RaTraPla vs Tuning Simulator

The circle does not add up. One piece too few, one too many — and on the carpet it fits anyway, because every joint can twist a little. That is what RaTraPla calculates. Which is why rings close here that would never close on squared paper. RaTraPla plans layouts for wooden toy railway — not with generic track, but with the pieces that are actually in your box. Please note: the app's screens are in German; a glossary of the labels is at the end. HOW IT WORKS Pick a configuration, start a plan, set the build area if space is tight, tap a piece. Each new piece attaches to the open end of the last one, and the line grows. Dragging moves the whole connected chain; letting go snaps it back into place. Rotate in 45° steps, mirror, duplicate, delete — all in the bar above the pieces. THE PLAY AT THE JOINTS Push two pieces together, hold one, and twist the other gently as far as it goes. The gap that opens on the far side is the play. Measure it once, enter it in millimetres — and RaTraPla knows how far your track can really bend. Because a ring does not close thanks to "a few percent of tolerance". It closes because many joints each twist a little. Tap two open ends: if the play is enough, one button pulls them together. If it is not, the app tells you to the millimetre how much is missing. PEG AND SOCKET Wooden track has a direction: socket at the front, peg at the back. RaTraPla draws both, and never offers you a fit that does not exist in reality. It even knows those puzzling short pieces with two pegs or two sockets — and shows you in a drawing what they are for. YOUR BOX, YOUR MEASUREMENTS Measure your track and enter what you find: lengths, radii, angles, turnouts. Curves and turnouts get a small scale drawing that follows the values as you edit them and shows where to put the ruler. Enter how many of each piece you own, too. The bill of materials then tells you what your plan needs and what is still missing. You may plan beyond your stock — that is what wish lists are for. Three configurations come with the app. The one for IKEA LILLABO was measured on real track; the ones for BRIO and Eichhorn carry the widespread wooden-railway standard and are meant to be checked against your own pieces. Every value is editable, and you can build a system of your own. BUILT FOR SMALL HANDS Open ends catch the finger, so they stay easy to hit even when the plan gets crowded. And under almost every setting there is a sentence saying what it is good for — this app has a very thorough test engineer. YOUR FILES ARE YOURS Everything is stored as readable JSON in your own iCloud Drive folder "TrackPlanner", visible in the Files app — or locally on the device if you are not signed in to iCloud. A plan carries its configuration with it: pass on the plan, and the measurements travel along. No account, no sign-in, no ads, no tracking. The app talks to no server other than your own iCloud, which holds your RaTraPla files. And then the circle adds up after all. Not because the arithmetic works out, but because every joint twists a little — and because you measured, once, how much. RaTraPla was called TrackPlanner until November 2026. The iCloud folder keeps the old name, so existing layouts stay where they are. RaTraPla is an independent project and is not affiliated with BRIO, Eichhorn or IKEA. Those names only say which track fits which. GLOSSARY OF ON-SCREEN LABELS Baufläche = build area Brücke = bridge Enden zusammenführen = join two ends Gerade = straight Gleispläne = track plans Konfigurationen = configurations Kreuzung = crossing Kurve = curve Offene Enden = open ends Rampe = ramp Schienenteil = track piece Spiel an den Stößen = play (mechanical slack) at the joints Stoß = joint between two pieces Stückliste = bill of materials Verzug = how far a joint is pushed out of true, as a side gap in mm Vorrat = stock (pieces owned) Weiche = turnout Wunschzettel = wish list

A simulated engine on a dyno, run by a standalone ECU you tune yourself. Change the fuel map, the timing or the boost and watch what happens to the power curve, the mixture and the knock sensor. It behaves like the real thing. The engine model runs every combustion event. Lean it out and it misfires. Add too much timing and it knocks, then cracks a piston. Fit bigger injectors without telling the ECU and it floods. THE ECU - Fuel VE, lambda targets, ignition, boost target and wastegate duty, idle, warmup, cranking, accel enrichment and dead times - Closed loop, knock control, rev and boost limiters, auto learn and "Fix from pull" - Select cells, drag curves, type values, interpolate and smooth, in a grid or in 3D - Lay the data log over any table and see which cells ran lean or knocked THE ENGINES - Ten engines: fours, a flat four, straight sixes, V6s and V8s - Naturally aspirated, turbo, twin turbo, supercharged and nitrous - Nearly 100 parts: injectors, pumps, lines, regulators, turbos, housings, wastegates, blowers, cams, pistons, rods, head gaskets and fuels, E85 included THE DYNO - Hold any rpm at any throttle, or do a full wide open throttle pull - Power, torque, mixture, boost and timing on every run - A full data log you can zoom into - Engine health: knock, over-revving, boost and heat all wear parts out, and some failures are sudden CAREER MODE Start with a rented unit, a small dyno, a stock project car and $1,500. Customers bring in cars with vacuum leaks, tired fuel pumps, stuck wastegates, burnt valves and lying sensors, or ask for a power target on a budget. Find the fault, fix it, tune it and hand it back for a test drive that grades your work. - Eleven kinds of job, from base tunes to E85 conversions, race class builds, blown engine rescues and cars three other shops couldn't fix - Four rival shops with owners and an 8-week season. Beat them at Dyno Day and their customers switch to you - Cars come back weeks later. A tune too close to the edge breaks on a hot day and returns on warranty; a safe one turns the customer into a regular - Intermittent faults that only show hot, cold, under boost or near redline - Eight story customers who bring the same car back chapter after chapter, with your parts and tune still on it - Diagnostic tools, a bigger dyno, more bays, weather, deadlines, rent and 31 achievements DAILY CHALLENGE One broken engine a day, the same for every player. Nine hours on the clock to find the faults and tune it, then see where you land on the leaderboard. Tuesdays and Saturdays are free on the Turbo Four. LEARN A guided tutorial takes a broken project car from flooding on the stand to a full tune. Twelve more lessons cover VE tuning, MBT, knock, boost control, injector swaps, fuel system limits, E85, nitrous, big cam idle and cold starts. GAME CENTER Leaderboards for the daily challenge, peak horsepower and horsepower per litre. A pull only counts if the engine is still alive five seconds later. FREE AND PRO The Turbo Four, the guided tutorial and the Tuesday and Saturday daily challenges are free, with every part and every table. Tuning Simulator Pro is a one-time purchase that unlocks all ten engines, custom builds, every lesson, Career mode and the daily challenge every day. No subscription, no ads, no account.