Introduction

• Car Model & Year: 2013 Lexus GS350 AWD Lux
• Goals for the Build: I’m building a reliable, powerful, and subtly impressive GS350 AWD Lux that delivers a satisfying driving experience without compromising on comfort. This car should impress casual enthusiasts with a bit of wow factor while remaining unobtrusive, as I drive high-class business partners frequently. The project allows me to pursue mechanical excellence, focusing on handling, braking, acceleration, and sound quality. Over time, I’m open to any modification that adds to this pursuit, even a custom carbon fiber roof for style, despite its low practical value.

Current Build Overview

Engine:

• Tuned by Loi, 91 octane tune
• High Spark, premium coil packs
• NGK, spark plugs, 94122
• Non Stop Tuning, aluminum water pump pulley
• Non Stop Tuning, aluminum tensioner and idler pulleys
• AEM340 (50-1220), Low pressure fuel pump

Intake:

• Custom intake by DickH, coated inside and outside in silver (Ti) ceramic by Polydyn
• Injen, X-1101-BB
• K&N, valve cover breather
• AEM, intake cold box, severely modified
• Trigga Spec, Tundra 76mm throttle body with spacer & coolant delete
• Trigga Spec, ported lower and upper intake manifold
• RR Racing, air/oil separator
• DEI, Cool-tape

Exhaust:

• PPE, headers with ceramic coating
• Apexi, resonated midpipe with ceramic coating
• Magnaflow, X-pipe 2.5" with ceramic coating
• Revel, axle-back with ceramic coating

Drivetrain:

• Import Performance Transmission, fully built tranny
• Import Performance Transmission, upgraded valve body, overbored
• Import Performance Transmission, high-stall torque converter
• Import Performance Transmission, built AWD transfer case
• Tru-Cool, LPD, tranny cooler
• Super Now, rear differential lower bushing collar

Wheels/Tires:

• Konig, F3S forged wheels, 18.5x8 with a +35 offset
• Toyo, Proxes sport A/S, 235/45/18
• Mishimoto, aluminum lug nuts

Brakes:

• Stoptech, Sportstop cryo sport drilled & vented rotors, all around
• Akebono, performance ultra premium, front
• Akebono, ProACT ultra premium, back

Suspension:

• KYB, Gas-A-Just shocks with AVS, all around
• RR Racing, USRS race edition bushings
• Spoon Sports, subframe collars front & back

Weight Reduction:

• Anti-Gravity, lithium battery
• Seibon, carbon fiber trunk lid painted to OEM spec
• Spare tire, tools, and trunk carpet delete

Exterior:

• RR Racing, vented carbon fiber badge on the front bumper
• Xpel, XR plus nano ceramic window tint, all around
• Feynlab Ceramic Ultra V2, all around

Detailed Modification Log

tunedbyloi@gmail.com 91 Octane Tune:

Purpose/Reason for the Upgrade: The stock ECU programming on the Lexus GS350 AWD Lux is designed to prioritize reliability and emissions, often at the expense of performance. With my extensive modifications—such as the larger throttle body, ported intake manifolds, and improved exhaust flow—the factory tune was bottlenecking the car's potential. After thorough research and discussions with D3 Performance and fellow enthusiasts like JGScott, I decided to go with tunedbyloi@gmail.com for a custom 91-octane tune. D3 Performance, in particular, speaks very highly of Loi’s tuning expertise, as Loi is a customer of theirs. This endorsement, combined with Loi’s reputation for exceptional results, gave me confidence in my decision.
Installation Process: Loi uses VF Tuner Wi-Flash for ECU calibration, hardware that I did not initially have. To facilitate the tuning process, I purchased this equipment specifically for the tune. I also already had RR Racing’s tuning hardware and license, but Loi’s expertise with VF Tuner and Wi-Flash made it the better choice for my goals. The tuning process started with logging data from my car’s setup and sending the information to Loi. With the VF Tuner hardware, Loi created a custom calibration tailored to my exact modifications. Through remote iterations and adjustments, the tune was finalized to ensure optimal performance. Loi’s communication and precision made the process efficient and hassle-free.
Performance & Driving Experience: The post-tune results are transformative. One standout improvement is the exceptionally smooth power delivery, which is even better than the factory tuning—something I didn’t think was possible. After the porting and installation of the larger throttle body, I had sacrificed a noticeable amount of smoothness and swift power delivery in exchange for raw performance gains. Loi’s revised tune not only recovered that smoothness but also enhanced it to a level beyond stock, creating an effortless and polished driving experience. Throttle response is now precise and immediate, yet retains the refinement expected of a luxury sedan. Mid-range power delivery is notably stronger, making acceleration and overtaking effortless. Despite the performance boost, the tune doesn’t compromise comfort or fuel efficiency during relaxed cruising. Loi’s tune ensures all my modifications work seamlessly together, creating a car that feels perfectly balanced and alive.

No CEL is made only possible with the Loi Tune as otherwise the PPE headers throw a code.

High Spark, Premium Coil Packs

• Purpose/Reason for the Upgrade: To enhance ignition reliability and optimize combustion efficiency. These premium coil packs provide a stronger, more consistent spark, which can improve performance, responsiveness, and overall engine smoothness. These came highly recommended by my tuner tunedbyloi@gmail.com.
• Performance & Driving Experience: After installation, the car demonstrated slightly smoother idling and noticeably enhanced throttle response. Acceleration felt more responsive, and overall, the engine ran with greater consistency. This was done together with the NGK 94122 spark plugs.
• Photo:
  

NGK, 94122 Spark Plugs

• Purpose/Reason for the Upgrade: To improve ignition performance with high-quality spark plugs that support efficient combustion. These spark plugs are known for their reliability and help maximize power output. These were recommended to me over the Brisk plugs I had by tunedbyloi@gmail.com. They are ruthenium and one step colder.
• Performance & Driving Experience: With the new spark plugs in place, the engine delivered a more responsive feel, particularly during acceleration. The car felt smoother and more refined overall, contributing to a better driving experience. This was done together with the High Spark coilpacks.
• Photo:
  

Non-Stop Tuning, Lightweight Water Pump Pulley

• Purpose/Reason for the Upgrade: The primary goal was to reduce rotational mass, thereby enhancing engine responsiveness and efficiency. A lighter pulley decreases the load on the engine, potentially leading to improved acceleration and performance in a subtle way. The pulley is high grade aluminum that is anodized for durability and looks. They only had the purple available, so purple is what I got.
• Performance & Driving Experience: Post-installation, there was a very slight increase in throttle response. While the gains are subtle, they contribute to a more engaging driving experience. Additionally, the lightweight pulley did not introduce any negative effects such as increased noise or vibrations.
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This upgrade aligns with the overall goal of enhancing performance without compromising reliability or comfort.

Custom Intake by DickH, with Injen X-1101-BB Filter, AEM cold box, K&N Valve Cover Breather, intake coated inside and outside silver (Ti) ceramic by Polydyn

• Purpose/Reason for the Upgrade: The aFe Takeda CAII had on there stepped down significantly at the throttle body flange to my large Tundra throttle body. I knew this was a restriction so kindly DickH made me a mandrel bent intake tube that matches in dimeter the inlet of the large Tundra I have on. He also printed a gorgeous MAF sensor hosing with a very nice bellmouth opening and a very close to stock inner diameter where the sensor went in. Then he tapered it super smoothly to the large intake diameter. Masterful. I went way to wild with the intake filter, it is a huge overkill in every dimension. I really should have gone smaller, it was very difficult to fit.
• Important Notes:
  • The AEM cold box did not even come close to accommodating the giant Injen x-1101-BB filter I had to hammer it quite a bit to accommodate the large filter
  • I also had to cut the stock plastic cover that goes over the filter quite a bit to accommodate for the very large filter
  • Loi Tuned it and said that it absolutely needed tuning at the fuel trims were +%19.5 with this intake
  • I got rid of the hose that comes off the valve cover and stuck the breather right on the opening.
  • Polydyn screwed up they were not supposed to coat the inside but they accidentally did coat the inside in Ti ceramic like the outside
• Performance & Driving Experience: I switched from the aFe stage 2 oiled system and going from that to this was an enormous difference at least as much of a difference going from the RR racing intake I had before to the aFe stage 2. It pulls much harder, like surprisingly much more, it did as much difference as the PPE headers. It's shocking really. It now pushes me into the seat somewhat hard. The intake sound is deeper, much more refined, smoother, and quieter at WOT. The power comes much more smoothly. The throttle response is improved too. In 15 years of modifying cars, I have never had an intake do so much.
• Photos:
  
  

notrigga@gmail.com Ported 76mm Throttle Body & Ported Lower and Upper Intake Manifold

• Purpose/Reason for the Upgrade: Following advice from tunedbyloi@gmail.com, I upgraded to the notrigga@gmail.com ported 76mm throttle body along with a ported lower and upper intake manifold. This combination is designed to increase airflow significantly, reducing restriction and maximizing power and torque throughout the RPM range. The ported intake manifold complements the throttle body upgrade by ensuring that the increased airflow is fully utilized, enhancing throttle response, overall power, and sound.
  
• Installation Process:
  • Preparation & Components: Shipping and packing were excellent, and the kit included all necessary hardware and new gaskets for both the intake manifold and throttle body.
  • Throttle Body Installation: The 76mm throttle body is substantially larger than stock, making for an impressive visual upgrade in the engine bay. Installation required some adjustments:
    • Bracket Fitment: The rear and passenger side brackets didn’t align perfectly, so I omitted bolting those in.
    • Clearance Adjustment: I unbolted the hard fuel line under the throttle body for clearance.
    • Coolant Line Delete: Opted to delete the coolant line to the throttle body to further reduce heat soak. However, an option to circulate coolant remains if needed.
    • Noise and Vibration Management: Trigga Spec added a soft material to the bottom of the throttle body to prevent any noise or vibration due to contact with the bracket below.
    • Note: The throttle body will not fit without a spacer due to the mesh inside the initial opening of the upper intake manifold. Conveniently, the kit comes with a matching spacer.
  • Intake Manifold Installation: The ported lower and upper intake manifold installation was straightforward. Trigga Spec’s porting work removes restrictions within the manifold, allowing smoother airflow that works in tandem with the larger throttle body to improve performance across the board.
  • Final Steps: Reassembly was smooth, and the new components fit securely, ready for testing.
• Performance & Driving Experience: Together, the ported intake manifold and larger throttle body deliver a significant boost in torque across the entire RPM range. The intake manifold’s porting optimizes airflow through each cylinder, allowing for quicker throttle response and smoother power delivery. The overall sound is much deeper and more aggressive, transforming the car’s character entirely. Notably, the car feels especially responsive at mid-to-high RPMs, with the intake manifold’s improved flow shining under heavy throttle. Initially, the cold start time increased slightly, taking about two seconds to crank due to the larger throttle body opening, and there was a high idle during the first hour, but this smoothed out as the engine adjusted.
  
• Conclusion: The Trigga Spec throttle body and ported intake manifold work in perfect synergy, creating a more powerful, responsive, and audibly satisfying engine. The performance boost, enhanced sound, and overall driving experience make this upgrade well worth it for anyone looking to elevate their GS350.

RR Racing Air/Oil Separator

• Purpose/Reason for the Upgrade: I installed the RR Racing air/oil separator to reduce the amount of oil entering the intake manifold. This setup is especially helpful in minimizing carbon buildup over time, enhancing both the performance and longevity of the engine. While the GS350’s port injectors help keep valves clean, I wanted additional protection to capture excess oil vapor before it reaches the intake.
  
• Installation Process:
  • Hardware Issue: Initially, RR Racing did not include the necessary hardware for installation. However, they quickly responded to my concern and provided the missing components. Once I had the correct hardware, the installation was very simple and straightforward.
  • Installation Steps: With the hardware in place, I mounted the separator as instructed, connecting it to capture oil vapor from the PCV system before it could enter the intake manifold. I also recently replaced the PCV valve with a new OEM one to ensure optimal performance.
  • Final Check: After securing the separator, I tested it under idle and driving conditions to confirm it was capturing oil effectively.
• Performance & Driving Experience: The air/oil separator has been surprisingly effective at capturing oil, collecting about an ounce of liquid every 1,500 miles. The oil it captures is thicker than expected, indicating it’s doing a thorough job of trapping unwanted oil vapor. While this isn’t a major performance upgrade, it provides noticeable benefits for engine longevity by reducing oil in the intake manifold and carbon buildup. The separator also offers a degree of satisfaction in emptying the canister, knowing it prevents oil from entering the intake and potentially compromising performance.
  
• Conclusion: For anyone seeking to improve the reliability of their GS350, the RR Racing air/oil separator is a worthwhile addition. Although not a massive direct performance upgrade, it aids in maintaining cleaner internals, which supports both performance and reliability in the long run. It's an easy-to-maintain mod with clear, practical benefits.

Apexi Resonated Midpipe with Ceramic Coating & Revel Axle-Back with Ceramic Coating Exhaust

• Purpose/Reason for the Upgrade: I installed the Apexi mid-pipe and Revel axle-back combination to improve exhaust flow, increase performance, and enhance sound while keeping the overall setup discreet. To maximize exhaust velocity and retain heat, I had both components fully coated in black ceramic by a top-tier shop in Phoenix, AZ. This setup was chosen to achieve peak performance without making the car stand out too much visually or audibly.
  
• Installation Process:
  • Preparation & Ceramic Coating: Both the midpipe and axle-back were professionally ceramic-coated to manage heat and maintain exhaust velocity. The ceramic finish also gives the components a sleek, subdued look that blends well with the car’s aesthetic.
  • Midpipe Installation: The Apexi midpipe was selected for its performance gains and matched perfectly with the internal diameter of the Revel axle-back, which I confirmed with Apexi’s team before purchase. The midpipe installation was straightforward, with careful handling of the ceramic coating to prevent scratches.
  • Axle-Back Installation: Although I considered the Apexi axle-back for its sound, I chose the Revel axle-back to avoid the need for a new rear diffuser, which would have made the car more conspicuous. The Revel axle-back provided the desired sound improvements and installed smoothly, connecting perfectly with the Apexi midpipe.
  • Final Check: After installation, I checked for exhaust leaks and verified the alignment to avoid any potential rattles or vibrations.
• Performance & Driving Experience: The results have been outstanding. This combination produces a deeper, more aggressive tone compared to the stock setup. Below 50% throttle, it’s actually quieter, likely due to the H-pipe design in the Apexi midpipe. However, as throttle input increases beyond 50%, the exhaust becomes progressively louder, hitting an aggressive yet tasteful scream at around 7,200 RPM with all mods active. The added performance is most noticeable above 3,500 RPM, where the car gains a significant kick. The setup achieves a perfect balance of sound and performance, allowing the car to blend in under casual driving conditions but come alive at higher RPMs.
  
• Conclusion: The Apexi resonated midpipe with ceramic coating and Revel axle-back exhaust provide an ideal combination for those seeking enhanced performance, sound, and a subtle aesthetic. This setup delivers a refined yet aggressive exhaust note without being overly loud, aligning well with my goal for a high-performance yet understated build.

Super Now Differential Lower Bushing Collars

• Purpose/Reason for the Upgrade: I installed the Super Now differential collars on the lower part of the differential bushings to reduce the play in the OEM rubber bushings without fully replacing them. This small but effective modification enhances power delivery, making it more immediate and consistent, aligning with my goal for a more performance-oriented driving experience.
  
• Installation Process:
  • Preparation: Due to some rust on the bolts connecting the mid-pipe to the axle-back flange, I chose not to disconnect them. Instead, I removed three exhaust hangers from each side, which allowed the entire pipe to drop down a few inches for access to the bolts securing the differential.
  • Collar Installation: The installation process was straightforward. The Super Now lower collars are designed to fit over the factory rubber bushings, reducing slack and compressing the bushings without needing to replace them.
  • Compatibility with Upper Collars: I initially inquired with Top End Motorsports about pairing these collars with the Think Design upper collars. However, it’s not advisable to use both, as the Super Now collars already compress the bushings significantly. The upper collars would likely increase metal-on-metal contact, creating more noise without effectively reducing slack.
• Performance & Driving Experience: The impact of these lower bushing collars is substantial. Power delivery feels far more immediate and progressive, with improved predictability under throttle. There is also a noticeable reduction in noise under wide-open throttle. At low RPMs with partial throttle, I experience a slight increase in driveline noise within the cabin, but this is minor compared to the benefits. Overall, the consistency and responsiveness of power delivery have improved, giving the car a more cohesive and performance-focused feel.
  
• Conclusion: The Super Now lower bushing collars have transformed my car’s drivability, making it feel more cohesive, luxurious, and responsive. For anyone looking to improve power delivery without sacrificing comfort, this upgrade is a worthwhile addition. Top End Motorsports provided excellent customer service throughout the process, addressing my compatibility questions and ensuring a smooth experience.
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Konig F3S Forged Wheels

• Purpose/Reason for the Upgrade: I upgraded from rotary forged Konig Rennforms to the fully forged Konig F3S wheels to further reduce weight, improve performance, and enhance the car’s aesthetic appeal. These F3S wheels are not only lighter at just 17 lbs each but also offer a significant reduction in rotational mass, contributing to better acceleration and handling.
  
• Installation Process:
  • Size and Fitment: I went with 18x8.5" wheels with a +35 offset, which fit perfectly and clear the factory calipers without the need for spacers—a great advantage for simplicity and alignment.
  • Center Caps: The F3S wheels feature push-in center caps, which is a significant improvement over the older style. Previously, the aluminum bolts on the old center caps would strip easily, even after just one or two tire balances. The new push-in design has a solid seal, and Konig’s attention to detail shows—they even provided three bottles of oil for the caps, a signed certificate, and some other nice touches, making the whole experience feel premium.
• Performance & Driving Experience: The F3S wheels have noticeably reduced rotational mass, even when compared to the already lightweight Rennforms. The car feels more responsive, with quicker acceleration and improved handling. One trade-off I noticed is that the fully forged construction seems to transmit slightly more vibration, especially at low frequencies. However, this is likely influenced by my solid LCA bushings and stiffer struts as well. Overall, the F3S wheels provide a superb balance of performance and refinement.
  
• Conclusion: The Konig F3S wheels have exceeded my expectations. They are not only exceptionally lightweight and performance-oriented but also beautifully crafted. The level of care and quality from Konig, right down to the push-in center caps and attention to detail, has made this upgrade a worthwhile choice. I’m extremely satisfied with how the F3S wheels enhance both the look and feel of my car.
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Toyo Proxes Sport A/S Tires

• Purpose/Reason for the Upgrade: I chose the Toyo Proxes Sport A/S tires in a 235/45/18 size as my all-season performance tire of choice. These tires provide excellent grip, responsive handling, and enhanced braking performance, all of which align with my goal of maximizing traction and stability without compromising daily drivability.
  
• Installation Process: Mounted on my lightweight Konig wheels with Mishimoto aluminum lug nuts. The combination of these lightweight wheels and high-grip tires was designed to reduce rotational weight and improve overall handling.
  
• Performance & Driving Experience: The Toyo Proxes Sport A/S tires have significantly improved braking performance and traction, providing an impressive level of grip, especially in corners. The car feels more planted, sticking to the ground during sharp turns, which enhances confidence in handling. I kept the tire dimensions the same to maintain the factory suspension geometry, as it complements the active suspension system and provides a balanced, predictable handling experience.
  
• Conclusion: The Toyo Proxes Sport A/S tires are a fantastic choice for anyone seeking reliable all-season performance. They’ve transformed the car’s handling, braking, and cornering capabilities, making it feel more responsive and secure without altering suspension geometry.
• Photo, when I first installed it with the old Konig Rennform wheels:
  

Stoptech SportStop Vented and Cross-Drilled Rotors (Cryo-Treated)

• Purpose/Reason for the Upgrade: I chose the Stoptech SportStop vented and cross-drilled rotors for improved cooling, enhanced durability, and reduced rotational mass. The rotors were cryo-treated by Stoptech to improve wear characteristics and heat absorption, making them ideal for spirited driving without the need for track-level heat management.
  
• Installation Process: Installation was straightforward except for a minor issue: the threads on the OEM front left caliper were stripped, which required replacing the caliper with a new OEM unit to ensure a secure fit. These rotors feature angled vents, so correct orientation during installation is essential for effective cooling. The angled vents help to expel heat more efficiently, maximizing the rotors' performance in daily driving and spirited use.
  
• Performance & Driving Experience: The vented and cross-drilled design significantly improved braking performance, with enhanced cooling and consistent stopping power, even under heavy braking. The overall braking experience has remained smooth and without any noticeable increase in noise or vibration.
  
• Conclusion: The Stoptech SportStop vented and cross-drilled rotors are an excellent choice for enhanced daily driving performance. They deliver a reliable, durable braking experience that balances cooling, reduced weight, and consistent braking. This setup is highly recommended for those who want high-performance brakes without the additional weight of larger rotors.

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Akebono Ultra Premium Brake Pads

• Purpose/Reason for the Upgrade: I installed Akebono performance ultra premium pads up front and ProACT ultra premium pads in the rear, based on a recommendation from JGScott. Akebono only offers the performance version for the front pads, but both options provide consistent, reliable braking. This setup maintains quiet, smooth operation and predictable, linear braking performance, making it a solid upgrade over the OEM pads for my daily driving needs.
  
• Installation Process: The installation process was very straightforward, Lexus made the calipers thoughfully for the mechanic.
  
• Performance & Driving Experience: The Akebono pads deliver fantastic braking performance. They are extremely quiet and provide very linear, progressive braking, which enhances predictability and control. There’s no noticeable reduction in braking power compared to the OEM pads, but I’ve observed an increase in braking consistency across different load levels, making the overall braking feel smoother and more reliable.
  
• Conclusion: The Akebono ultra premium pads are a fantastic choice for anyone seeking a high-performance yet refined braking experience. They pair well with the Stoptech rotors, offering a quiet, smooth, and responsive setup that feels like a definite improvement over stock. For daily driving and spirited use, this pad setup checks all the boxes without sacrificing comfort or reliability.

KYB Gas-a-Just Struts with AVS Capability

• Purpose/Reason for the Upgrade: I chose the KYB Gas-a-Just struts with AVS capability to improve handling and minimize body roll while retaining the car’s OEM suspension geometry. By maintaining the original ride height, the CV axles stay at the optimal angle, ensuring efficient power delivery to the wheels and preserving the car’s smooth performance without compromising comfort.
  
• Installation Process: Installation of the KYB Gas-a-Just struts was straightforward, and their compatibility with the car’s AVS system allowed for a seamless integration with the factory setup. No modifications to the suspension geometry were necessary, keeping the alignment and handling characteristics true to the original design.
  
• Performance & Driving Experience: The KYB Gas-a-Just struts have drastically improved the car’s stability, making it feel almost completely flat in corners. Body roll is virtually eliminated, and the struts maintain a smooth, comfortable ride quality that’s perfect for daily driving. The decision not to lower the suspension has allowed the car to retain its OEM setup, which feels remarkably well-balanced. The car responds quickly and predictably in high-speed corners, with no compromises in comfort or drivability.
  
• Conclusion: The KYB Gas-a-Just struts with AVS capability offer an impressive blend of control and comfort, making them ideal for anyone looking to enhance handling while preserving factory suspension geometry. For a car that needs to balance performance with a refined ride, these struts provide the best of both worlds.

RR Racing USRS Race Version Lower Control Arm (LCA) Bushings

• Purpose/Reason for the Upgrade: I installed the RR Racing USRS race version LCA bushings to enhance the car’s suspension rigidity, steering precision, and overall handling. While initially concerned about using track-oriented bushings on a street car, I decided the potential improvements in stability and responsiveness would be worth it. These bushings effectively reduce movement within the lower control arm, ensuring that more energy is directed toward handling and performance.
  
• Installation Process: The installation was smooth, and I found the bushings fit perfectly within the OEM setup. I initially expected significant vibration, but my concerns were alleviated once I experienced the results. While the bushings do introduce some added vibration, it is minimal and well-dampened by the car’s insulated cabin, maintaining a level of comfort fitting for a luxury cruiser.
  
• Performance & Driving Experience: The impact of these bushings on the car’s performance is dramatic. The increased rigidity has made cornering much more stable and predictable, with a noticeable reduction in body roll. High-speed cornering feels smooth and controlled, allowing the car to carve through turns with impressive precision. The bushings also improve braking consistency and throttle response, as they prevent wasted energy from internal movement within the bushings during acceleration or deceleration. This upgrade makes the car feel significantly more agile and responsive, almost like a smaller, sportier vehicle rather than a larger luxury sedan.
  
• Conclusion: The RR Racing USRS race version LCA bushings have greatly elevated the car’s handling dynamics, making it more performance-oriented without sacrificing comfort. For anyone focused on improving predictability, steering feedback, and cornering stability, these bushings are a must-have. This is a fantastic upgrade for performance-oriented enthusiasts who want the best of both worlds: luxury comfort and track-ready responsiveness.

Spoon Sports Subframe Collars

• Purpose/Reason for the Upgrade: I installed the Spoon Sports subframe collars to significantly enhance the car's responsiveness, stability, and linearity of dynamic load distribution. Despite being a simple modification, these collars have a profound impact on handling and overall driving feel. The goal was to improve the car's performance without introducing any negative effects or compromising comfort.
  
• Installation Process:
  • Compatibility Note: It's important to mention that the Spoon Sports rigid collars are not compatible with other collars designed to compress the subframe bushings, such as the Super Now Rear Member Collars on this platform. This is due to potential interference and the differing functions of these components.
  • Installation Steps: The installation was very straightforward and headache-free for both the front and rear subframes. The collars fit seamlessly into the existing setup without the need for any special tools or extensive modifications. The process involved:
    • Lifting the vehicle securely to access the subframe mounting points.
    • Removing the subframe bolts to create enough space for the collars.
      • I had to remove the entirety of the rear member having jacked up for support. This gave me very easy access.
    • Inserting the collars into place, ensuring proper alignment.
      • Dont forget lots of copper grease beforehand.
    • Retightening the bolts to the manufacturer's torque specifications.
  • Time Required: The entire installation took under three hours and can be considered a DIY project for those comfortable with working under the car.
• Performance & Driving Experience: The impact of the Spoon Sports subframe collars is remarkably significant:
  • Improved Responsiveness: The car responds more immediately to steering inputs, making driving feel more direct and engaging.
  • Enhanced Stability: There's a noticeable increase in stability during cornering and over uneven road surfaces. The car feels more planted and composed.
  • Linear Load Distribution: The collars help in distributing dynamic loads more evenly, resulting in smoother transitions during acceleration, braking, and turning.
  • No Negative Effects: Impressively, these benefits come without any drawbacks. The ride quality remains comfortable, with no increase in harshness or noise. In fact, the car feels even more luxurious due to the improved solidity.
  • Overall Feel: The car now exhibits a higher level of refinement, making daily driving more enjoyable and spirited driving more rewarding.
• Conclusion: I cannot recommend the Spoon Sports subframe collars enough. This modification offers substantial improvements in handling and driving pleasure without any compromises. It's a must-have upgrade for anyone looking to enhance their vehicle's performance and feel, whether for daily commuting or enthusiastic driving.

Antigravity Group 24 Li-Ion Battery

• Purpose/Reason for the Upgrade: I chose the Antigravity Li-Ion battery as my first performance modification to reduce weight and improve handling. By removing the heavy OEM battery, I was able to significantly lighten a key area of the car, shifting the center of mass to a more favorable position for handling and balance. This mod eliminates dead weight in an area far from the car’s center, where weight reduction has the greatest impact on handling and dynamics.
  
• Installation Process: Installation of the Antigravity Li-Ion battery was straightforward. After removing the original battery, the Antigravity battery fit securely into the battery compartment, and I was able to utilize the stock mounting points. The battery is well-equipped with advanced technology, providing more than I need, but it’s the lightest option available, so I’m extremely satisfied with the choice.
  
• Performance & Driving Experience: The benefits of the Antigravity battery were immediately noticeable:
  • Improved Handling: Reducing weight at the front of the car enhances balance and shifts the center of mass toward the center of the vehicle, resulting in more stable and responsive handling.
  • Enhanced Acceleration: The car feels lighter and more agile, and there’s a subtle but noticeable improvement in acceleration due to the reduction in overall weight.
  • Quick, Reliable Starts: The car cranks immediately without hesitation, making starts feel stronger and more confident.
  • Battery Performance: Despite being lightweight, the battery delivers excellent cranking power, consistent with my needs for daily and spirited driving.
• Comparison to Other Weight Reduction Mods: The only other weight-saving mod I’m considering that could rival this battery swap is a custom carbon fiber roof, which would cost around $8,000 for a high-quality job. However, in terms of practicality and immediate results, the Antigravity battery is an outstanding option for anyone seeking significant weight reduction without compromising functionality.
  
• Conclusion: The Antigravity Li-Ion battery is an excellent investment for anyone looking to improve handling and reduce unnecessary weight. This simple mod provides noticeable gains in both performance and balance, making it a top recommendation for enthusiasts. It’s a perfect choice for achieving better handling and acceleration in a cost-effective and straightforward way.

​​​​RR Racing Vented Carbon Fiber Badge

• Purpose/Reason for the Upgrade: I installed the RR Racing vented carbon fiber badge to add a subtle, unique touch to the car’s exterior while allowing for a bit of added airflow. While I generally prefer a factory appearance, this small modification adds a hint of performance styling that goes largely unnoticed yet still brings a sense of satisfaction.
  
• Installation Process:
  • Sizing Issue: Initially, RR Racing sent the incorrect size badge, but they quickly resolved the issue by sending the correct one. The replacement badge fit well overall, with only very slight gaps at four small spots—barely noticeable, but worth mentioning for perfectionists.
  • Attachment Method: I used high-temperature JB Weld to secure the badge, which worked exceptionally well and provided a strong, stable hold.
  • Attention to Detail: Because the vented badge design allows visibility through it, the OEM badge’s mounting tabs were slightly visible, which I found distracting. To address this, I carefully used a Dremel to recess the tabs just enough so they wouldn’t be visible from any angle. This required precision but was worth the effort to achieve a clean, uninterrupted look.
• Performance & Aesthetic Impact: Although the badge is a small detail, it brings a sense of personal satisfaction every time I look at it. The vented design contributes a negligible amount of airflow improvement, and while it isn’t a noticeable performance enhancement, it’s a nice touch that complements the car’s overall style. The carbon fiber finish blends seamlessly with the exterior and maintains a subtle, refined appearance.
  
• Conclusion: The RR Racing vented carbon fiber badge is a minor yet pleasing modification for anyone who appreciates fine details. It adds a unique, understated look that aligns with the car’s style and my own preference for a mostly OEM appearance. This upgrade may go unnoticed by others, but it adds that extra touch I enjoy every time I see it.

PPE Headers with Ceramic Coating

Purpose/Reason for the Upgrade: The factory exhaust headers on the Lexus GS350 AWD Lux are shorty log-style designs with integrated catalytic converters, prioritizing cost and emissions compliance over performance. This configuration is highly inefficient for managing exhaust pulses, resulting in limited power output and suboptimal airflow. Upgrading to PPE equal-length 3-1 headers significantly enhances exhaust flow, optimizes exhaust pulse management, and increases throttle response and overall performance. The ceramic coating, handled by RR Racing, improves heat dissipation and adds a clean, high-quality aesthetic. This is the most substantial power-gain hardware modification I’ve done to date, followed closely by the TriggaSpec ported intake manifold and throttle body.

Installation Process:

• Preparation: Removing the factory headers, with their integrated catalytic converters, was a complex task due to tight engine bay clearances. Aces Performance Exhaust in Pasadena expertly managed the installation, ensuring precision and attention to detail.
• Gaskets: The headers were installed using high-quality Lexus OEM gaskets provided by RR Racing, which I purchased the headers and coating services from. These gaskets offer superior durability and sealing compared to the flimsy aftermarket options, ensuring long-term reliability.
• Ceramic Coating: The headers were professionally coated in a high-temperature black ceramic finish by RR Racing. This coating reduces heat transfer to the engine bay and enhances component longevity, contributing to a more efficient overall setup.

Performance & Driving Experience:

• Power Gains: The PPE headers deliver significant power gains across the RPM range, with a noticeable boost in mid-to-high RPM performance. The equal-length 3-1 design efficiently manages exhaust pulses, providing smoother flow and more consistent power delivery. As the most impactful hardware upgrade, the headers have dramatically transformed the car's acceleration and overall driving experience.
• Sound: The new headers have introduced a deeper, more aggressive exhaust tone. However, there is noticeable rasp around 3,500 RPM, which I have decided to tolerate. While the sound is raw and exhilarating under higher throttle inputs, the rasp is somewhat embarrassing and lacks a refined, high-quality tone.
• No CEL: Despite the removal of the catalytic converters, the tune by Loi eliminates any check engine lights (CEL), ensuring seamless operation without compromises.

Conclusion: Upgrading to PPE headers with ceramic coating is a game-changer for the GS350 AWD Lux, eliminating the performance bottleneck of the stock log-style headers while adding significant power, sound quality, and efficiency. The installation, expertly handled by Aces Performance Exhaust, and the use of proper Lexus OEM gaskets from RR Racing ensured a flawless fit and reliable performance. This modification, as the most significant power upgrade in my build, truly elevates the car’s potential and driving experience.

Seibon Carbon Fiber Trunk Lid (Painted to OEM Spec)

Purpose/Reason for the Upgrade:
The decision to upgrade to the Seibon carbon fiber trunk lid was driven by the desire to reduce weight and enhance the car's performance, particularly in handling and acceleration. The OEM steel trunk lid added unnecessary weight to the rear of the vehicle. By switching to a lighter carbon fiber trunk lid and having it painted to match the factory finish, I achieved a balance of performance gains and functional continuity. Additionally, I opted to delete the GS350 AWD badge during this process, as the previous owner had painted it black in an amateurish way, which detracted from the car’s clean appearance. I also chose not to transfer the OEM spoiler lip, opting for a spoilerless setup to enhance elegance and further minimize weight.

Weight Savings:
The OEM steel trunk lid weighed approximately 27 lbs, while the Seibon carbon fiber trunk lid, even after being professionally painted, weighed a little under 19 lbs. This resulted in a total weight reduction of about 8 lbs. Choosing a spoilerless setup contributed to additional weight savings and reinforced the sleek, minimalist aesthetic.

Installation Process:

1. Preparation:
   • The Seibon trunk lid was delivered prepped for painting. I selected one of Houston's best paint shops to ensure a flawless OEM color match.
   • Before painting, the trunk lid was test-fitted to confirm proper alignment and compatibility with factory components.
2. Professional Painting:
   • To achieve a perfect color match, the shop opted to blend the paint into the adjacent panels, such as the rear fenders, rather than only painting the trunk lid. This process ensures seamless color continuity under different lighting conditions and angles.
   • Multiple layers of paint and clear coat were applied to match the factory finish.
3. Badge Deletion:
   • The GS350 AWD badge was removed entirely due to the poor-quality black paint job by the previous owner. The clean trunk lid without the badge aligns with the minimalist aesthetic I prefer.
4. Installation, Alignment & Modifications:
   • Installation was performed by professionals to ensure precise alignment and functionality of the trunk lid, including hinges, latch, and weather sealing.
   • While the Seibon trunk lid aligns well in most areas, the rear-most highest corner sits slightly higher than the OEM alignment. This is a minor imperfection but worth noting for those who value perfect fitment. Despite this, the overall fitment is excellent and doesn’t detract from the trunk lid’s functionality.
   • The backup camera hole provided by Seibon was too small for proper fitment, requiring the shop to enlarge it slightly to accommodate the OEM camera. This modification was done carefully to ensure the camera fit perfectly without compromising its functionality.
   • All factory components, including the backup camera and trunk lighting, were successfully transferred to the new trunk lid after the modification.

Performance & Driving Experience:

• Weight Reduction Impact: The approximately 8-lb reduction in rear-end weight enhances the car’s balance and responsiveness, particularly during sharp cornering and acceleration. Choosing a spoilerless setup further minimized weight and contributed to a clean, refined look.

Conclusion:
The Seibon carbon fiber trunk lid is a functional upgrade that aligns well with the goals of my build. The weight savings and performance improvements are subtle yet meaningful. The decision to go spoilerless enhances the car’s elegant design while contributing to additional weight reduction. Although the slight misalignment in the rear-most corner and the need for a camera hole modification were minor challenges, they were resolved effectively and do not detract significantly from the overall results. For enthusiasts seeking a practical performance enhancement with understated style, this painted trunk lid is a solid choice.

Magnaflow Tru-X 2.5” X-pipe, Ceramic Coated

After a lot of planning and research, I had a Magnaflow Tru-X 2.5” X-pipe installed—and it’s one of the most transformative mods I’ve done so far. This mod was initially recommended to me by JGScott. This guy is a wealth of very honest and good information in the platform, huge thanks to him from me.

Coating: Ceramic-coated by Polymer Dynamics—absolutely top-tier shop.
Installation: Welded in by Exhaust Works (the original shop in Tucson) on Harrison Performance’s direct recommendation. The welding work was extremely clean and professional.
Fitment: The Apexi midpipe routes around the transmission at a natural 45°, and it fed straight into the X-pipe like it was meant to be there. We were able to position it as close to the collectors as physically possible. Welds were treated with high-temp spray ceramic and cured properly.

I kept the H-pipe that’s part of the Apexi midpipe as well, so the car now runs a dual-crossover setup. I was concerned about possible interference or turbulence—but the effect has been extremely positive.

Sound & Feel

The exhaust tone has changed substantially. The X-pipe has:

• Smoothed out exhaust pulses
  
• Reduced overall rasp
  
• Quieter, more refined tone across the entire RPM band
  

That said, there is still buzz between 2,700 and 3,800 RPM at partial throttle, but it's much less offensive than before. This may be the natural resonance point of the straight-through mufflers combined with the overall system geometry. It doesn’t dominate the experience, but it’s there and worth noting for others going the same route.

Performance

The gains here were shockingly real.

• Throttle response: Instantly sharper. Massive difference.
  
• Power delivery: Smooth and progressive. Previously, with just the H-pipe, there was a slight turbo-lag-like surge when going WOT. That’s gone—now it pulls linearly and confidently.
  
• Cornering confidence: Increased due to the predictable throttle modulation—makes the car feel much more planted and communicative.
  
• Overall power: Noticeably stronger, especially mid-range. It’s hard to quantify without a dyno, but it’s enough to feel clearly across multiple drives.
  

Final Verdict:

The X-pipe delivered beyond expectation. If you're running straight-through mufflers, or if your current setup feels a little unpredictable or raspy, this mod is a serious upgrade in both performance and refinement.

Still some mild buzz in a narrow RPM band at partial throttle, but the overall sound signature, throttle feel, and power delivery make this one of the best mods I've done so far.

Non Stop Tuning Al Tensioner and Idler Pulleys

I recently installed the NST lightweight aluminum idler and tensioner pulleys. These pulleys weigh less than half the OEM steel pulleys, significantly reducing rotating mass. This upgrade provided a noticeable improvement in throttle response, making the engine feel slightly more responsive and rev-happy.

Installation required removal of the OEM dust shields from both pulleys, as the NST design eliminates the need for them. Overall, I'm quite satisfied with this upgrade—it aligns perfectly with my goal of incremental performance enhancements and weight reduction for the GS350.

Photo:

IPT Fully Built A760H Transmission + High-Stall Torque Converter + Tru-Cool LPD Cooler

Purpose/Reason for the Upgrade:
With power and responsiveness increasing across the build, I wanted a transmission that delivers durability, crisper shift control, and better launch characteristics without compromising daily drivability. IPT rebuilt the A760H with their overbored/modified valve body and a high-stall torque converter, and I added a Tru-Cool LPD auxiliary cooler to keep temperatures tightly controlled in all conditions.

Installation Notes:

• Transmission: IPT fully built A760H
  
• Valve body: IPT overbored, revised hydraulics for higher line pressure and faster clutch apply
  
• Torque Converter: High-stall (AWD-spec)
  
• Cooler: Tru-Cool LPD, plumbed in series with factory heat exchanger
  
• Transfer Case: IPT-built AWD transfer case installed with the transmission (freshened, set up for tight, consistent coupling)

Performance & Driving Experience:

• Temps: Stable and consistent — never exceeds ~190°F in any condition so far.
  
• Launch/Acceleration: Non–brake-boosted launch now flashes to ~2,400 rpm (≈ +400 rpm vs. before). The car definitely accelerates faster and lurches forward with authority.
  
• Shift Quality (general): Noticeably quicker and cleaner than stock overall, with a subtle, pleasant gear-train whine and much sharper feedback. Throttle response is massively improved.
  
• High-RPM behavior: At WOT near 7,400 rpm, the upshift is precise but feels a touch slower right at the top; everywhere else it’s snappy.
  
• Light-throttle manners: Most shifts are smoother than stock, but:
  • 1→2 has a distinct “kick” under light throttle.
    
  • 2→3 shows a small bump, less than 1→2.
    
• With the IPT-built transfer case in place, the driveline feels tighter with more immediate torque transfer, matching the transmission’s sharper calibration.

Impressions:
The drivetrain feels tighter and more connected than stock, with better modulation and confidence everywhere. This upgrade meaningfully improves the car’s character while keeping daily civility.

Technical Notes:

• The firmer 1→2 at light throttle is consistent with higher line pressure, reduced/removed torque-reduction, and the converter’s coupling behavior at low speed. Solid bushings (USRS + diff collars) transmit more of that engagement to the cabin, so it’s more perceptible.
• A freshly built transfer case can reduce perceived lash, which can make a firm 1→2 engagement feel more pronounced at light throttle—normal for a performance-oriented setup.

AEM340 (50-1220) Low Pressure Fuel Pump

Purpose/Reason for the Upgrade:
With a much more power comin in from my fully built motor, we needed more fueling.
Installation Notes:
The AEM340 (50-1220) directly replaces the OEM fuel pump, there is no modification needed and it slots right in.
Impressions:
It seems to be slightly louder when priming. Even with stock motor full bolt on the car does feel a bit faster after 7,000rpm with the AEM340 but the difference is subtle and could be placebo. It is however crucial for the upcoming motor.

 

Nice 🥰

 

Sub'd!!

 

Sweet, I got a lot more in the works.

Here is the list I am going with:
Write up for the cf carbon lid
Ceramic coated PPE header
Customizing the ceramic coated Apexi resonted midpipe with additional Vibrant bottle-style resonators
Non-Stop Tuning custom lightweight tensioner and idler
Driveshaft Shop custom carbon fiber driveshaft
write up of all the new OEM parts, there is a lot
and more

 

Added a write up of the Seibon carbon fiber trunk lid, painted OEM spec. Photos are coming soon.

 

looking forward to the photos.

 

Thanks for writing up EVERYHTING!

There were a few things I was considering that I'm going to end up doing for sure now.

Spoon collars, Antigravity battery, intake

My car is heavily suspension modded and I think these things will be great additions

 

You are very welcome.

I put in a 2.5” ceramic coated Magnaflow X-pipe where the midpipe naturally has a 45 degree bend around 20” after the collectors. It had made massive difference in power and smoothness of exhaust pulses and therefore throttle response.

Like massive difference. I will write that up soon. Of course I have straight trough mufflers which work particularly well with X-pipes and also I moved the primary (in my case) crossover to a more optimal position, closer to the collectors.

Next is Valvebody detent mod, followed by custom lightweight idler and tensioner pulleys by Non-stop tuning, then CF driveshaft.

i got lots more in the works too. Like a ported head perhaps.

 

I added my write up of the X-pipe install, which has been very stellar.

Up next: tranny valve body detent mod,
Non-Stop Tuning cutom lightweight idler and tensioner pulley,
Trigga Spec ported head,
DriveshaftShop, custom carbon fiber driveshaft

 

@Holgram I'm excited to see your write up regarding the NST Idler and Tensioner Pulley. I ended up purchasing the NST crankshaft and water pump pulley after your review.

 

I’ll let you know don’t worry.
It’ll either be that first or the IPT valve body and torque converter. Anyways something is going on the car late May for sure.

 

I Installed the Non Stop Tuning idler and tensioner, I am super happy with it. I added an entry to the original post above, which might be breaking because it's too long. I noticed at least one photo disappeared.

I ordered a fully built tranny from Import Performance Transmissions, high stall torque converter, significantly upgraded valve body, more and harder clutch packs and more, total overkill but I already started on it.

On the side, I started building a fully new OEM head ported expertly by Trigga Spec, with +1mm overbored valves, 11.5mm lift Web Camshafts head.

Next the tranny goes on, then the heads, JE Pistons is looking to make a 4032 forged .25mm overbore, OEM compression pistons. With that this car should handle even FI with ported heads + manifolds + 11.5mm + oversized TB + +1mm valves, which is a level of stress I don't think anyone has put on these things. But I did shed quite a bit of rotational mass over stock too on the platform. Which of course will not nearly fully compensate.

I also have other things in the works like full Figs diff bushings rather than then SuperPro collars I have now which work great, and Driveshaft Shop cf driveshaft.

 

As this build continues to evolve into a truly tailored NA platform, I want to pause and pay respect to someone whose work has played a quiet but meaningful role in many of my past projects — George from MaxBore.



George tragically passed away recently in a car accident, and with him, the tuning community lost one of its finest craftsmen. He wasn’t flashy, didn’t make noise on social media, but his work spoke volumes: consistent, precise, reliable. He had a way of making throttle bodies feel like functional art — always sealed perfectly, always done right. I had the honor of working with him for over a decade across multiple builds, and his attention to detail left an impression that went far beyond the machine.



This stage of my build — dialing in a custom high-RPM intake manifold and considering a carefully bored throttle body — felt like the natural time to reach back out to him. That he’s no longer here to answer that call has added a note of reverence to this process. I know for a fact that he’d be proud of the level of care going into this project, especially with how airflow, geometry, and harmonics are being balanced with reliability and drivability.



Massive thanks to JGScott, who connected me with DickH — a fabricator and designer who shares the same spirit of thoughtfulness, innovation, and purpose-driven engineering. We’ve been working together on what I believe may become the most complete intake solution ever attempted for the 2GR-FSE platform.



This build is for those who love subtle excellence, and I hope in some small way it honors George’s legacy.

 

Very sad that George passed away so early.

 

Quick note for everyone following: I’ve spun off a supplemental thread focused on the powertrain side of the build — the 2GR-FSE engine and A761H transmission.

That thread has a fair amount of detail already, but it’s not the full story. If you’re curious about something specific or want me to dig deeper, feel free to ask — I’ve got way more info than what’s posted there.

Here’s the link:
👉 White Pigeon Powertrain: 2GR-FSE Engine & A760H Transmission Build