3point4

Hi All.

I have a 2000 3.4 2wd auto and wanted to know if I could expect 7 rwhp from STS reduction pulleys and 8 rwhp from electric fans for a total of 15 rwhp. (about $400)

Is this a pipe dream?

My truck runs fabulous on cheapest gas with my improved intake, amsoil foam filter and air box mod. [ But I want a little more of course :-) ]

bob200587

just dont change your alternator pulley, it will reduce its output. If you wanted to you could change everything but the alternator to electric stuff, get a big alternator to power it all.......Ive seen electric water pumps, electric fans, the A/C could be done electrically some how and the PSP, I'm sure that could be done someway.....that would leave you with only 1 drive belt accessory, freeing up tons of power in theory. Alas it sounds like something never before attempted.

rimpainter.com

The electric fans will never get you 8 WHP. They won't even get you 8 CHP. Trust me.

Headers might be your best bet, and even that is debatable (trust me again). If headers did give you that type of gain, it will only be at a narrow band of the rev range and the install really sucks. HP/$$ ratio is barely worth it.

If I had to get more power/acceleration out of my rig (in your case) on a budget, I would get an exhaust system (like Jardine), shave some weight, run full synthetics, and look into changing the gearing or dropping down a tire size.

Flamedx4

Pipe dream. Electricity to run the fans still has to be made by the alternator. You don't gain HP (or very very little) what you do gain is quicker throttle response. Reduction pulleys might net a bit, but then your a/c compressor and alternator are less efficient, so for a street vehicle this may not be the best option.

Electric water pumps, electric fans, electric A/C ...that would leave you with only 1 drive belt accessory, freeing up tons of power in theory - nope - it only defers all those power-robbing options to the alternator - which if it can make enough power still takes horsepower to do it, but in reality will just give it an early death. Electric pumps and stuff are great for drag racers - they only have to keep running for a minute or so. But for street vehicles this stuff doesn't work. Been tried many many times over the decades. Straight mechanical drive is more effeicient than making electricity then using electricity, you lose something in the transfer - it's not 100% effecient.
And then there's weight to consider - these things take real horsepower to run them - ever seen how big a 5 hp or 10 hp electric motor is?

dexter

would pulleys really help that much??

tulsa_97SR5

OK, I'm probably showing my ignorance here, but I'll ask anyway.

The ac compressor has a clutch, so it's only sapping power when you have the AC on right? What about the power steering & power brake pumps? I don't need pb unless i'm pushing the brake, but is it sapping power 100% of the time from the engine? Same with ps, only really needed at slow speeds. Could a clutch be added to the ps & pb to disconnect them when not needed? How much power do they really take, I'm guessing less than 1 hp each.

As for the alternator, depending on what all you have added it adjusts to provide the needed current. Say you are drawing 60 amps at about 14v. That works out to just over 1hp. Since it's not 100% efficient maybe it's sapping 1.5 - 2 hp from the motor to make that 60amps. You could probably wire something up that would trick the alternator into shutting off for a little bit, so the vehicle draws all needed electricity from the battery, thus getting the extra 2hp for a brief period. Not sure how long you could run it that way without draining the battery too far & damaging it.

That's it for my silly ideas.

yoda92

That is untrue , the alterator itself will have to work harder not the engine . The belt that drives it will still be spinning at the same speed with the same effort. The only way what your saying would be true is when the car is ideling,It might idle alittle higher to compensate.

As far as gaining 8hp who knows . I would say save your 400 until you can afford a supercharger .

Flamedx4

Um, no that isn't how it works. Increasing the load on the alternator increases its resistance to turning - if it has to make more power it will take more torque to turn it. That energy comes from the engine, requiring some power and fuel to do it.

Flamedx4

Right, the power steering is only robbing power when you move the wheel off center - none (for the purpose of this discussion anyway) driving in a straight line.
The a/c compressor only takes energy when the compressor is on an "on" cycle.
Power brakes on most vehicles are vaccum operated and don't rob power, but on the models where the brake booster is hydraulic it robs engine power, and only when braking.
And yes, you could indeed design some sort of alternator cutout for full throttle - its common on the ac compressor already in many newer cars. BUT, if you decide to try this - be sure you learn how an alternator works - disconnecting imporperly it while it's turning can destroy most alternators. Then when it comes back on it and your system has to handle the sudden demand and associated surge. A simple relay and throttle switch may not do it. But it's not a bad idea at all.

tulsa_97SR5

OK, so as is my way I post first then do my research. I guess moving the ps & pb off the engine is being done with hybrids, and a new 42v toyota car. Like you said, it's not more efficient IF you are running them all the time. The cars that do this only power those as needed, so they should come out ahead. I can see this especially for driving on the highway for an extended period of time.

yoda92

Are you sure about that ?? Your saying the resistance will increase how would that be posible. What is in an alternator that can change the resistance ? Its kinda like one of thoes bike lights that you used to flip down and it would rub on the bike wheel spinning the whatever it is inside . If you were to put a light bulb that would require more power to light up that wouldnt increase the resistance it just wouldnt light or it would be dim

mike_d

he's right. the resistance (that is the torque required to turn the alternator would increase) would change.

here's a good experiment to do to prove it to yourself. get two small 1.5V electric motors out of a toy or something (if you can get lego motors, those will be easy to work with). hook the two shafts of the motors together and power one of the motors witha 1.5V batery. it will then turn the other motor which will act as a generator. if you measure the potential difference on the wires of the second motor you'll probably see something close to 1.5V (assuming the motors are identical - if they're not identical then you'll see a voltage that's proportional to the number of windings in the two motors - i'm not going to explain that here). right now, the driving motor is only overcoming it's friction plus the friction in the driven motor (generator). hook a light bulb or even a 3rd motor up to the wires of the driven motor. you'll instantaneously notice that the driving motor will slow down. that's because it not only has to overcome the mechanical friction, it also needs to do work to push the electricity through the other device you hooked up.

the same happens in the car. the crankshaft is turning the alternator (via a belt). if you have nothing electrical turned on, the only draw from the alternator is it's friction. as soon as you turn on electrical accessories, the alternator needs to work to push the electricity around and it requires more energy. you can notice this on an old car that doesn't have computer a controlled idle. look at the idle speed with and without the headlights on. when you turn the lights on the idle will drop a couple hundred rpm because the engine needs to work harder. in a car with comptuer controlled idle, when you turn the lights on, the comptuer automatically gives more fuel which keeps the idle at the same speed.

mike_d

one more thing: think about it this way. if you could get electricity for free by turning an alternator, then why not power your whole house with a small gas engine turning an alternator? or even better, power your whole neighborhood with the same engine. it can't be done because you need to use energy to make electricity.

Volts*Amps=Power in watts.

about 750 watts = 1 horsepower

for example: headlights 12V*10A=120 watts = 0.16 horsepower

yoda92

I still disagree. I would need to see proof.The electric motor deal Im not sure about.your trucks engine is basicaly a generator. The alternator is designed to provode the electricty to your vehicle once it is running. From what you guys are saying is that if I am cruising down the highway with my lights on radio blasting and whatever else I could turn on that would draw power from the alternator would cause me to loose power. I dont think that is right. Now maybee if im sitting at a light will all theses things on the engine would have to work alittle harder because the alternator is not turning as fast at idle.

Im not sure what is in an alternator but I think the faster it spins the more power it will make but that is limited the the engine rpms . What inside the alternator can cause it to increase resistance

I dunno maybee Im wrong , I have been known to be wrong once or twice

tulsa_97SR5

Basically, an alternator doesn't have rare earth magnets moving across stator coils to generate current, it uses electromagnetic coils rotating past stator coils to generate current. At a any given RPM the current fed into the electromagnetic coils can be increased, making the alternator harder to turn, and making it generate more current. If the car needs little juice, feed the coils almost no current, it's really easy to turn and generates almost no current out.

if that explanation makes sense i'll be amazed, maybe this wiki article will do the trick.

edit: all this is the reason trying to slow down the alternator with a diff pulley size won't help, the alternator will just regulate more current to the rotating coils, which makes the alternator draw more hp from the motor, still producing the same amount of current.

Rick F.

Is it me or did everyone get caught up in the technical aspects of the post and fail to recognize the bottom line, being that he wants some additional RWHP for cheap? I'm surprised nobody mentioned any of the following:

1. Deckplate Mod, with or w/o hi-flow filter (e.g., Amsoil)
2. ISR Mod
3. Elbow Mod
4. Hi-flow cat/muffler (that WAS mentioned)
5. Upgraded ignition wiring
6. Any other "cheapo" mods that I may have missed

If I recall, the deckplate mod alone dynotested at something in the realm of 5-7 additional hp.

rimpainter.com

Rick-

I didn't mention intake mods because it sounds like he already has the deckplate mod or similar at the bottom of his first post. Worth mentioning though.

So 3point, what intake are you running?

3point4

I'm running the stock airbox with an amsoil foam filter inside.

I have the airbox lid open less than an inch. A photo is worth a thousand words here, but I'm holding back the amsoil with 2 2-inch pvc pipe pieces that are each about an inch long. These are held up from falling into the box by looping a piece of heavy wire through them and around the 2 metal airbox clips.

The end result is probably the same as the deckplate mod. I can also totally open the lid this way, but I lose a little midrange power and am forced to run premium when I do that.

Great responses all - thank you!

3point4

I forgot to mention that I ditched the elbow and plugged the intake tube resonator holes and re-routed the lines that went to them. The pcv is left as is.

I doubt I'll do anything to the exhaust because I don't think swapping out the muffler and t-pipe for any other combination will get me anything but noise.

rimpainter.com

Well, if you ditched the elbow you should close up that lid. Keep the hot air out of the intake. I think it's an urban legend that you have to run premium with the deckplate mod. I thought I did too, but then I realized I was wasting my money. Now it doesnt matter.