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-   -   Electric water pump (https://www.ft86club.com/forums/showthread.php?t=145216)

TorontoB 05-05-2021 06:33 PM

Electric water pump
 
How much power saving can be saved with electric water pump?

Ashikabi 05-05-2021 07:04 PM

Quote:

Originally Posted by TorontoB (Post 3429981)
How power saving can be saved with electric water pump?

I'm just guessing but I'll say 5hp. Doesn't sound worth the money to me unless you're really determined to get every pony out of the motor with no boost

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humfrz 05-05-2021 10:48 PM

Quote:

Originally Posted by TorontoB (Post 3429981)
How much power saving can be saved with electric water pump?

Very little.

:slap:

Get back in the box! - ;)

scion fr-s 05-05-2021 11:26 PM

Quote:

Originally Posted by humfrz (Post 3430045)
Very little.

:slap:

Get back in the box! - ;)

Little is better than none. :laughabove:

humfrz 05-05-2021 11:38 PM

Quote:

Originally Posted by scion fr-s (Post 3430060)
Little is better than none. :laughabove:

Don't encourage him - that's a dumb idea.

Hell, I can remember when water cooled cars didn't have water pumps - :iono:

scion fr-s 05-06-2021 01:18 AM

Quote:

Originally Posted by humfrz (Post 3430064)
Don't encourage him - that's a dumb idea.

Hell, I can remember when water cooled cars didn't have water pumps - :iono:

I learned “little is better than none” from bubba’s 101 auto class. LOL. It is the same as doing an ac delete. Very minimal weight savings.

Ashikabi 05-06-2021 08:03 AM

Quote:

Originally Posted by scion fr-s (Post 3430079)
I learned “little is better than none” from bubba’s 101 auto class. LOL. It is the same as doing an ac delete. Very minimal weight savings.

I don't believe that is correct. Your crank directly drives the water pump, which means it uses horsepower to do it. Going electric would free that horsepower. Up to the point that your alternator has to work a little harder that is. You might save a couple pounds but that "hp" change is pretty inconsequential.

Don't get me wrong, plenty of people do it. That's why electric pumps exist. It's just gonna be a really expensive 1.2hp

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churchx 05-06-2021 08:18 AM

Electric power also doesn't magically appear. Generator spun by engine saps those HP aswell. Unless of course you charge battery with trickle charger prior every drive and have generator disconnected. Belt or gear driven or electrically driven .. only differences should be in way how energy is taken from crankshaft, directly and proportionally to rpms in former case, or just somwhat averaged over time in later case, as generator and alternator acts more depending on charge of battery, not rpms of engine. Still, to pump X volume of fluid with Y resistance you still spend Z energy .. possibly with less losses in mechanically direct drive. But electric will still need that energy taken from somewhere.

Berserker 05-06-2021 09:50 AM

I did one on my Stang & probably will do one eventually on my Brz. Like mentioned above it will draw more from the alternator, if anything it's microscopic gains but a big thing is the cooling in the pits. If you remove your thermostat you can have the water pump circulating in the pits while the car is off prepping for the next round or just coming off the track for cool down purposes.

Calum 05-06-2021 07:46 PM

Quote:

Originally Posted by churchx (Post 3430119)
Electric power also doesn't magically appear. Generator spun by engine saps those HP aswell. Unless of course you charge battery with trickle charger prior every drive and have generator disconnected. Belt or gear driven or electrically driven .. only differences should be in way how energy is taken from crankshaft, directly and proportionally to rpms in former case, or just somwhat averaged over time in later case, as generator and alternator acts more depending on charge of battery, not rpms of engine. Still, to pump X volume of fluid with Y resistance you still spend Z energy .. possibly with less losses in mechanically direct drive. But electric will still need that energy taken from somewhere.

There could be an advantage to driving it electrically. It would give the ecu the option to reduce the field voltage and reduce the power drawn from the alternator, to reduce the power its taking from the crank, during full throttle. It could continue to power the pump off the battery for brief moments of full throttle. Not really sustainable for racing, but on the street you could gain a solid 3-5hp.

That's entirely not worth it, IMO. But there is sound theory behind the idea.

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churchx 05-07-2021 12:47 AM

Only with extra safeguards in place. Think of what happens if battery is drained almost completely by pump and not charged at normal rate. If you stop engine, you will not be able start back again, once charge is drained .. waterpump may stop working completely. And no battery likes deep discharges, which usually reduce maximum charge it may hold, so soon battery will need to be changed. And if/when (at very late stage) alternator/generator is told to charge back as much as they can emptied battery, "power sap" will be much greater. Now throw in lightweight reduced capacity battery.
Mechanical direct driven pump sounds more fail-safe to me, which seems important bit for track (ab)use.

makinen 05-18-2021 08:51 AM

Quote:

Originally Posted by churchx (Post 3430394)
Only with extra safeguards in place. Think of what happens if battery is drained almost completely by pump and not charged at normal rate. If you stop engine, you will not be able start back again, once charge is drained .. waterpump may stop working completely. And no battery likes deep discharges, which usually reduce maximum charge it may hold, so soon battery will need to be changed. And if/when (at very late stage) alternator/generator is told to charge back as much as they can emptied battery, "power sap" will be much greater. Now throw in lightweight reduced capacity battery.
Mechanical direct driven pump sounds more fail-safe to me, which seems important bit for track (ab)use.

You do too unsure the tech.
BMW's are already using electric water pumps long time ago.
The electric water pump usually used in our FA20 platform only draws 7.5A max and usually within 50% duty. Even just charging two tablets can take such amperes. If the alternator can't provide those amperes along with charging the battery, the engine can't live with a mechanical water pump too.

Ashikabi 05-18-2021 09:05 AM

Quote:

Originally Posted by churchx (Post 3430394)
Only with extra safeguards in place. Think of what happens if battery is drained almost completely by pump and not charged at normal rate. If you stop engine, you will not be able start back again, once charge is drained .. waterpump may stop working completely. And no battery likes deep discharges, which usually reduce maximum charge it may hold, so soon battery will need to be changed. And if/when (at very late stage) alternator/generator is told to charge back as much as they can emptied battery, "power sap" will be much greater. Now throw in lightweight reduced capacity battery.
Mechanical direct driven pump sounds more fail-safe to me, which seems important bit for track (ab)use.

That and it would be a nightmare to tune that into a computer that was never intended to run an external pump

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churchx 05-18-2021 05:34 PM

Quote:

Originally Posted by Ashikabi (Post 3433685)
That and it would be a nightmare to tune that into a computer that was never intended to run an external pump

Hmm .. IRL it might be less of an issue, as imho many that do that extensive mods may also run aftermarket ECU, such as Motec. Still, main bit i wanted to point out in my post, that no magic energy will be freed by going electric, thus no performance gains are to be expected.


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