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FORMULAS FOR ESTIMATING VHP-G, GSI & GL BRAKEHORSEPOWER AND INTAKE MANIFOLD PRESSURE

VHP G Series Engines:1. The following are guides for estimating the average brake horsepower or intake manifold pressure of

VHP-G engines using standard timing. If the nameplate timing specifies a timing other than the

standard timings listed in Table 1 or Table 2, these formulas will not apply. The formulas are based on a

statistical average of test data. Reference Service Bulletin 14-2755A (or latest revision).

2. There are many factors that influence the accuracy of the formulas. The most influential are:

A. Exhaust Oxygen:

The only accepted method of measurement is with an exhaust oxygen meter analyzer to

measure the percentage of exhaust O2 present. Any other method will only increase the marginof error. See S-sheet S8483 (or latest revision) for percentages of excess exhaust oxygen as

related to the carburetor adjustment. The measurement must be taken at the exhaust elbows.

Reference Service Bulletin 14-2755A (or latest revision).

B. Spark Timing:

For ignition timing refer to Table 1 and Table 2 below. Reference Service Bulletin 14-2755A (or

latest revision).

C. Intake Manifold Pressure Measurements:

Use the taps that are provided in the intake manifold. Pressures are measured in inches of

mercury (inches Hg gauge) with a digital manometer. Reference Service Bulletin 14-2755A (or

latest revision).

NOTE: Other method s of measurement may increase the margin of error .

D. Intake Manifold Temperature Measurement:

Use the taps that are provided in the intake manifold. Temperatures should be measured by

thermocouple for maximum accuracy. Reference Service Bulletin 14-2755A (or latest revision).

NOTE: Other method s of measurement may increase the margin of error .

E. Site Altitude:

Altitude must be known at the engine site. Altitude is measured in feet.

F. Engine Speed:Use a digital tachometer to measure engine speed.

3. The engine must be in good operating condition and properly adjusted in order to obtain reasonable

agreement with these formulas.

4. These formulas are only good for engines operating on commercial quality natural gas. The use of

other fuels will increase the margin of error.

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NOTE: Changing the engine t iming w i l l also the exhaust emiss ions and fuel econom y.

CAUTION! Engine damage may result if detonation occurs. If detonation occurs at the specified name

plate timing, a timing adjustment be made to retard the ignition timing until NO audible detonation

exists.

The formulas below for VHP "G" gas engines are based on the following data ranges:45-110 psi BMEP

50-110F inlet air temperature

800-1200 rpm engine speed

Standard natural gas ignition timing

Exhaust oxygen 0.3% to 1.3% dry

Accuracy is 5% on power and 2 inches Hg for intake manifold pressure at rated load.

Table 1. Standard Ignition Timing Chart for "G" 8:1 Compression Ratio Engines

Engine 900-1200 RPM

F2895G 24BTDC

F3521G 24BTDCL5108G 24BTDC

L5790G 24BTDC

L7042G 24BTDC

P9390G 28BTDC

Table 2. Standard Ignition Timing Chart for "G" 10:1 Compression Ratio Engines

Engine 600-1000 RPM 1001-1200 RPM

F2895G 20BTDC 20BTDC

F3521G 22BTDC 24BTDC

L5108G 22BTDC 24BTDC

L5790G 20BTDC 20BTDC

L7042G 22BTDC 24BTDC

P9390G 24BTDC 24BTDC

To calculate power or intake manifold pressure use the following procedure:

a. Enter the value of each parameter identified in Column 1, into Column 2. use the units as given

in Column 1. For naturally aspirated engines, intake manifold pressure is actually a vacuum,

therefore enter this value as a negative, with a minus "-" sign in front of it. The factor "Intake Manifold

Pressure (Inches Hg gauge) X Engine Speed (rpm) will also be negative.

b. After entering the values in Column 2, the program will automatically multiply by the constants in

Column 3, calculate the results and total in Column 4.

c. The total BHP or IMP result at standard temperature (77F) in Column 4 will automatically be

inserted into the BHP77 or IMP77 in Column 7. Enter the value for the Intake Manifold Temperature

at Site (IMTsite ) or (BHPsite) in Column 5. The BHPsite or IMPsite will be calculated in Column 6.

Definitions:

IMPsi___ = Intake Manifold Pressure (inches Hg gauge) At Site Intake Manifold Temperature

IMP7 ___ = Intake Manifold Pressure (inches Hg gauge) At 77F Intake Manifold Temperature

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IMTsi___ = Intake Manifold Temperature (F) Measured At Site

VHP GSI Series Engines:

1. The following are guides for estimating the average brake horsepower or intake manifold pressure of

VHP-GSI engines using standard timing. If the nameplate timing specifies a timing other than thestandard timings listed in Table 3, these formulas will not apply. The formulas are based on a statistical

average of test data. Reference Service Bulletin 14-2755A (or latest revision).

2. There are many factors that influence the accuracy of the formulas. The most influential are:

A. Exhaust Oxygen:

The only accepted method of measurement is with an exhaust oxygen meter analyzer to

measure the percentage ofexhaust O2 present. Any other method will only increase the margin

of error. See S-sheet S8483 (or latest revision) for percentages of excess exhaust oxygen as

related to the carburetor adjustment. The measurement must betaken at the exhaust elbows

before the turbocharger. Reference Service Bulletin 14-2755A (or latest revision).

B. Spark Timing:

For ignition timing refer to Table 3 below. Reference Service Bulletin 14-2755A (or latestrevision).

C. Intake Manifold Pressure Measurements:

Use the taps that are provided in the intake manifold. Pressures are measured in inches of

mercury (inches Hg gauge) with a digital manometer. Reference Service Bulletin 14-2755A (or

latest revision).

NOTE: Other method s of measurement may increase the margin of error .

D. Intake Manifold Temperature Measurement:

Use the taps that are provided in the intake manifold. Temperatures should be measured by

thermocouple for maximum accuracy. Reference Service Bulletin 14-2755A (or latest revision).

NOTE: Other method s of measurement may increase the margin of error .

E. Site Altitude:

Altitude must be known at the engine site. Altitude is measured in feet.

F. Engine Speed:

Use a digital tachometer to measure engine speed.

3. The engine must be in good operating condition and properly adjusted in order to obtain reasonable

agreement with these formulas.

4. These formulas are only good for engines operating on commercial quality natural gas. The use of

other fuels will increase the margin of error.

NOTE: Changing the engine t iming w i l l also the exhaust emiss ions and fuel econom y.

CAUTION! Engine damage may result if detonation occurs. If detonation occurs at the specified name

plate timing, a timing adjustment be made to retard the ignition timing until NO audible detonation

exists.

The formulas below for VHP "GSI" gas engines are based on the following data ranges:

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65-160 psi BMEP

85-130F inlet water temperature

800-1200 rpm engine speed

Standard natural gas ignition timing

Exhaust oxygen 0.3% to 1.3% dry

Accuracy is 5% on power and 2 inches Hg for intake manifold pressure at rated load.

Table 3. Standard Ignition Timing Chart for "GSI" Engines

Engine 600-1000 RPM 1001-1200 RPM

F2895 21BTDC 21BTDC

F3521 24BTDC 24BTDC

L5108 18BTDC 15BTDC

L5790 21BTDC 21BTDC

L7042 24BTDC 24BTDC

P9390 21BTDC 21BTDC

To calculate power or intake manifold pressure use the following procedure:

a. Enter the value of each parameter identified in Column 1, into Column 2. Use the units as given

in Column 1.

b. After entering the values in Column 2, the program will automatically multiply by the constants in

Column 3, calculate the BHP results and total in Column 4.

VHP GL Series Engines:

1. The following are guides for estimating the average brake horsepower or intake manifold pressure of

VHP-GL engines using standard timing. If the nameplate timing specifies a timing other than the

standard timings listed in Table 3, these formulas will not apply. The formulas are based on a statistical

average of test data. Reference Service Bulletin 14-2755A (or latest revision).

2. There are many factors that influence the accuracy of the formulas. The most influential are:

A. Exhaust Oxygen:

The only accepted method of measurement is with an exhaust oxygen meter analyzer to

measure the percentage ofexhaust O2 present. Any other method will only increase the margin

of error. See S-sheet S8483 (or latest revision) for percentages of excess exhaust oxygen as

related to the carburetor adjustment. The measurement must be taken at the exhaust elbows

before the turbocharger. Reference Service Bulletin 14-2755A (or latest revision).

B. Spark Timing:

For ignition timing refer to Table 4 below. Reference Service Bulletin 14-2755A (or latest

revision).

C. Intake Manifold Pressure Measurements:

Use the taps that are provided in the intake manifold. Pressures are measured in inches of

mercury (inches Hg gauge) with a digital manometer. Reference Service Bulletin 14-2755A (or

latest revision).

NOTE: Other method s of measurement may increase the margin of error .

D. Intake Manifold Temperature Measurement:

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Use the taps that are provided in the intake manifold. Temperatures should be measured by

thermocouple for maximum accuracy. Reference Service Bulletin 14-2755A (or latest revision).

NOTE: Other method s of measurement may increase the margin of error .

E. Site Altitude:

Altitude must be known at the engine site. Altitude is measured in feet.

F. Exhaust Manifold Pressure:

Use the taps that are provided in the exhaust outlet. Pressures are measured in inches of

mercury (inches Hg) by a mechanical device.

NOTE: Other method s of measurement may increase the margin of error .

G. Engine Speed:

Use a digital tachometer to measure engine speed.

3. The engine must be in good operating condition and properly adjusted in order to obtain reasonable

agreement with these formulas.

4. These formulas are only good for engines operating on commercial quality natural gas. The use of

other fuels will increase the margin of error.

NOTE: Changing the engine t iming w i l l also the exhaust emiss ions and fuel econom y.

CAUTION! Engine damage may result if detonation occurs. If detonation occurs at the specified name

plate timing, a timing adjustment be made to retard the ignition timing until NO audible detonation

exists.

The formulas below for VHP "GL" gas engines are based on the following data ranges:

2895GL, 3521GL, 5790GL,7042GL,9390GL Engines

65-160 psi BMEP

85-130F inlet water temperature

800-1200 rpm engine speed

Standard natural gas ignition timing

Lambda=1.74 (9.8% O2 dry)

Accuracy is 5% on power and 2 inches Hg for intake manifold pressure at rated load.

Table 4. Standard Ignition Timing Chart for "GL" Engines

Engine 600-1000 RPM 1001-1200 RPM

F2895 10BTDC 11BTDC

F3521 10BTDC 10BTDCL5108 14BTDC 14BTDC

L5790 10BTDC 11BTDC

L7042 10BTDC 10BTDC

P9390 10BTDC 10BTDC

To calculate power or intake manifold pressure use the following procedure:

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a. Enter the value of each parameter identified in Column 1, into Column 2. Use the units as given

in Column 1.

b. After entering the values in Column 2, the program will automatically multiply by the constants in

Column 3, calculate the BHP results and total in Column 4.

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SAMPLE CALCULATION FOR A VHP "G":

The following example shows how to calculate estimated brake horsepower for a VHP "G" engine.

The engine is running at 1000 rpm at an altitude of 1000 ft., and has a measured site intake

manifold temperature of 95F and a measured site intake manifold pressure (vacuum) of -5

inches of mercury gauge. After performing the calculations in Table 1,insert the horsepower

value obtained for the standard 77F into the adjustment formula to obtain actual site estimatedhorsepower.

F2895G BHP Prediction

Column 1 Column 2 Column 3 Column 4

Parameter Multiplier Result

Compression Ratio (8.2 or 10) 10 x 5.24 = 52.4

Intake Manifold Pressure (Inches Hg gauge) -5.0 x 4.24 = -21.2

Engine Speed (RPM) 1000 x 0.41 = 410

Intake Manifold Pressure (Inches Hg gauge) -5 x Engine Speed (RPM) 1000 = -5000 x 0.0166 = -83

Exhaust Oxygen (% dry) 0.3 x -25.3 = -7.59

Altitude (ft) 1000 x -0.012 = -12

Intercept 1.00 x 10.7 = 10.7

BHP77= = 349.31

Intake Manifold Temperature (F) 95

Column 5 Column 6

BHP77 x 537/(460+IMTsite(F)) = BHPsite = 340.0

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SAMPLE CALCULATION FOR A VHP "GSI":

The following example shows how to calculate the expected intake manifold pressure (inches Hg gauge) for a

F2895GSI. The engine is running at 1000 rpm at an altitude of 1000 ft. It is driving a 95% efficient generator

with a measured output of 340 kWe. The radiator fan uses 26 horsepower. Intake manifold temperature is

measured at 130 F. The engine is equipped with a catalyst and so has an exhaust oxygen level of 0.3%.

Site power = (340 x 1.341) / 0.95 + 26 bhp = (456 / 0.95) + 26 = 480 + 26 = 506 bhp

F2895GSI Intake Manifold Prediction

Column 1 Column 2 Column 3 Column 4Parameter Multiplier Result

BHP 506 x 0.0183 = 9.26

Intake Manifold Temperature(F) 130 x 0.0379 4.93

Engine Speed (RPM) 1000 x -0.00689 = -6.9

BH 506 /RPM 1000 0.506 x 33.9 17.2

Exhaust Oxygen (% dry) 0.30 x 1.3 = 0.39

Altitude (ft) 1000 x 0.001 = 1

Intercept 1.00 x -18.3 = -18

Calculated Intake Manifold Pressure (Inches Hg gauge) = 7.54 2 inches Hg

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SAMPLE CALCULATION FOR A VHP "GL":

The following example shows how to calculate estimated brake horsepower

for a L7042GL. The engine is running at 1200 rpm. Altitude is 750 feet above

sea level. Engine settings are the standard 10 BTDC ignition timing and

9.8% exhaust oxygen. Intake manifold pressure was measured as

28.5 inches Hg gauge inches Hg gauge, and intake manifold temperature was

measured as 135 F.

L7042GL BHP Prediction

Column 1 Column 2 Column 3 Column 4

Parameter Multiplier Result

Intake Manifold Pressure (Inches Hg gauge) 28.5 x Engine Speed (RPM) 1200 = 34200 x 0.0281 = 961.02

Intake Manifold Temperature (F) 135 x -2.01 = -271.35

Engine Speed (RPM) 1200 x 0.461 = 553.2

Altitude (ft) 750 x -0.0281 = -21.075

Intercept 1.00 x 255 = 255

Calculated BHP = 1480

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F2895G, GSI, GL Prediction

F2895G BHP Prediction

Column 1 Column 2 Column 3 C

Parameter Multiplier R

Compression Ratio (8.2 or 10) x 5.24 =

Intake Manifold Pressure (Inches Hg gauge) x 4.24 =

Engine Speed (RPM) x 0.41 =

Intake Manifold Pressure (Inches Hg gauge) 0.00 x Engine 0 = x 0.0166 = Exhaust Oxygen (% dry) Speed x -25.3 =

Altitude (ft) (rpm) x -0.012 =

Intercept 1.00 x 10.7 =

Intake Manifold Temperature (F)

BHP77= =

BHP77 x 537/(460+IMTsite(F)) = BHPsite =

F2895G Intake Manifold Prediction

Column 1 Column 2 Column 3 C

Parameter Multiplier R

Compression Ratio (8.2 or 10) x -0.281 =

BHP x 0.0118 =

Engine Speed (RPM) x -0.00263 =

BHP 0 /RPM 0 x 35.8 =

Exhaust Oxygen (% dry) x 1.25 =

Altitude (ft) x 0.001 =

Intercept 1.00 x -17.2 =

Intake Manifold Temperature (F)

IMP77= =

(IMP77+29.92) x (460+IMTsite)/537-29.92 = IMPsite

F2895GSI BHP Prediction

Column 1 Column 2 Column 3 C

Parameter Multiplier R

Intake Manifold Pressure (Inches Hg gauge) x 5.16 =

Intake Manifold Temperature (F) x -0.74

Engine Speed (RPM) x 0.398 =

Intake Manifold Pressure (Inches Hg gauge) 0 x Engine 0 = x 0.0136 =

Exhaust Oxygen (% dry) Speed x -25.8 =

Altitude (ft) (rpm) x -0.0187 =

Intercept 1.00 x 82.4 =

Calculated BHP77= =

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F2895G, GSI, GL Prediction

F2895GSI Intake Manifold Prediction

Column 1 Column 2 Column 3 Col

Parameter Multiplier Res

BHP x 0.0183 =

Intake Manifold Temperature(F) x 0.0379

Engine Speed (RPM) x -0.00689 = BHP 0 /RPM 0 x 33.9

Exhaust Oxygen (% dry) x 1.3 =

Altitude (ft) x 0.001 =

Intercept 1.00 x -18.3 =

Calculated Intake Manifold Pressure (Inches Hg gauge) =

F2895GL BHP Prediction

Column 1 Column 2 Column 3 Col

Parameter Multiplier Res

Intake Manifold Pressure (Inches Hg gauge) x Engine = x 0.0112 =

Intake Manifold Temperature (F) Speed x -0.123

Engine Speed (RPM) (rpm) x 0.171 =

Altitude (ft) x -0.0112 =

Intercept 1.00 x 39.5 =Calculated BHP77= =

F2895GL Intake Manifold Prediction

Column 1 Column 2 Column 3 Col

Parameter Multiplier Res

BHP /RPM = x 86.5

Intake Manifold Temperature(F) x 0.0148

Engine Speed (RPM) x 0.0038 =

Altitude (ft) x 0.001 =

Intercept 1.00 x -22.2 =

Calculated Intake Manifold Pressure (Inches Hg gauge) =

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F3521G, GSI, GL Prediction

F3521G BHP Prediction

Column 1 Column 2 Column 3 C

Parameter Multiplier R

Compression Ratio (8.2 or 10) x 0.409 =

Intake Manifold Pressure (Inches Hg gauge) x 9.23 =

Engine Speed (RPM) x 0.431 =

Intake Manifold Pressure (Inches Hg gauge) 0.00 x Engine 0 = x 0.0164 = Exhaust Oxygen (% dry) Speed x -36.2 =

Altitude (ft) (rpm) x -0.015 =

Intercept 1.00 x 163 =

Intake Manifold Temperature (F) =

BHP77=

BHP77 x 537/(460+IMTsite(F)) = BHPsite =

F3521G Intake Manifold Prediction

Column 1 Column 2 Column 3 C

Parameter Multiplier R

Compression Ratio (8.2 or 10) x -0.0315 =

BHP x 0.0155 =

Engine Speed (RPM) x -0.00279 =

BHP 0 /RPM 0 x 23.2 =

Exhaust Oxygen (% dry) x 1.43 =

Altitude (ft) x 0.001 =

Intercept 1.00 x -20.2 =

Intake Manifold Temperature (F)

IMP77= =

(IMP77+29.92) x (460+IMTsite)/537-29.92 = IMPsite =

F3521GSI BHP Prediction

Column 1 Column 2 Column 3 C

Parameter Multiplier R

Intake Manifold Pressure (Inches Hg gauge) x 10.8 =

Intake Manifold Temperature (F) x -0.83

Engine Speed (RPM) x 0.394 =

Intake Manifold Pressure (Inches Hg gauge) 0 x Engine 0 = x 0.0126 =

Exhaust Oxygen (% dry) Speed x -26.5 =

Altitude (ft) (rpm) x -0.0234 =

Intercept 1.00 x 202 =

Calculated BHP77= =

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F3521G, GSI, GL Prediction

F3521GSI Intake Manifold Prediction

Column 1 Column 2 Column 3 Col

Parameter Multiplier Res

BHP x 0.0206 =

Intake Manifold Temperature(F) x 0.0379

Engine Speed (RPM) x -0.00569 =

BHP 0 /RPM 0 x 21.4 Exhaust Oxygen (% dry) x 1.16 =

Altitude (ft) x 0.001 =

Intercept 1.00 x -19.7 =

Calculated Intake Manifold Pressure (Inches Hg gauge) =

F3521GL BHP Prediction

Column 1 Column 2 Column 3 Col

Parameter Multiplier Res

Intake Manifold Pressure (Inches Hg gauge) x Engine = x 0.014 =

Intake Manifold Temperature (F) Speed x -0.0166

Engine Speed (RPM) (rpm) x 0.226 =

Altitude (ft) x -0.014 =

Intercept 1.00 x 40.2 =

Calculated BHP77= =

F3521GL Intake Manifold Prediction

Column 1 Column 2 Column 3 Col

Parameter Multiplier Res

BHP /RPM = x 71.2

Intake Manifold Temperature(F) x 0.00138

Engine Speed (RPM) x 0.00369 =

Altitude (ft) x 0.001 =

Intercept 1.00 x -22.7 =

Calculated Intake Manifold Pressure (Inches Hg gauge) =

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L5108G, GSI, GL Prediction

L5108G BHP Prediction

Column 1 Column 2 Column 3 Co

Parameter Multiplier ResCompression Ratio (8.2 or 10) x 14.4 =

Intake Manifold Pressure (Inches Hg gauge) x 6.31 =

Engine Speed (RPM) x 0.729 =

Intake Manifold Pressure (Inches Hg gauge) 0.00 x Engine 0 = x 0.0302 =

Exhaust Oxygen (% dry) Speed x -46.3 =

Altitude (ft) (rpm) x -0.0204 =

Intercept 1.00 x -69.9 =

Intake Manifold Temperature (F)

BHP77=

BHP77 x 537/(460+IMTsite(F)) = BHPsite

L5108G Intake Manifold Prediction

Column 1 Column 2 Column 3 Co

Parameter Multiplier ResCompression Ratio (8.2 or 10) x -0.429 =

BHP x 0.00561 =

Engine Speed (RPM) x -0.00327 =

BHP 0 /RPM 0 x 21.6 =

Exhaust Oxygen (% dry) x 1.35 =

Altitude (ft) x 0.001 =

Intercept 1.00 x -14.4 =

Intake Manifold Temperature (F)

IMP77= =

(IMP77+29.92) x (460+IMTsite)/537-29.92 = IMPsite =

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L5108G, GSI, GL Prediction

L5108GSI BHP Prediction

Column 1 Column 2 Column 3 ColumParameter Multiplier Resu

Intake Manifold Pressure (Inches Hg gauge) x 7.77 =

Intake Manifold Temperature (F) x -0.937

Engine Speed (RPM) x 0.634 =

Intake Manifold Pressure (Inches Hg gauge) 0 x Engine 0 = x 0.0245 =

Exhaust Oxygen (% dry) Speed x -44 =

Altitude (ft) (rpm) x -0.0323 =

Intercept 1.00 x 147 =

Calculated BHP77= =

L5108GSI Intake Manifold Prediction

Column 1 Column 2 Column 3 Colum

Parameter Multiplier Resu

BHP x 0.00893 =

Intake Manifold Temperature(F) x 0.0349

Engine Speed (RPM) x -0.00515 =

BHP 0 /RPM 0 x 21.6

Exhaust Oxygen (% dry) x 1.36 =

Altitude (ft) x 0.001 =

Intercept 1.00 x -19.5 =

Calculated Intake Manifold Pressure (Inches Hg gauge) =

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L5108G, GSI, GL Prediction

L5108GL BHP Prediction

Column 1 Column 2 Column 3 Colum

Parameter Multiplier Resul

Intake Manifold Pressure (Inches Hg gauge) x Engine = x 0.0199 =

Intake Manifold Temperature (F) Speed x -0.957 Engine Speed (RPM) (rpm) x 0.359 =

Altitude (ft) x -0.0199 =

Intercept 1.00 x 106 =

Calculated BHP77= =

L5108GL Intake Manifold Prediction

Column 1 Column 2 Column 3 Colum

Parameter Multiplier Resul

BHP /RPM = x 49.9

Intake Manifold Temperature(F) x 0.0479

Engine Speed (RPM) x -0.00018 =

Altitude (ft) x 0.001 =

Intercept 1.00 x -22.9 =

Calculated Intake Manifold Pressure (Inches Hg gauge) =

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L5790G, GSI, GL Prediction

L5790G BHP Prediction

Column 1 Column 2 Column 3 Col

Parameter Multiplier Res

Compression Ratio (8.2 or 10) x 23.7 =

Intake Manifold Pressure (Inches Hg gauge) x 1.8 =

Engine Speed (RPM) x 0.954 =

Intake Manifold Pressure (Inches Hg gauge) 0.00 x Engine 0 = x 0.0404 = Exhaust Oxygen (% dry) Speed x -59.2 =

Altitude (ft) (rpm) x -0.0247 =

Intercept 1.00 x -237 =

Intake Manifold Temperature (F)

BHP77= =

BHP77 x 537/(460+IMTsite(F)) = BHPsite =

L5790G Intake Manifold Prediction

Column 1 Column 2 Column 3 Col

Parameter Multiplier Res

Compression Ratio (8.2 or 10) x -0.508 =

BHP x 0.00337 = Engine Speed (RPM) x -0.00242 =

BHP 0 /RPM 0 x 19.8 =

Exhaust Oxygen (% dry) x 1.25 =

Altitude (ft) x 0.001 =

Intercept 1.00 x -14.8 =

Intake Manifold Temperature (F)

IMP77= =

(IMP77+29.92) x (460+IMTsite)/537-29.92 = IMPsite =

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L5790G, GSI, GL Prediction

L5790GSI BHP Prediction

Column 1 Column 2 Column 3 Colum

Parameter Multiplier Resu

Intake Manifold Pressure (Inches Hg gauge) x 10.5 =

Intake Manifold Temperature (F) x -1.01

Engine Speed (RPM) x 0.734 =

Intake Manifold Pressure (Inches Hg gauge) 0 x Engine 0 = x 0.0274 = Exhaust Oxygen (% dry) Speed x -50.6 =

Altitude (ft) (rpm) x -0.0379 =

Intercept 1.00 x 178 =

Calculated BHP77= =

L5790GSI Intake Manifold Prediction

Column 1 Column 2 Column 3 Colum

Parameter Multiplier Resu

BHP x 0.00815 =

Intake Manifold Temperature(F) x 0.0374

Engine Speed (RPM) x -0.00533 =

BHP 0 /RPM 0 x 17.7

Exhaust Oxygen (% dry) x 1.34 =

Altitude (ft) x 0.001 =

Intercept 1.00 x -19.6 =

Calculated Intake Manifold Pressure (Inches Hg gauge) =

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L5790G, GSI, GL Prediction

L5790GL BHP Prediction

Column 1 Column 2 Column 3 Colum

Parameter Multiplier Resul

Intake Manifold Pressure (Inches Hg gauge) x Engine = x 0.0227 =

Intake Manifold Temperature (F) Speed x -0.575

Engine Speed (RPM) (rpm) x 0.364 =

Altitude (ft) x -0.0227 = Intercept 1.00 x 91.5 =

Calculated BHP77= =

L5790GL Intake Manifold Prediction

Column 1 Column 2 Column 3 Colum

Parameter Multiplier Resul

BHP /RPM = x 43.3

Intake Manifold Temperature(F) x 0.0244

Engine Speed (RPM) x 0.00194 =

Altitude (ft) x 0.001 =

Intercept 1.00 x -21.5 =

Calculated Intake Manifold Pressure (Inches Hg gauge) =

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L7042G, GSI, GL Prediction

L7042G BHP Prediction

Column 1 Column 2 Column 3 Co

Parameter Multiplier Re

Compression Ratio (8.2 or 10) x 17.7 =

Intake Manifold Pressure (Inches Hg gauge) x 13.4 =

Engine Speed (RPM) x 0.977 =

Intake Manifold Pressure (Inches Hg gauge) 0.00 x Engine 0 = x 0.0381 = Exhaust Oxygen (% dry) Speed x -58.8 =

Altitude (ft) (rpm) x -0.03 =

Intercept 1.00 x 46.2 =

Intake Manifold Temperature (F)

BHP77= =

BHP77 x 537/(460+IMTsite(F) = BHPsite =

L7042G Intake Manifold Prediction

Column 1 Column 2 Column 3 Co

Parameter Multiplier Re

Compression Ratio (8.2 or 10) x -0.365 =

BHP x 0.0062 = Engine Speed (RPM) x -0.0032 =

BHP 0 /RPM 0 x 13 =

Exhaust Oxygen (% dry) x 1.19 =

Altitude (ft) x 0.001 =

Intercept 1.00 x -16.4 =

Intake Manifold Temperature (F)

IMP77= =

(IMP77+29.92) x (460+IMTsite)/537-29.92 = IMPsite =

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L7042G, GSI, GL Prediction

L7042GSI BHP Prediction

Column 1 Column 2 Column 3 Colu

Parameter Multiplier Resu

Intake Manifold Pressure (Inches Hg gauge) x 15.6 =

Intake Manifold Temperature (F) x -0.964

Engine Speed (RPM) x 0.838 = Intake Manifold Pressure (Inches Hg gauge) 0 x Engine 0 = x 0.0302 =

Exhaust Oxygen (% dry) Speed x -50.9 =

Altitude (ft) (rpm) x -0.0458 =

Intercept 1.00 x 262 =

Calculated BHP77= =

L7042GSI Intake Manifold Prediction

Column 1 Column 2 Column 3 Colu

Parameter Multiplier Resu

BHP x 0.00833 =

Intake Manifold Temperature(F) x 0.025

Engine Speed (RPM) x -0.00495 =

BHP 0 /RPM 0 x 13.2

Exhaust Oxygen (% dry) x 1.14 =

Altitude (ft) x 0.001 = Intercept 1.00 x -19.2 =

Calculated Intake Manifold Pressure (Inches Hg gauge) =

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L7042G, GSI, GL Prediction

L7042GL BHP Prediction

Column 1 Column 2 Column 3 Colum

Parameter Multiplier Resu

Intake Manifold Pressure (Inches Hg gauge) x Engine = x 0.0281 = Intake Manifold Temperature (F) Speed x -2.01

Engine Speed (RPM) (rpm) x 0.461 =

Altitude (ft) x -0.0281 =

Intercept 1.00 x 255 =

Calculated BHP77= =

L7042GL Intake Manifold Prediction

Column 1 Column 2 Column 3 Colum

Parameter Multiplier Resu

BHP /RPM = x 35.1

Intake Manifold Temperature(F) x 0.0691

Engine Speed (RPM) x 0.003 =

Altitude (ft) x 0.001 =

Intercept 1.00 x -27.9 =

Calculated Intake Manifold Pressure (Inches Hg gauge) =

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P9390G, GSI, GL Prediction

P9390G BHP Prediction

Column 1 Column 2 Column 3 Col

Parameter Multiplier Res

Compression Ratio (8.2 or 10) x 38.7 =

Intake Manifold Pressure (Inches Hg gauge) x 7.91 =

Engine Speed (RPM) x 1.43 =

Intake Manifold Pressure (Inches Hg gauge) 0.00 x Engine 0 = x 0.0622 = Exhaust Oxygen (% dry) Speed x -111 =

Altitude (ft) (rpm) x -0.04 =

Intercept 1.00 x -232 =

Intake Manifold Temperature (F)

BHP77= =

BHP77 x 537/(460+IMTsite(F) = BHPsite =

P9390G Intake Manifold Prediction

Column 1 Column 2 Column 3 Col

Parameter Multiplier Res

Compression Ratio (8.2 or 10) x -0.596 =

BHP x 0.00224 = Engine Speed (RPM) x -0.00166 =

BHP 0 /RPM 0 x 11.9 =

Exhaust Oxygen (% dry) x 1.57 =

Altitude (ft) x 0.001 =

Intercept 1.00 x -14.9 =

Intake Manifold Temperature (F)

IMP77= =

(IMP77+29.92) x (460+IMTsite)/537-29.92 = IMPsite =

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P9390G, GSI, GL Prediction

P9390GSI BHP Prediction

Column 1 Column 2 Column 3 Colum

Parameter Multiplier Resu

Intake Manifold Pressure (Inches Hg gauge) x 15.4 =

Intake Manifold Temperature (F) x -0.144

Engine Speed (RPM) x 1.06 = Intake Manifold Pressure (Inches Hg gauge) 0 x Engine 0 = x 0.0445 =

Exhaust Oxygen (% dry) Speed x -97.5 =

Altitude (ft) (rpm) x -0.0599 =

Intercept 1.00 x 170 =

Calculated BHP77= =

P9390GSI Intake Manifold Prediction

Column 1 Column 2 Column 3 Colum

Parameter Multiplier Resu

BHP x 0.00538 =

Intake Manifold Temperature(F) x -0.00255

Engine Speed (RPM) x -0.00404 =

BHP 0 /RPM 0 x 11.2

Exhaust Oxygen (% dry) x 1.63 =

Altitude (ft) x 0.001 =

Intercept 1.00 x -16.4 =

Calculated Intake Manifold Pressure (Inches Hg gauge) =

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P9390G, GSI, GL Prediction

P9390GL BHP Prediction

Column 1 Column 2 Column 3 Colum

Parameter Multiplier Resul

Intake Manifold Pressure (Inches Hg gauge) x Engine = x 0.0375 = Intake Manifold Temperature (F) Speed x -1.06

Engine Speed (RPM) (rpm) x 0.473 =

Altitude (ft) x -0.0375 =

Intercept 1.00 x 335 =

Calculated BHP77= =

P9390GL Intake Manifold Prediction

Column 1 Column 2 Column 3 Colum

Parameter Multiplier Resul

BHP /RPM = x 26.4

Intake Manifold Temperature(F) x 0.0278

Engine Speed (RPM) x 0.00699 =

Altitude (ft) x 0.001 =

Intercept 1.00 x -28.3 =

Calculated Intake Manifold Pressure (Inches Hg gauge) =

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L5115GL Prediction

5115GL BHP Prediction

Column 1 Column 2 Column 3 C

Parameter Multiplier R

Intake Manifold Pressure (Inches Hg gauge) x 22.49 =

Intake Manifold Temperature (F) x -1.27 =

Exhaust Manifold Pressure (Inches Hg gauge) x 4.49 =

Exhaust Oxygen (% dry) x -173 = Ignition Timing (BTDC) x 14.6 =

Waukesha Knock IndexTM

(WKITM

) x -0.312 =

Engine Speed (RPM) x 0.342 =

Altitude (ft) x -0.027 =

Intercept 1.00 x 1735 =

Calculated BHP77= =

5115GL Intake Manifold Prediction

Column 1 Column 2 Column 3 C

Engine Speed (RPM) x -0.0254 =

Exhaust Oxygen (% dry) x 0.42 =

BHP x 0.00699 =

Ignition Timing (BTDC) x -0.00899 =

Waukesha Knock IndexTM

(WKITM

) x 0.0205 = Intake Manifold Temperature (F) x 0.056 =

Exhaust Manifold Pressure (Inches Hg gauge) x 0.84 =

Altitude (ft) x 0.00016 =

Intercept 1.00 x 10.84 =

Calculated Intake Manifold Pressure (Inches Hg gauge) =

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Column 1 Column 2 Column 3

Parameter (User Inputs) Multiplier

Intake Manifold Pressure (Inches Hg gauge) x 24.0471 =

Intake Manifold Temperature (F) x -0.9570 =

Exhaust Oxygen (% dry) x -32.6793 =Ignition Timing (BTDC) x 6.6498 =

Waukesha Knock IndexTM

(WKITM

) x -1.4489 =

Engine Speed (RPM) x 0.5845 =

Altitude (ft) x -0.0240 =

Intercept 1.00 x 7.0878 =

Calculated BHP =

This formula for the VHP 3524GSI gas engine is based on the following data ranges:

-12.9) - 15. IMP (in Hg) 700 - 1200 Engine Speed (Rpm)

111- 144 IMT (F) 225 - 925 BHP

0.22 - 1.56 Exhaust oxygen ( % dry) 50 - 173 BMEP (psi)

12 - 27 Ignition timing (BTDC) 130 - 150 ICWT (F)

37 - 94 WKITM

180 - 240 JWT (F)

Bhp Prediction Accuracy is 36 Bhp ( 4.3 % on power at a rated load of 840 Bhp @ 1200 Rpm

Column 1 Column 2 Column 3

Parameter (User Inputs) Multiplier

Brake Horsepower (BHP) x 0.0416 =

Intake Manifold Temperature (F) x 0.0398 =

Exhaust Oxygen (% dry) x 1.3590 =

Ignition Timing (BTDC) x -0.2765 =Waukesha Knock Index

TM(WKI

TM) x 0.0603 =

Engine Speed (RPM) x -0.0243 =

Altitude (ft) x 0.0010 =

Intercept 1.00 x -0.2947 =

Calculated IMP =

This formula for the VHP 3524GSI gas engine is based on the following data ranges:

-12.9) - 15. IMP (in Hg) 700 - 1200 Engine Speed (Rpm)

111- 144 IMT (F) 225 - 925 BHP

0.22 - 1.56 Exhaust oxygen ( % dry) 50 - 173 BMEP (psi)

12 - 27 Ignition timing (BTDC) 130 - 150 ICWT (F)

37 - 94 WKITM

180 - 240 JWT (F)

Bhp Prediction Accuracy is 36 Bhp ( 4.3 % on power at a rated load of 840 Bhp @ 1200 Rpm

BRAKE HORSEPOWER PREDICTING FORMULA -- VHP 3524GSI

INTAKE MANIFOLD PRESSURE PREDICTING FORMULA -- VHP 3524GSI

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Column 4

Result

IMP 11.3

IMT 127

EXH O2 0.30 TIMING 22

WKI 94.0

RPM 1200

ALTITUDE 800

7

7 BHP 840

)

Column 4

Result

BHP 840

IMT 127

EXH O2 0.30

TIMING 22 WKI 94.0

RPM 1200

ALTITUDE 800

-0.3

-0.3 IMP 11.3

)

Sample Calculation

Sample Calculation

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Column 1 Column 2 Column 3

Parameter (User Inputs) Multiplier

Intake Manifold Pressure (Inches Hg gauge) x 39.348812 =

Intake Manifold Temperature (F) x -1.00296 =

Exhaust Oxygen (% dry) x -50.07904 =Ignition Timing (BTDC) x 7.6696731 =

Waukesha Knock IndexTM

(WKITM

) x -1.969549 =

Engine Speed (RPM) x 0.8394128 =

Altitude (ft) x -0.039349 =

Intercept 1.00 x 17.23084 =

Calculated BHP =

This formula for the VHP 5794GSI gas engine is based on the following input/output ranges:

(-12) - 17 IMP (in Hg) 700 - 1200 Engine Speed (Rpm)

117 - 145 IMT (F) 372 -1518 BHP

0.1 - 1.7 Exhaust O2 ( % dry) 50 - 173 BMEP (psi)

12 - 27 Ignition timing (BTDC) 128 - 153 ICWT (F)

36 - 95 WKITM

180 - 241 JWT (F)

Bhp Prediction Accuracy: 64 Bhp ( 4.6% at rated load of 1380 Bhp @ 1200 Rpm)

Column 1 Column 2 Column 3

Parameter (User Inputs) Multiplier

Brake Horsepower (BHP) x 0.0254137 =

Intake Manifold Temperature (F) x 0.025489 =

Exhaust Oxygen (% dry) x 1.2726951 =

Ignition Timing (BTDC) x -0.194915 =Waukesha Knock Index

TM(WKI

TM) x 0.0500536 =

Engine Speed (RPM) x -0.021333 =

Altitude (ft) x 0.001 =

Intercept 1.00 x -0.4379 =

Calculated IMP =

This formula is based on the following input/output ranges:

(-12) - 17 IMP (in Hg) 700 - 1200 Engine Speed (Rpm)

117 - 145 IMT (F) 372 -1518 BHP

0.1 - 1.7 Exhaust O2 ( % dry) 50 - 173 BMEP (psi)

12 - 27 Ignition timing (BTDC) 128 - 153 ICWT (F)

36 - 95 WKITM

180 - 241 JWT (F)

Bhp Prediction Accuracy: 64 Bhp ( 4.6% at rated load of 1380 Bhp @ 1200 Rpm)

BRAKE HORSEPOWER PREDICTING FORMULA -- VHP 5794GSI

INTAKE MANIFOLD PRESSURE PREDICTING FORMULA -- VHP 5794GSI

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Column 4

Result

IMP 13.7

IMT 129

EXH O2 0.40 TIMING 24

WKI 94.3

RPM 1200

ALTITUDE 800

17

17 BHP 1380

Column 4

Result

BHP 1380

IMT 129

EXH O2 0.40

TIMING 24 WKI 94.3

RPM 1200

ALTITUDE 800

-0.4

-0.4 IMP 13.7

Sample Calculation

Sample Calculation

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Column 1 Column 2 Column 3 Column 4

Parameter (User Inputs) Multiplier Result

Intake Manifold Pressure (Inches Hg gauge) x 45.990 =

Intake Manifold Temperature (F) x -1.368 =

Exhaust Oxygen (% dry) x -58.047 = Ignition Timing (BTDC) x 10.632 =

Waukesha Knock IndexTM

(WKITM

) x -2.811 =

Engine Speed (RPM) x 1.060 =

Altitude (ft) x -0.04599 =

Intercept 1.00 x 104.939 = 105

Calculated BHP = 105

This formula for the VHP 7044GSI gas engine is based on the following data ranges:

(-13.8) - 15.6 IMP (in Hg) 700 - 1200 Engine Speed (Rpm)

115 - 143 IMT (F) 444 - 1843 BHP

0.16 - 1.56 Exhaust O2 ( % dry) 50 - 173 BMEP (psi)

12 - 27 Ignition timing (BTDC 130 - 150 ICWT (F)

37 - 94 WKITM

180 - 240 JWT (F)

Bhp Prediction Accuracy is 84 Bhp ( 5.0% on power at a rated load of 1680 Bhp @ 1200 Rpm)

Column 1 Column 2 Column 3 Column 4

Parameter (User Inputs) Multiplier Result

Brake Horsepower (BHP) x 0.022 =

Intake Manifold Temperature (F) x 0.030 =

Exhaust Oxygen (% dry) x 1.262 =

Ignition Timing (BTDC) x -0.231 = Waukesha Knock Index

TM(WKI

TM) x 0.061 =

Engine Speed (RPM) x -0.023 =

Altitude (ft) x 0.001 =

Intercept 1.00 x -2.282 = -2.3

Calculated IMP = -2.3

This formula for the VHP 7044GSI gas engine is based on the following data ranges:

(-13.8) - 15.6 IMP (in Hg) 700 - 1200 Engine Speed (Rpm)

115 - 143 IMT (F) 444 - 1843 BHP

0.16 - 1.56 Exhaust O2 ( % dry) 50 - 173 BMEP (psi)

12 - 27 Ignition timing (BTDC 130 - 150 ICWT (F)

37 - 94 WKITM

180 - 240 JWT (F)

Bhp Prediction Accuracy is 84 Bhp ( 5.0% on power at a rated load of 1680 Bhp @ 1200 Rpm)

BRAKE HORSEPOWER PREDICTING FORMULA -- VHP 7044GSI

INTAKE MANIFOLD PRESSURE PREDICTING FORMULA -- VHP 7044GSI

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IMP 12.2

IMT 126

EXH O2 0.29TIMING 22

WKI 94.3

RPM 1200

ALTITUDE 800

BHP 1680

BHP 1680

IMT 126

EXH O2 0.29

TIMING 22WKI 94.3

RPM 1200

ALTITUDE 800

IMP 12.2

Sample Calculation

Sample Calculation