HIN
HF MEMBER
Stara Toyota
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HOW TO READ TURBO MAPS
What you need to do is find you airflow rate based on: your desired boost (PSI) engine size and engine redline. you need to find your Airflow rate at Three points first point is at Redline second point is usually at 75% of redline or where ever the compressor hits full boost, whichever is at a lower RPM and the Third is at 50% of Redline. All you need to know is basic math, add, subtract, multiply and divide. You will deal with different units of measurement (lb, cfm, psi).
*Note: /=Divide, X=Multiply, and +=Add
Basics you will use these numbers later on:
*PRESSURE RATIO = (14.7 + desired PSI) / 14.7 = PR
*Convert CFM to LB per MIN = CFM x 0.070318 = LB/MIN (@ sea level and 112 degrees*).
*LITERS TO CUBIC INCHES DISPLACEMENT = # of Liters x 61 (ex: 1.8 x 61= 109.8 cid)
*CFM = Cubic Feet per Minute
*Now using my Elantra w/4G67 (1.8l) as an example:
1.8L (109.8 cid), 7000 Redline, desired boost is 10 PSI
#1 CALCULATING AIRFLOW RATE AT REDLINE and 10 PSI
cid = Cubic Inches Displacement
VE = Volumetric efficiency in percent
.5 = (given) 4-stroke engine fills cylinder only on one-half the revolutions
1728 = converts cubic inches to cubic feet
*Airflow in CFM = (cid x rpm x .5 x VE %) / 1728 = CFM no boost
CFM x PR = CFM under boost
So for my Elantra:
PR = (14.7 + 10) / 14.7 = 1.69
Airflow = (109.8 x 7000 x .5 x .95) / 1728 = 211.27 CFM (no boost)
211.27 x 1.69 = 357.05 CFM under 10 PSI
Now since most compressor maps have their flow rates in LB/MIN we need to convert CFM to LB/MIN. a cubic feet of air (length + width + height) weighs different at diff. Altitudes and different temperatures. To simplify it well just assume we are at sea level and the air temp is 112 *. The conversion number is 0.070318.
So for CFM TO LB/MIN = CFM x 0.070318 = LB/MIN
357.05 x 0.070318 = 25.10 LB/MIN.
So now we have:
BASIC ENGINE FLOW RATE = 211.27 CFM
ENGINE FLOWRATE with 10 PSI = 357.05 CFM (25.10 LB/MIN)
PRESSURE RATIO (PR) = 1.69
So now we know our flow rate in LB/MIN.
A 1.8L with 10 PSI of boost at 7000 RPM (redline)
flow rate = 25.10 pounds of air per minute (LB/MIN)
PR = 1.69
This is POINT NUMBER ONE. Now we do the same for 75% of redline and 50% of redline.
#2 CALCULATING AIRFLOW RATE AT 75% RPM RANGE
Now we will find the airflow rate at 75% redline = 5250 RPM (0.75 x 7000 = 5250)
(109.8 x 5250 x .5 x .95) / 1728 = 158.45 CFM no boost
158.45 x 1.69 = 267.78 CFM under 10 PSI
267.78 x 0.070318 = 18.83 LB/MIN
Now we have:
BASIC ENGINE FLOW RATE = 158.45 CFM
ENGINE FLOWRATE with 10 PSI = 267.78 CFM (18.83 LB/MIN)
PRESSURE RATIO (PR) = 1.69
#3 CALCULATING AIRFLOW RATE AT 50% RPM RANGE
As you may already know the point at which the compressor reaches full boost is largely determined by the Turbine side. I usually calculate a third point just incase. I plot this third point on the compressor map this way if boost comes way early (50% redline) I know where I lie on the map.
And to find the airflow rate for 50% of redline = 3500 RPM (0.50 x 7000 = 3500)
(109.8 x 3500 x .5 x .95) / 1728 = 105.63 CFM no boost
105.63 x 1.69 = 178.52 CFM under 10 PSI
178.52 x 0.070318 = 12.55 LB/MIN
Now we have:
BASIC ENGINE FLOW RATE = 105.63 CFM
ENGINE FLOWRATE with 10 PSI = 178.52 CFM (12.55 LB/MIN)
PRESSURE RATIO (PR) = 1.69
GATHER YOUR DATA
We have just figured out our engine's airflow rate at 3 RPM points (Redline, 75% and 50%) you only need 2 at the minimum but you can use as many points as you want.
POINT 1 (7000 RPM)
FLOWRATE with 10 PSI = 357.05 CFM (25.10 LB/MIN)
PRESSURE RATIO (PR) = 1.69
POINT 2 (5250 RPM)
FLOWRATE with 10 PSI = 267.78 CFM (18.83 LB/MIN)
PRESSURE RATIO (PR) = 1.69
POINT 3 (3500 RPM)
FLOWRATE with 10 PSI = 178.52 CFM (12.55 LB/MIN)
PRESSURE RATIO (PR) = 1.69
These are the three points you will start referencing onto the different compressor maps, ideally you want all three to be within the highest percentile in the compressor map.
Using this map of a T3 “Super 60” trim first let me explain all the numbers on the map
1-Left side, pressure ratio
2-Bottom side, airflow rate (LB/MIN on this map)
3-Dashed line on far left side of "ovals", surge limit
4-Numbers on far right, 56400, 78800, 96300 etc, compressor RPM.
Now all you have to do is take the each RPM point and put them on the compressor map, use the airflow rate and PR wherever they intersect is where the point will go. Ideally you want all points to be in the highest Comp. Efficiency. % (which is the Oval in the middle), especially the redline and the 75% redline points.
Go ahead and give it a try, but that’s pretty much how you select compressors if any of the points lie:
*In a low Comp Efficiency %
*In the surge limit
*Too high a Comp. RPM
You need to look at a different Compressor map cause the one your looking at is the wrong size, each Compressor trim has its own compressor map.
You also need to draw /find the surge limit line.
Its easy all you do is go to the bottom of the compressor map and draw a line from PR = 1 and airflow rate = 20% of maximum, and draw a line from that to the RPM point at which full boost starts 3500 and 5250, as long as this line stays to the right of the surge limit you're ok. This line represents your rpm line from zero PSI to full boost (10 PSI).
So from PR = 1
And flow rate at idle:
Max flow rate x .20 = idle flow rate
357.05 x .20 = 71.41 CFM
71.41 x .070318 = 5.02 LB/MIN
PR = 1
Airflow @ idle = 5.02 LB/MIN
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gdyby nie inne wydatki przewidziane na ten roku to może bym się zainteresował 
GRATULACJE!!! Jeszcze turbinka i bedziesz musial go sprawdzic na 1/4mili 
...Ale i tak moje uznanie ze przebrnoles przez najgorsze...teraz juz z gorki bedzie 
. Tymczasowo postaram się przerobić seryjne przeguby i złożyć tak, przynajmniej dopóki nie bedzie turbo to powinny wytrzymać.
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