how much boost will i have
how much boost will i have I have a d1sc with a 6 rib belt drive on a stock ls1. The crank pulley is 6" and i have 3 blower pulleys 4", 3.4", and a 3.2" how much boost will each make? I will have a front mount intercooler.
Checkout this equation that was posted by another member on here.
https://ls1tech.com/forums/forced-in...55-pulley.html
{[(crank pully diameter) / (Blower pulley diameter)] x (blower step up ratio) x (engine rpm)} / (max blower speed)... multiply that number by the max rated cfm of the blower. Store that number on paper or in your calculator... then take your discplacement in cubic inches and multiply by the same rpm used in the first equation... divide by 1728 to convert to cubic feet... divide by 2 to account for the 2 revolutions per 1 combustion cycle... now divide the first number you stored by this number... multiply this number by 14.7... this will give you your absolute pressure... then subtract 14.7... this will give you your boost pressure at the rpm you specified.
example for d1sc with 7" crank pully at 6000rpm and 370 ci of displacement...
{[(7/3.55)(4.10)(6000)] / 62000rpm} x 1400cfm = 1095.32cfm
[(370ci x 6000rpm)/ 1728] / 2 = 648.36cfm
1095.32 / 648.36 = 1.705 bar
1.705 x 14.7 = 25.066 psi absolute
25.066 - 14.7 = 10.366 psi boost at 6000 rpm
if your crank pully is a different size or your blower is different just plug in the relevant numbers and rework the equation... goodluck
example for d1sc with 7" crank pully at 6000rpm and 370 ci of displacement...
{[(7/3.55)(4.10)(6000)] / 62000rpm} x 1400cfm = 1095.32cfm
[(370ci x 6000rpm)/ 1728] / 2 = 648.36cfm
1095.32 / 648.36 = 1.705 bar
1.705 x 14.7 = 25.066 psi absolute
25.066 - 14.7 = 10.366 psi boost at 6000 rpm
if your crank pully is a different size or your blower is different just plug in the relevant numbers and rework the equation... goodluck
Last edited by Zeke34; Mar 21, 2009 at 04:30 AM.
