The alternator does not act like an A/C compressor, it does not affect HP by how much draw is on the alternator, the only thing it can affect is battery charging, thats why most guys with monster systems move to deep cycle batteries...

Everything else I won't agree or disagree with, I'd like to see someone try it... but I prolly wouldn't spend my christmas money on it <img src="/forums/images/graemlins/wink.gif" alt="" />

Peter

You better go do some more research because that is totally wrong. The more load you put on the electrical system, the more the alternator has to work. Energy is coming from somewhere. The more load is on the alternator, the more engine power it takes to drive that alternator. The reason guys with large sound systems use deep cycle batteries is because they do just that.. they deep cycle... meaning the have a longer reserve capacity and are able to handle a load for long periods of time. A cranking battery cannot handle a long current draw on it for the same length of time that a deep cycle battery can. The alternator still has to charge the battery as it depleats. The alternator does not "make" power... it simply converts kinetic energy to electrical energy. The more is asked of it, the more it HP it takes to turn it.

Don't belive me? Start your car. Listen REAL close.
Turn all accessories off. Then turn on your headlights. You WILL hear the alternator load up and drag the engine down slightly.

Go put your vehicle on a dyno sometime. Run a dyno run with your headlights and all your electrical accessories running. Then make a run without. You WILL see a HP decrease when you run with accessories on.

I just have a comment on the usage of the word "suck" and the subsequent correction.. Sure, the atmosperic pressure is pushing in on the vacuum (or lower pressure area) created by the dropping piston, but our usage of the word "suck" typically implies active application of a vacuum (or lower pressure area) to move air or fluid. Based on your correction, you could just as easily say "NO.. You didn't really suck on that straw to drink Pepsi. You contracted the muscles of your mouth/throat to decrease the volume of your oral cavity, invoking Boyle's law. So actually, the higher atmospheric pressure "pushed" the Pepsi into your mouth.. so there". I agree that this device is not going to increase pressure enough to assist an engine, but your terminology correction didn't really bolster your argument much.. Engines, in our usage of the english language, suck.. Literally, not figuratively... well sometimes that too!! <img src="/forums/images/graemlins/smile.gif" alt="" /> As always, just my $.02.

JD

The alternator does not act like an A/C compressor, it does not affect HP by how much draw is on the alternator

Sorry Peter, but the alternator does require an input of energy (HP) to make electricity. Did you think it was free energy? How much does it take? Without considering losses to heat and inefficency, it takes about 1HP to produce 60A.

Michael

Actually....

This electric blower... well...

Try this, a turbo vane, spins at about 60k rpm(more on some), with an extreme pitch, which is why they dont make boost until the the velocity and pressure build in the exhuast...
My thought, HUGE electirc motor, with a METAL compressor fan.....

My thought, POS, waste of money

On most alterntor systems, it is not myth that they reduce power, as most now a one-wire, and draw directly from the battery, thus causeing more power to charge the battery.

NOW, why do race cars still use alternators right?

Well, some dont...BUT, they are running HUGE deep cycle bats..or they are running totally nehcanicla iginition (magneto) and the electronis themselves dont draw enough power to affect anything.., but these are alcky and nitro motors..

regular bracket racers use alts, because, the ignition and other components, draw power, and as the power increases, it drops the voltage, and iginiton etc start to lose power..

So... yes, more power draw(electrically), more load on the engine/alt..othewise, like was stated, perpetul power...

I say go with a small homebuilt turbo set-up...or a centrifigal charger(non roots or screw)..thise are THE most efficient power adders..(except nitrous, adn no one wants to touch that one), the turbo being the most efficient...

Again, improve the exhaust, adn the airflow in...larger tubing, less bends less restrictions...

More exhaust out, the more you can get in, and if you improve the intake...

From there, you are getting into mechanical, or computer mods...

Anyway...

Chase

Actually, a magneto draws a HUGE amount of power. A magneto, like an MSD or Mallory unit, is not reliant upon a battery. Alky and Nitro motors run magnetos for a couple of reasons. First and foremost is the amount of current they deliver. We run a 44amp MSD mag on our race car. Top fuel cars run 2 of those 44amp mags. The primary reason for running a mag is that when running a motor with close to 50lbs of boost, the electrical resistance during compression is so high that the plugs won't fire without major power. In a nitro motor, we run our plug gap at 0.017" and a 44amp MSD mag... this is the only way to over come the resistance. You cannot turn a 44mag by hand. It takes a tremendous amount of power just to turn one of those things. However, the outcome is just like a blower, it takes a lot of power to turn one, but the boost they provide far outweights their parasitic draw.
The battery on our race car is there for two reasons. It's there for the starter and it's there for the computer. Other than than, the race car is capable of running without an outside power source such as a battery. There's only two ways of turning off a pro car, such as ours. 1) you kill it's fuel supply... and 2) you ground out the points box on the mag. Simply turning off the battery switch will do absolutely nothing.

Bracket racers use alternators because they are cheap.
An MSD Pro Mag 44 like we run is about $3500 with the points box and mag. Also, plenty of bracket racers don't use alternators at all. They simply plug in a battery charger when they get back to the pits and let it charge while they wait for their class to be called again. I could see this as a problem in a constant round robin race, but normally they are fine.

Hmmm... I agree that there's obviously a HP draw to run the alternator (as opposed to not running one at all) but I don't really know if it's more or less HP just cause you're running more accessories. I mean, I'm not saying anyone is wrong or right -- more trying to clarify the answer a little more. I've removed/repaired/rebuilt/replaced quite a few alternators -- what, inside there, will actually tell the alternator, "Hey buddy, run a little faster, produce more power, will ya?" To me (without an overwhelming amount of electrical knowledge, mind you) it would seem that the alternator would simply spin, producing whatever power it was capable of producing at the given RPM, and not just ramp up just because you're running more accessories. So what's the real deal here? Is there something in there that says, "Hey, Billy just cranked up his amp and started blasting the tunes, we need to do something about that before his car won't start after the car show..."

Again, just asking <img src="/forums/images/graemlins/confused.gif" alt="" />, not TELLING. <img src="/forums/images/graemlins/confused.gif" alt="" />

-Chris

I am totally with ya, I was trying to keep it simple, as not alot of poeple understand this...

I soemtimes go to far, without going far enough on here...

And FWIW, we are running the mag with mech injection on a 14-71 littlefield built by the blower shop, keeping this one simple(other than box, t-brake etc), but correct, we run a small(group 24 I think) battery for elecs, adn just charge it with the genny/charger

and yeah, forgot the starter...

Chase

Chris, yes there is something, it's called the regulator.
Here's a link for you.
http://www.autosite.com/garage/subsys/bachargs.asp

This link shows the basics of how a charging system works and how load is applied.

Cool, what are you running, Pro Mod or Top Sportsman?
We run 14-71 Littlefield also. We do our own blowers other than the nylatron.. we strip the nylon ourselves.

We run a TurboStart 16 volt battery because with a freshly built motor, a freshly stripped blower, and that mag, it's so hard to get it to turn over and fire. Once fired, it sure makes the nitro smell good though <img src="/forums/images/graemlins/smile.gif" alt="" />