Evening all, i recently installed a March Pulley to the crank of my LT1 Impala SS. I do have the stock pulley over the march pulley as well, in addition to adding a 592k6 Belt. So ive covered all bases except one which involves the alternator pulley. Would like to add that missing link but im having a slight hard time finding the correct pulley for the alt. Can anyone please help??? Thanks


Here is what ive found so far:

March Performance Steel Alternator Pulleys 121-08 - SummitRacing.com

 

That's just a standard drive pulley, not over nor under drive.
What does this mean: "I do have the stock pulley over the march pulley as well".
I take it your March crank pulley is a smaller diameter than the stock one to under drive the accessories?
How well is your alternator keeping up now? An under drive alternator pulley is going to slow it down more still, dropping power output more than you already have.

 

Not my picture, but the exact bolt on as in the pic. You can see the belt around the march pulley while the stock is bolted to the march unit.

 

As for the benefits, the little extra power is there especially at highway speeds. Just a minor dim when in idle, but that seems to be few and far in between. Not much of an issue, but id like to get that extra pulley to further prevent any future mishaps. I got to get a retune soon for some changes prior to today and upcoming mods, so anything beyond mechanical, i will have the tuner take car of it via pcm.

 

So the March is just a plain pulley and not a harmonic dampener/pulley, as some other brands are?

 

Im trying to understand the question. LOL, but this is the march pulley




That replaces the stock pulley which in turn replaces the belt as well down to a smaller size. Some people run the pulley by itself which is said to be a big NO NO!!! So after i installed the pulley, i put the stock (larger) pulley over the march piece and bolted everything back together. The larger stock is still needed to prevent vibrations to the crank and so on, hence why it still needs to be bolted up piggy backing the march piece.

 

The march pulley is much smaller than the stock. One other big benefit is it doesnt have to come off to remove the opti. (YAY)

 

You just answered my question that you didn't understand, lol.
Your March pulley isn't a harmonic dampener like the stock one is, which is why you have to piggy back the stock one. I've seen under drive pulleys that are also a harmonic dampener, so you wouldn't have to piggy back the stock one.

 

WOW, okay cool. Im sorry i didnt understand what you were saying sir. Here lately my focus has been a little off at times. LOL, but i do appreciate your help thus far. If i could at least find the specs of the stock alternator pulley, i can cross reference that to summit so that i can buy it. I almost bought one today, but they offer 4 different versions and they are all off by tenths that being the inner diameter. Thats the secondary information i could use, but a for sure part number would perfect. Thanks

 

Yeah, you'll have to see if google can be your friend so you can find out what the shaft diameter is on your alternator. But again, are you looking to slow down your alternator even more or bump it back up a little? Your lights dim a little at idle, but what is the volt gauge reading?