JTI Tuning Cheat Sheet v2

Engine

Target HP

Peak boost kPa gauge

Displacement L

Cylinders

Max RPM

Spec'd Parts

Injectors cc/min rated

Injector rating pressure bar

Base fuel pressure bar — 4bar FPR on car

Injector dead time ms @ 13.8V

Fuel pump LPH rated

Pump derate @ boost rail %

Fueling

Ethanol content % — drives density & stoich

Full-power lambda

BSFC lb/hp·hr — FI E85 ≈ 0.84–1.05

Max injector duty %

Conditions

Ambient air °C

Ambient pressure kPa

Charge air temp °C post-intercooler

—

injectors pump convergence

From Airflow · what the engine demands

Max fuel flow

— LPH

Per-cyl fuel

— cc/min

Injector needed @ IDC

— cc/min

Estimated HP from BSFC

—

From Target HP · what the goal requires

Pump needed

— LPH

Injector needed

— cc/min

Target AFR

—

Stoich · density

—

Hardware, corrected

Effective injector flow

— cc/min

Effective pump flow

— LPH

Summary duty

— %

Peak IDC, worst PW cell

— %

VE table — editable (load % × RPM)

Type over any cell. Max VE for the airflow method reads the whole table.

Boost target multiplier — editable (fraction of peak boost)

Injector pulse width (ms) — ideal gas law, incl. dead time

Cells over your max duty glow hot. Cylinder air mass uses charge air temp, absolute manifold pressure = ambient + boost × multiplier.