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Discussion Starter #1
Will using an electric water pump allow me to bypass my P/S pump, but still run the alternator? Does anyone that drag do this?
 

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The Mierze electric water pump has a "dummy" pulley (AKA "idler") on it. The belt length and routing is the same as with a normal mechanical pump.
 

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RocketSled said:
The Mierze electric water pump has a "dummy" pulley (AKA "idler") on it. The belt length and routing is the same as with a normal mechanical pump.
I was looking into running one of these pumps and was wondering how much HP an TQ it would free up. Does anyone know off hand?

D.J.
 

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OneQuickCoupe said:
I was looking into running one of these pumps and was wondering how much HP an TQ it would free up. Does anyone know off hand?

D.J.
Prolly ~10hp. Maybe 10 ft-lbs too.
 

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Thanks for the quick reply guys. 7 to 10 on one of these engines is pretty good and ranks right up there with an aftermarket exhaust system and other high dollar items. This pump isn't cheap either. Anyone know who has the best price?

D.J.
 

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Discussion Starter #7
RocketSled said:
The Mierze electric water pump has a "dummy" pulley (AKA "idler") on it. The belt length and routing is the same as with a normal mechanical pump.

Thanks, what I really want to know is if there is anyway to route the belt to bypass power steering but leave the alternator on for drag strip use AKA short belt mod a la 5 liter mustangs. If one could bypass P/S, hp will go up a lot . . .
 

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The life of an electric water pump is much less than that of a mechanical water pump. Something to think about considering how much trouble it is to replace the water pump. Unless you race your car, it also isn't worth the money for the horsepower gains.
 

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I would have to disagree. One the best mods I ever did.

1) Gives you about 5-8 h.p. max. O.K.

2) Keeps engine perfectly cool at 185-190 for maximum horsepower all the time (No heat soak at all). Every ten degees above 185-190, leads to about 7 h.p. lost on 346, more on a 427. Heat also leads to wear, oil fouling and breakdown.

(I have lot of other things, Ron Davis radiator, DRM distribution block, C5R Carbon Fiber Vented Hood, Accusump, etc. to boot) Oil change is about $100 now, 13 quarts :eyes: ...
 

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Richard Branca said:
Thanks, what I really want to know is if there is anyway to route the belt to bypass power steering but leave the alternator on for drag strip use AKA short belt mod a la 5 liter mustangs. If one could bypass P/S, hp will go up a lot . . .
No, I don't think that is possible. You'll have to take a few passes with it off and then either charge battery or put belt back on to charge. I think 6 hp is what I gained. On the track I have run the same times with belt on and off however.
 

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Discussion Starter #11
Rob,

Thanks, that's exactly what I wanted to know.

Rich
 

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We've had this discussion before. The pump doesn't free up very much HP at all. The pump draws power from the Alternator. The Alternator needs to dissipate more power, and that increases the load on the engine, and that eats the HP again. It's thermodynamics 101, you never get something for nothing.

The mechanical pump runs proportional to crank speed. This inherently means that the mechanical pump spins at below-optimal speed at idle and above-optimal speed at red line.

The advantage is that the electric pump runs at a constant optimal speed all the time. Heat transfer is improved at lower engine RPM because the flow rate is higher than normal, and power loss is reduced at the higher engine RPM because the pump isn't being forced to spin faster than it has to.

As to whether electric pumps are more or less reliable than mechanical... I'd have to say they're more reliable. A modern pump uses a brushless DC motor, there are no moving parts to wear out, except for the armature shaft bearings. The electric pump bearings and seals only need to withstand rotary forces (around the axis of the pump's rotation). The mechanical pump bearings and seals need to take the side loads from the belt tension. In my experience, the primary failure that occurs in water pumps is either a broken drive shaft or a failed bearing/seal. Both would be less likely with an electric pump.

If you haven't guessed, I've been seriously considering this myself. Besides the anticipated improvement in cooling system efficiency, it has the added benefit that, if I blow a belt off my Vortech, I still have a functioning water pump and I can continue to drive the car (at least until the battery goes dead).
 
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