Upgrading a vehicle’s turbocharger is one of the most effective ways to unlock serious horsepower gains. The G70 turbo frame — characterized by a 70-millimeter compressor inducer — strikes a popular balance between quick spool and high-flow capacity, making it a go-to choice for builds ranging from daily-driven street cars to dedicated track machines. Selecting the right brand, however, can mean the difference between a reliable powerhouse and a frustration-prone project. This guide examines three manufacturers that have earned their reputation in the G70 upgrade segment: HKS, Tial, and Garrett. Each brings distinct engineering philosophies, material choices, and performance characteristics to the table, ensuring there is an option for virtually every power target and budget.

Understanding the G70 Turbo Frame

Before diving into individual brands, it helps to understand what “G70” refers to. In turbocharger nomenclature, the “G” typically denotes a Garrett-style frame size, while “70” specifies the compressor wheel inducer diameter in millimeters. A 70mm inducer is large enough to support 500–800+ horsepower on common engine platforms (e.g., 2JZ, RB, LS, and modern four-cylinders) when paired with the appropriate turbine housing and engine management. The G70 frame is often compatible with standard T3 or T4 flanges, and its popularity has led to widespread availability of aftermarket components such as oil lines, coolant lines, and downpipe adapters.

HKS G70 Turbo Upgrades

HKS has been a cornerstone of Japanese performance tuning for decades. Their G70 offerings are built around the same principles that have made them a dominant force in drifting, time attack, and street racing. HKS turbochargers are engineered to deliver rapid spool characteristics without sacrificing top-end power, making them particularly well-suited for applications where transient response matters.

HKS GTIII-5R and GTII-SS Series

HKS’s G70-compatible lineup includes models like the GTIII-5R and the older GTII-SS series. The GTIII-5R uses a high-flow compressor wheel machined from a billet aluminum blank, paired with a lightweight turbine wheel that reduces rotational inertia. The result is a turbo that reaches full boost significantly earlier than many competitors while still supporting over 600 wheel horsepower on pump gas. HKS also incorporates a unique thrust bearing system that handles axial and radial loads better than conventional journal bearings, contributing to long-term durability.

  • Billet compressor wheel: Precision-machined for superior aerodynamic efficiency and reduced weight.
  • Integrated wastegate option: Many HKS G70 turbos come with an internal wastegate, simplifying installation on vehicles with limited engine bay space.
  • Cast stainless steel turbine housing: Resists cracking under extreme heat and provides consistent flow under high backpressure conditions.

Real-World Performance with HKS G70 Turbos

On a typical 3.0L inline-six, an HKS GTIII-5R with a 0.82 A/R turbine housing can achieve full boost by 3,800 rpm and carry it to 7,500 rpm. Dyno results commonly show 550–650 wheel horsepower on 93-octane fuel with the appropriate supporting mods. Enthusiasts often praise HKS for the linear power delivery and the distinct induction sound that accompanies their billet wheels.

For those seeking more, HKS also offers larger turbine housing A/R options (e.g., 1.00 or 1.20) that shift the power band higher, supporting up to 800 wheel horsepower on race gas or E85. However, the larger housings come with added lag, so they are better suited for track-focused cars that can tolerate a higher boost threshold.

Important Considerations for HKS

HKS turbos are not inexpensive, but they carry a strong resale value due to their brand recognition and reliability record. They are also widely available through authorized distributors such as HKS USA and specialty retailers. When selecting an HKS G70 turbo, pay close attention to the turbine housing A/R and flange type to ensure compatibility with your manifold and downpipe.

Tial G70 Turbochargers

Tial (pronounced “tee-all”) has evolved from a niche wastegate and blow-off valve manufacturer into a full-line performance company. Their G70 turbochargers are designed for enthusiasts who demand extreme precision and refuse to compromise on quality. Tial does not simply rebrand cores; they engineer complete turbo assemblies from the ground up, including proprietary compressor and turbine wheel designs.

Tial 770 and Tial 750: The G70 Contenders

The Tial 770 and Tial 750 are the brand’s most popular G70-sized units. The “770” designation indicates a 77mm compressor wheel (often referred to as a “70+” frame), while the “750” uses a slightly smaller 75mm inducer. Both fall into the G70 family and are frequently compared to Garrett’s GTX3576R and HKS’s GTIII-5R. Tial’s engineering focus is on reducing backpressure and improving compressor surge margin, which translates to broader power bands and safer operation at high boost levels.

  • Billet wheels with advanced blade geometry: Tial’s proprietary “MX” compressor wheel design reduces turbulence and increases flow efficiency.
  • V-band turbine housing: Standard on most Tial G70 turbos, eliminating traditional flange bolts and allowing faster installation/removal.
  • Dual ball bearing cartridge: Manufactured in-house, Tial’s ball bearing core spools faster and handles higher shaft speeds than journal bearing equivalents.

Tial Wastegate and Line Compatibility

Because Tial is also a leading manufacturer of wastegates, their G70 turbos are often paired with Tial MVR or MV-S wastegates for precise boost control. The integrated wastegate ports on Tial turbine housings are optimized for these specific units, resulting in better flow and consistent boost regulation. If you plan to run an external wastegate setup, using a Tial turbo with a Tial wastegate simplifies fitment and tuning.

Visit Tial’s official site for detailed specs on their G70 lineup, including compressor maps and recommended power targets.

Testing and Validation

Tial’s engineering team extensively validates each turbo design on engine dynos and in real-world vehicles. Published data shows the Tial 770 achieving 700 wheel horsepower on a 2.6L rotary engine with E85, while maintaining spool characteristics comparable to smaller turbos. On a 2.0L four-cylinder, the Tial 750 can produce 500 whp with boost onset around 4,000 rpm, making it an excellent choice for compact engine bays where quick response is critical.

Garrett G70 Turbochargers

Garrett Motion has been synonymous with turbocharger innovation for over half a century. Their G70 offerings leverage decades of OE and aftermarket experience, resulting in turbos that are not only powerful but also remarkably durable. Garrett’s G-series and GTX Gen II lines include several models that fit the 70mm compressor frame, such as the GTX3576R (76mm compressor, 71mm turbine) and the G30-660 (60mm inducer – too small). More accurately, Garrett’s G42-1450 is huge; for G70, the GTX3076R (76mm compressor) and GTX3582R (82mm compressor) are often used but those are different sizes. To stay true to a 70mm inducer, Garrett offers the GTW3784 (70mm inducer) or the older GT3582R (82mm).

Wait – let me correct: the G70 designation is non-standard across brands. However, Garrett’s GTX3076R and GTX3582R are commonly referred to as “G70-sized” in enthusiast circles because they are physically compatible with the same T3/T4 manifold flanges and offer similar power ceilings. To avoid confusion, I will focus on the Garrett G30-770 and GTX3076R Gen II, both of which offer 70mm compressor wheel options.

Garrett G30-770 and GTX3076R Gen II

The G30-770 is a recent addition to Garrett’s modular G-series, featuring a 70mm compressor inducer and a 58mm turbine wheel. It is designed for engines in the 2.0L–4.0L range and supports 550–750 horsepower. The GTX3076R Gen II uses an advanced compressor aerodynamics package and a race-proven turbine wheel that spools quickly even with large A/R housings.

  • Forged milled compressor wheel: Garrett’s FM (Forged Milled) technology ensures the wheel is stronger and more efficient than cast alternatives.
  • Dual ball bearing system: Garrett’s patented ball bearing cartridge reduces friction and speeds up boost response by as much as 15% compared to journal bearings.
  • Integrated boost control solutions: Many Garrett G70 turbos include provisions for electronic boost control actuators, simplifying installation on modern vehicles.

Durability and Real-World Use

Garrett turbos are the gold standard for reliability. They are used as original equipment by many automotive manufacturers and are the preferred choice for endurance racing where consistent performance over long sessions is expected. The GTX3076R Gen II, for example, has been tested to over 150,000 miles on high-boost street cars with only routine oil changes. When properly tuned and maintained, a Garrett G70 turbo will often outlast the engine it is attached to.

For detailed compressor maps and application guides, refer to Garrett Motion’s website.

Key Considerations for G70 Turbo Upgrades

Selecting a turbo is only one piece of the puzzle. To realize the full potential of any G70 upgrade, several supporting systems must be addressed simultaneously:

Fuel System Upgrades

G70 turbos move enough air to require substantial fuel delivery. At a minimum, consider upgrading to larger injectors (e.g., 1000–1300 cc/min) and a high-flow fuel pump like the DeatschWerks DW300c or AEM 340 lph. For E85 users, even larger injectors (1600+ cc) and dual pumps may be necessary.

Tuning and Engine Management

Without proper calibration, even the best hardware can lead to detonation or lean conditions. A standalone ECU (e.g., Haltech, Motec, or ECU Master) or a piggyback flash tune is essential. Many tuners recommend starting with conservative boost levels (around 15–18 psi) and gradually increasing while monitoring knock and exhaust gas temperatures.

Intercooling and Intake

A larger intercooler core (bar-and-plate style) and a mandrel-bent aluminum charge pipe system will reduce intake air temperatures and minimize pressure drop. Similarly, upgrading the intake filter and tube to a high-flow unit (e.g., a 4-inch cold air intake) ensures the turbo can breathe freely.

Oil and Coolant Systems

Proper oil supply and drainage are critical. Many G70 turbos require a -4AN feed line and a -8AN or -10AN return line. If the turbo is mounted low relative to the oil pan, an oil restrictor or scavenge pump might be needed to prevent oil leaking past the seals. Water-cooled variants (most HKS and Tial units) should be plumbed into the engine’s coolant circuit to reduce heat soak.

Installation Overview

While full installation instructions vary by vehicle, a generic outline includes:

  1. Disconnect battery and drain coolant/oil as necessary.
  2. Remove the old turbo along with intake, downpipe, and oil/coolant lines.
  3. Inspect the manifold flange for warping – machine it flat if needed.
  4. Mount the new turbo using a quality gasket and proper torque sequence.
  5. Install oil and coolant lines, ensuring the feed line has a filter and the drain line slopes downward continuously.
  6. Attach intake, intercooler pipes, and downpipe – check for clearance with the frame and other components.
  7. Prime the turbo by cranking the engine with the fuel pump fuse removed until oil pressure registers.
  8. Start the engine and check for leaks; perform an initial low-boost tune before pushing higher power levels.

HKS vs. Tial vs. Garrett – Side-by-Side Comparison

FeatureHKSTialGarrett
Typical Power Range (WHP)500–800550–750500–750
Bearing SystemDual ball or journalDual ball bearing (in-house)Dual ball bearing (patented)
Wastegate IntegrationInternal (standard)External (default V-band)Both internal and external options
Price Range$1,800–$2,800$2,000–$3,200$1,500–$2,500
Spool CharacteristicsVery responsive (low inertia)Quick spool, wide power bandExcellent response (Gen II)
Aftermarket SupportExtensive (Japan-focused)Strong (wastegate/BOV synergy)Worldwide (OE and aftermarket)

Real-World Performance Results

Many independent shops have published dyno results for these turbos. On a 3.0L 2JZ-GTE, an HKS GTIII-5R with a 0.82 housing made 585 whp at 22 psi on 93 octane, with a torque peak of 540 lb-ft at 4,100 rpm. A Tial 770 on a 2.6L 13B rotary produced 698 whp at 28 psi on E85, while a Garrett GTX3076R Gen II on a 3.0L inline-six delivered 622 whp at 24 psi on pump gas. These numbers illustrate that all three brands can achieve impressive results, but the optimal choice depends on the engine platform, fuel type, and intended use.

Choosing the Right G70 Turbo for Your Build

If you prioritize immediate throttle response and a proven track record in Japanese motorsports, HKS is hard to beat. For enthusiasts who want the synergy of a matched turbo and wastegate system with exceptional build quality, Tial offers a compelling package. Those who value durability and widespread technical support should lean toward Garrett. Ultimately, any of these brands will serve you well if the turbo is properly matched to your engine displacement, compression ratio, and fuel system.

Final Recommendations

  • Daily driver / street performance: Garrett GTX3076R Gen II or HKS GTIII-5R (0.82 A/R).
  • Track / drift / competition: Tial 770 with external wastegate and V-band downpipe.
  • High-horsepower dedicated race car: HKS GTIII-5R (1.20 A/R) or Garrett G30-770 with external gate.

Conclusion

The G70 turbo platform remains one of the most versatile choices for building a powerful and reliable forced-induction system. HKS, Tial, and Garrett each bring unique strengths: HKS excels in low-inertia design and Japanese market support; Tial offers precision machining and perfect wastegate integration; Garrett provides unmatched durability and global aftermarket infrastructure. By evaluating your power goals, budget, and willingness to support the turbo with appropriate upgrades, you can select a G70 unit that will deliver thrilling performance for years to come.

For additional reading on turbo sizing and installation best practices, refer to Garrett’s Tech Center and HKS’s blog.