"An electronic pump will keep your engine cooler..."
That's an overly broad statement, and in many cases simply not true. Mechanical water pump's volume moved varies with engine rpm. The volume can vary from 10-20 gpm at idle up to 100 gpm at high revs. Most electrics fall in the 30-50 gpm category. You can see that at high engine rpm, most mechanical pumps move about twice as much coolant as the electrics do.
The question is how much do you need moved at what rpm to cool your engine? And the answer to that varies all over the place - especially depending on how the engine is used.
One of the benefits of electrics is that they're capable of moving more coolant when the engine is at low rpm than the mechanical's are. Also, they can be on or off independant of what the engine is doing. That's great for drag racing or autocross. For road racing though where the engine sees extended periods of time at high rpm (30 minutes to 24 hours) - the electric has to be sized accordingly. Any HP gain is going to come from either switching the pump completely off (can't do that for autocross/street/road racing), or from the fact that the engine doesn't actually need to move all the coolant the mechanical pump is moving. On the street (most rpm is below 3000), you're not moving much, if any, more coolant with the mechanical than you are with the electric running wide open. To really take advantage of the electric on the street, you need to control it with a variable speed controller ( www.dccontrol.com) that minimizes the electric pump power usage. For street use - one challenge is that if you have a failure on your electric, you can't just run to the local parts store for a replacement. You could be out of business for a while awaiting parts.
Related to costs - if you don't have an electric fan already, then in addition to the pump you've got to have a fan. Running fan and pump you've got to have an alternator capable of supplying that power. And most folks need some way of modifying the belt drives to work with no water pump pulley in the middle anymore. It's VERY easy to spend $500-$1000 converting one from a mechanical pump/fan. Only you can decide if the 5-10HP you free up (mostly over 3500 rpm) is worth that kind of expenditure/trouble.
For a drag racer/autocross car that doesn't see extended street use and is competing in a competitive rules-constrained class where every HP is a help - it might be worth it. A lot of drag racers don't even run an alternator - just charge the battery between runs and they may only use the elec. pump before and after the run. Many use the mechanical pump and simply run it off of a small electric motor/belt drive. To me, that seems an easier/cheaper/equally effective solution for drag racing or autocrossing. For street use or road racing, I'd stick with a mechanical.
I agree with Michael on this one. The cost of switching over on a street car along with not having the availability to replace it if it does go out would make me spend my money elsewhere. There are a lot of other things on the market that will net you similar or more HP for less money.
Only unless you have squeezed every last little bit out of your combo and are looking for those extra few HP, or race a class that has very strict rules, I can't see going with one.
yep. Thanks that makes sense to me. What is all incorporated in doing a alternator upgrade? Ive been looking at one in Summit, I believe its a powermaster alternator. Does it just bolt in and plug right up or is there more to it?
Go to www.pa-performance.com and search around for their installation instructions/tech. It'll give you an idea what's involved in the various alt. upgrades.
Meziere makes a elec. pump that has an idler pully built in. kinda looks like a stocker, but its is a little beefier and you can still hook up the accesories like stock. granted that pump is about $400, i like mine that doesn't have the pulley.