malibutwinturbo

i found some compressor maps that are in CFM

garrett's site says to get CFM from lb/min is to multiply the lb/min # by 0.076 cubed

so is this right?

51lb/min = .022CFM & 30.77lb/min = 0.0135CFM

baron340

umm not quite... so you're starting with cubic feet per minute. The density of air at sea level at 70* F is .0745 pounds per cubic foot. If you mulitply that .0745 by cfm you get lb/min... look at the units and how it works out. (ft^3/min)*(lb/ft^3)=(lb/min) ... side note... the density of air changes quite a bit based on temperature and altitude. so in general that will work, but to get more specific you need to use your altitude and whatever temperature you're at, but 70 and sea level is standard for measurements... use this http://www.denysschen.com/catalogue/density.asp and multiply by whatever number that gives you instead of .0745... if you're going from cfm to lb/min just divide instead of multiply.
51 lb/min = 3.7995 ft^3/min

malibutwinturbo

3.7995 is completly off the chart for this turbo, well, these are very small ones

the horizontal axis reads 0.0 all the way to 0.30

heres one of the maps, i have this turbo, i just want to know how to the proper math, so i could match it up to something, but i was trying to compare it to my malibu & my old van just to see what it says

http://www.---------------/turbocalc/...&product_id=83

baron340

well maybe you're right then, i dunno.. i know close to nothing about reading those maps, but beyond that units conversion above, i have no idea where a mistake could be coming from. maybe there is something in the way those units get calculated that i'm missing. hopefully someone with greater mathematical/engineering genius than I can help

malibutwinturbo

yeah, it doesn't sound right, but i dunno ...maybe i should have taken more math classes back in high school, lol

rprznt

listen up good noobs, this is the ----.

in ideal conditions at sea level. (close enough for hmt)

cfm * 0.069 = lbs/min

lbs/min * 14.49275 = cfm.

so...

100 cfm = 6.9 lbs/min
100 lbs/min = 1449.3 cfm.

see easy, btw that turbo, malibu is way too small for a twin on a stang, they go on 1.5l hondas.

malibutwinturbo

i know its small, i just wanted comparison numbers thats all, & i don't have a mustang