Waterpumps and Power: Electric vs. Belt Driven

[90mustangGT]

How much power does an Electric WP free up?

 

[HISSIN50]

my crude recollection of something i read was 5-10 HP, but i would not take this for anything - just my foggy recollection.

interesting question.

for the price, i dont know that i would run out and get one - they are fairly pricey, no?

 

[Michael Yount]

I wish I could remember the mag article - I read just the other day on electric vs. mechanical. They freed up on the order of 8-10HP at peak. However, that's not the whole story. First, you need to be sure that you have enough alternator to manage the load. And you need to understand where the application makes sense, and where it doesn't. The electric pumps don't flow at peak anywhere near what the mechanical pumps do at high engine rpm. So, for example, on a road race application, a mechanical pump will move a lot more water than an electric pump will. However, on the street, where most time is spent at low rpm - the electric may move more water than the mechanical since it's output is not dependant on engine speed. Also, for autocross and drag applications, the pump can be run independantly to cool down things between runs.

If you decide to go that route, two thoughts. First - use this to control your pump - www.dccontrol.com. One unit can be used to control both pump and electric fans varying current and speed to both minimizing current load and unit speed. Second, get the parts needed to rebuild the unit - cause if you have a failure, you're not gonna find repair parts at your local parts place.

 

[crunchie12268]

Yeah there pricey, but you would have to convert to electric fan too right? Then that would probably take a toll on your charging system. But if you converted to electric fan and electric pump you would have some noticiable power gains.

 

[hllon4whls]

I wish I could remember the mag article - I read just the other day on electric vs. mechanical. They freed up on the order of 8-10HP at peak. However, that's not the whole story. First, you need to be sure that you have enough alternator to manage the load. And you need to understand where the application makes sense, and where it doesn't. The electric pumps don't flow at peak anywhere near what the mechanical pumps do at high engine rpm. So, for example, on a road race application, a mechanical pump will move a lot more water than an electric pump will. However, on the street, where most time is spent at low rpm - the electric may move more water than the mechanical since it's output is not dependant on engine speed. Also, for autocross and drag applications, the pump can be run independantly to cool down things between runs.

If you decide to go that route, two thoughts. First - use this to control your pump - www.dccontrol.com. One unit can be used to control both pump and electric fans varying current and speed to both minimizing current load and unit speed. Second, get the parts needed to rebuild the unit - cause if you have a failure, you're not gonna find repair parts at your local parts place.

Question:

At what point do you move too much of a quantity of water that it is moving to fast to effectively remove heat from the engine? It needs some time to absorb the heat and then release it through the radiator.

 

[Michael Yount]

hllonwhls - t'stat is there to control temp and flow; water pump circuit has a bypass hose (that little 90 degree bugger between t'stat housing and pump that's such a pain to remove) to prevent damage to the pump when t'stat is closed. Not to worry about moving too much water if you have the rest of the system in good working order. In any event, I'd be more concerned about moving too little than moving too much. That, and moving enough air across the coil....

 

[90mustangGT]

Thanks for the input. Gave me more to think about.

I am running a 160A 3G alternator. Crunchie is right about most EWP's, but I think the Moroso unit has an idler pulley I have heard the mechanical fan can bolt to and still run the belt. I have a Black Magic Fan already.

This is a drag application so I dont' think flow will be that much an issue because as hllon4whls pointed out, at a ceritan point, the cooling effect of higher flow ratio begins to decline. 37gpm is pretty good flow, more than I will need. Maby a stoker 408, but not a 306.

Since I poked a hold in the GoDan 3 Core so I am probally going to upgrade to a 31x19x3" Griffin Aluminum. Only $179 I'd be a fool to go back to the copper/brass.

An electric WP will cost around 300-350, and of course there is the controller. Might consider the controller Michael pointed out. There is another controller that you can mount inside the car that has a digital gauge and you can controll the temps that way.

Probally all togeather around $400-450 but for 8-10rwhp as well as the controll issue, it may be worth it, I dont' know. I know that cool down between runs is an issue. Also, u/d pullies usually only give about the same gains, but we all know the gain is more than the dyno records due to reducion in rototional mass/weight.

I am also deleting P/S, and I deleted A/C and the A/P a long time ago, so I will only be running the alt, and that's with a 3" crank pulley, although I have a strong battery and dont' drive mine daily, and when I do I drive when traffic is minimal so sitting around idling isn't that much an issue.

I am spending a lot on my car, but when it is all said and done, I think it will be worth it.

 

[Michael Yount]

Sounds like you're thinking it through rationally.

You needn't worry about 'over pumping' the system if you have the proper t'stat or flow restrictor in place as you should.

Since it's primarily a racer, weight is probably the most important thing - and contrary to popular myth, light weight is the alum. radiator's single advantage. For the same size, number of rows and fins/inch, a copper core transfers more heat than an aluminum core. But in the size you're talking about, either will have more than enough capacity, and the copper unit is much heavier.

 

[Michael Yount]

As for the cost/performance benefit, only you can decide. But for what it's gonna cost to put the elec. pump on, you could almost put a nice nitrous shot on it. MUCH bigger bang for the buck.....just a thought.

 

[90mustangGT]

As for the cost/performance benefit, only you can decide. But for what it's gonna cost to put the elec. pump on, you could almost put a nice nitrous shot on it. MUCH bigger bang for the buck.....just a thought.

Oh, trust me, that is apart of the plan by the end of the next racing season. I want to build it all motor strong, but have a shot for an extra punch.

Since it's primarily a racer, weight is probably the most important thing - and contrary to popular myth, light weight is the alum. radiator's single advantage. For the same size, number of rows and fins/inch, a copper core transfers more heat than an aluminum core. But in the size you're talking about, either will have more than enough capacity, and the copper unit is much heavier.

I think the bulk of the weight of a radiator would be all the fluid inside of it. My GoDan cooled pretty good, considering it was identical to the stocker only thicker with and extra row. If the Griffin is big enough I will probally sell the Black Magic and get a dual fan setup. Running hot sucks.

 

[Michael Yount]

While the coolant adds weight, it's not incremental weight - you have to have the coolant no matter which core material you use. So forget coolant weight. Empty your copper unit, and maybe you can weigh the Griffin when you get it and tell us what the difference is. I can't believe how heavy my copper/brass unit is with the fans installed. Love to switch to alum to save a few pounds, but I'd have to have it custom made - not worth it to me, especially since the system/unit is working so well.

Go to www.spal-usa.com and check out their fully shrouded dual 11" unit. I have it in mine - keeps that temp gauge rock steady with the DC Control unit.

 

[90mustangGT]

I will definatly do that. I'll try to fill them with water and see what difference it makes there. I am doing a lot of weight reduction, parisidic reductions. I hope I can afford the EWP, and I feel I will need to because the PS is not going back on, so I will either have to run a standard rotation, or a pulley system, either way it will cost 100+, might as well spend some more and get something that really will help.

Here is a true example even if it sounds stupid. 5HP here, 10hp there, 8hp on this, 6 hp by deleting that.... it all adds up. Even with 4 little mods there, that's 29HP, thats a big difference. Then you combine that with 8lbs here, 25lbs there, 44 lbs on top, 60 on bottom, that's 137lbs.

My goal is to break into the 7's in the 1/8th mile, all motor on drag radials. I think I will get there by the end of next year. Not just with these mods, but others as well, I'm looking at the whole package. Hopefully I'll have it running by the end of next year. I have to get it going, but not until it is right.

 

[EMW150]

I'm running the CSI pump and I'll tell you, that thing is awesome for drag racing. Idleing in the staging lanes on a 100 plus degree day the thing sits at less than 160 degrees. I have a manual override switch on the pump that I tic tok in the staging lanes to keep it from getting too cool. After the burnout pulling up to the tree it's about 165-170. That alone is worth some ET because the engine is cool. So it's a bigger advantage than just the rotational loss you get with mechanical water pumps. At the end of a pass the water temp is right around 180 and by the time I get back to get my slip it's back down to 170. On the street the thing's a real pain. I have it on a thermostatic switch but it doesn't work right. When the pump is off, the water in the block heats from the bottom up in the block so you only get migrational heat up where my switch is mounted. If you wait till the switch kicks it on you get a temperature spike because then the pump circulates the hot water from the water jackets of the block to the intake where the sending unit is located. So when I run it on the street, I manually tic tok the pump till it gets up to 160 degrees. I have a way to fix it, just haven't done it yet.

 

[Michael Yount]

EMW - I'd use the variable current/speed controler on the pump, and simply toggle the 'trigger' wire on the controller to shut it off while racing. For street use, it will sense temps. at the t'stat housing, and hold them constant to within 3F +/- provided you have the radiator/fan to remove the heat from the engine.

 

[EMW150]

EMW - I'd use the variable current/speed controler on the pump, and simply toggle the 'trigger' wire on the controller to shut it off while racing. For street use, it will sense temps. at the t'stat housing, and hold them constant to within 3F +/- provided you have the radiator/fan to remove the heat from the engine.

So the variable current/speed controller will circulate water constantly but at a much lower gpm until the sender calls for more cooling?

 

[Michael Yount]

That's right - as little or as much as is needed to maintain the control temp. It will also SIMULTANEOUSLY variably control the electric fan - one unit for both. I've got one controlling my fans, and it's one of the slickest pieces I've bought for the car.

My t'stat is 180F (opens around 182F fully open around 184F); set point for the fan control is 187F. When I'm at a cruise, no fans at all as the t'stat temp is slightly lower. When I pull up to a light, you can see the fans ease on after about 20 seconds from coming to a stop. Depending on ambient temp, they run anywhere from 10% to 50% speed maintaining the temp around 187F. I pull off from the light and within 15 or 20 seconds of hitting 30 mph or so, the fans start to wind down and go back completely off. We rigged an old Volvo tach with a custom faceplate to match the rest of my gauges - and it reads % of fan speed - kind of like a fan tach. VERY entertaining.

You won't be disappointed with the controller - it renders relays and temp switches absolutely obsolete. www.dccontrol.com. You can reach the principal Brian Baskin at [email protected] if you have questions about which unit you need for your application.

 

[EMW150]

Thanks for the info. Sounds like a cool setup. I'll have to check with CSI also just to make sure that running at variable voltage won't harm the pump motor. It shouldn't but can't be too careful.

 

[Michael Yount]

Ask the same question of Brian too - he's got a lot of experience driving different fans/pumps with it -- maybe even more than the pump manufacturers have. My understanding is that it's actually EASIER for the motor because there's no startup current spike needed to get the motor going. Longer life for motor, alternator and battery by driving one variably and 'easing' into start up rather than cycling on/off at full warp speed. Not to mention you don't use anymore current than you have to which optimizes energy usage. Green race car - sort of....

 

[EMW150]

Ask the same question of Brian too - he's got a lot of experience driving different fans/pumps with it -- maybe even more than the pump manufacturers have. My understanding is that it's actually EASIER for the motor because there's no startup current spike needed to get the motor going. Longer life for motor, alternator and battery by driving one variably and 'easing' into start up rather than cycling on/off at full warp speed. Not to mention you don't use anymore current than you have to which optimizes energy usage. Green race car - sort of....

Good point. Again thanks for the heads-up.

 

[Michael Yount]

Just so's you know I'm practicing what I preach.....

http://www.etnracing.com/pages/Tech/FanControl.htm