<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:[/color]<HR><font face="Verdana, Arial" size="2">As you can tell I'm interested in submarines, but I never thought I would use any of that knowledge and try to apply it to a car. [/color][/QUOTE]

Nathan, as you can tell from my previous posts, I like analogies. And I like your submarine/cavitation analogy! Perhaps the horsepower savings are a combination of things including optimum pump speed without cavitation, constant current draw throughout the engine speed range, and efficiencies of some other mechanics. Can anyone point me to a dyno test somewhere that shows the before and after mod?

 

You're not actually pushing electricity with force. [img]http]//www.corvetteforum.cc/ubb/smile.gif[/img]

 

Actually you are. A generator is simply an electric motor being used backwards. Electricity creates a magnetic force that will move a motor. In order to move a generator, you have to push against that force.

 

I was speaking in the sense of you're not pushing electrons like you'd push a bowling ball.
What you're pushing "against" is a magnetic field. And with a generator, that field goes away as soon as you stop pushing of course.


[This message has been edited by Thud (edited 07-18-2001).]

 

Fair enough [img]http]//www.corvetteforum.cc/ubb/smile.gif[/img]

 

Is there one for the L98?

 

The voltage regulator in an alternator attempts to maintain a constant 14.7 volts across the battery by regulating the current in the field winding. A fully charged battery draws little current and any electrical devices in the car are provided current by the alternator. when the battery voltage falls at or below 13.2 volts which is the no load battery voltage, the battery begins to deliver current to the cars electrical system. The alternator cannot deliver full output current at engine idle speeds because it isn't turning fast enough. There is a limit to the current that can safely flow in the field winding, otherwise the voltage regulator would be able to maintain alternator full output current even at idle. The alternator can deliver full output at even slow normal driving speeds.
An electric water pump operates a centrifugal rotor just as the mechanical pump does, and requires essentially the same HP as the mechanical pump for the same coolant delivery rate (gal per hour). At the same delivery rate, the electric pump should require more engine HP than the mechanical because its motor is not 100% efficient and the alternator is also not 100% efficient and the engine must deliver to the alternator not only the pump rotor HP, but also the alternator loss and the electric motor loss and the belt loss and alternator bearing loss. By comparison, the mechanical pump only requires the rotor HP from the engine plus belt loss and bearing loss. If there is a HP gain from an electric waterpump, then it could only be due to its limited ability to deliver coolant, which is less than the mechanical pump. A mechanical pump at 4000 rpm requires 2 HP. A 2 HP 12 v electric motor is several times larger than a starter motor, and I doubt very much that electric water pumps use 2 HP electric motors.

 

JFB, Do you really feel it necessary to post the same crap on two threads when your arguments have already been negated multiple times before you start?

Anybody who wants can read my reply to this argument here

http://www.corvetteforum.cc/ubb/Foru...ML/010127.html

Scorp, to answer your question, yes I think they do make one for the L98

 

you guys argue about the same stuff over and over with all these views and physics books and opinions....

Why doesnt someone dyno their car, then switch to an electric pump and get some REAL answers.

Well, then I'm sure someone would argue about the millions of variables that changed the out come blah blah blah

Anyways, anyone with some REAL experiance on this subject care to post?

Bill

 

Sounds like an interesting mod, anyone know where to order the parts at or a site detailing this modification being done?

Sorry I'm a complete amateur and like to see things well documented before trying them just yet

I'm just trying to get into these cars, I'm picking up my '88 Vette tommorrow I can't wait.

 

Nathan,
What I have said about electric water pumps hasn't been negated even once by anyones post. Your claim that my statements have been negated multiple times is incorrect.
I posted in both places because I read the same incorrect statements in both and wanted to set the record straight. I also have not seen anyone post the results of a dynamometer test with the mechanical and electric waterpump along with coolant flow rates to show an advantage either way.
If you wish to show that my statements are incorrect, do so with logic and the laws of physics which are irrefutable. Insulting comments and claims based on hearsay and outright untruths have no place on the forum.

 

from the research i've done it seems like in most cases most electric pumps do not move enough water for street use. one exception i've read about here is the meziere pump for the LT1. it apparently pumps enough water. for the L98 you have the added problem of belt routing (the lt1 is gear driven, no belt issues there). sure there are pumps that will fit the l98, but what would you do with the belt?

[This message has been edited by samc (edited 07-19-2001).]

 

A man of numbers, I can respect that. If you read my posts about how a car FEELS like it handles vs. how it really does. If you want, numbers, just gimmie some time. I look forward to your numbers that disprove it also, since you seem to know they exist. I wish you luck in your quest for statistics.

I do have to ask though, do you have an electric water pump? Have you even seen an electric water pump? I can tell you from first hand experience, and other people on the forum will tell you the same thing that you can run one without any problems with flow rates, etc. The STANDARD duty Meziere unit pumps 35 gallons per minute, constantly. That's a lot of water. Also read the section on optimal speeds of propellers, cavitation, etc. Mechanical pumps lose effeciency the faster they are turned and increase drag. It's the same reason you can't fly a prop plane at the speed of sound, as the prop spins faster it begins to create so much resistance that the increase in thrust is negated by the resistance. Again, you run into cavitaion, only in air this time, it causes so much vibration that it will literally tear the engine apart. Hence a better way of doing things, the jet engine. Same thing for submarines like I mentioned earlier, they are abandoning the traditional propeller for a pump-jet, or basically a jet engine for the water. Enough laws of physics for you? How much more physics do you want?

Also note that water can only gain or lose heat a certain amount per given amount of time, called the specific heat of a substance, pumping it through the radiator faster than this won't help anything, if the water moves in and out so fast that it didn't dissapate any of it's heat, what have you accomplished? (Have some more physics) Also realize the internal resistance of the cooling system. There are a lot of twists and turns in there which create friction, which not only slows the water, it creates heat itself. Do you remember your physics the man who proved that he could heat water by aggitating it enough? (A little more physics)

It sounds to me like somebody here doesn't believe in physics or slept through that particular class.

Anyway, I'm about tired of arguing this, but to put it to rest I'm willing to find flow numbers, etc. Any of my electric water pump brothers want to help in this quest so we can turn this back into an advice forum, not an argument?

 

Hmm, I get to work this morning and after 2 minutes of searching I have already come up with this dyno graph.

 

Okay, so how much does this electric pump cost compared to the mechanical pump? What is the mean time between failures? Do I have to buy two electric pumps for every one mechanical or vice versa? How much does this horsepower gain cost? Where is the sense spending hundreds of dollars to gain 10 HP when you could spend half as much someplace else? Just something to think about as well. I have the LT1, so now I'm curious.

 

I don't know how much a stock pump costs, but a Meziere heavy duty unit will cost $214 from www.internetracerssupply.com

They list the life expectency to be 2500 hours. That doesn't sound like a lot, but think about it.

If you average a speed of just 30 mph in your car every time you drive it, you are looking at a 75,000 mile life. That seems to be about the time some people start having trouble with the stock ones. If you average 50 mph, you are up to 125,000 miles. Also note that if you do ever have to replace it you could then do so without having to remove the water pump housing from the engine, making replacement a much easier job.

Really 10 hp for $200 isn't really THAT expensive. If you couple that with some other mods that reduce parasitic power loss, such as a lightweight flywheel, etc, you will have a motor that'll scream hard, all the way to the redline.

Does anybody know what a genuine GM replacement water pump would cost??

 

Also check out this site

http://www.edelbrock.com/automotive/waterpumps.html

They show stock and competing mechanical water pumps as only flowing 35 gpm when they get up to 5700 rpm, that's only 100 rpm away from the redline!!! The Meziere unit flow 35 gpm all the time.

Anybody else want to argue?

 

I wanna argue!!!

Did you bother to check what pressure that the Meziere water pump pumps the full 35 Gallons at??? I can't remember exactly, but it is near no pressure, which is not real world. You might want to check out what it flows at given the pressure of the cooling system.

Is that a good argument.

Nathan. You seem to have a good amount of knowledge and you seem to be humble enough to admit when you are wrong, but I think that you are a little quick to assert what you are saying is fact! Your first round was fact, only to be shown you were mistaken. Then you jumped straight to your next assumption and asserted it at fact!

My point is, there are a lot of people who are reading this and putting faith in what is said here. There also seems to be a lot of misinformation here asserted as fact. If it is a theory or a guess, we ought to make a conscious effort to make sure people know it is a guess so they don't take bad information away from here.

I don't know everything and I freely admit that. What I will always try to do here is make sure people understand that if I am not sure, they will know I am not sure.

Please don't take this as a bash, because it is not! I just don't want to see anyone here get burned because of bad information.

Lastly, I singled out Nathan because of the comment "Anyone else what to argue?" which sounded like a comment meaning I have all the answers and you guys know nothing, but the truth is, there are a lot of people guilty of this and I am sure that I am also, so if anything I am talking about myself also.
Anyway, Everyone have a wonderful day and keep waving. [img]http]//www.corvetteforum.cc/ubb/smile.gif[/img]

 

The "anybody else want to argue" was pointed towards the people who say I can't back up my arguments. There you have it, numbers, proof positive.

Do I have all the answers? No, or I wouldn't hang out here, why would I need to?

You are correct, the meziere unit is listed as 35 gpm free flow rating, however that is perfectly valid when compared to other free flow ratings as it is. Otherwise how can compaines advertise ratings? Can they say it flows 27.2 gpm in a 92 corvette without a throttle body bypass who's radiator cap might be a little weak and only keeps 12 psi but it flows less on a 95 z-28 with a throttle body bypass but with a healthy pressure cap. No I didn't think so, they have to go on free flow ratings because other numbers don't mean anything.

I'm sorry if I offend you and if you thought me to be a little arrogant, but when my knowledge gets insulted by somebody who doesn't do any research just because they don't like what I have to say? That puts a person in the mood to prove themselves correct and make the other person look like the fool they are.

In this particular case this product, is not just and add gimick, it WORKS. Too many people use it, and I'm yet to find any with bad results. I also have the numbers and facts to prove it above.

BTW, where have I been disproved yet? I said it doesn't take LOT of force to push electricity. I have also said before I started that I wasn't SURE how the regulator works, so my GUESS was incorrect, big deal. Gimme where I said something was a 100% stone cold proven fact and I was wrong, I'll bow to you. Read carefully. I only pick arguments that I can win.

Now, like I said, can we quit with the arguing?



[This message has been edited by Nathan Plemons (edited 07-19-2001).]

 

BUT!

the eternal question --- WHY? --- this is what opened this thread.

jfb is correct in stating that you don't get something for nothing. therefore one can obviously conclude that the Electrical Pump setup does not move the water with the same 'energy' (Flow&Pressure) as the Mechanical Pump (not as much, but still enough to do the job!).

this opens up a whole new train of thought;
i wonder if a guy could come up with a 'smart' alternator/regulator system that could unload the alternator, and draw from the battery, when high HP is in demand.