whenson417

I was watching one of the car shows on SPEED channel this weekend and they ran a segment where they replaced the stock water pump with an electric one and ran the before and after dyno's and saw a 20hp gain. Anyone tried this on the Renesis yet to see how much parasitic losses could be recovered by eliminating the water pump? I don't think I will ever do it but I am pretty curious.

Jaguar_MBA

Hmm let me guess that 20HP gain was on a Large Block Chevy? What type of car was electric water pump on. Normally the electric water pump is a Domestic Modification...as far as I am aware.

whenson417

I believe it may have been a Ford truck. I have an old Summit catalog that actually has one listed for a Rotary engine. I am sure it is for an older rotary but I am sure someone will think to make one for the Renisis if it shows potential.

Xyntax

It would be nice to have an electronic one. My water pump leaked at 10K Miles, and the service guy at the dealership told me that the water pump might have not be too sturdy for our high redlines. He told me that the stock water pump wasn't specially made for 9000 redlines, but it was expected that it should hold up.

If we could get an electric water pump installed, we could have (1) much more dependable water pump life span and (2) free up the power to spin the pump and give it to the rear wheels instead.

TeamRX8

iTrader: (25)

just pray the motor never goes, a rotary will fry in a heartbeat from overheating

Xyntax

^ That would be a major concern for this mod. What would be the difference in efficiency between pulley-driven and electric? I read that in street cars, our water pumps were designed to be more efficient at lower RPM since that's where we would be using the engine most of the time. For race applications, they would prefer a high-RPM efficiency setup. Some do this by reducing their water pump pulley.

Anyone?

epitrochoid

many people have failed water pumps simply from a manufacturing defect exploited by high rpm driving...something that important, especially on a rotary, needs to be over manufactured to hell, but it isn't.

i wouldn't go electric, but I may underdrive the pump since apparently my motor lives more above 4k than below. this would stop the cavitation at high rpm too.

savedsol

(WARNING THREAD RESURRECTION)

I know MazMart is talking about an upgraded water pump but why did this thread die 18 months ago? It seems with an electric pump you can pick your flow rate, free some HP and not worry. To Team's point about it dying, look at all the dead stock ones at 40K miles. No difference.

I'm not an engineer so I can't/won't be the guinea pig but thought I might try to spark the interest of those that are - again. There are plenty of universal electric pumps at Summit and Jegs.

nycgps

iTrader: (1)

if the electric one is direct bolt on and requires just minor modification. I will take one.

I do TONS of high RPM runs .... kinda kills my mpg but its just too much fun I cant stop ... thats probably one of the reason why I replace my Radiator so early

Im just waiting for Mazmart's pricing ...

maxxdamigz

iTrader: (1)

I like Mazmarts idea more than an electric pump. Make a pulley driven water pump that flows/performs better at high RPMs. Rather than gaining HP, you gain reliability and saftey factor. An electric water pump still draws power from the system. The alternator and electrical system will have to draw off the engine to provide the power for the pump. I doubt the overall system efficiency is improved by using electrical rather than mechanical power. You gain peak dyno hp because the battery can run the pump for the short burst without drawing a lot on the alternator.

If a mechanical pump breaks, it leaks but still turns. If an electrical pump goes, coolant flow stops.

Georgia8er

The only thing with electric water pumps is most of them aren't made for street cars. They often do not provide enough flow to keep an engine cool, it was an easy way to free up some hp on drag cars, which aren't sitting in traffic. I've read some now do provide enough flow, but like maxxdamigz said, the power to drive the pump still has to come from somewhere.

olddragger

iTrader: (3)

yep I spoke of this 18 months ago and I still believe it is a good thing.
5 yrs ago would you have thought you would have been driving a car with electric power steering?
ewp offers many avantages
1- constant flow of coolant not dependant on rpms(this could be a real benefit for around town driving)
2- continue coolant flow after engine has been turned off--like a turbo timer.
3- gain in usable power (no parasidic lost)

ewp's can be set up with variable speed simply. If that is what you want.

I wish i had the know how to do this. I havent been able to find the engineering that can calculate the cooling needs and break it down into the gallons per minute they rate the pumps at. I would almost bet my car that there would be a high rpm gain of 7-10 hp.
olddragger

r0tor

iTrader: (1)

a belt turning a pulley attached to a pump is more efficient then a belt turning a pulley on an alternator, the alternator generating electricity, electricity flowing to a motor, the motor converting electricy into motion to drive a pump

when looking at the power gains, you have to know if the electric pump is actually pumping the same amount of fluid at the stocker, and if they actually were running the pump off of the alternator and didn't have it dyno rigged...

BaronVonBigmeat

I think a bladeless water pump would be the way to go for high-RPM cars like ours, since they don't have problems with cavitation. You can have your cake and eat it too--adequate flow at low RPM's, no cavitation at higher RPM's. That's if you're going to stay with a belt-driven setup of course, for an aftermarket company it would probably be easier to take an off-the-shelf electric water pump and adapt it to the renesis.

Keef

It's not about efficiency though

If you have one less thing on the belt, than there should be less strain on the engine especially at higher RPM's

If your worried about the alternator than get a better battery...