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Getting started
The method: stock to finalYour first session, step by stepTroubleshooting
Engine & fuel
VE and speed-density fuellingLambda, AFR and target mixturesInjector scaling and dead timeFuel system capacityE85 and the stoich setting
Spark & knock
Ignition timing and MBTKnock, knock sensors and false knock
Boost, heat & limits
Boost control and wastegatesHeat: IAT, EGT, coolant and protectionMechanical limits
Reading results
Reading a dyno sheet and logCorrection factors and fair comparisons
Reference
Same concept, different namesWhat real software has that this does not (yet)
Engine & fuel

E85 and the stoich setting

Same λ targets, much more fuel, lots of knock margin, cooler charge. The ECU must know which fuel is in the tank.

Ethanol blends need far more fuel per unit of air: E85's stoichiometric ratio is about 9.8:1 against gasoline's 14.7:1. The λ targets do not change — best power is still around 0.86 — but the mass of fuel behind each λ does. The ECU's stoich setting is the number that converts λ into fuel mass.

Switch to E85 without changing the stoich setting and the engine runs about 1.5× lean: λ 0.78 becomes λ 1.17 under boost. On a turbo car that melts a piston in one pull.

What you get for it

  • Knock resistance comparable to 100-octane race fuel: timing that knocked on 93 does not knock on E85.
  • The fuel evaporates and cools the charge noticeably, which raises density and knock margin further.
  • Lower exhaust temperature for the same load.

What it costs

  • ~40 % more injector duty and pump flow. Check capacity before the first pull.
  • VE will read slightly different because the cooler, denser charge and different fuel density are not in the ECU's model; correct from the wideband as usual.
  • Real cars also need cold-start, flex-fuel blending and materials compatibility, which this simulator leaves out.
Now try it.

Set the injector data, stoich and limits on a virtual car, then pull it and see what the numbers do. Free, in the browser, no account.

Open the Scalars tab in the dyno →