Ok guys I ordered some parts from summit and I bought a underdrive pulley for my altermator I know they free up some hp but is it good on the street will the alternator turn enough to feed everything ???? I have seen it on a lot of race cars but was curious if its ok to run one on the street

 

I wouldn't.

It's hard to go fast with a dead battery.

The stock alternators in these things can't charge the battery on a rainy day in traffic with the headlights, wipers, and defroster on, regardless of their rated output. I'd hate to see what would happen if I reduced the output further.

- Eric

 

Mines not stock it a high output late 80's unit one wire set up it seems to run my electric fans water pump radio and lights fine the volt needle only drops when you flip the switch for my fans etc. But this looks like it might be one of those things I might just use at the track and ill just have a spare alt. But I'm gonna see how it does on the street I only use electric water pump drive and fans on the track on the street I put the fan and pulley back on I only use the electric fans if I'm stuck in traffic

 

Yeah pretty much what Eric said.

Had 2 different ones on my Alero, one smaller one larger. The larger one killed 2 batteries before I could figure it out and the smaller one fried an alternator.

Of course on a Honda Civic, it adds more horsepower than 4 stickers

 

The problem gets WORSE with those wretched 1-wire Alternators!!!! Those things need "charged" to start working ! If your cr is auto trans you gotta put it in neutral and rev it up to get the alternator "jump-started" each time you let it idle down below a certain RPM with a Large pulley on it!! Unless youre planning on 7500 RPMS or higher -- you litterally have no need for an underdriven alternator! ( at least not that i can see!)

 

Well om gonna try it out at the track see how it works if it frees up some hp then ill buy a sopare alt to swap at the track because I constanly used to throw belts during my burnouts and I would always run my fastest when I did

 

As noted, one-wire alternators don't charge at idle with the stock pulley. An underdrive pulley makes it worse. More importantly, the drag from the alternator is a function of the load. Changing the pulley diameter will make an immeasurable difference in performance, particularly if you don't change the load. And unless you are doing back-to-back tests at the track and correcting for weather, any results are meaningless. A much cheaper and easier trick is the old alternator cut-out switch. Turn it off when you stage the car to eliminate any alternator load during the run, turn it back on when you hit the return road to keep the battery charged.

 

Thanks joe that sounds like something that I should do and I'm gonna give it a try I never thought about that thanks again

 

Those are race car race car bull/chit and should stay on a race car not a street car and besides you probably wouldn't notice any difference other than your car might not start when you want it to.