Smi3D Aero Concept | Chassis Scan & Comparative CFD Optimization

Stop Guessing Aero Upgrades: Prove the Concept Before You Build

Bolting on a homemade plywood splitter or a universal rear diffuser often increases drag without generating usable downforce. Worse, unverified aero packages can stall in high-speed corners or shift the aerodynamic balance violently under braking.

The Smi3D Aero Concept package eliminates this risk. We scan your actual chassis geometry, benchmark its current aerodynamic behavior, build a tailored digital aero concept within your racing class limits, and re-run CFD to verify the exact improvements in downforce, drag, and balance.

What’s Included

• Chassis 3D Laser Scanning: Complete optical scanning of the chassis underbody, suspension geometry, exhaust system, and body panels on a 2-post lift.

• Baseline CFD Benchmark: Initial virtual wind tunnel simulation in AirShaper to establish starting downforce, drag, and aero balance.

• Digital Concept Modeling (Rhino 8):

  • Front Splitter: Optimized forward projection and ground seal profile.

  • Flat Floor System: Digital underfloor panels isolating turbulent exhaust, driveline, and suspension pockets.

  • Rear Diffuser: Expansion chamber modeled with race-proven expansion angles (7°–12°) packaged around subframes and differentials.

  • Side Skirt Extensions: Digital vertical seals designed to limit lateral airflow bleed under the chassis.

• Secondary Validation CFD Run: Re-simulating the upgraded vehicle under identical atmospheric and velocity parameters.

• 45-Minute Engineering Debrief: Video consultation reviewing before-and-after performance metrics, center-of-pressure shifts, and physical fabrication guidance.

Technical Deliverables

• Comprehensive Aero Comparison Report (PDF):

  • Before vs. After Comparison: Direct numerical delta for downforce (kg & N) and aerodynamic drag.

  • Aero Efficiency (L/D Ratio): Exact calculation of downforce gained per unit of drag added.

  • Aero Balance Shift: Verified balance percentages (Front % vs. Rear %) ensuring high-speed cornering stability.

  • Surface Pressure & Streamline Plots: Side-by-side renders illustrating suction peaks beneath the floor and clean flow attachment through the diffuser.

• Sealed Concept 3D Geometry: 1x Watertight OBJ / STL mesh of the upgraded concept for dimensional reference and packaging planning.

Important Scope Note: Aero Surface vs. Mechanical CAD

This package focuses strictly on aerodynamic surface design and flow verification. It provides the proven dimensions, angles, and surface profiles needed for a functional underbody package.

• Included: Aerodynamic surfaces, expansion angles, concept profiles, and CFD validation data.

• Excluded: Mechanical mounting brackets, structural FEA analysis, fastener layouts, and 1:1 CNC-ready DXF/STEP cutting files.

• Detailed mechanical engineering for CNC manufacturing, laser cutting, or mold production is available on an hourly engineering rate (1,250 NOK/hr) upon request.

Requirements & Prerequisites

• 2-Post Lift Access: Required on scan day for optical line-of-sight across underfloor structures and suspension linkages.

• Clean Underside: Underbody and wheel arches must be thoroughly pressure-washed prior to arrival.

• Static Track Ride Heights: Exact front and rear ride heights measured on level ground must be provided.

• Rulebook Regulations: Maximum allowable splitter projection, diffuser limits, and minimum ground clearance must be declared prior to modeling.

The 5-Step Process

1. Intake & Rulebook Review: We confirm your racing series constraints, target track velocities, and measured ride heights.

2. On-Site 3D Scanning: Comprehensive optical laser scan carried out at your facility or partner shop (approx. 4 hours).

3. Baseline Benchmark: Data cleanup, watertight Rhino 8 mesh conversion, and baseline CFD solve.

4. Concept Modeling & Validation: Modeling of the underfloor concept surfaces, mesh merging, and execution of the secondary CFD run.

5. Report & Strategy Debrief: Delivery of the comprehensive PDF comparison report and 3D concept data, followed by a 45-minute remote strategy debrief.