Toyota 4Runner Performance Upgrades: Complete Modification Guide

The Toyota 4Runner is known for its legendary reliability, rugged build quality, and exceptional off-road capability. However, it’s no secret that factory performance leaves substantial room for improvement. The 4.0L V6 delivers adequate power for daily driving, but enthusiasts quickly discover that modest modifications transform this capable SUV into a genuinely impressive performer both on pavement and off-road.

Whether you’re looking to boost horsepower for highway passing confidence, improve throttle response that feels frustratingly delayed from the factory, enhance off-road handling through serious suspension work, or build a comprehensive overland rig capable of tackling remote terrain for weeks at a time, the 4Runner platform offers tremendous upgrade potential. This isn’t just about making your SUV faster—it’s about creating a more capable, more confident, more enjoyable vehicle that excels in whatever role you need it to fill.

The beauty of modifying a 4Runner lies in the platform’s versatility. You can build a street-focused performance SUV with improved acceleration and handling, a hardcore rock crawler with maximum articulation and clearance, a long-range overland expedition vehicle with self-sufficiency for extended trips, or a balanced do-everything rig that excels across multiple disciplines. This comprehensive guide covers every proven performance upgrade for the Toyota 4Runner, from simple bolt-ons taking a weekend to install, to comprehensive builds requiring professional expertise and substantial investment.

Understanding the 4Runner Platform

Before diving into modifications, understanding what makes your 4Runner tick—and where its limitations lie—helps you make intelligent upgrade decisions and avoid wasting money on ineffective modifications.

Fifth Generation 4Runner (2010-Present)

The current fifth-generation 4Runner has remained largely unchanged since 2010, a testament to Toyota’s philosophy of refining proven designs rather than constant redesign. This long production run means excellent aftermarket support with countless proven modifications available.

Engine Specifications: 1GR-FE 4.0L V6

• Displacement: 3,956cc (4.0 liters) providing strong low-end torque
• Configuration: 60-degree V6 with dual overhead cams
• Power Output: 270 HP @ 5,600 RPM (modest by modern standards)
• Torque Output: 278 lb-ft @ 4,400 RPM (adequate for most situations)
• Compression Ratio: 10.0:1 (allows forced induction potential)
• Fuel System: Multi-port electronic fuel injection
• Valvetrain: Dual VVT-i (Variable Valve Timing with intelligence)

Transmission Options:

• 5-speed automatic (2010-2016): Proven durability, adequate gearing
• 6-speed automatic (2017-present): Improved efficiency, better gear spacing

Drivetrain:

• Part-time 4WD or full-time 4WD depending on trim
• Solid rear axle with excellent articulation potential
• Locking rear differential available (highly recommended for serious off-roading)

Platform Strengths

Body-on-frame construction provides exceptional durability and modification flexibility. Unlike unibody crossovers, the separate frame handles stress from heavy loads, aggressive off-roading, and modifications without compromising structural integrity.

Solid rear axle delivers superior off-road capability through better articulation and strength compared to independent rear suspension. This old-school design allows fitting larger tires, handling rock impacts, and maintaining traction through extreme terrain.

Proven reliability means these engines routinely exceed 200,000 miles with basic maintenance. The 1GR-FE V6 has earned reputation for bulletproof durability—critical when venturing into remote areas where breakdowns mean serious consequences.

Extensive aftermarket support results from the 4Runner’s popularity. Every conceivable modification exists in bolt-on form from multiple manufacturers, creating competition that keeps prices reasonable while ensuring quality options.

Excellent resale value protects your investment. Quality modifications often increase resale value rather than hurting it, unlike many vehicles where modifications are viewed negatively.

Platform Limitations

Conservative factory tuning leaves 20-30 horsepower on the table even before physical modifications. Toyota engineers prioritize reliability and emissions compliance over peak performance, creating opportunity for substantial gains through tuning alone.

Modest power output of 270 HP feels adequate in daily driving but underwhelming during highway passing or when loaded with cargo and passengers. Modern minivans produce more power—a reality that motivates many modifications.

Throttle lag from electronic throttle control creates frustrating delay between pedal input and engine response. This drive-by-wire system prioritizes smoothness over immediacy, though simple modifications dramatically improve responsiveness.

Weight considerations mean the 4Runner tips the scales at 4,400-4,800 pounds depending on trim. This substantial mass requires more power than lighter vehicles to achieve comparable acceleration. However, the weight contributes to planted highway feel and off-road stability.

Fuel economy averages 16-17 MPG combined, reflecting the truck-based platform and aerodynamics of a brick. Performance modifications typically reduce economy by 1-2 MPG, though careful tuning can sometimes maintain or even improve efficiency during highway cruising.

Generation-Specific Considerations

2010-2013 (4th Gen carryover engine): These early 5th gen models use a slightly different engine management system. Most modifications work across all years, but always verify compatibility. The 5-speed automatic is slightly less responsive than the later 6-speed.

2014-2016 (Updated electronics): Toyota updated various electronic systems, including revised throttle mapping. These years benefit greatly from throttle controllers addressing the increased lag.

2017-Present (6-speed automatic, updated styling): The 6-speed transmission provides better gear spacing and improved efficiency. The additional gear helps acceleration and reduces highway RPM slightly. This is the most refined version and the best starting point for modifications.

Basic Bolt-On Performance Upgrades

These fundamental modifications provide the foundation for any performance build, delivering noticeable improvements without requiring extensive work or accepting major compromises.

1. Cold Air Intake & Engine Airflow Upgrades

Replacing the restrictive factory air intake system represents the easiest and most popular first modification for 4Runner owners seeking improved performance.

Performance Gains: 8-15 horsepower, noticeably improved throttle response, enhanced engine sound
Cost Range: $250-500
Installation Time: 1-2 hours with basic hand tools

How Air Intake Upgrades Work

The factory airbox prioritizes silence, packaging efficiency, and protection from water ingestion during off-road use. These priorities create unnecessary restriction that limits power and throttle response. Performance intakes address these restrictions while maintaining adequate filtration and water protection.

Cooler, denser air from improved routing increases oxygen content, allowing more fuel to burn for increased power. Every 10°F reduction in intake temperature typically adds 1-2% power through improved volumetric efficiency.

High-flow filters with dramatically more surface area allow greater airflow without sacrificing filtration. Modern oiled cotton gauze filters flow 40-60% better than paper elements while maintaining excellent particle capture—critical for protecting expensive engines.

Smooth, mandrel-bent tubes eliminate the corrugations and sharp transitions that create turbulence and restriction. The factory intake includes multiple bends optimized for packaging rather than flow, costing power unnecessarily.

Top Cold Air Intake Options

K&N 77-9037KP Typhoon ($450-500): K&N’s complete system includes heat shield, mandrel-bent aluminum tube, and their signature high-flow filter. The enclosed design prevents hot air ingestion even during extended idling or slow-speed off-road driving where underhood temperatures soar.

Dyno-proven gains of 12-14 horsepower combine with noticeably improved throttle response. The million-mile filter warranty means you’ll never buy another filter—simply clean and re-oil every 50,000 miles. The CARB exemption order makes it legal in all 50 states, eliminating compliance concerns.

Installation takes 90-120 minutes with basic hand tools. The complete kit includes everything needed with detailed instructions. Expect more pronounced induction sound under acceleration—some love it, others find it excessive.

AEM 21-8028DP Brute Force ($350-400): AEM’s Brute Force system uses a dry synthetic filter requiring no oil, appealing to those preferring minimal maintenance. The oilless design prevents MAF sensor contamination, a common issue with over-oiled filters causing check engine lights and rich running.

Expect 10-12 horsepower gains with improved throttle response. The powder-coated heat shield provides excellent protection while the aluminum tube flows efficiently. Build quality is exceptional—this system will outlast the vehicle with basic care.

TRD Performance Air Intake ($400-450): For those prioritizing warranty protection, Toyota’s factory TRD intake maintains full warranty coverage while delivering performance gains. The conservative design produces 8-10 horsepower—less than aftermarket alternatives but backed by Toyota engineering and support.

Installation by Toyota dealers ensures no warranty disputes. The system is engineered specifically for the 1GR-FE engine with extensive testing across various climates and conditions. For new vehicle owners concerned about warranty implications, this represents the safe choice.

Installation and Tuning Considerations

Verify compatibility with your specific year and trim. Some 4Runner variations use slightly different intake configurations requiring model-specific kits. The 10 minutes spent confirming fitment prevents ordering the wrong system.

Disconnect the battery for 15 minutes before and after installation to reset adaptive fuel trims. This allows the ECU to relearn optimal parameters for the new intake, maximizing performance gains and preventing check engine lights.

Position the filter properly to avoid water ingestion during deep water crossings. While intake manufacturers design for water protection, deep water can overwhelm any intake system. Consider a snorkel if you regularly cross deep water.

Clean and maintain the filter according to manufacturer specifications. Over-oiling causes MAF sensor contamination; under-oiling allows dirt through to damage the engine. Follow instructions precisely for optimal longevity.

2. Exhaust System & Headers

Upgrading your exhaust system allows the engine to expel gases more efficiently while giving your 4Runner a deeper, more aggressive tone that matches its capability.

Performance Gains: 12-20 HP depending on system type
Cost Range: $400-1,500
Installation: 2-4 hours moderate mechanical skill

Exhaust System Options

Cat-Back Exhaust Systems ($600-1,200):

Cat-back systems replace everything from the catalytic converters rearward, addressing the restrictive muffler and pipes that prioritize silence over performance.

Borla S-Type Cat-Back ($900-1,000): Borla’s S-Type delivers aggressive sound without drone—a remarkable achievement. The patented multi-core design uses straight-through construction surrounded by sound-absorbing materials, maximizing flow while canceling problematic resonant frequencies.

Expect 15-18 horsepower gains combined with noticeably improved throttle response. The aggressive sound under acceleration gives way to surprisingly civilized cruising volume. Premium stainless steel construction ensures decades of rust-free service. The million-mile warranty demonstrates Borla’s confidence.

Installation takes 2-3 hours for moderately skilled enthusiasts. The fitment quality is exceptional—everything aligns perfectly without struggling or forcing components.

MagnaFlow Competition Series ($600-700): MagnaFlow’s straight-through perforated core design maximizes flow while creating a deep, refined tone. The sound is aggressive during acceleration but civilized during cruising, making it ideal for daily-driven 4Runners that must remain livable.

Performance gains of 12-15 horsepower place this among the more affordable quality options. The lifetime warranty demonstrates MagnaFlow’s confidence in their stainless steel construction. Polished tips add visual appeal, looking professional rather than aftermarket.

Headers ($700-1,200):

Headers replace the restrictive factory exhaust manifolds with tuned-length tubes optimizing exhaust scavenging.

Doug Thorley Headers ($800-900): Doug Thorley’s headers represent the gold standard for 4Runner applications. Tri-Y design optimizes scavenging across the RPM range rather than just at peak power, improving drivability and torque production where you actually drive.

Installation is complex, requiring 6-8 hours and substantial disassembly. Most owners pay shops $600-800 for professional installation. However, the 18-22 horsepower gains combined with noticeable torque improvement justify the investment and effort.

The lifetime warranty covers the headers themselves, though installation labor obviously isn’t covered. Quality construction means these headers will outlast the vehicle with basic maintenance.

Sound Level Considerations

Understanding realistic sound levels prevents buyer’s remorse:

• Stock: 72-74 dB at idle (very quiet, refined)
• Cat-back systems: 78-82 dB (noticeable but civilized)
• Headers + cat-back: 82-86 dB (aggressive, muscle car tone)
• Full exhaust with high-flow cats: 84-88 dB (loud, attention-getting)

For context, normal conversation occurs at 60-70 dB, while prolonged exposure above 85 dB can cause hearing damage. Most enthusiasts find 80-84 dB ideal—aggressive enough to sound mean during acceleration while remaining tolerable during highway cruising.

3. ECU Tuning & Throttle Controllers

Electronic modifications optimize power delivery and responsiveness without any physical hardware changes, representing some of the most cost-effective performance upgrades available.

Performance Gains: 15-25 HP from tuning, dramatically improved throttle response from controllers
Cost Range: $300-800
Installation: 30 minutes to 2 hours

Throttle Controllers

Electronic throttle controllers address the frustrating lag built into the factory drive-by-wire system. Toyota’s conservative throttle mapping prioritizes smoothness over immediate response, creating delays that frustrate enthusiasts.

Pedal Commander ($300-350): Pedal Commander’s unit intercepts signals between the accelerator pedal and ECU, modifying the relationship for dramatically improved responsiveness. Four modes with nine sensitivity levels provide extensive adjustability from economy to sport to off-road settings.

Installation takes 15 minutes—plug the unit inline with the accelerator pedal connector, mount the control module, and you’re done. The transformation is immediate and dramatic. The throttle responds instantly to inputs, eliminating the spongy feel plaguing stock 4Runners.

Eco mode actually improves fuel economy by requiring less pedal travel for equivalent power, reducing over-application. Sport mode creates aggressive response ideal for spirited driving. Off-road mode provides precise low-speed control for technical terrain.

Sprint Booster V3 ($350-400): Sprint Booster offers similar functionality with slightly different tuning characteristics. Some users prefer Sprint Booster’s progressive calibration that feels more natural than Pedal Commander’s more aggressive mapping.

The plug-and-play installation requires no special tools or expertise. Multiple mode options allow customization for different driving situations. Removable design means you can return to stock instantly if needed for dealer service.

ECU Tuning Options

OV Tune Custom ECU Tuning ($600-800): OV Tune specializes in Toyota/Lexus applications with extensive experience optimizing the 1GR-FE engine. Custom tuning based on your specific modifications extracts maximum power while maintaining reliability and drivability.

The process involves sending your ECU to OV Tune for reprogramming. Turnaround time is typically 3-5 business days. The custom calibration optimizes fuel delivery, ignition timing, VVT operation, and transmission shift points for your specific combination.

Expect 20-25 horsepower gains on an otherwise stock engine, more with supporting modifications. More importantly, the improved throttle response, transmission behavior, and overall drivability transform the driving experience. The power delivery becomes more linear and predictable.

URD Tuner ($450-500): URD (Ultimate Racing Development) offers plug-in ECU tuning specifically developed for Toyota applications. The handheld tuner uploads custom calibrations optimized for various modification levels from stock to supercharged.

Installation is straightforward—plug into the OBD-II port, select your tune, and wait 10-15 minutes for upload. The device stores your factory calibration, allowing complete return to stock for dealer service or when selling the vehicle.

Pre-loaded tunes include options for stock, bolt-ons, and forced induction. Expect 15-20 horsepower gains on stock engines, with improvements scaling based on modifications. The real benefit is improved drivability through better throttle mapping and transmission programming.

4. Throttle Body Spacers

While controversial in the performance community, throttle body spacers can provide minor gains when combined with other breathing modifications.

Performance Gains: 3-8 HP (modest, supporting modification)
Cost Range: $100-200
Installation: 30-45 minutes

How They Work

Throttle body spacers create additional volume and promote air swirl before entering the intake manifold. The theory suggests improved fuel atomization and more even cylinder distribution, though actual benefits vary widely between applications.

For the 4Runner’s 1GR-FE engine, realistic expectations are 3-5 horsepower gains—modest but measureable when combined with intake and exhaust modifications. The primary benefit is slightly improved throttle response from the additional plenum volume.

Recommended Option: Airaid 310-629 ($130-150)

Airaid’s helical-bore spacer promotes airflow swirl while adding volume. Installation takes 30-45 minutes—remove the throttle body, install the spacer with new gaskets, reinstall the throttle body, and you’re done.

Don’t expect miracles—this modification complements other breathing improvements rather than providing standalone gains. For the modest cost and simple installation, it’s worthwhile as part of comprehensive intake/exhaust upgrades.

Intermediate Performance Modifications

Moving beyond basic bolt-ons addresses the 4Runner’s unique character as an off-road-capable SUV, where suspension and handling matter as much as engine power.

5. Suspension Upgrades: The Foundation of Performance

For 4Runners, suspension represents the most impactful modification category. Quality suspension transforms capability, handling, and ride comfort more dramatically than engine modifications.

Cost Range: $800-5,000 depending on system complexity
Installation: 4-8 hours for experienced DIYers, professional installation recommended

Bilstein 5100 Adjustable Shocks ($600-800)

Bilstein 5100s represent the most popular 4Runner suspension upgrade, offering adjustable height capability with dramatically improved damping compared to stock.

Front shocks allow 0-2.75″ lift adjustment through threaded preload collars. This adjustability lets you fine-tune height for specific tire sizes or load conditions. The monotube design provides consistent damping without fade during demanding use.

Rear shocks don’t offer height adjustment but dramatically improve ride quality and control. The improved valving handles weight variations better, maintaining composure whether empty or fully loaded with gear.

Expect transformed ride quality—better control over rough terrain, reduced body roll during cornering, and maintained comfort during highway cruising. These shocks handle 33″ tires without rubbing when properly adjusted, making them ideal for mild builds.

Installation takes 4-6 hours for moderately skilled DIYers. The fronts require strut disassembly and adjustment before installation. Rears are straightforward bolt-in. Many owners install these themselves, though shops charge $400-600 for professional installation.

Fox 2.5 Coilovers with Remote Reservoirs ($2,500-3,000)

Fox coilovers represent a serious upgrade for enthusiasts demanding maximum performance both on-road and off.

Internal bypass technology provides position-sensitive damping—softer initial compression for small bumps, then progressively firmer as compression increases. This creates exceptional ride quality across varied terrain without compromises.

Remote reservoirs increase fluid capacity for better heat dissipation during demanding use. Extended off-road driving or aggressive on-road use generates heat that degrades damping consistency. The additional fluid volume maintains performance longer.

Adjustable compression and rebound allows fine-tuning for specific uses—softer for highway comfort, firmer for aggressive off-roading, or anywhere in between. The 12 clicks of adjustment provide extensive customization potential.

Installation requires significant mechanical skill and proper tools, particularly for accurately setting spring preload and adjusting damping. Most owners pay shops $800-1,200 for professional installation ensuring proper setup.

The transformation is dramatic—these coilovers provide race-quality damping with street-friendly comfort when properly adjusted. For serious enthusiasts, they’re worth every penny of the substantial investment.

Icon Stage 3 Suspension System ($3,000-3,500)

Icon’s Stage 3 system represents one of the most comprehensive bolt-on suspension upgrades available, including coilovers, rear shocks, and all necessary components for a complete transformation.

2.5″ front coilovers with internal bypass and remote reservoirs provide exceptional performance. The CDC (Compression Damping Control) valving offers wide adjustability for different driving styles and terrain.

Rear 2.5″ shocks with piggyback reservoirs match the front’s capabilities, creating balanced performance front to rear. Proper damping balance is critical—mismatched front/rear shock quality creates unpredictable handling.

Extended range of travel improves off-road capability through better articulation. The increased travel allows wheels to follow terrain without lifting, maintaining traction through sections that would cause stock suspension to lose contact.

This represents serious investment, but the results justify the cost for dedicated off-road enthusiasts. The system handles 35″ tires, provides excellent on-road manners, and excels during serious off-road use.

6. Wheels & Tires: The Most Visible Performance Upgrade

Wheels and tires dramatically affect performance, capability, and appearance. The right combination improves grip, ground clearance, and off-road traction while transforming the 4Runner’s stance.

Cost Range: $2,000-4,000 for complete wheel and tire package
Installation: 2-3 hours including mounting, balancing, and alignment

Tire Selection Strategies

All-Terrain Tires (Daily Driver Focus):

BFGoodrich KO2 ($1,200-1,400 for set of 5): The KO2 has earned legendary status through decades of proven performance. Aggressive tread provides excellent off-road traction while maintaining reasonable on-road manners. Road noise is noticeable but not excessive—a reasonable trade-off for the off-road capability.

33×10.50R17 (285/70R17) fits stock suspension with minor trimming. The KO2’s tough sidewalls resist punctures during rock crawling and handle trail debris well. Expect 40,000-50,000 miles of life with proper rotation and maintenance.

Winter performance is exceptional for an all-terrain—the 3-peak mountain snowflake rating certifies severe snow capability. This makes KO2s ideal for year-round use in varied climates.

Falken Wildpeak AT3W ($1,000-1,200 for set of 5): Falken’s Wildpeak offers exceptional value with performance rivaling tires costing 30% more. Aggressive tread pattern handles mud, snow, and rocks while silicon-enhanced compound maintains flexibility in cold weather.

The reduced cost compared to BFG allows upgrading to slightly larger sizes or investing savings elsewhere. Performance differences between Wildpeak and KO2 are minimal in real-world use—both are excellent all-around performers.

Mud-Terrain Tires (Off-Road Priority):

Nitto Ridge Grappler ($1,400-1,600 for set of 5): Nitto’s hybrid tread design provides mud-terrain capability with reduced road noise. Alternating shoulder grooves provide self-cleaning characteristics in mud while maintaining acceptable highway manners.

Expect noticeably more road noise than all-terrains but less than traditional mud-terrains. The aggressive sidewall lug design provides additional traction in deep ruts and protects sidewalls during rock contact.

35×12.50R17 fits with 3″ suspension lifts and requires minor fender trimming. The dramatic appearance transformation justifies the effort for many owners.

Wheel Considerations

Method 502 VT-Spec ($250-300 each): Method’s beadlock-capable wheels provide race-proven strength in surprisingly lightweight packages. The 17×8.5″ size accepts 33-35″ tires while maintaining proper offset for no rubbing and minimal stress on wheel bearings.

The matte black finish looks aggressive while hiding brake dust and trail damage. Beadlock capability allows future upgrade to true beadlocks for extreme rock crawling if desired.

Black Rhino Armory ($200-250 each): Black Rhino’s Armory combines good looks with genuine strength. The load rating handles fully-loaded 4Runners without concern. Multiple finish options allow matching personal aesthetic preferences.

The simple five-spoke design is timeless rather than trendy—these wheels won’t look dated in a few years. Easy to clean designs matter for off-road vehicles accumulating mud and trail debris regularly.

7. Brake Upgrades

Adding power and larger tires requires corresponding brake improvements. Stock brakes struggle with increased weight and speeds, making upgrades essential for safety.

Cost Range: $400-1,500 depending on system complexity
Installation: 2-4 hours for competent DIYers

Brake Pad Upgrades

PowerStop Z26 Street Warrior Pads ($150-200): PowerStop’s carbon-fiber ceramic compound provides excellent bite without excessive dust or noise. The low-dust formula keeps wheels cleaner while the superior fade resistance handles aggressive driving and towing.

Installation is straightforward for anyone who’s performed brake work. The pads include hardware and lubricant, simplifying the process. Expect dramatically improved pedal feel and shorter stopping distances.

EBC Yellowstuff Pads ($200-250): For aggressive driving or frequent towing, EBC’s Yellowstuff compound excels. High-friction material works well even when cold while resisting fade during extended use. Dust production increases but performance justifies the trade-off.

These represent the performance extreme before requiring dedicated track pads. For daily driving with occasional spirited driving or towing, they’re excellent choices.

Complete Brake Kits

PowerStop K137-36 Truck & Tow Kit ($800-1,000): PowerStop’s comprehensive kit includes drilled and slotted rotors, Z36 truck and tow pads, stainless steel brake lines, and all necessary hardware. Drilled rotors improve cooling while slots help evacuate brake dust and water.

The stainless brake lines reduce expansion under hard braking, improving pedal feel and response. The combination transforms braking performance dramatically, particularly when towing or loaded with gear.

Installation takes 3-4 hours for experienced DIYers. Shops charge $400-600 for professional installation including bleeding the brake system properly.

Advanced Performance Modifications

These modifications represent serious commitments requiring substantial budgets and professional installation, but deliver dramatic performance increases.

8. Forced Induction: Supercharger Systems

Forced induction transforms the 4Runner from adequate to genuinely quick, adding 100+ horsepower while dramatically improving towing capability.

Cost Range: $5,500-7,500 for complete systems
Installation: Professional installation mandatory, 20-30 hours labor

URD Supercharger Kit ($6,500-7,000)

URD (Ultimate Racing Development) specializes in Toyota forced induction with extensive experience supercharging 1GR-FE engines. The complete kit includes everything needed for a reliable, emissions-compliant installation producing genuine performance.

Eaton TVS1320 supercharger provides roots-type positive-displacement characteristics—instant boost from idle creating dramatically improved low-end torque. This suits the 4Runner’s character perfectly, delivering strong power exactly where you need it for daily driving and towing.

Running 7-8 PSI boost on 91 octane fuel, expect 100-120 horsepower gains combined with 80-100 lb-ft additional torque. The transformation is dramatic—the formerly adequate 4Runner becomes genuinely quick, with effortless highway passing and strong acceleration from any speed.

The intercooled system maintains safe intake temperatures even during extended operation. Air-to-water intercooler design provides excellent heat rejection while fitting entirely under the hood without modifications.

Supporting modifications included:

• Upgraded fuel injectors handling increased demand
• Fuel management system ensuring proper air/fuel ratios
• All mounting brackets and hardware
• Comprehensive installation instructions

Professional installation costs $2,500-3,500 depending on shop rates. The complexity and critical nature of proper installation makes professional installation mandatory for most owners. Improper installation risks expensive engine damage.

Real-world performance:

• 0-60 MPH: 6.2 seconds (from 7.5 stock)
• Quarter mile: 14.8 @ 92 MPH (from 16.2 @ 84 MPH)
• Highway passing power dramatically improved
• Towing capability significantly enhanced
• Fuel economy decreases 2-3 MPG average

The CARB exemption order makes this system legal in all 50 states—critical for California owners or those in states following California emissions standards.

Magnuson Supercharger System ($5,500-6,500)

Magnuson’s MP62 system represents a more affordable alternative providing similar performance characteristics. The Eaton MP62 roots-type supercharger produces instant boost like the URD system, maintaining excellent low-end characteristics.

Expect 90-110 horsepower gains running 6-7 PSI boost. The slightly more conservative boost levels provide increased reliability margin while still delivering dramatic performance improvement. The complete kit includes all necessary components for a professional installation.

The polished supercharger appearance looks impressive through the hood—for owners wanting visible modifications, this adds appeal. Performance differences between URD and Magnuson systems are minimal in real-world use.

9. Armor & Protection (Performance Through Capability)

For 4Runners, protection equals performance—armor allows pushing harder off-road without fear of expensive damage.

Cost Range: $1,000-4,000 for comprehensive armor
Installation: 4-8 hours depending on components

Essential Armor Components

RCI Metalworks Front Skid Plate ($350-400): 3/16″ steel construction protects the front differential, oil pan, and transmission from rock impacts. Heavy-duty design handles serious abuse during rock crawling or high-speed desert running.

Installation requires drilling through the frame for mounting bolts. Many owners combine installation with other underbody work to minimize vehicle downtime. The peace of mind during aggressive off-roading justifies the investment.

CBI Off-Road Rear Bumper ($1,200-1,400): CBI’s swing-out rear bumper provides dual jerry can mounts, tire carrier rated for 35″ tires, and integrated recovery points. The solid construction handles recovery operations without concern about damage.

The powder-coated finish resists trail damage while the modular design allows customization with additional lighting, camping table mounts, or other accessories. Installation takes 4-6 hours for moderately skilled enthusiasts.

Demello Off-Road Flat Top Sliders ($800-900): Rock sliders protect rocker panels during side impacts while providing jacking points and steps. The flat-top design creates stable platforms for additional storage or working on the vehicle’s side.

Bolt-in installation avoids welding while maintaining strength adequate for aggressive use. The powder-coated finish maintains appearance despite trail abuse and rock contact.

Supporting Modifications

These upgrades ensure your 4Runner remains reliable and capable as power and use intensity increase.

10. Cooling System Upgrades

Mishimoto Aluminum Radiator ($350-450): Increased core thickness and improved fin design provide 25-30% more cooling capacity than stock. Supercharged 4Runners or those seeing extended off-road use benefit dramatically from improved cooling.

TRD Oil Cooler ($400-500): Maintains proper oil temperatures during towing or aggressive driving. Installation requires minimal modification and provides insurance against overheating during demanding use.

11. Electrical and Lighting

National Luna Dual Battery System ($800-1,000): Dedicated auxiliary battery powers accessories without draining the starting battery. Essential for overland builds running refrigerators, lights, and communication equipment for extended periods.

Baja Designs Squadron Series Lights ($400-600 per pair): LED driving lights dramatically improve nighttime visibility. The compact design fits various mounting locations while producing incredible output with minimal power draw.

Real-World Build Examples

Understanding realistic costs and results helps you plan your build effectively.

Stage 1: Street Performance ($2,500-3,500)

Goal: Improved daily driving performance and responsiveness

Modifications:

• K&N cold air intake ($450)
• Borla cat-back exhaust ($1,000)
• Pedal Commander throttle controller ($350)
• OV Tune ECU calibration ($700)

Expected Results:

• 35-45 HP increase
• Dramatically improved throttle response
• Enhanced exhaust sound
• Better highway passing confidence
• Maintained daily drivability

Stage 2: Balanced Performance ($6,000-8,000)

Goal: Significant performance with improved capability

Modifications:

• Stage 1 items
• Bilstein 5100 suspension ($800)
• 285/70R17 BFG KO2 tires ($1,400)
• PowerStop brake kit ($900)

Expected Results:

• Complete transformation in character
• Excellent on-road performance
• Improved off-road capability
• Maintains comfort and practicality

Stage 3: Maximum Performance ($15,000-20,000)

Goal: Ultimate street/trail performance

Modifications:

• URD supercharger system ($6,500)
• Icon Stage 3 suspension ($3,500)
• 35″ tires on Method wheels ($3,000)
• Comprehensive armor package ($2,500)
• All supporting modifications

Expected Results:

• 100+ HP gains
• Genuine off-road capability
• Professional-quality suspension
• Protected for aggressive use
• Significant capability transformation

Maintenance Considerations

Modified 4Runners require adjusted maintenance to ensure longevity.

Oil Changes: Every 5,000 miles (3,000 for supercharged)
Transmission Service: Every 30,000 miles
Differential Service: Every 30,000 miles
Suspension Inspection: Every 10,000 miles
Brake Inspection: Every 10,000 miles or before major trips

Conclusion: Building Your Ultimate 4Runner

The Toyota 4Runner platform offers exceptional modification potential, allowing you to build anything from a comfortable highway cruiser with improved power to a serious off-road machine capable of tackling challenging terrain for extended expeditions.

Starting with basic bolt-ons like intake, exhaust, and throttle controllers provides meaningful improvements for reasonable investment. These modifications transform daily driving character without compromises in reliability or practicality.

For enthusiasts seeking comprehensive builds, combining forced induction with quality suspension creates 4Runners rivaling dedicated performance SUVs while maintaining Toyota’s legendary reliability. The key lies in thoughtful planning, quality components, and professional installation where necessary.

Remember that the 4Runner excels at doing many things well rather than one thing perfectly. Your modifications should enhance this versatility rather than compromise it. Whether building for performance, capability, or both, the 4Runner platform rewards thoughtful upgrades with dramatically improved capability and enjoyment. For more guidance on Toyota performance modifications, Toyota’s official TRD division offers valuable resources.