Diesel Exhaust Backpressure Calculator: Riser & Silencer Reserve Only
Inputs
Customer Information
Maximum Allowable Backpressure
Select the correct units for the indicated Max Backpressure.
Engine Specs
Pipe System
Pipe Material
Silencer Reserve (15–50% of Max Backpressure)
⚠️ WARNING: This reserve value is not recommended by Centek Engineering.
This section reserves a portion of the maximum allowable backpressure for silencers. Centek
Engineering recommends using a 50% reserve to ensure best safety practices.
⚠️ Please fill in all required fields before calculating.
Outputs
Customer Name
N/A
Work Order
N/A
Engine Type
N/A
Description
Metric Units
US/Imperial Units
Turbo Diameter
0.00 m
0.00 in
Pipe Diameter
0.000 m
0.000 in
Exhaust Gas Temperature
0.00 °C
0.00 °F
Exhaust Gas Flowrate
0.00 m³/s
0.00 CFM
Gas Velocity (Turbo)
0.00 m/s
0.00 ft/s
Gas Velocity (Pipe)
0.00 m/s
0.00 ft/s
Turbo Inner Area
0.00 cm²
0.00 in²
Pipe Inner Area
0.00 cm²
0.00 in²
Density (rho)
0.00 kg/m³
0.00 lb/ft³
Dynamic Viscosity (mu)
0.00 Pa·s
0.00 lb/ft·s
Kinematic Viscosity (nu)
0.00 m²/s
0.00 ft²/s
Reynolds Number (Turbo)
0
Reynolds Number (Pipe)
0
Friction Factor
0.00
Flow Regime (Turbo)
Unknown
Flow Regime (Pipe)
Unknown
Equivalent Lengths
Pipe Component
Count
Equivalent Length (m)
Equivalent Length (ft)
Short Radius 90° Elbows
0
0.000
0.000
Long Radius 90° Elbows
0
0.000
0.000
45° Elbows
0
0.000
0.000
Pipe Type
Meters
Feet
Equivalent Length (m)
Equivalent Length (ft)
Flex Pipe (Bellows)
0.000
0.000
0.000
0.000
Straight Pipe
0.000
0.000
0.000
0.000
Total Equivalent Length of Pipe Components + Pipe Types
0.000
0.000
Pressure Outputs
Description
kPa
psi
inches H₂O
inches Hg
Turbo Pressure (Initial):
0.000
0.000
0.000
0.000
Backpressure: Max Allowed
0.000
0.000
0.000
0.000
Backpressure: Silencer Reserve %
0.000
0.000
0.000
0.000
Backpressure: Pipe (Darcy method)
0.000
0.000
0.000
0.000
Backpressure: Pipe (Swamee method)
0.000
0.000
0.000
0.000
Total Backpressure: Pipe + Silencer Reserve % (Darcy method)
0.000
0.000
0.000
0.000
Total Backpressure: Pipe + Silencer Reserve % (Swamee method)
0.000
0.000
0.000
0.000
The Darcy-Weisbach (Colebrook-White) method is a physics-based approach
that calculates pressure drop using fundamental fluid dynamics, accounting for flow
velocity, pipe diameter, total equivalent length, and internal surface roughness. For
enhanced confidence in results, the Swamee-Jain method, an explicit approximation
commonly used for rapid verification, is also provided. Minor variations between these
two methods are normal.
STATUS:
Important Notice
Whats New in 1.0.2:
Inclusion of Portal, Reset, Back, and Next buttons.
Inclusion of silencer reserve percentage.
Inclusion of Calculate button.
Values no longer update until calculate button is pressed.
Known Bugs:
PSI output not working properly.
Incorrect rounding on PSI output under certain conditions.
Upcoming Improvements:
Add combustion constant feature for enhanced accuracy.
Inclusion of all CENTEK silencers.
Inclusion of wet exhaust calculations.
Add dark mode ui.
Color adjustments.
Quality of life improvements. Submit any suggestions you have to me via email.