the heavy alternator

[Andres]

Hey guys, does anyone has seriusly considered getting rid of the heavy alternator, we have thought on this a couple of times, but i dont know if a fully charged battery can last the endurance doing ignition plus gearshift (we have a solenoid to do gearshift). I´m getting to the motor electrical charts now... just wondering any thoughts or knowledge...

[Lyn Labahn UW-Madison]

I do not think that a standard motorcycle size battery could do it. We have had malfunctioning charging systems cause our car to run only on the battery and it doesn't last nearly long enough to run an endurance length event. Although on our car we did have a digitial display, lots of sensors, and an electronic throttle going.
I think to be absolutely sure that you would survice endurance you would need a large battery that would offset the gains of ditching the charging system.
In my personal opinion, I don't think that the judges would like to see something like that either. But don't let me stop you from testing it out at least if you wish, I would love for you to prove me wrong!

2002/2003 Team Leader
Best overall average finish of the new millenium http://fsae.com/groupee_common/emoticons/icon_smile.gif

[Kevin Hall]

I know we are all race drivers, and never kill the engine, even when we go into a spin....... I would be leary of taking away my only means of starting the engine midway through the race. I know that if all goes well, it might be alright.

I know how well these cars start even after a day of freshman drivers......meaning a few extra starts for the day. Nobody can come push start you. If testing proves otherwise, all the power to you. I'd love to know, but I don't know if you'll be willing to share your secret after all, it may be 10lbs less for you http://fsae.com/groupee_common/emoticons/icon_smile.gif

Kevin Hall
University of Saskatchewan
Engine Guy Extraordinaire

[Michael Jones]

Not to mention that on driver change, you have to shut off the car and can't use any external method of charging to start back up again. At the very least, you're looking at two perfect starts plus regular current draw.

On a new, fully charged battery on a warm day with no starting delays or unforeseen stoppages due to other cars misfortunes, perhaps you're cool on battery alone, depends on the rest of the current draw. That's a lot of ifs for a one-shot race though.

A robust electrical sysetm would also be a selling point given the target market, and as such would be a valid question in design, I'd think. The average weekend autocrosser probably wouldn't want to have numerous fully charged batteries to swap in and out. The alternator at least makes it more idiot-proof.

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Cornell Racing
http://fsae.mae.cornell.edu

[Brent Howard]

I think that taking the alternator off would break away from the goal of the competiton which is to design a car for a weekend racer...do you think that they want to have to constantly recharge the battery...or change it if they have to turn the car off more than once?

Brent

www.ucalgary.ca/fsae (http://www.ucalgary.ca/fsae)

[Andres]

The thought of taking weight away makes you think on everything, after I posted I thought on the presentation event and the fact that no one would like to have to buy a battery every 25 km...

But maybe you can have a battery charger and two batteries, you can have one charged and the other one on the car, change them before the battery dies, and recharge it outside the car. There you have a car that wont cost you thousand on batteries and weight less...

but the fact that scares me the most is that I have to unplug the regulator rectifier that feeds the computer, in case that you dont know, the computer sensors are electronically speaking amazing, considering the electrical noise (well they amazed me, noise less than 30mV).