Acura ARX-05 DPi – IMSA Prototype Remaster. Part of the AW Assetto Corsa Mods Collection.
The Acura ARX-05 DPi stands as one of the defining championship-winning weapons of IMSA’s modern prototype golden age. Built on the sharp ORECA 07 spine and propelled by the production-derived 3.5L twin-turbo AR35TT V6, it was renowned for its lightning-fast front-end bite, intricate aero balance, and aggressive mid-range powerband. Yet, most Assetto Corsa versions completely butcher this engineering icon—slapping on generic, copy-pasted LMP2 physics, artificial infinite-grip aero maps, single-turbo engine profiles, and sloppy visual meshes with zero attention to real data.
Most community physics packages ignore the strict reality of IMSA’s BoP constraints and the physical traits of the AR35TT engine package. This update is a ground-up, data-driven physics and visual overhaul, rebuilding the Acura ARX-05 DPi from scratch to capture the brutal downforce, turbo boost thresholds, and razor-thin chassis setup windows of the real-world IMSA champion.
🏎️ The ARX-05 Remaster Philosophy
Our goal was simple: throw out the lazy, borrowed physics templates and restore the true mechanical personality of this twin-turbo prototype. We stripped away the inaccurate, single-turbo behavior and rebuilt the entire powertrain, chassis, and aero package using real online technical data and telemetry. This overhaul forces you to manage real turbo spools, respect tight gear steps, and handle precise prototype balance without modern arcade crutches.
🛠️ Key Technical Changes in This Update
1. Authentic AR35TT Twin-Turbo Power, Boost Profile & Fuel Consumption
We completely threw out generic engine files to reconstruct the true 3.5L twin-turbocharged V6 racing powerband.
- Recreated Turbo Profile: Power and torque curves now strictly match real-world engine output under IMSA BoP mandates. Boost builds up realistically across the mid-range, demanding deliberate throttle control out of slow hairpins to keep the rear tires from spinning up.
- Realistic Fuel Consumption: Recalibrated the fuel burn model to mirror real IMSA race stints. On a full tank, you face an authentic 40- to 45-minute stint window, making fuel strategy, fuel mapping, and lift-and-coast management vital during endurance events.
2. Xtrac P1159F Transmission & Dual Gear Sets
No more inaccurate, single-gearbox setups that leave you bouncing off the rev limiter halfway down the back straight.
- Xtrac P1159F Ratios: The 6-speed sequential gearbox and final drive ratios have been re-engineered using actual online technical specs for the Xtrac P1159F unit.
- Two Track-Tailored Gear Sets: The remaster includes two selectable gear setups—a tight, punchy set optimized for high-downforce sprint tracks (Laguna Seca, Mid-Ohio) and a taller set engineered for high-speed venues (Daytona, Sebring) to hit 190+mph without over-revving the engine.
- Refined Gearbox Mechanics: Shift cut times and downshift engagement logic have been tightened to match electronic paddle-shift response, backed by ECU protection to prevent engine over-revs.
3. IMSA Aero Balance, Suspension Kinematics & Weight Distribution
- Corrected Mass & Distribution: Total weight and center of gravity have been adjusted to reflect the rear-heavy bias of the twin-turbo V6, intercoolers, and Xtrac casing sitting over the back axle.
- High-Downforce Prototype Suspension: Suspension kinematics, spring rates, roll centers, and damper curves were rewritten from scratch to support true prototype downforce loads. The chassis now properly reacts to dynamic pitch and roll changes without bottoming out or breaking underbody aero sealing.
- IMSA-Spec Aero & Tire Compounds: Downforce and drag profiles are calibrated to real IMSA telemetry data. Custom slick compounds capture the narrow thermal window and slip angles of prototype racing rubber, punishing cold tires and requiring precise pressure management.
🏁 Visuals, Mesh & Bug Fixes
To match the overhauled physics, the exterior model, cockpit, and collision mesh received an extensive structural pass:
- Custom 3D Collider: Discarded the undersized, generic collision box. The car now features a custom-fitted 3D collider built strictly to the physical dimensions of the ORECA-based bodywork, eliminating phantom curb launches and invisible track collisions.
- Remodeled Exterior Elements: Rebuilt and refined numerous exterior assets—including updated optical lenses, headlights/taillights, aero dive planes, wing endplates, and bodywork vents.
- Cockpit Remodel: Overhauled the interior to repair clipping meshes, fix misaligned digital dash elements, and correct driver view orientation.
- Sound Tweaks & Polish: Refined internal and external acoustics to highlight the crisp AR35TT turbo spool, wastegate vents, and straight-cut sequential gear whine. Fixed legacy bugs including broken telemetry readouts and aero calculation errors.
- Skins Meyer Shank and Wayne Taylor skins from great Akrapovic is included.
The telemetry is verified, the twin turbos are spooled, and the Xtrac gear sets are staged. Can you handle an authentic, data-driven DPi prototype, or will the boost threshold catch you off guard? Download the update now and find out.
18/08/2026 Performance Update: Added LODs made by Moor1804, changed front grill mesh, fixed reported bugs with steering wheel alignment and windshield texture. Improved visual quality of cockpit LR, minor skin corrections.
25/08/2026 BOP Update: Rev limit set as per available IMSA data, added rev lights for second display, LODs improved to fix disappearing lights, digipanel replaced with csp version.
Installation Requirements
- Base Model: Model Is provided and is included with data.
- Method: Extract the contents into the content car’s folder, overwriting the
data,extension, anduifolders if necessary. - Requirement: Latest version of Custom Shaders Patch (CSP) is highly recommended for the lighting and tire shader fixes.
Download the Technical Physics and Model Data (Google Drive)