ok finally the answer i was lookin for, thanks caprice managr. but since they move less water dont they not cool as well?

 

by the way

 

The amount of load doesn't slow down the alternator. It either supplied enough juice or it doesn't.

 

Where did you come up with that hypothesis. Electricity has nothing to do with pully's and cranks....Well not al leats in the internal cubustion engine Alternator takes over after the car is started, ignition, stereo, power windows, power locks, all the crap on your dash, injectors, A/C.... no pully's no crank. The crank is driven by explosions in your piston chamber

 

i think ur wrong, but i could be wrong, what does everyone else think

 

There is nothing in the alternator to slow it down. You can spin it by hand. lol

 

The increase in current draw on an electrical system from an EWP does not cause the alternator pulley to have more drag on the engine, period. Like Justin00SS stated "it either has enough juice or it doesn't."

 

This is why I said the numbers produced were for my combination. I have no doubt that they would be different on different dynos, etc...Remember, I'm also the guy who basically laughs at dyno numbers, I just thought it was an interesting comparison...I wish we hadn't added the Kooks stepped LTs (which was interesting because before and after install of the stepped Kooks replacing LPE 1 5/8 shorties showed zero hp/tq gain!) before I hit the track to see if there was any gain with the ewp...Was it worth the money? The jury is still out on that...It will be easier to replace it when it goes bad over the factory unit,and if it helps put less wear on the front cam bearing then its a good mod...Its nice to be able to run the thing in the staging lanes to help cool off the motor while you wait...

--Alan

 

lol i hate to be on a side by myself but im afraid that an alternators drag on the motor is affected by the cars requirement for electricity. beleive it or not. yes, you can spin an alternator by hand, but for one, you are spinning it at low rpms, and 2 it is not drawing much current. lets say your running a very minimal amount of electrical components. where is the rest of the "juice" going. nowhere, because its not making it. some goes to the battery, but once it is full, it doesnt keep charging it. my dad will taught me this theory, and hes an electrical engineer

 

There are no gears in the alternator to speed it up or slow it down. Not in car alternators anyway. Maybe with larger industrial alternators.

A cars alternator produces a set about of electricity (amps) at a certain rpm. Spinning it faster then that will not make it produce anymore. Just like spinning a motor faster and faster does not mean it will make more hp.

The only drag from and alternator is if you went with a heavy heavy duty one for putting out alot more amps then then stock. Like a 300amp alt or something.

That would mean there is more are more metal coils for the alt to spin through the magnets to create hp and more metal means its heavier and harder to turn.

But the alternator doesn't get harder to turn because of the power being drained from it. It either has the juice or it doesn't.

 

wow so do I...not

 

Increasing the amp draw on the alternator circuit causes the alternator to become "harder" to spin thus drawing more power from the engine. This is specified by the laws of thermodynamics. Think about it. If what some people were saying was true, that an alternator does not get "harder" to spin based on the current draw, then I could have a 5 horse power motor turning an alternator driving a 9000 Amp 12 Volt motor that makes 100KW(135 HP).

So yes, an electric water pump does put load on the engine. However it frees horsepower by not moving as much water.

The problem with water pumps is that they need to spin fast enough at IDLE so that they can keep the car cooled. That’s fine, but they don't have a variable ratio drive. What this means that at 1600 RPM (twice Idle) the pump is spinning twice the speed and using twice the energy. But the engine’s demand for coolant hasn’t increased by double. then by 6000rpm the Pump may actually not be moving water very efficiently at all (generally impeller designs that are efficient at 800 rpm are not efficient at 6000rpm) it's probably cavitating pretty badly. This is the trade off that all your belt driven accessories have. They must spin fast enough to provide adequate service at idle but that means they are probably not very efficient at 6K.

The Electric water pump solves this by always spinning at the happy medium. Faster than idle but still in it’s efficiency range.

Also Notice that on ws6.com that the dyno run with the electric WP shows that the HP difference increases directly with RPM. This is because the EWP isn't more efficiant at lower RPM that the stanrd pump, but at much higher RPM.


How an Alternator works
-------------------------------------------------
Notice that to maintain voltage in the face of increase amp draw the internal rotor’s magnetic field is increased thus increasing the magnetic forces on input shaft increase.

 

To produce more amps you need more metal. More metal equals heavier and harder to turn durr.

But 140amp alternator is still a 140am alt and doesn't get harder to turn as the load is increased.

Besides. Its not going to strain the alt anyway. Its gonna put a load on the bat first.

What's the first thing that starts getting drained when the alt goes out? The battery. If the alt is giving the charge then it gets it from the battery.

 

when your have 2 different guys, with 2 differant body styles, that put up numbers with lt1 power,like you two have i sit back and learn. you guys keep posting. i don,t know what wp i am going to run with my 95 z28. ooh ,bye the way thanks

 

THANK YOU. finally someone with some electrical sense. i was looking for a link to explain this better but he summed it up for me

 

yep DING DING DING sticky that **** lol

 

I would guess most of you have jump started a vehicle at some point. Ever notice that when the final connection is made the idle on the chargING vehicle hickups a little???

What is that if not response too extra LOAD?

 

also, a thanks you

 

Man, I got railroaded a couple months ago when making this argument in another thread. This is absolutely true. The alternator's output is not constant, but rather adjusts to the load. The current rating on an alternator is the maximum continuous current rating, which is just how much it is capable of supporting. When the engine is running and the alternator is functioning, the battery is not supplying the power for the accessories, it is all from the alternator. The electric WP runs completely off the alternator, which is driven by the engine, and will put a similar load on the engine as a mechanical pump at a given flow rate, assuming equal pumping efficiency. The HP gain comes from the fact that the EWP pumps less water at higher rpms than the mechanical pump. The EWP flow is adequate, as the mechanical pump is pumping more than it needs to at high rpm. The car jumping example is a perfect example of how electrical load (dead car) translates to mechanical load on the running car.

 

i hope all the guys that thought they were so smart are reading these now lol