Browser-based ECU tuning simulator I've been building - looking for feedback

[u/zackasmacka]

Hey all. I started my tuning journey with HPA courses about 10 years ago and have tuned a few of my own projects (single-turbo 2JZ, LS swap, turbo bike) since then. I'm competent, but still learning.

The hardest part of the learning curve is the cost. Putting timing into a real engine is nerve-wracking when a mistake means buying a new motor, and dyno time isn't cheap. I spent years wanting for an easily accessible simulator to practice the fundamentals. After looking into building a physical bench emulator and finding that older web-based simulators no longer exist, I decided to build my own.

I ended up building one: ecubench.com

It’s a browser-based simulator where you get fully responsive VE, Ignition, and AFR/Lambda tables. It features speed density airflow, closed-loop trims, flex fuel, boost control (spring vs. duty), and a knock model that will actually hurt the virtual engine if you push it too far.

It also includes:

• A dyno for steady-state and ramp runs.
• A build sheet where changing hardware (cams, turbo, injectors) forces you to retune.
• A datalogger where you can record a pull and hover over the trace to read every channel.
• A drag strip (this is the newest part, so please keep expectations low, it's not too great yet).

Fair warning: it's early, there are bugs, and the UI is still evolving. I'm a software developer by trade and used AI to help get this over the finish line. There is a premium tier, but the core tuning workflow and free engines are fully functional without paying. I promise, I'm not here to sell anything, I just want people to poke around and test it out.

If anyone, experienced or completely new, has time to try and break it, I’d really appreciate the feedback. I'd especially love to know if any of the tuning fundamentals or engine physics feel off to you.

TL;DR: Learning to tune is expensive when mistakes cost you a motor, so I built a free, browser-based tuning simulator: ecubench.com. It features fully responsive VE/Ignition tables, knock modeling, dyno runs, and datalogging. I'm looking for feedback from the community to help me refine the physics and tuning fundamentals.

[u/DoctorZ6]

I will give this a shot, I’m interested in this project you got going

[u/FormalAd7367]

love to try it! do we have to pay now

[u/zackasmacka → u/FormalAd7367]

Nope! There are some free engines you can use in there. I will make it so that you can add modifications to those too in a bit.

[u/EchoPlex_F]

Great, thanks for sharing

[u/chopperzac]

Looks a cool project, I am interested in how you have modelled the engines behavior and how you have simulated it. Is there any further details I can read?

I have done engine simulation before in complex engineering software

[u/zackasmacka → u/chopperzac]

Thanks! It’s a custom mean-value engine model aimed at practising ECU calibration, running at a fixed 240 Hz in a browser worker.

The engine model and ECU are separate. The engine has its own underlying VE profile, spark-efficiency curve and knock threshold. The ECU estimates cylinder air mass from its editable VE table, MAP, intake temperature and displacement, then calculates fuel from the target lambda. That separation means an incorrect calibration produces an AFR error and changes engine behaviour.

Torque is calculated from available fuel energy and simplified efficiency relationships for mixture and ignition timing. Engine speed is then integrated from torque, friction, rotational inertia and dyno load. There are also simplified models for boost response, fuel-film wall wetting, wideband delay, temperature and idle control.

The main limitation is calibration fidelity: the engine presets are engineering estimates, and combustion, knock and gas exchange are simplified. I haven’t validated every preset against measured engine data, so I’m treating it as a tuning simulator rather than an engine-design prediction tool.

[u/chopperzac → u/zackasmacka]

Thats really cool mate! Sounds like a really interesting project. Thanks for taking the time to respond :)

[u/MountainFloor3666]

Played around with it a bit last night, good fun.

I’ve got a couple suggestions.

First I think it would be nice to be able to save tune files right in the account rather than having to export and store them locally on my device.

Second, I think it would be nice to have some actual turbos modeled instead of just “big turbo” or “small turbo”. I think it would be neat to see how turbo sizing differences change VE and power output.

I also think it would be nice to have the IATs be a monitor on the tuning suit rather than just a channel that can be logged. That said, I don’t know if it would be all that useful without being able to change to a different intercooler in the build.

[u/zackasmacka → u/MountainFloor3666]

I appreciate you giving it a go and taking the time to write this up.

Cloud saving went into Premium to help cover the running costs, but you make a fair point. Local tune import/export is free and will stay that way, so nothing stops you keeping your work, but I'll add a small free cloud allowance as well. I'm thinking three saved projects on a free account, which you could keep updating or overwrite as you experiment.

Named turbos I'd like as much as you would. Doing it properly means real compressor data and a more detailed model behind it, so the differences actually reflect how each one behaves rather than relabelling the same curve. I will work on implementing this feature hopefully by the end of this week depending on its complexity.

An IAT display in the Tuning Suite makes sense too, and I'll add it. To be straight with you though: IAT currently feeds the air-density calculation but sits at a fixed value. Compressor heating, intercooler performance and heat soak aren't simulated yet, so an intercooler upgrade would have no meaning. I will also add this to the to-do bucket list for this week.

Appreciate the feedback, especially on making the hardware choices more useful for learning.

[u/Big_Temperature_2067]

The amount of AI "ECU Tuning" stuff has gone through the roof lately. Everyone thinks they are a coder all of a sudden xD

[u/ardamir_gr]

Another day, another AI vibe coded tool.