sdm1234

iTrader: (8)

How much gpm does the stock water pump flow at cruise speed and top end? Thanks.

96capricemgr

iTrader: (1)

About 20gpm at 2000rpms through the restriction of the system and 66gpm at 6000rpms again as restricted by the system. Be careful comparing this to electrics which are free flow rated.

An often overlooked fact of physics is the ONLY way an electric pump can free up power is by moving less water.

LT1Falcon

iTrader: (3)

good point

Paul Bell

iTrader: (9)

The crank speed is stepped down to half to run the camshaft. Then the stock WP drive gear steps it up by like three times. That's a lot of strain on any gear reduction setup.

Somewhere here on the internet, there's a website that shows dyno'ed results for the various upgrades to our cars. As I recall, the EWP swap freed up 6 HP over stock.

It's the way that the step down/step up gear setup gets the waterpump turning that wastes power. The EWP eliminates all that.
The HD EWP moves 55GPM. I'll bet the good folks at Meziere know to rate their products "as installed".

The EWP swap is a good upgrade. You rarely average 6000 RPM. At crusing speeds, the stock pump is moving way less than the Meziere. It's always moving that 55GPM. Downside? The HD 55 GPM pump hits the fan shroud requiring you to trim it.

96capricemgr

iTrader: (1)

While the gearing changes are inefficient so is taking rotation, making electricity and then turning it back into rotation.

Look into it, NONE of the electric WP I am aware of are restricted flow rated, just free flow, don't believe my then email them and ask. The aftermarket relies on people assuming the best of them, but that is not the reality of things, they are out to make a buck.

Please do the math all the formulas are available online figure out how any HP the .8 amps the Meziere draws equals in HP at 13.5 volts. We all agree that the electric frees up 6+ hp too the wheels, Meziere claims 11hp whatever. Once you begin researching I think you will be shocked just how weak these little motors are.

The info I posted about stock LT1 pump flow is from an SAE article and says .17hp per gallon, sure there is efficiency to be gained there but not on the level you guys suggest.

More analytical guys have noticed higher cruise temps with electrics too suggesting they are already down on flow compared too a stocker at cruise rpms. I understand the electric is one speed just saying that at cruise rpms the mechanical is already moving a lot of water.

I am not saying electrics wont do the job, they do and they do free up power making a car faster. What I am arguing is WHY.

Paul Bell

iTrader: (9)

AHHH, I found it:

http://www.ws6.com/mod-14.htm

It's part of this site showing the gains from all kinds of upgrades:

http://www.ws6.com/mycar.htm

They say the stock pump moves 25 GPM at 6,000 RPM. I don't know how these pumps were tested but I'll bet they did whatever it took to make the measurements as "real world" as possible. Their measurements were with what looks like the non-HD Meziere pump which has a lower GPM rating.

96capricemgr, you make some valid points but when it comes down to net RWHP, the electrics are obviously a less parasitic draw compared to the stock setup. I look at it this way: A few more amps loaded on the alternator to turn the EWP is not much load for an alternator that’s already turning. It’s got to be less torque loss than the original hokey gear setup.

I for one would advise anybody to do the upgrade to the 50GPM Meziere (yes, I goofed, the HD pump is 50, not 55 GPM like I previously stated).

We each have our own ways of getting down the track. It would be a boring world if we all did it exactly the same way.

speed_demon24

iTrader: (6)

The stock pump moves alot more than 25gmp at 6000 rpms....

donkey mule

Some really good info on this thread!

Imnotfast

iTrader: (1)

Was just on the phone today with CSR and will be setting up a real worls test in the windtunnel to get REAL facts and see how much of a change would happen. I believe the stock pump was around 42GPM at 5200rpm. Dont really remember that part from the testing days.

96capricemgr

iTrader: (1)

If my car were more of a drag car it would have an electric pump already, being a street car first it is the failure mode that scares me and the fact that at this point I think the $400 for a new pump and a spare would be better spent elsewhere on the car like suspension.

I have considered picking one up to throw on for a few months in fall. Use and electric and some ice and I could certainly see a reduction in ET.

https://ls1tech.com/forums/showpost....1&postcount=63
Now that I look at this again it says "pump rpm" which I think we agree is faster than engine rpm, not sure what to make of it but this is info from SAE not some kid on the internet. I can post a link to the paid download if anyone wants, like $12 but has a lot more in it than just this table.
The WS6 site has some good info but I believe the 25gmp claim for a stock pump is completely false. Where is all that energy going from the stock pump if it is not being used to move water? Energy does not just disapear.
I have agreed all along electrics are worth hp too the wheels and ET reduction at the strip so I will say his dyno finding are certainly realistic.

tonylittle

iTrader: (3)

subscribing

96capricemgr

iTrader: (1)

Just incase this question I posed got lost in my rambling of the last reply.
If all the extra energy the mechanical uses is not used to move more water what is happening too it?

MrDude_1

iTrader: (4)

well, if its sucking the power, but not flowing, then the pump is cavataing...

but really, we all know the pump is moving more water at high RPM.. thing is, its moving more then enough...

so if we cut the the pump away from being engine RPM dependant, then we can set it to flow just enough to keep it cool, without trying to spin an impeller to 7000rpm when it only needs to spin to half that...

so yes, we are moving less water to free up power.. and while theres an inefficiency shown from making electricity, then turning it back to mechanical energy, its compensated for by less load at high RPM because you're not trying to pump water at that high RPM. the water pump is remaining constant.
on the flip side, it may be drawing MORE power at idle.. lol.

trevmust

I heard that the EWP run like an electric fan, in the sense that you can program it to run coolant through until te engine reaches a pre-set temperature. I've heard that after a day at the track you ideally want to let your car idle the temp down... But idk, could just be hearsay.

bowtienut

iTrader: (1)

Transient, short-term power like dyno pulls and 1/4 mile runs, the EWP wins every time. No doubt at all in the 6 hp claim at high rpm. You don't see the loss of the alternator replenishing the battery in those situations.
For low power cruising, I could see the EWP being more efficient because of its lower flow rating than the mechanical pump; it's not pumping as hard against all of the system restrictions and a partially closed thermostat. And it doesn't need to.
For extended high power situations, the mechanical gets the nod.
Even cruising at 80 in summer heat with my stock engine, I saw an increase in steady-state temp of 3 to 5 degrees after going from the mechanical to the Meziere HD pump. I run a 160 deg tstat. That tells me right there that it flows less at 2000-2500 rpm.
For a roadracing application, I'll take the mechanical setup.

quik95lt1

iTrader: (7)

holy ressurection from the dead lol

BALLSS

no kidding. This topic has been discussed in many threads over the years.

..and after 14 years my Meziere is still going strong with over 75k miles on it. For me I swapped in 99 because chronic OEM pumps failed and killed Opti (all under warrenty). I swapped to EWP when my 96 went out of warrenty, never looked back and never had a coolant contaminated Opti issue since. Bought a spare used EWP for $50 like 12 years ago I keep in the trunk if/when this one fails. Swap will take 10 min tops (coolant bypass mod done) even if it is on the side of the road.

As far as running "hotter" at sustained FWY speeds. I see none by the gauge reading. It is common for 100+ degree days in summer and even higher on the runs to Vegas when it is 115 here in SoCal. yeah EWP will free up RWHP just like any electric driven accessory would that was run "mechanically". Many new cars now have electric power steering vs mechanically driven to free up HP but more importantly free up parasitic engine drag to increase milage rating.

Mechanical pumps increase flow as RPM increases. EWP is constant at any RPM. My car did not cross the 1/4 mile traps any hotter with a EWP over mechanical and I have 100's more passes with EWP than mechanical pump.

IIRC Meziere will completely rebuild their EWP's for $100 but fortunately I have not yet needed that service.

speed_demon24

iTrader: (6)

Electric power steering pumps save power the same way electric waterpumps do, by moving less fluid. A mechanical power steering pump has to move enough fluid at idle for parking lot maneuvers, but after that its pretty much trying to pump way more fluid than it has to. And on the highway and in straight lines they can turn the flow way down on the electric power steering pumps.

There is no such thing as free energy. Move less fluid = takes up less power.

autodoctor911

Sorry, I came across this thread on a google search, and I wanted to bring the subject up as discussed here.

I understand that an electric pump will use more HP to flow the same amount of coolant as a mechanical pump, primarily due to the inefficiency of making the electricity to power it in the alternator.

As I see it though, the only time you are concerned about power losses in a performance/racing application is when the throttle is all the way open.

Otherwise, you can get more power, just by applying more throttle.

If you are road racing or street driving you are only at full throttle for less than half of the time at most. If the alternator exciter is set up to cut out at full throttle, as is the case with most modern FI engines, then all of the power for electrical accessories will come from the battery while at full throttle, and the battery will be charged when the engine is at part throttle or better yet, during deceleration, acting as a form of regenerative braking to a limited extent, by helping to slow the motor and the car, while making electricity to charge the battery.

I think it would be easy enough to do the same thing on an older FI engine that doesn't have this, or a carbureted engine with the use of a relay and a kickdown switch on the gas pedal. just use a normally closed relay to provide power to the L or I terminal of the alternator, that will open when grounded by the kickdown switch.

with alternator deactivation at WOT, any HP loss at other throttle positions is irrelevent. Fuel economy on the other hand would be impacted negatively by using an electric pump that flows as much as a mechanical one.

Is there any aftermarket inline water pumps that have a variable speed?
Likewise, is there a module available that could control it?
BMW has successfully converted many of their engines to electric water pumps(variable speed controlled by the DME(engine control module), so it can be advantageous even with regard to fuel economy if the speed is regulated.

hrcslam

It's not as simple as cutting power to the EWP at WOT. This is a function of thermal dynamics. Once the engine starts producing more power (heat) than the cooling system (radiator, fans, pump, etc.) can maintain the engine will gain temperature. It doesn't need to be at WOT or high rpms for this to happen.

Increasing radiator cross section helps a lot, but our radiators are already large and we have little space to go any bigger. Increasing radiator thickness helps, but not as much as cross section.

Increasing coolant flow helps too. The slower the coolant flows the the more it cools in the radiator, but the more it heats in the engine too. The cooling system works best when the coolant in the radiator and the air flowing through it are furthest apart. The longer the coolant stays in the radiator the less the temperature differential between the air and the coolant are and less efficient it is, the hotter the engine will run. Cold coolant in a radiator and hot coolant in the engine does it no good.

You need the coolant flowing at all times. Drag racing works great for EWP because the engine is only at high thermal outputs for seconds at a time. Even hot lapping puts my runs about 4-5 minutes apart and runs in the seconds. Daily driving is o.k too because most of us will stay under 2500rpm 99% of the time. In both scenarios the engine has ample time to cool down between high thermal outputs.

Road racing or other lap track events do not like EWP. Once our engines start to maintain 3000 rpms (or even higher depending on the rest of the cooling system) the thermal output of the engine exceeds the thermal cooling capability of the cooling system and it WILL start to heat up. Kept there for long periods (like road racing) will cause the engine to over heat.

The EWP's are NOT flow rated on specific applications (as told to me by Meziere), they are free flow rated. They do not, and can not, flow remotely the same amount of water as the mechanical pump can. Not even close. The physics behind the power used isn't even remotely close to comparable. However, it is suitable for certain applications, like drag racing.