What is pressure ratio on turbo map?
The Pressure Ratio is the total absolute pressure produced by the turbo divided by the atmospheric pressure (14.7 psi). The total absolute pressure is basically the atmospheric pressure plus the amount of boost we’re running/going to run.
What do turbo numbers mean?
Using Precision Turbo’s ‘chargers as examples, the numbers represent the diameters of the inducer and exducer on the compressor and turbine wheels (measured in millimeters, from tip to tip of the blades on each wheel). With a 62/66, the first two digits are the compressor wheel size (62mm).
How do you calculate turbo pressure ratio?
Calculating Pressure Ratio ( PR= P2c / P1c ) Pressure ratio is a variable equation that combines ambient pressure with gauge pressure divided by ambient pressure. This identifies where the compressor will perform its max duty cycle.
How do you calculate psi for boost?
You can ROUGHLY estimate max boost as follows. The 0.9 factor is the ~VE for the typical intake tract under non-boosted conditions. The number 3,456 is just a mathematical factor to make the units come out properly. 1,000/546 = 1.83*14.7 = 26.9 – 14.7 = 12.2psi is the approximate max boost at 6,000rpm with 1,000cfm.
How do you know what size turbo to get?
Most of the time, the size of the turbine depends on its wheel’s exducer diameter, or the part of the wheel air passes over last. A larger bore in the housing will typically yield more power. Sort of. The trick is keeping the turbine wheel’s diameter within 15 percent of the compressor wheel’s, give or take.
How do I know what size turbo I need?
The calculation is simple: Divide the absolute outlet pressure that you think you want (14.7 + boost pressure) by the absolute inlet pressure that the Earth says you can have (14.7) and you’ve got your pressure ratio.
What does the size of a turbocharger matter?
Typically, a turbocharger is sized to give sufficient surge margin, while also keeping the operational points on the compressor map at areas above 65-percent,” explained Rufini. Speed lines are the last additional bit of information contained within the compressor map.
What do the circles on a compressor map mean?
There will always be a specific area for any compressor where it is most efficient at creating pressure. These areas are called efficiency islands and are represented by oblong circles in the compressor map. These circles look very much like a topological map that indicates height for hills or mountains.
What do the islands on the compressor map mean?
The islands created on the compressor map are defined by the compressor’s ability to move air under pressure while adding the least amount of heat to the discharge air. Expressed as a percentage, they show how efficiently a given mass of air (in lbs/min.) is compressed at a given pressure ratio.
What does the bottom axis of a turbocharger mean?
The bottom axis represents the corrected mass flow. This is how much air the turbocharger flows per unit of time. This could be rated in Kilograms per second or pounds per minute (these are the two most common.) The vertical axis represents the pressure ratio of the compressor.