does not cost horsepower to run...."
Wow, now I'm really impressed with their basic knowledge of mechanics and the laws of physics . Where do I get me a subscription to this priceless rag? Ka-barf!
I went and read the test. What a crock of sh*t. There was no alternator on the engine so they have not measured how much power it takes to run it- you know, the thing that makes the power to run the pump?
They also stated the following " An electric motor, on the other hand, does not cost horsepower to run...."
Wow, now I'm really impressed with their basic knowledge of mechanics and the laws of physics . Where do I get me a subscription to this priceless rag? Ka-barf!
I only skimmed the article briefly and than looked at the results chart. It told me more than enough - that it was a waste of time.
09-20-2008, 03:58 PM
#15
Le Mans Master
Just some thoughts:
1) An electric pump has the same flow rate regardless of RPM. It is not belt driven and does not vary speed. They are good for racecars that cool down between rounds since thepump gives max flow with the engine at idle. Where electric pumps come up short is at extended rpm (i.e. highway cruising).
2) Electric fans are good because they only run when needed. Mine barely run in town and don;t run at all on the the highway. So, in effect, I do get free HP on the highway.
1) An electric pump has the same flow rate regardless of RPM. It is not belt driven and does not vary speed. They are good for racecars that cool down between rounds since thepump gives max flow with the engine at idle. Where electric pumps come up short is at extended rpm (i.e. highway cruising).
2) Electric fans are good because they only run when needed. Mine barely run in town and don;t run at all on the the highway. So, in effect, I do get free HP on the highway.
09-20-2008, 04:13 PM
#16
Safety Car
Any less load freed up physically (like a water pump) will allow the engine to make more horsepower. How much more depends on your combo. At the dyno, I have seen from 3 to 12 hp increases. At the track, racers that must run an alternator also run an electric water pump if they can do it. Same goes for electric fans.....there is a net horsepower increase.
09-20-2008, 04:46 PM
#17
Le Mans Master
[QUOTE=C3 Stroker; It doesn't take any more power to turn the alternator no matter what the load in amps ...
Huh ? I guess that's why the belt never slips or squeals when there is a high electrical load ?
Huh ? I guess that's why the belt never slips or squeals when there is a high electrical load ?
09-20-2008, 05:10 PM
#18
Safety Car
[QUOTE=Aktbird;1567180503][QUOTE=C3 Stroker; It doesn't take any more power to turn the alternator no matter what the load in amps ...
Huh ? I guess that's why the belt never slips or squeals when there is a high electrical load ?[/QUOTE]
Let me clarify this....If your alternator is rated to handle a 100 amp load at 2500 rpm, using 100 amps will not slow it down or increase drag at that speed. If you are using less amps, then, yes, you may benefit from slightly less drag until you increase demand. So in that reguard I stand corrected. But at full throtle (racing situation), you are at max charging power....the load makes no difference.
Huh ? I guess that's why the belt never slips or squeals when there is a high electrical load ?
[/QUOTE]Let me clarify this....If your alternator is rated to handle a 100 amp load at 2500 rpm, using 100 amps will not slow it down or increase drag at that speed. If you are using less amps, then, yes, you may benefit from slightly less drag until you increase demand. So in that reguard I stand corrected. But at full throtle (racing situation), you are at max charging power....the load makes no difference.
Up to the max rating of the alternator, the hp requirement is proportional to the required amperage output.
09-20-2008, 05:22 PM
#20
Let me clarify this....If your alternator is rated to handle a 100 amp load at 2500 rpm, using 100 amps will not slow it down or increase drag at that speed. If you are using less amps, then, yes, you may benefit from slightly less drag until you increase demand. So in that reguard I stand corrected. But at full throtle (racing situation), you are at max charging power....the load makes no difference.
The effort it takes to turn an alternator is directly related to the load put on it. The corollary is the amount of current consumed by an AC electric motor is directly related to how much load is put on it. I learned both in day one of 8th grade high school electronics.
Alternators are not rated to carry a load, they are rated for output. There's a difference. I learned that on day 2.
Engine RPM has nothing to do with load.
Last edited by Mike Ward; 09-20-2008 at 05:25 PM.