race alternator

[LS6 Tommy]

On a "total loss" system (battery only, no alternator) you give up more power from voltage drop than you do on a normal system from alternator drag. Total loss systems are "Old School". Even a really good race alternator may not keep a vehicle properly charged in street use. They usually have a much higher "turn on" RPM than a street alternator & may not put out much at normal cruising RPM.

Tommy

 

[grizwald]

so, you'd use a standard 90-100 amp alt? i do have one of those bigger moroso pulleys to try on it. i never used it cause i was having charging issues with the smaller pulley...so slowing the alt down didn't seem like a great idea.

 

[Doober]

Was the smaller pulley on a regular or race alternator? Regular alternators kick in somewhere around 800-1,200rpm I believe, depending on mfr/application. Even if the pulley slowed it down 50% you'd probably still be ok since it would kick in around 2,400rpm tops.

 

[grizwald]

it was a stock alternator...not sure from what.

 

[gbodystuff]

I would suggest swapping to a CS style alt, re-wire your system and not have to worry about "when it kicks in"-these alts maintain system voltag regardless of RPM. If you are pulling big amps @ idle, it'll keep running over 14V and put out whatever amperage you need. For the record, go with a new GM alternator-they have patents on the regulator designs where the window time for sensing voltage load is extremely quick reacting allowing for seemingly effortless system voltage stabilization-this is not someting you'll find in any parts store alternators or aftermarket for that reason. You can't beat a factory GM serpentine with a high output factory GM alternator....nothing is better imo.

 

[Robert1320]

Like I said the old stocker 65 or 75 amp with a standard pulley on a 750 rwhp driver.

 

[Doober]

I would suggest swapping to a CS style alt, re-wire your system and not have to worry about "when it kicks in"-these alts maintain system voltag regardless of RPM. If you are pulling big amps @ idle, it'll keep running over 14V and put out whatever amperage you need. For the record, go with a new GM alternator-they have patents on the regulator designs where the window time for sensing voltage load is extremely quick reacting allowing for seemingly effortless system voltage stabilization-this is not someting you'll find in any parts store alternators or aftermarket for that reason. You can't beat a factory GM serpentine with a high output factory GM alternator....nothing is better imo.

I'm not sure if it was in reference to what I said, but that's basically what I was trying to say as well about the alternator charging... I don't know what makes a 'race alternator' what it is, but I assume they are designed to not put as much drag on the engine as a stock alternator, but as long as it doesn't throw a belt I wouldn't imagine there would be an issue with a stock one (aside from the constant high RPMs).

 

[grizwald]

doober...you hit the nail on the head as far as my main concern goes. i'm more worried about puting unneccessary drag on the engine. but, i'm starting to think i'm worrying a little too much about that. i think i'll just toss a stock style alt with the bigger pulley on it and see what happens.

 

[Robert1320]

doober...you hit the nail on the head as far as my main concern goes. i'm more worried about puting unneccessary drag on the engine. but, i'm starting to think i'm worrying a little too much about that. i think i'll just toss a stock style alt with the bigger pulley on it and see what happens.

Big pulley... don't expect it too charge at idle.

 

[grizwald]

just wanted to say thanks for all the input. i decided to go with a CS130 style alternator (140 amp) and have one on its way. your input played a big role in this decision. i also am ditching the stock plug and going to a one wire set up. main reason...simplicity. thanks again guys!