About this video

• Video Title: How to PURIST in Forza Horizon 5 (how to build/tune)
• Channel: giron228
• Speakers: giron228
• Duration: 00:22:56

Overview

This video explains the concept of a "Purist" build in Forza Horizon 5, which excludes engine swaps, drivetrain swaps, and Forza aero. The presenter details how the PI (Performance Index) system works and how to exploit it for better car builds. The video then walks through various upgrade categories, including tires, aero, suspension, power, drivetrain, and tuning, providing specific recommendations and strategies for optimizing car performance within the game's mechanics.

Key takeaways

• Purist Build Definition: A purist build in Forza Horizon 5 avoids engine swaps, drivetrain swaps, and Forza aero.
• PI System Understanding: The PI system rates car performance based on AI driving on stock tunes and base game tracks. Understanding this system allows for "free pace" by applying tunable upgrades.
• Key Upgrades: Tires, weight reduction, and anti-roll bars are crucial early upgrades for drivability and PI efficiency.
• Tire Strategy: Different tire compounds are suited for various classes and handling characteristics, with PI exploitation possible through tire width adjustments.
• Power Optimization: Maximize average horsepower by using upgrades like cams, specific transmissions, and centrifugal superchargers, while strategically hiding power from the PI system.
• Suspension Tuning: Understanding the trade-offs between different suspension types (race, rally, drift) and their impact on handling and PI cost is vital.
• Tuning Fundamentals: Key tuning aspects include tire pressures for grip and heat management, gearing for optimal speed and acceleration, alignment for cornering grip, anti-roll bars for rotation, springs for ground connection, damping for suspension movement control, braking bias, and aero for downforce.
• Differential Importance: Rally and drift differentials are generally preferred over race differentials for stability and predictability, with specific choices depending on the car's setup (e.g., tire width differences, FWD).
• Building vs. Tuning: The video separates the "build" phase (applying upgrades) from the "tuning" phase (adjusting sliders) for a comprehensive approach to car optimization.

The video offers a deep dive into building and tuning "Purist" cars in Forza Horizon 5, emphasizing how to manipulate the game's Performance Index (PI) system for competitive advantage.

Understanding the PI System for Exploitation: The core idea is that the PI system, which assigns a performance rating to cars, is based on an AI test drive on stock tunes across base game asphalt tracks. This creates opportunities for players to "lie" to the system. Key exploits include:

• Tire Width: Widening rear tires more than front tires makes the car appear less prone to oversteer to the PI system, lowering its PI cost without sacrificing actual handling potential once tuned.
• Tuning Blindness: The PI system is unaware of post-upgrade tuning. Therefore, adding many adjustable tuning parts theoretically increases a car's potential pace without a proportional PI increase.
• Shift RPM: Cars have a preset, often suboptimal, shift RPM. By using manual clutch and tuning upgrades that allow higher optimal shift points, players can create a discrepancy between the car's actual acceleration and what the PI system perceives.

Key Upgrade Categories and Nuances:

• Tires:

  • Compounds: Each compound (Street, Vintage, Drag, Sport, Rally, Drift, Semi-Slick, Slick) offers different grip characteristics (longitudinal vs. lateral, low-end vs. top-end). Rally tires are presented as a good all-around choice.
  • Class-Specific Choices: The video links tire types to PI classes (B, A, S1) based on their lateral G-force ratings. For example, in B-Class, vintage tires are preferred over street tires for classic cars if available. Front-wheel-drive cars in B-Class might benefit from drag tires for their off-the-line traction.
  • PI Exploitation: Changing tire width is a major PI manipulation tool.

• Aero:

  • Roll Cage & Front Tire Width: These are considered "purist" versions of rear and front aero upgrades. A roll cage adds a handling buff, especially for cars lacking natural downforce. Increasing front tire width helps cars with poor inherent aero turn better.
  • When to Apply: If a car struggles to achieve its target class's lateral Gs, a roll cage or wider front tires are necessary.

• Suspension:

  • Tiered Quality: Higher tier suspensions offer more "balance," which sounds good but can be detrimental in Forza due to the inherent handling characteristics of cars (often favoring understeer with wide rear tires).
  • Imbalance is Key: For some cars, especially those with significant front/rear tire width differences, using stock or lower-tier suspension is better because it allows for more dynamic weight transfer, which helps the car turn.
  • Race vs. Rally vs. Drift: Race suspension is for high-speed balance. Rally suspension is a low-speed alternative that further imbalances weight transfer for more turning. Drift suspension is stiffer but can sometimes reduce steering filter.
  • Ride Height: Maxing ride height is recommended to allow suspension components to work effectively. Raking the car (lower rear) can improve turn-in at high speeds.

• Power Upgrades:

  • Maximizing Hidden Power: The goal is to increase average horsepower while minimizing PI gain.
  • Cams: Adjust power output profile and peak RPM, crucially affecting the set shift point. Use cams when there's a significant drop-off in the power curve. Be cautious, as adding cams can sometimes increase the PI disproportionately if the optimal shift point moves too close to the new redline.
  • Transmission (Street/Sport): Changes final drive ratio and gear count, affecting how well the PI system's shift point aligns with optimal RPM. Often reduces PI and can fix top-speed limitations.
  • Centrifugal Supercharger: Highly effective as it provides more power at higher RPMs, aligning well with the PI system's bias towards lower RPM shifts. Apply liberally if available.
  • Other Engine Parts: Exhausts are good for weight reduction. Naturally aspirated cars benefit from exhaust manifold upgrades. Intercoolers and oil coolers add power but also significant weight, often not worth the trade-off if weight gain is disproportionately higher than power gain.

• Tuning Sliders (Detailed Nuances):

  • Tire Pressures: Lower pressure = more grip, less responsiveness, more heat. Aim for equal pressures front-to-rear at racing speeds to ensure predictable handling.
  • Gearing: Optimize for class-specific top speeds and the "start finish rate" on Horizon Mexico circuit for a competitive edge. Adjust based on power band (shorten for peaky engines, widen for broad powerbands). First gear in race transmissions should be lengthened for easier launches.
  • Alignment (Camber & Toe):
    • Camber: Keep it low (0 to -0.9°). More front camber increases oversteer; more rear camber increases understeer. The video suggests a starting point of -0.7 front and -0.4 rear.
    • Toe: Use for extreme adjustments. Front toe-out increases turn-in; rear toe-in increases corner exit stability. Avoid going beyond ±0.3° as it degrades feel.
  • Anti-Roll Bars (ARBs): Primary tool for rotation. Stiffer rear ARB and adjustable front ARB is the general strategy. Max out the rear and adjust the front for responsiveness.
  • Springs: Softer springs = more grip. Balance spring rates based on car's weight distribution (e.g., 50% distribution suggests equal spring stiffness). Stiffer springs are needed if ARBs aren't sufficient to control over/understeer.
  • Ride Height: Maximize it for full suspension travel. Raking the car can improve turn-in.
  • Damping:
    • Rebound (Suspension Down): Aim for around 9, softer is better as long as the car doesn't bounce excessively. Test on bumpy tracks. Ratio should generally follow spring rates.
    • Bump (Suspension Up): Aim for around 3. Affects weight transfer vs. responsiveness. Soften front bump for braking grip; soften rear bump for corner exit traction.
  • Brakes: Avoid upgrading unless necessary for PI. Brake bias is reversed in the UI (left setting = rear bias, right = front bias). A slight rear bias (left) is often preferred. Brake pressure can be set to 120% (to simulate lockup threshold) or 90% (for full trigger/key press without lockup).
  • Aero (Adjustable): Minimize front aero if only adjustable. If only rear is adjustable, minimize it unless the car becomes excessively oversteery at high speeds, then add minimal rear aero. If both are adjustable, max front and minimize rear while maintaining balance.
  • Differential:
    • On Throttle (XL): Locked diff (100%) provides predictable power delivery but can break traction. RWD cars often benefit from 100% XL for predictability, coping with traction loss via throttle control. FWD cars may need lower settings.
    • Off Throttle (DEL): Lower DEL values (near 0) are generally preferred for better turning. Higher values can increase stability but limit turning. Deviate from 0 only if experiencing specific issues like lock-ups under braking or for FWD cars.
    • Differential Types: Rally diff for stability/predictability, Drift diff for more rotation, Off-road diff for FWD cars.

The video stresses that these are guidelines, and exceptions exist. Players are encouraged to test and tune based on their car and driving style.