Katech_Zach

The reason is because energy can not be created or destroyed, only converted from one type to another. Whether you turn the pump with mechanical energy or electric energy generated from mechanical energy by the alternator, it still comes from the crankshaft. Converting energy almost always results in losses to thermal energy, so usually the less number of times you have to convert energy, the more efficient. On top of that, the electric pump still has a idler which has parasitic losses.

zeshawn

thx for the explanation Jason that sounds more like it

MTIRC6Z

"1) Is Jim Hall still running the EWP on his car or has he removed it in light of this latest info about how inadequate such a pump is? 2) How much damage was done to Jim's Katech engine due to the EWP? 3) Also, I presume this 'dangerously low flow' issue must mean that Meziere is lying about the 55gpm rating of their pumps?"

So of my 3 questions, only #1 appears to have gotten some response but not conclusively so in that apparently Jim Hall is selling his EWP, or is it that he's selling EWPs to customers not the one which was on his personal car?

Qu#2 & 3 appear unanswered.

My understanding was that a stock WP flows about 55gpm@4-4500rpm, so if a EWP (which is supposed to flow 55gpm at all times) has "dangerously low flow" I'm failing to understand something, OR does the "dangerously low flow" happen at 6-7000 rpm?

Cheers, Paul.

soldier4life

Jayfabs

Tonylmiller

I would expect a belt driven pump to be more efficient due to the losses in generating electricity. However, I do not know how an alternator works. Does it put the same load on the engine all the time, regardless of electrical load, or does the mechanical load vary with electrical load?

vetteLT193

The answer is it depends... especially on newer cars. It used to be the alternator was 'on' when the engine was running. It would crank out 14-ish volts and that was that. They typically produced more than needed so by converting to electric you were just using what would have been wasted anyway which is why it is a winner.

On newer cars this is variable. Newer GM stuff starts out 'on' and produces 14-ish volts to recover from the starting then after a few minutes the alternator steps down and only maintains 12 volts. I know for sure other manufacturers do a lot more. As an example in my BMW M3 the alternator typically only charges on deceleration unless it has to. This makes the electricity 'free' by using the engine when it would otherwise be wasted.

The other issue that many don't talk about is the pump speed. Manufacturers put in a pump that will pump enough at idle to keep the engine cool. At high RPM's it is pumping way more than is needed. Many race cars use pumps that will not maintain temp at idle because they spend their time at high RPM's so they can get more power with a slower pump and get better cooling (too much flow can be bad for cooling) The electric pump can be set for ideal coolant flow all the time. This is typically a great thing. Also, for cool down you can run the pump for a few minutes after shut down which is also a good thing.

redbird555

See the below link I referenced. The ls3 pump is the same as an ls7 impeller wise so the results should be more than valid. Everyone who has tested this with the exception of katech, myself included have gained power with an ewp.

I have ran 3 different meziere ewp's on 3 different cars over the years. None of them have had a failure except once when I blew the fuse and had to replace it.

Unless you road race where the engine will need the extra flow at high for EXTENDED periods of time then an ewp is no problem.

In traffic my temps are down 10 degrees more or less as well as just driving around town. I beat on m car pretty regularly including many WOT blasts through a few gears and never have a temp issue. The only way I could see it being an issue would be on a road course where you're holding high rpms for minutes at a time. other than that its better in every department.


If you look in the below link this 5g gains 18 whp from a water pump and UDP. I agree with you on how alt's work nowadays but still Katechs explanation simply does not make sense and isnt supported by any other evidence that i have seen. The additional alt load created by the ewp is nothing compared to the resistance of a mech pump at high rpm.

Jayfabs