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

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

Overland Tailor Tuning (OTT) is proud to announce the official release of our highly anticipated ECU and TCU tuning solutions for the 2024+ Toyota Tacoma & 2025+ Toyota 4Runner featuring the 2.4L (T24A-FTS) engine in both gas and hybrid variants. After more than 6 months of 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 3rd Gen Tacoma, 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: 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 4th Gen Tacoma and 5th Gen 4Runner Calibration from OTT will initially be available only through an authorized OTT retailer. DIY options are coming soon, however. 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 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:

• Multiple Calibrations for Each Trim: With the new generation ECUs, there are multiple calibrations available for each vehicle trim, unlike previous generations where a single calibration covered up to 2-3 model years. Due to this, not every vehicle will be immediately available at launch. OTT has worked hard to build the most extensive library of available calibrations to support as many vehicles as possible from the start so the impact should be relatively minimal.
• 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!
• New 2025 Models: With the release of the 2025 models, OTT is in the process of building a calibration library for these new ECU ID’s. It should be expected that 2025 model year vehicles will require us to read the files, and these files might not be immediately available until we’ve built the library.
• 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 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

-----------------------------------------------------------------------------------------------------------------------------------------

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

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

 

We've seen much higher-than-expected interest in DIY tuning options, so we want to keep the community informed on what’s required to tune the new 4th Gen Tacoma & 6th Gen 4Runner with our calibration files. Here’s what you need to know.

Required Hardware & Costs

To flash the new ECU in the 2025+ 4Runner, you will need:

• VFTuner WiFlash Device
• VFTuner License (4G Lite)
• (4) License Credits
• VFTuner CAN-Connect Cable

This complete package is available directly from OTT for $950 USD w/ OTT Stage 1 Calibration Pack.

For Existing VFTuner Users

• VFTuner Legacy (Tactrix) devices are not compatible with the new platform. If you have a Legacy device, you will need to purchase the VFTuner WiFlash Lite Kit with Gen4 Flash Protocols:
  • VFTuner WiFlash Lite Kit
• If you already own a WiFlash device, contact VFTuner at Support@ovtune.zendesk.comto inquire about converting your existing license to the Gen 4 Lite Kit protocols.
  • We do not have details on whether this is a free or paid upgrade, so please check with VFTuner directly.
• You will still need to purchase additional Licensing Credits for the new platform:
  • VFTuner License & Credits

VFTuner CAN-Connect Cable

• The Gen4 ECU cannot currently be flashed through the OEM OBD2 port.
• The VFTuner CAN-Connect Cable allows for easy plug-and-play integration, providing a secondary OBD2 port with no permanent modifications.
• Installation is simple—remove the kick panel and insert the connector in line with an existing harness.
• VFTuner CAN-Connect Cable

Calibration & Tune Packs

• The full suite of calibration files will be available in two ways:
  • Included with the full package purchase (all required hardware/software)
  • Standalone Tune Pack for those who already own the necessary equipment – $450 USD
• The Tune Pack includes all available calibrations and future updates for a single Calibration ID.

For more information or to purchase, please email info@overlandtailor.com.

If you have any questions, feel free to reach out. We’re excited to see such strong interest in DIY tuning and look forward to supporting the community!



**We are currently out of stock on CAN-Connect cables** -03/07/25

 

Here come the tunerz hawking mods that void warranty.

While nobody is anywhere close to being out of warranty yet.

 

NICE

 

I've come to make a quick buck

 

As soon as folks put 35’s, armor, racks, bumpers, etc… on their 6th Gen’s, they’ll appreciate the tune.

If you’re keeping it stock and snuggling with your warranty paperwork to sleep at night, it’s probably not for you.

 

Some people dont care about warranty
I begged for a way to make my wifes 2023 feel like my 2008 and her previous 2012, the new vehicle was literally watered down so badly that my wife (daily driver) wanted me to get rid of it. I bought the 2023 sight unseen, picked it up, brought it home, kitted it out identical to the 2012 before she ever sat in the seat. Literally from day 1 she was complaining about how it felt, drove, ran, shifted, ect ect. I started doing research and found the OTT tunes and after spending a month reading i figured that was the best way to get it running better. I finally got it done with about 9,000 miles on the ticker and it completely transformed the way the vehicle ran, shifted, cruised, ect ect. Its worth every penny.

 

Haters guna hate. I had a 2017 Civic turbo. Cute little 4 door. Flashed it. Omg was that thing fun (after the flash).

Waiting another year or two for toyota to get the kinks out and then looking at probably a tacoma. Sooo excited its turbo because I'll get it flashed for the first week.

Dyno results in this thread looks great. Im super excited to see what people do with this new gen turbo platform.

Im glad we have people like OTT doing The Lord's work here. Can't wait to have a platform to utilize this on.

 

Did you have any problems with getting the Civic smogged in California?

 

No there wouldn't be an issue with that.

CA also changed it's smog laws. I had a visual done on it. It didn't actually get tested, just a visual. And I sold it 5 years ago.

 

Tuning is a sure way to void your warranty and for a good reason, even if tuner knows what they are doing, it still puts extra stress on the engine. Plus your truck after the tune is going to be more sensitive to bad fuel. Plus you more likely to have heat related issues, especially at slower speed or when towing. Plus, your gas mileage going to be worse.

 

Every flash I've ever looked at for cara j was interested, the fuel economy got better with a flash under normal driving conditions.

Heat: not an issue with these vehicles. Potentially with some sports cars. Even then with just a flash, no. Not an issue.

Void warranty: ehhhhhh gray area. Maybe if you tell them. So uh. Don't do that.

 

Once you tune, there is a flag in the ECU that will let any dealer know it was tuned, even if you revert back to the stock tune.

 

This is incorrect. Our software/flashing method leaves ZERO trace of anything that has changed. Other software/methods this is not the case.

Our development truck has well over 1000 flashes on the truck. Here's some screenshots of the vehicle history showing no RoB data or flags are stored for flashing.

There are a few people in here spewing information that is flat false and opinion based, from folks with no interest in the product/service we offer (which is perfectly fine), but lets remember to separate opinion from fact. We can back up what we claim. We have active Toyota Master Tech's as part of OTT, who can validate what Toyota can/cannot see.

As you can see with these screenshots, Even after 1000 flashes there is no "flag/record" of our truck ever being tuned. Warranty is fully in tact.

 

There's like 1 single actual 2025 4Runner owner here, maybe 2. So you're marketing to no one here basically.

 

In my ram trucks the ECU will have a notification that its been flashed.
You cant tell WHAT has been flashed, only that its been flashed. The dealer might ask
"Hey whats the flash in here, i see it was flashed on xxx date."
You can simply say
"ah i took it to a dealer and they did some sort of update or something i dunno"
My ram 3500 and 2500, i was constantly doing stuff to them and the dealer once looked at my 2500 and said.... "dang this thing has been flashed a lot, whats done to it" Little did they know i was having to flash it back to stock with Ezlynk over and over on long hauls 20+ hours straight when the DEF system would get mad, stick the injector wide open and throw codes and shut the truck down. I never put anything on either truck, never changed power or performance, but the OEM stuff was so unreliable for long hauls i had to basically reflash it back to stock parameters every so often to get it out of its locked up modes. I got rid of the 3500 with about 40,000 miles and maybe 5-6 reflashes back stock but the 2500 i kept maybe 75,000 miles and i bet it had 20+ flashes back to stock in it. All that to clear out the nannies and let it start over fresh .

 

Not much more can be said.

 

So…… One has to cough up say between $45,000.00 to say north of $65,000.00 for an over-priced 6th gen, and then cough up even more in addition to that to make that tiny piss ant 4 cylinder run right? Ummm…. no thanks. Sticking with my bullet proof ‘22 5th gen 4.0L V-6.

 

The "tiny piss ant 4cyl" mops the floor with the Dual VVTi 4.0L V-6. I'll take the 115 additional ft/lbs of torque at 2750RPM Alex.



Both vehicles stock, on stock calibrations.

 

JustDSM - Are there plans to create a tune for the Land Cruiser as well since you have a tune now for the Tacoma and 4Runner?

 

Yes! Absolutely. It's currently in development with two of our in-house vehicles. Despite the LC using the same engine as the Tacoma/4Runner platforms, the ECU uses an entirely different control strategy and we're adapting our data to that strategy. I'd love to give you an exact date, but I honestly can't at this point. We've got to iron it out, test it, and validate it before making it public. I don't think it'll be far into the future, though. If you follow our socials, we'll announce the release there first.

 

That dyno graph makes no sense, why does turbo torque curve drop off ~100 ft/lbs by the time it reaches red line? Is that turbo in the early stages of impeller failure or did Toyota undersized it to the point that it can't handle RPM? It almost looks like its has choked intake, but that unlikely to be the case even with stock Taco air box. Perhaps your test mule has some weird snorkle? If so, please take that off if you want to make meaningful comparison to NA V6.

This makes me doubt these results, because how bad the turbocharged curve looks like. Having NA outperform it at above 5250 is just embarrassing and not something I'd expected to see. In practical terms, this means in a rolling start V6 will overtake that turbo engine.

 

I cant guarantee any of this, this is purely speculation, but i work in offroad racing field and see a ton of turbo stuff and understand the tuning behind them from the OEMs.
If i had to guess, Toyota used a tiny turbo that could build full boost by 2700rpm so you are seeing boost making those numbers. The turbo is so tiny though when you stay in it full throttle for long it builds high IAT Intake Air Temps SO, Toyota did one of two strategies.
1) as the RPM increases their wastegate actuator starts bleeding boost off, so the longer you are in the throttle or the higher the RPM goes, the more it bleeds boost off to not hold full boost to redline to reduce IAT at high RPM and high loads to reduce knock
2) as the RPM increases they are likley pulling timing to reduce the liklehood of knock and detonation at the higher RPM.

I suspect its one of those two strategies, if not both.
Polaris uses #1 in their SxS, they build 14psi of boost initially when you stab the gas. As your wheel speed increases they bleed the boost off. As you increase speed, your wind resistance increases and the load on the engine increases. By the time you get to 40mph the ECU has bled you down to 12psi and when you get 60+ the ecu has bled you down to 10psi of boost. This is to reduce IAT on long pulls due to the small turbo building so much heat. They bleed boost down in a way to control IAT and reduce the chance of detonation
Can-am uses #2 in their SxS, they will pull timing as the boost increases and have multiple tables watching IAT. They have different timing and throttle strategies based on IAT. As the IAT increase, they will change timing and even limit throttle to keep IAT thresholds in check.

Both of these strategies are typical of OEMs to save the engines, because they are running tiny turbos. Tiny turbos can spool fast and easy but tiny turbos build a lot of heat. A great example is the Can-am SxS, it runs 14psi and its tiny turbo spools super fast but builds 190-200 degrees of IAT. Once people do a tune and bump it to 18psi they are making 240-260 IAT pre intercooler. A simple fix is a bigger turbo, BUT with a bigger turbo comes lag. A bigger turbo like the Whalen Green turbo drops the IAT at 14psi down to like 160 degrees and with more air it will make more power at 14psi than the stock turbo at 18psi BUT...... You get lag. So when you roll into the throttle, it takes for a minute till the turbo spools up. These OEMs are doing what they can to make small turbos have instant boost and full power now, i suspect Toyota did the same. If you see the power curve overlaid with boost you could probably see these tiny turbo Toyota used is likely already at full boost at 2700RPM. I dunno if they bleed boost off or what but thats what i would suspect.

 

I’d encourage you to educate yourself on how to read a dyno chart. At no point above 2300RPM, does the 4.0L make more horsepower or torque.

 

My experience with tuning comes from race track applications, so the approach is exactly opposite that what you suggest - big turbo with big cooling all optimized for high-RPM performance. Yes, you learn to live with the lag, but at least it doesn't choke once its on.

If your speculation with #1 is correct, then it is strong evidence that heat is a serious issue with this setup. More so, that approach has implications on long-term reliability, because wastgate actuators do fail (I had one fail on my old WRX, it did not grenade the engine with that setup) and coolers do get dirty and lose efficiency.

Personally, I prefer supercharging. This is what I have on my current track car. Plus, you don't get muffled exhaust so the soundtrack is much better. In WRX, getting on-boost was like getting rear ended, quite dangerous if you mess up the corner and somehow end up going on-boost before apex.

 

Not sure where you are seeing the NA calibration “outperforms” the turbo above 5252. Both blue lines are 4.0L stock torque and HP, both red lines are 2.4L turbo torque and HP. The red lines are clearly above the blue lines throughout the rpm range.

 

Dyno is always done at Wide Open Throttle (WOT), this gives advantage to turbocharged engine. With a partial throttle NA behaves quite similar to WOT, but turbo significantly degrades. Another issue is heat soak - these pulls typically done once with a cool engine. This again favors turbo, that will get heat soaked under prolonged load and degrade performance. So such dyno graphs inherently make NA look worse than it actually is in most circumstances. Last but not least, in determining how quick your car is, mass and torque in the upper RPM band is what matters. The only time low RPM performance matter is when you pull from a stop.

With all that in mind, and knowing that 6th Gen 4Runner is heavier, I made a prediction: "this means in a rolling start V6 will overtake that turbo engine." This is, obviously, a speculation. Also, quite likely pointless one as well, as both of these are slow as f*** and would have trouble keeping up even with stock Miata.

 

You do realize the dyno pulls are a rolling start, correct? The rpms are ~2000 and wheels are spinning before WOT applied.

There is no way the NA truck will magically overcome a 60 HP deficit sustained through nearly the entire rpm range. The area under the curves matters.

 

You are probably right. I am sure someone soon will do a drag race between 5th and 6th and post the result on YT.

 

Time vs Speed. The 6G is at 95+mph just as the 5G gets to 88mph.



Or.. You could also look at the time it takes to get from 50-80mph simulating an overtake on 2-lane highway. An actual scenario a 4Runner might be presented with.

In this instance, it takes the 5G 4Runner 3.728sec to get from 50 to 80mph. It takes the 6G 4Runner 2.968sec to do the same.