Engine Calculator

ENGINE
CALCULATOR

PHYSICS-BASED SPARK ADVANCE MODELLING

A precision engineering tool for computing Minimum advance for Best Torque (MBT) ignition timing across full RPM and MAP operating ranges — with integrated cam × head × manifold VE physics, knock safety modelling, exhaust-enthalpy turbocharger spool simulation, and a full dyno graph.

Integrated VE Model Turbo Enthalpy Spool Multi-Fuel Dyno Graph Knock Safety Editable Timing Table

LOW ADV

HIGH ADV

CORE FEATURES

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INTEGRATED VE MODEL

Cam × head × manifold computed together. Piston-velocity-weighted flow integral over the actual valve event, coupled to IVC timing and Helmholtz manifold resonance.

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MBT TIMING ENGINE

Full thermodynamic chain: VE, charge temp, DCR from slider-crank, Arrhenius knock, MFB50 target, geometry-derived burn duration, squish velocity, and dynamic compression ratio.

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KNOCK SAFETY MODELLING

End-gas temperature margin above autoignition threshold, configurable knock zone and max retard. Dedicated KNOCK MARGIN tab shows ΔT margin across the full RPM × MAP grid.

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TURBOCHARGER SIMULATION

Full compressor map with surge/choke detection, wastegate setpoint, boost ramp, intercooler efficiency, and per-cell EMAP from exhaust energy balance. 40+ turbo library.

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PHYSICS-BASED DYNO

Exhaust enthalpy spool model — turbine vs compressor power at each 5 ms step, A/R-scaled. Both NA and turbo start at −10 psig / 500 RPM. Calibrated to GTX3584RS twin on 325 ci.

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MULTI-FUEL SUPPORT

Built-in: 91 AKI, 93 AKI, E50, E85, E100, methanol. Full Arrhenius parameters, stoich AFR, LHV, charge cooling, and laminar flame speed per fuel.

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EDITABLE TIMING TABLE

Cell selection, multi-select ranges, ±1° incremental adjustment, bilinear smoothing. Compare against unconstrained MBT to visualise knock retard margin per cell.

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PROJECT PERSISTENCE

All engine, cam, fuel, turbo, head, and manifold data serialised to .eproject XML. Save and load between sessions. Full Excel workbook export with heat-map colours.

PHYSICS ENGINE

INTEGRATED VE (CAM × HEAD × MANIFOLD)

meanFlow = Σ(FlowBench(lift(θ)) × |v_piston(θ)|)
         ÷ Σ|v_piston(θ)|

vePeak = 0.85 × (meanFlow / 82)^0.27

N_opt  = 247500 / IVC × (1 + (dur−240)/600)

MBT ADVANCE TARGET

θ_MBT = MFB50_target + θ_burn + θ_delay

θ_burn  = [K1×(1000/N)^p + K2×(N/1000)^q]
         × (Patm/MAP)^0.35 × (SL_ref/SL)^0.5

θ_delay = A × P^(−n) × exp(Ea/RT) × (N/60) × 6

KNOCK MARGIN

T_crank = T_IVC × DCR^(γ−1)

Margin  = (AutoignitionK + SquishBonus)
        − T_crank

θ_final = MaxRetard + (Margin/Zone)
         × (θ_MBT − MaxRetard)

TURBO SPOOL (DYNO — PER 5 ms STEP)

P_turb   = ṁ_exh × Cp_exh × T_exh
           × η_turbine × √(0.83/A_R)

P_comp   = ṁ_air × Cp_air × ΔT / η_mech

dMAP/dt  = 0.0373 × max(0, P_turb−P_comp)

⚠️ LEGAL DISCLAIMER

LIMITATION OF LIABILITY & DISCLAIMER OF WARRANTIES

FOR INFORMATIONAL AND EDUCATIONAL PURPOSES ONLY. This software and all outputs are provided solely for informational, research, and educational purposes. The outputs do not constitute professional engineering advice, calibration recommendations, or ECU tuning guidance of any kind.

ASSUMPTION OF RISK. Internal combustion engines are complex mechanical systems subject to variables this software cannot fully model — manufacturing tolerances, fuel quality variation, coolant temperature, altitude, sensor accuracy, engine wear, and real-world operating conditions. Applying any timing value derived from this software to an actual engine carries inherent risk of engine damage, catastrophic mechanical failure, fire, injury, or death.

LIMITATION OF LIABILITY. To the fullest extent permitted by law, the authors and contributors shall not be liable for any direct, indirect, incidental, special, or consequential damages arising from use of or reliance on this software, even if advised of the possibility of such damages.

USER RESPONSIBILITY. Any person who applies timing values derived from this software to a vehicle or engine does so entirely at their own risk. All ignition timing calibration should be performed by a qualified engineer using validated data acquisition equipment under controlled conditions with conservative initial values.

By clicking “I Acknowledge — Continue” you confirm that you have read, understood, and accepted this disclaimer in its entirety.