Introducing 2025+ 4Runner 6th Gen ECU / TCU Tuning Solutions from Overland Tailor Tuning (OTT)

[JustDSM]

Overland Tailor Tuning (OTT) is proud to announce the official release of our highly anticipated ECU and TCU tuning solutions for the 2025+ Toyota 4Runner featuring the 2.4L (T24A-FTS) engine in both gas and hybrid variants. After extensive development and in-house testing, OTT is excited to offer a precision-engineered, comprehensive tuning solution designed to optimize performance, enhance drivability, and improve reliability.

For those who are familiar with OTT from our work with the 5th Gen 4Runner, you’ll find the same high level of commitment and precision in the new models. OTT’s tuning is designed with a focus on real-world reliability and performance, not just raw power—though the new platforms certainly deliver a punch! In some cases, they provide more than three times the gains compared to what was possible with the previous naturally aspirated platforms!

Key Features of OTT’s New Tuning Solutions:

• Reworked Throttle Control Strategies: The new generation ECUs feature a completely new throttle control strategy compared to previous Tacoma generations. With this new strategy, we offer throttle sensitivity options of “Stock,” “Base,” and “Enhanced,” allowing drivers to tailor their vehicle’s throttle response to their preference, replacing the previous “Lite,” “Mild,” “Medium,” “Spicy,” and “Super Spicy” naming conventions.
• Enhanced Throttle Response and Reduced Spool Time for Turbocharger: OTT’s tuning sharpens throttle response and reduces turbocharger spool time, allowing for more immediate low-end and midrange torque. This means the engine reaches usable boost pressure more quickly, improving drivability and acceleration, particularly during off-the-line starts and when accelerating from low RPMs. This results in a more responsive driving experience, with faster throttle reactions all with smooth delivery.
• Stage 0 Customization: OTT offers Stage 1 and Stage 0 tuning solutions, with TCU updates for each drive mode to enhance driving performance. Stage 0 is available on request for those requiring reduced output at lower boost levels.
• Fuel Requirements: OEM Spec through Stage 1 calibrations are designed for Regular to Premium fuel, with peak performance achieved on Premium (Recommended).
• Exclusive Calibration Capabilities: One such ability is OTT's offering of a proprietary MAF calibration that ensures perfect integration with a retrofitted TRD Pro/Trail Hunter airbox, without triggering CEL codes. In addition, OTT is developing solutions such as Auto Start-Stop disable and other advanced vehicle customization options (to be announced at a later date).

Why OTT’s Tuning is Different from Piggyback Controllers:

Unlike piggyback controllers, which manipulate the signals between sensors and the ECU, OTT’s tuning works natively within the factory ECU. This allows for precise and real-time adjustments to parameters like throttle response, fuel delivery, ignition timing, and boost control, ensuring that the ECU receives accurate information for optimal decision-making.

Piggyback Controllers vs. OTT’s Native ECU Tuning:

• Spoofing Sensor Signals: Piggyback controllers modify sensor inputs (e.g., MAF, boost pressure, and throttle position) before sending them to the ECU. This disrupts the ECU’s ability to make accurate, real-time adjustments.
• Manipulated Outputs: These devices alter ECU outputs like fuel delivery, timing, and boost but lack dynamic, real-time adaptation, leading to inefficient engine management under varying driving conditions.
• Risk to Vehicle Safety Features: Toyota’s ECUs have built-in safety mechanisms such as knock detection and overboost protection, and temperature-specific mapping which piggyback controllers can bypass, putting the engine at risk when factory signals are spoofed.

Why OTT’s Native ECU Tuning is Superior:

• Native Calibration: OTT calibrations are directly integrated into the OEM ECU code, ensuring seamless performance optimization without the need for premium fuel exclusively. Unlike some piggyback controllers that restrict fuel choice. When the ECU remains in charge of decision-making, OTT can offer flexibility, allowing the vehicle to run on Regular or Premium fuel.
• Reliability and Safety: By working natively within the factory ECU, OTT ensures your vehicle’s safety features, such as knock detection and overboost protection, and temperature-specific mapping remain fully operational.
• OEM-Level Integration: OTT’s tuning is fully compatible with your vehicle’s factory systems, avoiding triggering error codes or safety warnings during service.

The Importance of Retaining Full Access to Diagnostics and ECU Programming:

OTT’s tuning does not lock down the ECU or restrict access to factory programming modes. Unlike some newer tuning solutions, which may lock diagnostics modes and restrict dealership access to the ECU, OTT ensures that dealerships can perform diagnostics and service without interference, preserving warranty coverage and avoiding issues during routine maintenance.

Why Choose OTT Over Other Tuning Solutions?

• Native ECU Tuning for Reliability: OTT works directly within the OEM ECU, ensuring compatibility with Toyota’s factory safety features while maintaining system integrity.
• No Service Concerns: OTT’s tuning does not lock down ECU access, meaning your vehicle can be serviced at the dealership without restricting access to diagnostic tools or having to remove piggyback devices.
• Proven Performance: OTT’s tuning has been rigorously tested, providing proven horsepower and torque gains while ensuring your vehicle’s reliability and safety.

Pricing Information:

The 6th Gen 4Runner Calibration from OTT is currently only available only through an authorized OTT retailer. DIY options are in development and will be available in the near future. To ensure consistent support across the OTT network, we've developed custom hardware for our retailers, enabling direct ECU Read/Write processes for quick, efficient, and safe tuning.

• MSRP through authorized retailers: $650 USD
• DIY Kit Pricing: $950 USD (Includes VFTuner WiFlash Device & Software, Licensing Credits, Calibration suite, and shipping/handling)
  Note: DIY option currently requires a Windows-based PC. The software suite includes vehicle-specific protocols for reading/writing from the new generation ECU, as well as a comprehensive high-speed data logger.
  VFTuner "Legacy" users must upgrade to WiFlash for compatibility with the new ECU. An upgrade path will be available for prior WiFlash clients.

Revisions and Updates:

Revisions apply to your current calibration—whether it’s OEM Spec, Stage 0, or Stage 1. These updates are available at no additional cost (Retailers may charge a small service fee for time/labor related to revisions), ensuring that your tune stays optimized with the latest calibration advancements as software improvements become available.

OTT is also planning additional Staged packages to align with both current and upcoming bolt-on upgrades, keeping your vehicle’s performance evolving.

Additional Things to Know & Be Aware Of:

• Calibration Availability: We have a broad library of files ready, but new calibrations may occasionally surface. If your truck has a calibration that isn't yet available, it cannot be supported until we obtain a physical read of that ECU. If you help facilitate this by coming in for a read, OTT will offer a $50 incentive. OTT and VFTuner greatly appreciate your assistance!
• CARB-EO Compliance: OTT is working to obtain CARB-EO for Stage 1 calibrations, ensuring full compliance for customers in California and other similar-regulated states. This effort will ensure that OTT’s tuning solutions remain fully street-legal in these areas, allowing performance enhancements without violating emissions regulations.
• Revisions and Updates: Revisions apply to your current calibration—whether it’s OEM Spec, Stage 0, or Stage 1. These updates are available at no additional cost (Retailers may charge a small service fee for time/labor related to revisions), ensuring that your tune stays optimized with the latest calibration advancements as software improvements become available.
• OTT is also planning additional Staged packages to align with both current and upcoming bolt-on upgrades, keeping your vehicle’s performance evolving.

Stage 1 Dyno Results:

i-Force (SR5-TRD Trims)

RED: OEM Calibration, Stock Vehicle, 91 Octane
BLUE: OTT Calibration, Stock Vehicle, 91 Octane


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i-Force MAX (Hybrid TRD Trims, Inc. Pro/Trail Hunter)

RED: OEM Calibration, Stock Vehicle, 91 Octane
BLUE: OTT Calibration, Stock Vehicle, 91 Octane

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[Keroppi]

Great info thanks. I've heard good things from a 4th gen Tacoma buddy who's had his OTT Tune installed for a while now so I'm interested too.

Do you guys keep refining your tune over time or it pretty much stays in current version until/unless Toyota makes changes to the engine? What happens if/when your tune version is updated - do owners get free flash to latest version?

 

[Ramrod113]

Any negative effects on MPGs on the hybrid models? I know I know, its a 4runner, MPGs don't matter. Well, when they are low to begin with, we don't need them any lower

 

[JustDSM]

Great info thanks. I've heard good things from a 4th gen Tacoma buddy who's had his OTT Tune installed for a while now so I'm interested too.

Do you guys keep refining your tune over time or it pretty much stays in current version until/unless Toyota makes changes to the engine? What happens if/when your tune version is updated - do owners get free flash to latest version?

We’re always looking for ways to refine the product. Right now, we’re very happy with where things stand, and I’m confident it’s the best it can be given our current understanding of the ECU code. All of the core tuning areas—fueling, ignition, cam phasing, torque modeling, load/torque limiters, transmission shift logic, TCC lock/unlock strategies, etc.—are well defined and sorted. That said, we’re constantly learning, and when we discover new opportunities, we use that knowledge to improve the calibration incrementally.

When we do release an update (like the one we just announced), it’s always free for existing customers running our calibration. We make announcements through our social channels and forums like this one, and at that point you can reach out to your retailer to schedule a reflash to the latest file.

Any negative effects on MPGs on the hybrid models? I know I know, its a 4runner, MPGs don't matter. Well, when they are low to begin with, we don't need them any lower

We’ve been testing on our in-house TRD Off-Road Hybrid, and we haven’t seen a significant change in fuel economy between stock and our Stage 1 calibration. Where Stage 1 increases output and uses more fuel under load, the added torque and hybrid assist often let the truck maintain a lower average RPM—climbing a hill, for example, with torque instead of downshifting like it would stock. That generally balances things out and results in about a net wash for MPG.

Of course, if you’re heavy on the throttle, you’ll see a hit, but under normal day-to-day driving, you shouldn’t notice much difference (positive or negative). Just being transparent and realistic.

 

[don_king]

Wait you guys have a new update since I got mine tuned August 7!?

 

[alpa_chino]

If I get a tune today and later I get the sxth intake do I need a retune or will it learn on its own?

 

[JustDSM]

Wait you guys have a new update since I got mine tuned August 7!?

The recent update was for gas models only. Hybrid models are already current as of this posting. Since the Hybrid 4Runners arrived later, those updates were included right from their initial release.

Amazing pics BTW!!!

 

[JustDSM]

If I get a tune today and later I get the sxth intake do I need a retune or will it learn on its own?

We've extensively tested SXTH's intake and there are no issues running their intake with our calibration. They've done a great job modeling their intake to work with the factory MAF calibration (which is used in our base Stage 1 Calibrations)

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