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Water Pump efficency and engine performance

vol800

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Guys, stay with me on this question- some explanation is needed for it to make sense and I welcome qualified critique & opinion!

The metal casting quality of the VZ/VE waterpump is pretty ordinary (not smoothed out inside etc- lots of casting 'lips' and not super efficient.)

An engineer explained to me that poor impala design creates increased cavitation in water pumps resulting in the creation of tiny bubbles (like a boats propeller) which have decreased heat exchange efficiency against the surface area of the engine block = less efficient cooling.
He explained that by using computer modelling to engineer the best shaped impalas and smoothing out the pump body internally, a much greater cooling efficiency could be obtained resulting in a cooler running engine with less reliance on the old mechanical thermostat to open up and flood more water through the block- he stated that these pumps are used in Group A racing (can anyone confirm?)
He argued that the fitting of a retro engineered pump resulting in a cooler running engine will increase fuel efficiency but possibly disrupt the outcomes being monitored by the oxygen sensors in the exhaust system as gases would be burning at different temperatures at different engine loads than pre-programmed) so a custom tune is recommended to reset the perimeters for operational efficiency which the ECU would be trying to maintain on it's old manufacturers specifications otherwise..

Now, before I dismiss this as 'Snake Oil' selling in motor form, does anyone here care to challenge his assertion that such a pump would result in increased fuel efficiency (they claim 2l per 100!) and more power....
I'm skeptical... my VE 6.0L with A6 Trans is returning average 13LPH suburban/city driving which I'm relatively happy with (catback/CAI)

Other opinions very welcome- cheers
 

cpbait

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don't know, but how much better can they get it and at what cost?
over the standard i don't think there would be much of a difference, i know electric water pumps can make a difference, but on a standard car been told for the money you out lay its not worth it unless its a highly modified motor.

a tune with otrcai would be money better spent than the water pump engineered and tune in my opinion, unless you want to chase every last drop of hp out of the motor.

have heard water pumps can make a difference but at what cost do you want to pay?
 

vol800

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Thanks for your advice, and also clarifying some of my own underlying concerns as well- certainly the cost to benefit ratio is the largest factor for me right now. He reckons about $800 but supposed to pay itself off in 12 months with fuel savings... I'm deeply skeptical and will give it a miss, the car hasn't got a date down the quarter mile any time soon...:D
 

immortality

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certainly pump design pay's a large part in cooling capacity. however the running temp of the engine is still controlled by the thermostat, so unless you change that the engine running temps won't change. i'd also suggest that the cooling capacity/ability of your current setup(i.e. a basically stock engine) far exceeds what is required. where this gets complicated is with engines that are pushing the performance envelope (power = heat) and you have cooling issues. certainly electrical waterpumps increase power output as they reduce the mechanical load on the engine (i.e. parasitic drive losses). the question must also be asked, what else was modified along with the waterpump? there are certainly benefits in coolant flow by getting out the trusty die grinder and cleaning out the casting flashes that can be found in some cooling passages etc.

at the end of the day anybody can make claims of "this" or "that", i tend to believe things when evidence of somesort is supplied to backup the claims that are made
 
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