Some of my knowledge comes with experience, some with reading. Some of it I haven't read about in a year. However, I have read about alternators, I forget a lot of it. I DO KNOW it is stupid to run without the battery, the alternator normally has the battery there, it "sees" the battery disappear. What happens next I am not sure, but it does SOMETHING (I will try to find out what exactly happens) and you start ruining the alternator. Maybe not the alternator itself, but perhaps the regulator.

 

In most modern cars, the regulator is actually built into the ECU. I don't know if that's the case with our cars, but a lot are done this way now.

What I don't understand about the whole MIVEC thing is why Mitsu didn't make it throttle-position dependant. It would make so much more sense to have it kick at 3500 AT FULL THROTTLE, and wait longer (or not engage at all) under partial throttle. Perhaps they could also have it kick it at different points at say, 80% throttle. This way, if you're just cruising and don't need the extra power, it's not wasting fuel. It seems to me that it wouldn't be that much more difficult, especially considering that the car is already a throttle-by-wire setup.

 

i dont see how the change in the throttle line would cause a change im cam profiles. would have to add a major complexity to the car, which would be antoher major point of failure. the price would go up $1k, easy. mitsu would prob have to put a good solid year of r&d into this to get it production-ready for a 100k mile warranty. only way i can think of doing it is by using the throttle sensor in the ecu (do we have one?) to control the cams with a solinoid (which would eventually need to be replaced alot).

and i think the profiles were designed to smoothly shift at 3600rpms. shifting at diff points would prob give a much less smooth ride
but yea, it would be cool if it happened =)

 

No, what he's saying does not involve having different cam profiles. Just think of having what we have now, mechanically. But put in a controller that keeps mivec from happening if we are accelerating slowly and bring the rpm of engagement lower and lower as we push the gas more and more. Kind of understand what he means? I think that's what he meant lol. Nothing like i-VTEC where there are more than one profile.

 

I am with you on that!! I have tried to do that experiment and it never worked for me.I just cant drive slow EVER.. My car hates it and when I do drive slow she Sucks gas down so fast it ain even funny.Weird I think it has a personality of its own sometimes.. lol

on another note.. Thanks for the info..Too bad my car wont let me go slow enough to conserve gas.. lol

 

An alternator does change physical load on a motor, i test these things about 3-4 times per week at work. When and alernator is just spinning electical load free it has little to no resistance, when it has a normal load the resistance is much greater, at high electical load the alternator has emense physical load and can in some cases stop and idleing engine. The physical load is also greater the larger the alernator is like say 100 and up amps. I believe we have a 140 amp @least my S&S ralliart does?.

 

Yes that's exactly what I meant. Still only having two cam profiles, just as we do now, only changing the point at which it engages "high mode" dynamically.

 

woah... my thread has turned into a flaming debate!! *grabs popcorn*

 

having the throttle in the mivec equation causes too much complexity..

i don't know about you, but when I switch gears, i ease off the gas.. then in your situation will it cause the car too fall out of mivec? that would suck

-joe

 

what if it sensed the clutch being pressed? Say if you were in Mivec, then pushed in the clutch to shift, it would stay in mivec until it was made to do otherwise. and vice versa. if you weren't in mivec when you pushed in the clutch, you wouldn't be when you let it out in the next gear, unless you floored it.

 

if the engine drops below 3400rpm, you go 'out of mivec'. if the engine gets to +3600, you go 'in mivec' until the previous. i think its fine. you shouldnt driver over 70mph anywhere in the US anyway but if you are accelerating and you do it right, you should be over 3600 rpm very soon and should stay there even after you shift, unless ur REALLY slow.

 

Except in the states where the max is 75, or on freeways where if you drive below 85 you're gonna get run over and killed.

 

Absolutely wrong, take a simple physics class. Drawing more power from the cars electrical systems will absolutely cause a higher load on the alternator.

Simple experiment. Take a hand held crank style generator. Attach 1 flashlight bulb. Turn the crank at a set speed. Next, attach 4 bulbs in a series. It will be four times harder to turn the little generator at the same speed.

The alternator does not engage or disengauge, but it will be under minimal load when the battery is full. With that said, using less power will cause the alternator to have to convert less energy. They call it resistance for a damn reason.

 

maybe i should have said it makes no "noticable" load on your alternator.. it might take 1 or 2 hp to power the damn thing, but you won't instantly get 46mpg from turning off your radio.. it's not magic dude

-joe

 

See I ****ing knew that. Have the car idling and turn the rear defrost on, you can NOTICE a drop in RPM, similar to turning the A/C on. Also, my old car would idle fine with no electrical load on the engine. However if I turned the rear defrost, lights, wipers all on, the car stalled. It was a carb without adjustable idle. The alternator STALLED the engine, yes STALLED it, when I turned those things on while in gear. The load the alternator puts on the engine is larger than most think, it is producing electricity at 12 volts, the amount of current is huge when you are running lots of high power things.
Is this person just guessing when he said the alternator doesn't change load? I knew he was wrong, but no one else came in to correct him so then I did start second-guessing myself. It is simple, you can't gain more energy somewhere (electrical current) without losing energy elsewhere (some extra fuel to run the engine that tiny bit harder to run the alternator just that tiny bit harder.) Energy is converted, chemically from the fuel, mechanically in the engine and then electrically in the alternator. So the potential energy in the fuel is converted to electrical energy, gaining more electrical energy, you MUST lose some more fuel. You can't magically get more current out of the alternator without burning just a little bit more fuel to compensate. Extra electrical energy doesn't appear out of no where. Every system about running, braking and steering a car is about converting energy. Chemical to motion (gasoline in the engine), motion to heat (in the brakes), motion to electrical (alternator) , chemical to electrical (in the battery). Of course you don't gain energy somewhere without losing somewhere else. You can't keep moving at the same speed while the brakes are grabbing the rotors, unless you keep your foot on the gas to put more fuel in the engine, making up for the energy lost in the heat of the brakes.