onRails

Your private race engineer, in your sim cockpit.

Build a race setup. Fix what is making you slow. Do it without leaving your sim.

onRails is a transparent overlay that sits on top of your sim. Answer a few questions about how the car feels, and it helps you build a complete setup: springs, dampers, aero, brakes, diff, tailored to your car and track. Then, lap by lap or mid-race, tell it what the car's doing wrong and get the exact change to fix it. No spreadsheets, no alt-tabbing, no downloading a stranger's setup and hoping it works for your style.

Four tools. Two modules.

Setup Developer: builds your baseline setup from scratch, one guided question at a time, so you start every session with a setup that fits your driving, not a generic default.

Lap Wizard: turns your input into a specific change you can make right now, so you stop guessing and start fixing.

Corner Wizard: for when it's one corner, not the whole lap, killing your time, with targeted advice that won't unsettle the rest of the lap.

In-Race Engineer: a keyboard-only assistant for mid-race calls, so a handling problem can be fixed on the fly or at your next pit stop.

Setup Developer - build your own baseline, one question at a time

Pick your car and track, answer simple questions about how the car feels in each setup area, and onRails builds a complete starting setup around your answers. By the time you're done, you know why every value is what it is, not just what it is. All major car types and track layouts are supported.

Lap Wizard - fine-tune until it's fast and comfortable

You're in the ballpark, but something's off. Log your lap time, describe how the car behaved overall, and get a ranked list of specific changes with plain explanations. Confirm one, log your next stint, and watch the times drop.

Corner Wizard - when one corner is the problem

Pick the direction, the phase (entry, apex, exit), and what's happening, and get advice scoped to that corner alone, so fixing it doesn't unsettle the rest of the lap.

In-Race Engineer - help without leaving the cockpit

A keyboard-only assistant that takes up almost no screen space. One hotkey to toggle, numpad to answer a couple of quick questions, and you get a one-line pit-call recommendation you can act on immediately.

simReader - telemetry without touching a spreadsheet

onRails auto-detects your simulator and reads tire temps and lap times straight from shared memory with a single hotkey, no manual entry, no leaving the cockpit.

Supported sims: Assetto Corsa, Assetto Corsa Competizione, Automobilista 2, iRacing, Le Mans Ultimate, Project Cars 2, rFactor 2. Any other sim still works via manual entry.

Built for your cockpit

Runs as a windowed panel or a transparent overlay on top of your sim, no second monitor required. Panels, hotkeys, and theme are all yours to customize, fully localized, with built-in tutorials for every panel. Includes the companion eBook "Race Car Setup: Think Like a Race Engineer, Drive Like a Pro", free with your purchase.

Built for sim racers, by a sim racer.

Known Issues

AMD GPU users on Eyefinity may still see reduced frame rates with the transparent overlay due to Windows compositing overhead. Disabling overlay mode in Settings restores full performance.