I have been told that wiring a switch into the main hot wire going into the alternator will give you much of the same effect as unhooking the belt. That is something you could very easily do on the street, and then turn it back on.

 

what would the difference be with taking the belt off with an electric water pump or not?

 

Good question.

 

And how does this work???

 

I wouldn't do it anymore with the electric water pump because it is placing more load on an already heavly taxed battery. There is going to be a point where the reduction of voltage is going to start causing problems with things like the ignition system, fuel pump, etc. This will vary depending on battery condition and the load on the battery. I just wouldn't feel comfortable doing it with the extra load of the waterpump. Would it make a difference? Don't really know.

 

My guess would be that if the alternator is putting out electricity that it is putting a load on the belt, thus robbing horsepower. This is my understanding of this, someone correct me if I am wrong.

 

Right i understand the drag from the belt robs hp. But OutsiderIROC-Z said something about putting a switch into the main hot wire going into the alternator has the same effect. I took that as having the same effect as taking off the belt? Did i misunderstand something somewhere?

 

If you switch off the field windings in the alternator it will still turn, but it won't put any load on the engine since it's not producing any power.

 

Thanks, I get it now.

 

I didn't know how to verbalize it, but izzy did a good job doing just that. Thanks.

 

From a bolt on pulley to no belt i gained .04 in ET and about .6 in MPH on the SAME day and nearly identicle 60' (1.689 to 1.687 or something like that). However my best runs were made with an ASP replacement balancer. I acutally was faster with it on than with the belt off.

Load on the alternator however, does NOT affect how hard it is to turn over. A higher amperage alternator will take up more HP as the rotor inside it is heavier. Alts work on the principle of induction. Spin a magnet inside a field of coils and you get AC current. There is no way that the armature knows the load on itself. After the AC current is rectified, it goes through a voltage reg which will control your output. If you need more current, it will feed more voltage into the rotor making it a stronger magnet. However, as you make the north field stonger, you also make the south equally strong. The forces are going to cancel each other out negating the fact that its producing more amperage.

Basically what i am saying is, by outputting voltage, you arent making it harder to turn over than if you had no voltage flowing from it. The gains are simply from reduction of rotating mass when you remove the belt.

 

A gain is still a gain no matter how small, all those .02 and .03 add up eventually. I think anything is worth a try once.........

 

Even though i posted about the alt. belt i was also concerned with all the other pulleys on the belt since it is a street car i will be running. I think I will see a noticable gain with the belt off. As long as i keep the battery charged between runs, i should have no troubles.

Brandon