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iRacing GTP Hybrid Guide

GTP (Grand Touring Prototype) is the top class in iRacing IMSA and endurance racing. These hybrid prototypes—Cadillac V-Series.R, Porsche 963, BMW M Hybrid V8, Acura ARX-06—feature 50kW spec hybrid systems, ~1,030 kg weight, and high downforce. They require an A licence and are the fastest cars in multi-class racing.

Car Characteristics

  • Hybrid: Spec hybrid system. Power blended automatically between ICE and MGU. No manual deployment
  • Power: Combined ICE + hybrid output capped at series limits. ~50% state-of-charge target, balanced deployment
  • Downforce: Highest in the prototype ladder. Strong aero platform
  • Weight: ~1,030 kg. Lighter than LMP2, more power

Hybrid System (Real-Life Style)

iRacing's GTP hybrid now mirrors real LMDh behaviour. Power is blended seamlessly between the internal combustion engine and motor generator unit—you do not manually deploy. The system maintains a balanced state of charge and blends regenerative braking into normal braking. Drive the car like a non-hybrid: focus on smooth inputs, braking technique, and traffic management. The hybrid works in the background.

Series

  • IMSA iRacing Series – Multi-class with GTP, LMP2, and GT3. 45 minutes
  • IMSA Endurance Series – Longer multi-class events
  • Global Endurance Tour – Team endurance with GTP
  • Special Events – Daytona 24, Sebring 12, etc.

Traffic Management

GTPs lap LMP2s and GT3s constantly. You are the fastest class—plan passes on straights and wide corners. Avoid diving into tight sections where GTs cannot yield. See our Multi-Class Racing Guide for traffic awareness and blue flag info.

Aero Platform

GTPs generate significant downforce. Ride height and aero balance affect stability under braking and rotation in slow corners. Baseline setups work well; adjust for understeer or oversteer based on track. Each manufacturer has different characteristics—Cadillac, Porsche, BMW, and Acura differ in balance and feel.

Endurance Pacing

In longer races, tyre wear and fuel matter. Smooth inputs preserve tyres. Pace yourself in traffic; losing a few tenths to pass cleanly beats a 4x and damaged car.

Tip: With automatic hybrid, focus on smooth driving and clean traffic management. Consistent laps and predictable passes separate top GTP drivers from the rest.

Next: LMP2 Guide for the Dallara P217, or Endurance Guide for stint strategy.