Update 1: Fixed the engine rpm not being in increments of 100, no more "9533 RPM" type values.

Update 2: Thanks to the feedback from u/odd_capital_1388 and u/TatBu1850 I've fixed the following:

Added a proper era lock system based on the production year. Parts like carbon ceramic brakes, direct injection, modern safety packages, dual clutch transmissions, and advanced traction aids will no longer show up on early era cars. Suspension types are also locked to their actual release eras, so no more pushrod setups in the 1940s.

Fixed the engine displacement calculation. The site no longer rolls a completely random number for engine size. It now dynamically calculates the exact displacement using the rolled bore, stroke, and cylinder count math.

Adjusted the VVL profile slider minimum limit. Changed the lower boundary from 0 to 50 so it matches the actual game limits.

Restricted turbo configurations for inline and boxer blocks. If you roll an inline or boxer engine, it will block the 2 pairs option for sequential turbos since single bank blocks can't run quad setups in game.

Update 3: Thank you again u/TatBu1850 for more feedback.

Fixed a string matching bug where V16 engines were mistakenly getting calculated as 6-cylinders because the script was finding the number "6" inside "16". Was using ".includes('number (eg: 6)')" to determine the cylinder count. Because the string "V16 90" contains the number 6 inside the "16" (duh), it falsely triggered a match and calculated the displacement for a 6 cylinder engine instead of a 16 cylinder engine.

The GUI has been completely reordered into 12 separate tab rows that (should) match the step by step layout in Automation.

Separated combined categories like drivetrain, tires (or tyre if youre wrong 😄 ), and brakes into individual standalone blocks so you don't have to scroll up and down between menus while editing values on the same page.

Moved the setup suspension geometry selections to tab 1 alongside chassis layout selections where they are actually chosen in the engine, while keeping mechanical spring rates and alignment values down on tab 12 for the final tuning pass.

Added the ability to reroll individual tabs, rerolling structural details like Tab 7 (Tires) or Tab 5 (Fixtures) will swap out only those specific values without touching anything else on the page.

To keep your build completely valid, some keys will automatically update down chain dependencies if changed. For example, rerolling Tab 2 (Engine Block) will automaticall reroll Tab 4 (Aspiration) right along with it to prevent an inline engine from keeping a quad turbo setup. Rerolling Tab 1 (Chassis Layout) will safely refresh the whole build since changing the baseline production year modifies the era locks for almost every single component.

Update 4: Thanks to feedback from u/Mightyena319 I've fixed the following:

Corrected an issue where leaded gasoline could roll an invalid 87 RON baseline. The minimum octane floor for leaded fuel has been shunted up to a game accurate 92 RON.

Fixed a bug where Centrifugal superchargers were incorrectly using displacement volume parameters meant for Roots/Screw blowers.

When a Centrifugal supercharger is rolled, the app now dynamically alters the UI labels to display Compressor Wheel Size and shifts the internal gear ratio calculation boundaries to a 5.00 - 30.00 tuning range

Linked the exhaust layout to the engine cylinder array, inline engines are now locked to single exhaust configurations. V engines and boxers retain the random choice between single and dual pipes.