Temporarily disable alternator for more power?

[benemorius]

my friend: "Guess what I discovered? My new car has a feature that disables the alternator at full throttle to maximize power output."

me: "Dude! Why the hell did I never think of that!!!??"

So.... Is he serious? Should I try this mod on my 240? Has anyone ever heard of this or tried it for themselves?

Please comment! If nobody has any serious reason for me to reconsider, I'll be attempting to add such a mod to my s13 in the form of a dash-mounted switch controlling a beefy relay.

[Acuratechva]

what car does your friend have? i've heard AC automaticly shut off at full throttle but not Alternator especialy that there is no clutch on the alternator therfore you cant disable it besides taking the belt off.

i may be wrong but i think this is bull

[Silvia007]

That's the lamest thing I've ever heard in my entire life. Even if it does disable it, you might get .01hp out of it. What a waste.

[madbouncy]

I always thought normal car batteries weren't meant to be drained like that unless you get deep cycle. Though I have no idea how much your car needs to keep istelf going, as far as spark, and so on. I'd just be worried if I had too much stuff going and my battery was a little low it would just die if I floored it. It bothers me that my battery light has been on for the past couple weeks despite the hours of driving I keep doing. I figure eventually it'll just die on the highway or something.

[DAEDALUS]

Ditto to Acuratechva.

[benemorius]

Ford Focus ZX3 2002 or 2003 or somewhere around there.

It's true. He says when he floors it his lights dim and there is a noticible power increase. Here it is --> http://www.focussport.com/chip2.htm#3

Would disabling the alternator really provide such small gains? I can't imagine it is only stealing a fraction of a horsepower to run the entire friggin car and engine at full throttle.

The alternator can be disabled by removing the load from it (disconnecting it, in other words) using a relay or something, which is how I would do it.

[slow s13]

like it says in the article the alternator is realy easy to turn when its not engaged, this sounds ok for a NA car but I wouldnt want it on a turbo car when you need max performance out of your fuel pump and ignition if your pushing the limits. Im pretty shure the alternator has a turn on wire similar to a car stereo amp if you put a swich in there you could do it yourself.

[slow s13]

I did some calculations and there is no way this is worth it.

assuming the alternator is flowing 80 amps of current at 14.4volts

80 amps x 14.4volts = 1152 watts of power being made

converted to Horsepower thats 1.5448575 horsepower [international]

[DAEDALUS]

Well, back out efficiency of the alt too. It's at least 50% efficient, so 3hp tops. Might be a lot for a Focus!

[benemorius]

Thanks for the math. I guess it really doesn't draw that much. I was thinking at least around four or five horsepower. What can I say? I'm surprised.

[Chingon]

not to mention our alternators are rated at like 75 amps I think. The best one i discovered it's the mitsubishi model 1994 s14, at around 84.