I noticed that this (smaller) crank pulley was included with a box of misc parts that the previous owner included with the car when we purchased it.

Is the bigger one that was on the car a stock itr piece?

And is smaller one from another honda? (crv perhaps?)

Is this a way that people are able to run more boost?

Which pulley should I put on, and why?















It appears that the belts used go to alternator, then ac, then ps. (In order of closest to the motor to furthest away from it.) For reference, the vortech blower runs off of an extended serpentine belt which replaces the one that used to power the ac..... (middle belt, iirc)

 

id believe the smaller pulley would produce more boost as it would spin the charger more times per revolution than the bigger pulley

 

no thats not true the bigger the pulley the more boosted it will make on super charged cars

 

The bigger the crank pulley the more boost it will run, the smaller the supercharger pulley the more boost it will run. Its like looking at a 10 speed bicycle, do you put a small gear on the front and back to go faster? Big front, small rear will go the fastest.

 

posted in another thread, but you guys may get a kick out of it as well:

ok, i measured the two pulleys...

Big crank pulley circumference for:

alternator = 19in
air conditioner compressor = 19.75in
power steering pump = 13.25in


Small crank pulley circumference for:

alternator = 16.75in
air conditioner compressor = 16.5in
power steering pump = 13.25in


AND I measured the belts that came off the car:

31" alternator belt
34 5/8in power steering belt

(these were on there with the big crank pulley)

I decided to go with the smaller crank pulley after looking at the vortech blower and realizing that the blower pulley had also been replaced - with a smaller one to make more boost.....! I decided that with impeller speeds already high with a centrifugal blower, that I didn't need additional boost just yet, it may be hampering the efficiency of the thing + not safe according to the mfr..... I will call vortech to confirm.
This, coupled with the fact that I couldn't get any belts in the right size on short notice convinced me to put the smaller pulley on there (which I believe is the stock itr crank pulley).

fwiw, the oem crv a/c belt is 34" and 4-rib..... it also didn't fit with the big pulley.
Autozone was out of crv ps and alt belts.....

So whomever did this buildup was using a BIGGER crank pulley to get more boost AND a smaller blower pulley to get more boost.

If someone knows how to calculate the boost increase, please let me know - I think it's just a simple matter of multiplication.....