Electric Water Pumps??

[Brm Brm]

Anyone know the pros and cons of electric water pumps??
Its been suggested to me that they are much more effective than the normal mechanical items, whilst liberating a tad more power (common sense with no impeller to drive).

Are there any implications for power supply, problems fitting etc - apart from the intial cost (approx £200 from Demon Tweeks including a temperature control unit to automatically vary flow instead of a thermostat) they sound too good to be true - and would still be cheaper that an alloy radiator!

[2 Sheds]

I was involved with a couple of race cars 2 yrs ago, they fitted electric water pumps, which cost if i remember correctly about £120 each, from V8 Developments, curiously they were soon replaced with belt driven pumps !

[GreenV8S]

quote:Anyone know the pros and cons of electric water pumps??
Its been suggested to me that they are much more effective than the normal mechanical items, whilst liberating a tad more power (common sense with no impeller to drive).

Are there any implications for power supply, problems fitting etc - apart from the intial cost (approx £200 from Demon Tweeks including a temperature control unit to automatically vary flow instead of a thermostat) they sound too good to be true - and would still be cheaper that an alloy radiator!

Yes it is too good to be true! They are much less efficient because the power comes via the alternator and a motor, rather than straight off the fan belt. The 'saving' comes from the fact they have b*gger all flow capability compared to the mechanical pump. Oh, and the salesman for the Australian ones I saw recommended taking the stat out, blocking off the bypass and having this pump running direct between the engine and the rad. Pure madness for a road car, or one putting out significant amounts of heat. (TVR, anyone?)