Experimental Hirochi Aurata - Turbo R 999T DCT (Maverick R style) 1.0

Hirochi Aurata - Turbo R 999T DCT (Maverick R style)



Turns the Hirochi Aurata into a Maverick R style side-by-side: a stronger 999cc turbo triple, a 7-speed dual clutch transmission instead of the CVT, three drive modes, launch control and a simulated ART anti-lag that really cuts a cylinder, with its own idle sound.

1. 999T engine package

• 999T Long Block - forged 999cc internals with a freer-flowing head: torque rises from about +6% down low to +28% at the top, and the engine revs about 500 rpm higher than stock. Inertia and friction are raised slightly, and durability is raised to cope with the extra power and anti-lag heat.
• 999T Turbocharger + Intercooler - a bigger turbo, prepared for anti-lag.
• 999T ECU - about 240 hp, 8800 rpm limiter with an 80 ms time-based cut, stronger afterfire on the overrun, and faster engine sound response so the uneven ART firing comes through.

2. 7-speed dual clutch transmission

• Replaces the CVT with real gears: 3.60 / 2.70 / 2.07 / 1.63 / 1.32 / 1.10 / 0.95, reverse 3.30.
• 40 ms dual clutch handover, so upshifts are near-instant without a torque gap.
• Modes P R N D S M. In D it shifts early and calmly (about 3500-4500 rpm); in S or at full throttle it holds every gear to 8500 rpm. Downshifts blip the throttle to match revs, and pulling away the clutch engages between 3000 and 4500 rpm.
• Much less power is lost than through a belt CVT (3% drivetrain loss).
• Still works with the stock High / Low range box, AWD transfer case and diff locks.
• Factory-style 99 mph (159 km/h) top speed governor.
• Helical gear whine instead of the CVT belt sound.

3. Drive modes
Switch them with the drive mode button (radial menu or your drive mode keybind). The button shows the active mode in its colour.

• Normal (blue) - gearbox in D, quiet exhaust, launch control at 3500 rpm, no anti-lag.
• Sport (orange) - gearbox in S, louder and less muffled exhaust, launch control at 4500 rpm.
• Sport+ (red) - gearbox in S, the loudest exhaust, launch control at 5000 rpm and ART anti-lag switched on.

4. Launch control (two-step)

• Stand still, hold the brake and floor the throttle: the rev limiter holds the engine at the launch rpm of the current mode (3500 / 4500 / 5000). Release the brake to launch.
• In Sport+ the 5000 rpm launch gets its own sound: the dead-cylinder loop pitched exactly to 5000 rpm, so the two-step sounds like a cylinder-cut launch.

5. ART anti-lag with a real cylinder cut (Sport+)
The real Maverick R keeps its turbo spinning off throttle by cutting a cylinder, retarding the ignition and opening the throttle. This mod simulates that in the engine physics; it isn't only a sound effect.

• Cylinder cut - the mod follows the crank angle at physics rate and, in every 720° four-stroke cycle, skips cylinder 3's 240° firing window. A few degrees of random jitter and occasional extra misfires make it run unevenly like the real thing. The engine really runs on two cylinders: you can feel and see the lumpy idle.
• Dead-cylinder drag - the crank is slowed a little during the dead window, so the two live cylinders kick harder and the rpm swings in the 2-cylinder rhythm.
• Ignition retard - only about 45% of the combustion torque reaches the crank; the rest goes into the exhaust as heat and drives the turbine.
• Turbo kept spooled - an anti-lag controller feeds energy to the turbine to hold the turbo near 75,000 rpm while you are off the throttle, so boost is already there when you get back on the gas. Engine braking drops like with a real anti-lag system.
• Throttle open, idle raised - the throttle body opens and idle rises by 800 rpm (about 2200 rpm). A stiffer, faster idle controller keeps it steady, so the roughness comes from the firing pattern, not from hunting.
• Fuel - fuel consumption is about 1.4x while ART runs.
• When it is active - only in Sport+, at idle and up to 5% throttle. Getting on the gas restores all three cylinders, normal timing and normal idle immediately.
• Optional afterfire pops - the dead cylinder can dump its charge into the exhaust and pop (with an occasional flame) from every tailpipe. Off by default; enable it with "deadCylinderPops": true (UNREALISTIC) .

6. ART sound
BeamNG's engine sound is a smooth blend updated once per frame, so it can't reproduce an 18 Hz "missing cylinder" beat. The mod therefore plays its own sound while ART runs:

• A dead-cylinder loop made from the Aurata's own stock engine sound: every firing pulse was re-laid at the ART idle speed and every third pulse of each cycle removed, so it is the same engine, just limping on two cylinders.
• Its pitch follows the real engine rpm, and it plays from the engine position like the stock sound.
• It replaces (or mixes over) the stock engine sound with an equal-power crossfade, so there is no volume dip.
• When you lift off from high rpm it fades in smoothly as the rpm drops through 3900-3150. It stays on up to 5% throttle, fades out between 5% and 10%, and hands back to the stock sound the moment you get on the gas.
• Launch control at 5000 rpm has its own matching loop (see 4).

How to use

1. Spawn the Hirochi Aurata and pick the config Turbo R - 999T DCT (Maverick R style), or fit the parts in Vehicle Config: Engine > Internals / Intake / ECU, and Transmission.
2. Pick a drive mode. Sport+ for anti-lag and the 5000 rpm launch.
3. Launch: stand still, hold the brake, full throttle, release the brake.
4. ART: in Sport+ just lift off and listen. Get on the gas to leave ART.

Tuning
Everything about ART and its sounds can be changed in vehicles/utv/kiki_rdct/utv_999t_engine_parts.jbeam, in the "artAntiLag" section, and every value has a comment. You can change:

• the turbo rpm target, the throttle limit, how hard the cylinder cut is, the extra misfire chance, the idle raise and the ignition retard;
• the sound loop file and pitch, the volumes, the fade speeds and the rpm and throttle ranges;
• how much of the stock sound stays under the ART sound;
• the launch sound, and the optional pops.

Shift points and gear ratios are in utv_transmission_dct7.jbeam.

Requirements

• Only the stock Hirochi Aurata. No other mods needed.

Known limitations

• BRP does not publish the Maverick R gear ratios or torque figures. The ratios and the ~240 hp torque curve are designed estimates, not factory data.
• The game caps effect sound volume at 1.0, so the loudness of the ART sounds lives in the sound files themselves.

Disclaimer
This is a fan-made mod for the Hirochi Aurata and is not affiliated with, endorsed by or connected to BRP, Can-Am or Rotax. "Can-Am", "Maverick", "Rotax" and "BRP" are trademarks of their respective owners and are used only to describe what the mod is inspired by. The mod was built with the help of Claude Code (AI); every part was tested and tuned by me in-game.

Open source
This mod is open source. You are welcome to use, change and learn from my code and files in your own mods, as long as you credit me (Tamz129) as the original author and link back to this page. Please don't re-upload it unchanged as your own.

Credits

• Tamz129 - concept, tuning, testing, sound editing
• BeamNG GmbH - the Hirochi Aurata, the base game and its engine sound