Which size pulley should i go with?

[deftsound]

So I really want to get a smaller pulley so i can up the boost to about 9psi and get the numbers i want

My question is what size pulley should i go with? Right now im using the standard 3.6" 6 rib vortech pulley at 6psi

My tuner recommended a 3.48" 6 rib pulley but i just read spedermans thread and he said he was using a 3.25 6 rib to get 9 psi...

 

[spederman]

Deftsound, are you running an intercooler? I am and needed to pulley down to get 9psi. If you are running an intercooler then either a 3.33 or 3.25 should get you about 9psi. Also if you need a 3.33 or 3.25 Vortech 6 rib pulley, i can sell you either of mine since i went 8 rib now. I'm in Dallas so it wouldnt take very long to get to you in Galveston, PM me if you need one of the pulleys.

 

[deftsound]

Deftsound, are you running an intercooler? I am and needed to pulley down to get 9psi. If you are running an intercooler then either a 3.33 or 3.25 should get you about 9psi. Also if you need a 3.33 or 3.25 Vortech 6 rib pulley, i can sell you either of mine since i went 8 rib now. I'm in Dallas so it wouldnt take very long to get to you in Galveston, PM me if you need one of the pulleys.

no i dont have an intercooler...but why would that make a difference? Im leaning towards the 3.33...

 

[spederman]

no i dont have an intercooler...but why would that make a difference? Im leaning towards the 3.33...

When you get an intercooler, it drops your boost by a couple psi. Not sure on the exact technical explanation why but basically i think its because intercoolers arent super effecient. So when you get an intercooler you have to pulley down to keep the same boost level as you were without one. Also i have a power pipe which is supposed to increase boost by 1-2psi. You could try that too, if you already dont have one. I would say a 3.33 would get you where you want to be for sure.

 

[WydOpn]

When you get an intercooler, it drops your boost by a couple psi. Not sure on the exact technical explanation why but basically i think its because intercoolers arent super effecient. So when you get an intercooler you have to pulley down to keep the same boost level as you were without one...

A pretty good explanation of pressure loss with an intercooler:

http://www.superchargersonline.com/content.asp?id=16

 

[superhawkman]

Deftsound, are you running an intercooler? I am and needed to pulley down to get 9psi. If you are running an intercooler then either a 3.33 or 3.25 should get you about 9psi. Also if you need a 3.33 or 3.25 Vortech 6 rib pulley, i can sell you either of mine since i went 8 rib now. I'm in Dallas so it wouldnt take very long to get to you in Galveston, PM me if you need one of the pulleys.

How much do you want for your 6-rib 3.25 pulley ?
Shoot me a e-mail [email protected]
thanks

I have a 3.33 currently with a intercooler.

 

[Stan Weiss]

A pretty good explanation of pressure loss with an intercooler:

http://www.superchargersonline.com/content.asp?id=16

From the above web site
The reduction in air temperature increases the density of the air (more air molecules per cubic foot), which consequently increases your engine's ability to make more horsepower and torque. The decreased air temperature allows you to run more boost on a given octane of fuel before detonation occurs.

---------

Looking at boost pressure without knowing the input air temperature to the engine only tells half the story. The key as I have said in a number of posts here is DENSITY RATIO, or as said above how much does each cubic foot of air going into the engine weigh.

 

[98GTfromGA]

how much boost did you make with the 3.60", I made over 9lbs at 5500 rpm

 

[deftsound]

how much boost did you make with the 3.60", I made over 9lbs at 5500 rpm

i was peaking at 7lbs my tuner said