EDC15 Fueling & Power Calculator
Use this tool to estimate injection quantity (IQ, mg/str), fuel flow, and potential power for Bosch EDC15 diesel setups.
Estimation tool only. Real tuning still requires logs (MAF/MAP/IQ), EGT monitoring, and proper calibration of torque limiter, smoke limiter, duration map, and SOI map.
What is an EDC15 calculator?
An EDC15 calculator is a practical helper for people tuning older Bosch diesel ECUs (common on many 1.9 TDI and related engines). It gives quick ballpark numbers for airflow and fueling so you can make smarter map edits instead of guessing blindly.
In EDC15 tuning, one of the most common units is mg/str (milligrams per stroke). This is the language used in many maps such as:
- Driver wish
- Torque limiter
- Smoke limiter
- Duration map (in relation to requested fuel)
How this calculator works
1) Air mass estimate
The calculator estimates intake air density from boost pressure and temperature, then applies displacement and volumetric efficiency. This gives an approximate air mass available per engine cycle.
2) Fuel mass from AFR target
With a chosen target AFR, it converts available air into estimated fuel mass per stroke (IQ). Lower AFR (richer mixture) increases fueling request and usually smoke risk if airflow is not sufficient.
3) Power and torque estimation
Finally, using BSFC, it estimates theoretical power and torque at the entered RPM. This helps you sanity-check whether your requested IQ is in a realistic range for your turbo, injectors, and engine setup.
Typical ranges (rule-of-thumb)
| IQ (mg/str) | General interpretation | Notes |
|---|---|---|
| 25–40 | Stock / mild | Usually very safe with clean combustion on healthy systems. |
| 40–55 | Stage 1-ish | Common with moderate boost and careful smoke limiter tuning. |
| 55–70 | Stage 2 / larger nozzles | Requires better airflow and tighter calibration control. |
| 70+ | Aggressive build territory | High EGT and smoke risk if duration, timing, and boost are not aligned. |
How to use this in real map editing
- Set a realistic AFR target for your turbo and intended smoke level.
- Estimate IQ at your peak torque and peak power RPM zones.
- Cross-check those IQ values against torque limiter and smoke limiter axes.
- Make small map changes, then log MAF, MAP, IQ, and boost control behavior.
- Iterate carefully—never jump straight to extreme duration or boost values.
Important limitations
This calculator does not replace dyno testing, street logging, or professional calibration. It cannot detect:
- Nozzle flow imbalance
- Weak pump performance
- VNT control instability
- Incorrect SOI causing harsh combustion or high EGT
- Clutch slip or drivetrain losses
Treat the result as a planning number, then validate everything on real data.
Quick FAQ
Is this only for VW 1.9 TDI?
No. The logic is generic for many EDC15-style diesel setups, but default values are friendly for common 1.9 TDI builds.
Why include BSFC?
BSFC links fuel flow to power output. Better efficiency (lower BSFC) means more power for the same fuel mass flow.
Can I tune only from calculator results?
No. You still need logs, smoke/EGT observation, and safe calibration practices.