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)

 

i think Superchager boost is changed by size of pulley gear. bigger pulley gear more boost. small pulley gear less boost

 

enlightening!

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Black R &raquo;</TD></TR><TR><TD CLASS="quote">Is this a way that people are able to run more boost?</TD></TR></TABLE>

Try a boost controller. Wait, you already have one.

 

The CRV pulley is bigger than an Integra pulley. When you run a CRV pulley on a JRSC setup you get about 9.5-10 psi of boost, whereas the stock Integra pulley gives you about 7 psi. I dont have any experience with the Vortec kits, just JRSC.

 

Interesting.

Can you confirm whether this #: 75 7827E
is that off a crv?

Gah, I hate this vortech.....


Modified by Black R at 11:22 PM 1/4/2006

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Black R &raquo;</TD></TR><TR><TD CLASS="quote">Interesting.
Can you confirm whether this #: 75 7827E
is that of a crv?
Gah, I hate this vortech.....</TD></TR></TABLE>

The CRV pulley that is in my presence is older and the number is missing.

I am not at my house so I had to use a gay plastic grade school ruler to measure the pulleys. I measured a CRV pulley, on an engine, it was hard to measure on the ground in the dark but, it was a little bit over 6 inches. I then measured a GSR pulley that was on the parts shelf and it was just under 6 inches. I have heard that ITR pulleys are a bit smaller than the GSR ones but havent compared the two. Sorry about the vague measurements however, I am certain that the larger pulley in your pictures is a CRV pulley.

P.S. I haven't seen the vernier calipers since one of my undergrad engineering classes. I didnt know people used those anymore. I am so used to seeing the digital calipers.

 

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)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Kang &raquo;</TD></TR><TR><TD CLASS="quote">i think Superchager boost is changed by size of pulley gear. bigger pulley gear more boost. small pulley gear less boost</TD></TR></TABLE>


Wouldn't it actually be the opposite???


The smaller the more boost... eh.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dsav4shawn &raquo;</TD></TR><TR><TD CLASS="quote">
Wouldn't it actually be the opposite???


The smaller the more boost... eh. </TD></TR></TABLE>

No, the bigger crank pulleys make more boost than the smaller ones.

 

((Calling all Brad's...calling all Brad's)) Mythias could tell you. I was under the impression that the smaller wheel will yield more boost since it is spinning at a faster rpm.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Haleiwa-Brando &raquo;</TD></TR><TR><TD CLASS="quote">((Calling all Brad's...calling all Brad's)) Mythias could tell you. I was under the impression that the smaller wheel will yield more boost since it is spinning at a faster rpm.</TD></TR></TABLE>

You're looking at it wrong.

The engine spins at a fixed RPM. The pully size doesn't change the speed of the engine or the RPM's of the pulley itself.

A smaller wheel will move less belt. A larger wheel will move more belt. Based on the belt velocity, you'll get more or less boost (RPM) at the supercharger.

Now, if you change the pulley on the supercharger, it is an opposite effect. A smaller pulley on the blower means that you have more revolutions on the blower per inch of belt.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Haleiwa-Brando &raquo;</TD></TR><TR><TD CLASS="quote">((Calling all Brad's...calling all Brad's)) Mythias could tell you. I was under the impression that the smaller wheel will yield more boost since it is spinning at a faster rpm.</TD></TR></TABLE>

Edit: Chris F Beat me to it.


Modified by 98 Spec R at 11:36 PM 1/4/2006

 

p.s. Boosted ITRs

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chris F &raquo;</TD></TR><TR><TD CLASS="quote">p.s. Boosted ITRs </TD></TR></TABLE>

X2

All my supercharger experience has been on GSR motors and K-Series motors at Hasport Performance. A K24 with a supercharger in a regular Integra is .

 

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

You're looking at it wrong.

The engine spins at a fixed RPM. The pully size doesn't change the speed of the engine or the RPM's of the pulley itself.

A smaller wheel will move less belt. A larger wheel will move more belt. Based on the belt velocity, you'll get more or less boost (RPM) at the supercharger.

Now, if you change the pulley on the supercharger, it is an opposite effect. A smaller pulley on the blower means that you have more revolutions on the blower per inch of belt.</TD></TR></TABLE>

Ah ha! That is where I got it mixed up. I knew a smaller pulley had better effects. Couldn't remember which side it needed to be. So in essense, a smaller pulley on the blower side with a bigger pulley on the crank side = good times?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chris F &raquo;</TD></TR><TR><TD CLASS="quote">p.s. Boosted ITRs </TD></TR></TABLE>

Yeah...boosted R's are stoooopid. They were intended to be N/A you know?

^^^True story.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Haleiwa-Brando &raquo;</TD></TR><TR><TD CLASS="quote">
Yeah...boosted R's are stoooopid. They were intended to be N/A you know?

^^^True story. </TD></TR></TABLE>


agreed 100%

too bad both of the itr's we've got are boosted.

i won't count the itr powered hatch since it's not an itr - but hey, it is staying allmotor... although that motor is coming out and the built motor for allmotor is going in...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dsav4shawn &raquo;</TD></TR><TR><TD CLASS="quote">Wouldn't it actually be the opposite??? The smaller the more boost... eh. </TD></TR></TABLE>

The scary thing is you have a jrsc on your R, don't you?

 

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

You're looking at it wrong.

The engine spins at a fixed RPM. The pully size doesn't change the speed of the engine or the RPM's of the pulley itself.

A smaller wheel will move less belt. A larger wheel will move more belt. Based on the belt velocity, you'll get more or less boost (RPM) at the supercharger.

Now, if you change the pulley on the supercharger, it is an opposite effect. A smaller pulley on the blower means that you have more revolutions on the blower per inch of belt.</TD></TR></TABLE>

Yup.. Think of it like a bicycle, 18 speed. When your going fastest is when you are using the largest gear connected to the pedals and you are using the smallest gear on the wheel.

 

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

The scary thing is you have a jrsc on your R, don't you? </TD></TR></TABLE>


It is scary... that I have a JRSC. Oh well... I know that the smaller pulley on the charger yields more power. Can you believe that someone told me that Acura is made by Honda?

Oh well.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 98 Spec R &raquo;</TD></TR><TR><TD CLASS="quote">

No, the bigger crank pulleys make more boost than the smaller ones. </TD></TR></TABLE>

Smaller charger pulley = more boost. Larger crank pulley = more whatever.

 

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.....

 

fucked with it again tonight - yeah i'm that lazy.....

anyway, I was able to use the itr alternator belt with the itr crank pulley, but the gates belt that is sized correctly for the blower/ AC according to vortech has too much slack in it now (probably due to the fact that the blower has a 3.12" pulley on it instead of the larger 3.70" pulley that it comes with... The itr AC belt doesn't work either, so

So now I'm back to square one - going to put the crv crank pulley back on there, get a crv alternator belt and ac belt, and hope those will work. Otherwise, I'm going to spend most of my weekend trying out various belts.....

I hope this will prove useful for some poor schmuck in the archives when I get it all figured out.....

for reference, here are the part #'s for the belts that I removed (which were on there with the larger crank pulley):

alternator: 4PK0785 310K4 (31 3/8 in)
power steering: napa part # 25-040343 (34 5/8 in)


Modified by Black R at 6:21 PM 2/17/2006

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Black R &raquo;</TD></TR><TR><TD CLASS="quote">fucked with it again tonight - yeah i'm that lazy.....

anyway, I was able to use the itr alternator belt with the itr crank pulley, but the gates belt that is sized correctly for the blower/ AC according to vortech has too much slack in it now (probably due to the fact that the blower has a 3.12 pulley on it instead of the larger 3.7xxx that it comes with... The itr AC belt doesn't work either, so

So now I'm back to square one - going to put the crv crank pulley back on there, get a crv alternator belt and ac belt, and hope those will work. Otherwise, I'm going to spend most of my weekend trying out various belts.....

I hope this will prove useful for some poor schmuck in the archives when I get it all figured out..... </TD></TR></TABLE>

how many cars do you have???

2 sets of ITBS, a turboed R, a supercharged SOMETHING!!!!!!

 

this one:

https://honda-tech.com/zerothread?id=1065872


Modified by Black R at 5:59 PM 2/17/2006

 

I was running a crv crank pulley and a 15 psi small diameter drive pulley and I peaked at 19 psi. the blower is good for up to 25 psi according to vortech. See the bigger crank pulley gives more power to the accesories which the vortech is considered an accesory in this case like a/c or power steering. the smaller drive pulley is able to spin the charger faster making more boost. the inside of the vortech unit is a drive system almost like a transmission and it needs a certain rpm to engage the stepper pulley inside of the case to make boost. That is why it the vortech does not really start making boost till 4.5 K

 

k040520 is the gates belt part # for the blower - but with the smaller blower pulley, it's loose... too loose to snug up (~2 inches or more).

So I think for now we're going to stick to the smaller (itr) crank pulley and just get another blower belt...