Now whenever I see pulleys for sale, they always say an Alternator pulley and a Power steering pulley and they say that its proven to increase horsepower.....How does giving oversized pulleys to the alternator and the power steering increase your horsepower? I thought it was the crankshaft pulley that does that?

 

Bump

 

those lightweight pulleys dont create hp, they free up hp. this is because they are lighter and draw less power to spin them.

 

The pulleys "underdrive" the accessories (turn them less per engine revolution), thereby reducing the parasitic losses they cause.

 

yeah.. "parasitic losses," which means you won't gain much (2-4whp). but they do make the engine bay look nicer but if you're really worried about getting all the hp you can, lose the ac and ps all together. frees up weight too

 

They do help, and can help everybody. Not only because they are lightweight, but as you said, they are larger, thus lightening the load it takes to turn each pulley around. Think about it like this.. is it easier to use a short, small wrench or a longer handed wrench?? Go try it if you don't know, but the larger radius gives you better leverage and more torque. They made a huge difference for me, but your lights will dim a little when you are at idle.

Also, I do NOT recommend getting the lightweight (its just lightweight, i think.?.) crank pulley unless you are getting the crank balanced with it. A lightweight flywheel could be used, but the crank affects the balance of the internals my mechanic said.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by wickedplastikman &raquo;</TD></TR><TR><TD CLASS="quote">those lightweight pulleys dont create hp, they free up hp. this is because they are lighter and draw less power to spin them. </TD></TR></TABLE>

Really??


That is with an Unortodox Racing Pulley

 

reread fuckup, they don't CREATE, they FREE UP...


jesus go back to school, learn to read

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 96integra &raquo;</TD></TR><TR><TD CLASS="quote">reread fuckup, they don't CREATE, they FREE UP...


jesus go back to school, learn to read</TD></TR></TABLE>
damn, that was harsh...

 

96integra

Compulsive Liar/Whiner
(98%)

Dynos dont lie...^^^

 

... so how much of an increase can one expect from installing aftermarket pulleys does anyone have any experience thanks that dyno sheet is too small to read

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bigcrazydude1 &raquo;</TD></TR><TR><TD CLASS="quote">
Dynos dont lie...^^^ </TD></TR></TABLE>

Sure they do. Especially when you pull them right from the manufacturers website.

I dont buy that dyno for one second. The gain should be fairly even throughout the powerband and shouldnt make that much wtq anywhere.

 

Correct me if I am wrong-- b/c I personally have never used a dyno machine, but can you create a fake dyno graph??

Maybe with "MSPaint" or something similar to that, but I dont think for one minuet that Unorthodox would do something that shady just to sell a couple extra pulleys.

 

Of course you can, and Id say that one is a good candidate.

Not to mention you can skew the correction factor to make any #'s you want.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by KeithsDAteg &raquo;</TD></TR><TR><TD CLASS="quote">96integra

Compulsive Liar/Whiner
(98%)

Dynos dont lie...^^^ </TD></TR></TABLE>

I think 96Integra meant that the pulleys "gains" hp by reducing the amount of "lost" hp. I agree with him. The power was there to begin with, but with the stock pulley, because it is smaller, it will require more power to turn, so power is lost at the pulley. When you go with a larger/lighter pulley you have better leverage, thus you dont lose as much power.

Think of it as you are not losing AS MUCH power, rather than you are making power.

You are basically reducing the amount of power lost. Which is called parastic draw.

PS: and ya, I dont buy into manufacture dynoes. Plus, dynoes are never that accurate, especially when you are talking about as such a small number as 2-4hp. Even if you have the same car dynoed on the same dyno twice in a row, it will not read the same.