Idea ive had for a wile.... Options

[mandrek]

So here it goes, i have a 95 ST (7afe). that i DD and do auto-x with. i have been looking at doing a few mods to help with reducing paracitic drag off of the week 7A motor, and have come up with a few ideas that i would like to run by u all.

i have read a number of threads on hondas taking the MR2 EPS pump and running the set up as to remove parasitic drag off the motor. now, here is what i have been thinking of doing for a wile now, it should be a pretty simple set-up, but am looking into getting some info on the topic before i make the plung..

currently the PS and the water pumps share a belt on the 7A.

what i have thinking abut doing is adding a small electric motor to that side of the motor and remove those two pumps from pulling off the crank. sorta like this.

E-motor
(o)\
|----\
|-----\
(o)_(o)
^----^
PS-----water

not only would this remove 2 sorces of paracitic drag from the crank, but it would also avoid the water-pump from developing cavitation at high engine RPM's AND allow for the PS to be at full boost almost all the time..

the car is still not a dedecated track car so the on/off full PS boost may not be compleatly nesisary, but still an advantage wile auto-xing.

let me know what u all think.. looking for ALL input good or bad..

This post has been edited by mandrek: Mar 25, 2010 - 7:49 PM

[Ruroniarc]

I'd like to preface this statement with the fact that I am an Electrical and Computer Engineer from Worcester Polytechnic Institute. I do have some actual knowledge pertaining to what I'm talking about here, I'm not just making assumptions.

That being said, if you remove the belt that powers those two things, and move it to an electric motor, the electric motor will be pulling energy from your battery. In turn, your batter will be pulling energy from your motor through the alternator. Factor in the losses / efficiencies of the electric motor (Electric motors usually have no more than 85-90% efficiency). Then factor in the efficiency of your alternator producing power (which is just an electric motor run backwards (so, again, another 10% loss). Then factor in the weight of the new mount and electric motor (not much, but it's still there).

Therefore, you're already looking at (minimum) 25% efficiency loss.

There is a reason every car manufacturer powers their water pump and other accessories from the engine directly, because there is a 0 percent loss there. Instead of going from the engine to the pump |--|, you're trying to go from the engine, to the alternator, to the battery, from the battery, to the electric motor, to the pump |------|.

[mandrek]

I'd like to preface this statement with the fact that I am an Electrical and Computer Engineer from Worcester Polytechnic Institute. I do have some actual knowledge pertaining to what I'm talking about here, I'm not just making assumptions.

That being said, if you remove the belt that powers those two things, and move it to an electric motor, the electric motor will be pulling energy from your battery. In turn, your batter will be pulling energy from your motor through the alternator. Factor in the losses / efficiencies of the electric motor (Electric motors usually have no more than 85-90% efficiency). Then factor in the efficiency of your alternator producing power (which is just an electric motor run backwards (so, again, another 10% loss). Then factor in the weight of the new mount and electric motor (not much, but it's still there).

Therefore, you're already looking at (minimum) 25% efficiency loss.

There is a reason every car manufacturer powers their water pump and other accessories from the engine directly, because there is a 0 percent loss there. Instead of going from the engine to the pump |--|, you're trying to go from the engine, to the alternator, to the battery, from the battery, to the electric motor, to the pump |------|.

i had thought about that my self but was unsure as to what the exact numbers were (though i never went into a career with it, i did do 3 years od Electronics in high school and was deep into micro-precessors and such as one of my last study units,{about 8 years ago}) my assumtion was that the load the electric motor would draw from the system would be far less than what the alternator would be puting out. there are a number of OEM examples with the PS-Pump is run off of an electric motor, as well as water pumps being driven by electric motors for race aplications, (were the need for efficiancy is greatest) but i have yet to see both done at the same time, the idea was that since the two pumps sit side by side and would only require a bracket and an electric motor (and the room is there) than it might be worth a try.. damn it i hate crunching numbers..