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VE (volumetric efficiency) calculator
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| // from https://atgtraining.com/atg-volumetric-efficiency-calculator/ | |
| const calculateVe = ({engineSize, rpm, maf, iat, cylinder, pressuure, mafSelection, iatSelection, pressureSelection}) => { | |
| let val = 0, cid = 0, lb = 0, degc = 0, degf = 0, tempK = 0, v = 0, molorMass = 0.28705, gb_air_vol = 0, gsec = 0; | |
| let gb_theo_air_vol = 0, lMin = 0, estv = 0, load = 0, cylAir = 0, refCylAir = 0, estGross = 0, estRWHP = 0; | |
| cid = engineSize / 0.0163871; | |
| if (mafSelection == 0) { // g/sec | |
| lb = maf * 0.00220462 * 60; | |
| } else { // lb/min | |
| gsec = maf / (0.00220462 * 60); | |
| maf = gsec; | |
| lb = gsec * 0.00220462 * 60; | |
| } | |
| if (iatSelection == 0) { // fahrenheit | |
| degc = (iat - 32) * 5 / 9; | |
| } else { // celsius | |
| degf = iat * 9 / 5 + 32; | |
| degc = (degf - 32) * 5 / 9; | |
| } | |
| tempK = degc + 273.15; | |
| degc = (degc).toFixed(2); | |
| tempK = (tempK).toFixed(2); | |
| if (pressureSelection == 0) { // kPa | |
| } else { // in/hg | |
| pressuure = pressuure / 0.2953; | |
| } | |
| v = (maf * tempK * 0.28705) / pressuure; | |
| gb_air_vol = v * 60; | |
| gb_theo_air_vol = engineSize * rpm / 2; | |
| estv = (gb_air_vol / gb_theo_air_vol) * 100; | |
| cylAir = maf * 120 / (rpm * cylinder); | |
| refCylAir = engineSize * 1.168 / cylinder; | |
| estGross = lb * 10; | |
| estRWHP = estGross * 0.85; | |
| load = (cylAir / refCylAir) * 100; | |
| return { | |
| cylAir, | |
| refCylAir, | |
| estGross, | |
| estRWHP, | |
| estv, | |
| load | |
| } | |
| } | |
| console.log(calculateVe({ | |
| // constant | |
| engineSize: parseFloat('4.0'), // liters | |
| cylinder: parseInt('8'), | |
| // unit selections | |
| mafSelection: 0, | |
| iatSelection: 0, | |
| pressureSelection: 0, | |
| // variables | |
| rpm: parseInt('6500'), // rpm | |
| maf: parseFloat('145.00'), // g/sec | |
| iat: parseInt('100'), // fahrenheit | |
| pressuure: parseFloat('101.325'), // kaPa | |
| })) |
In terms of air/fuel ratio, pump gas is usually around 12.5:1 for maximum power and you add fuel with boost for safety. 10.5 or 11 isn't uncommon on boosted engines.
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AFR below 10: too rich; can seriously foul spark plugs and eventually wash the oil off cylinder walls
AFR above 13: too lean; run too hot