The HKS R TYPE Intercooler Kit (13001-AT008) is one of the most technically advanced OEM-replacement intercoolers developed specifically for the Toyota GR Yaris GXPA16 with the 1.6L G16E-GTS turbocharged three-cylinder engine.
Unlike cosmetic upgrades, this intercooler directly improves the engine’s thermodynamic efficiency by lowering the temperature of compressed intake air, allowing the engine to sustain higher power output without excessive heat soak.
The Engineering Problem
When the turbocharger compresses air, its temperature rises dramatically.
Typical temperatures:
- Ambient air: 25–35°C
- After turbo compression: 120–180°C
- Hard track driving: 180–220°C
Hot air is less dense.
Lower density means:
- less oxygen
- less combustion efficiency
- ECU pulls ignition timing
- higher knock tendency
- reduced horsepower
The intercooler exists to reverse this problem.
HKS Philosophy
HKS engineers designed this intercooler around continuous circuit driving, not just producing a single dyno number.
Their objectives were:
- maximum cooling efficiency
- minimal pressure loss
- OEM-level fitment
- improved airflow
- reliability under repeated heat cycles
- future-proof for higher horsepower builds
Unlike many oversized aftermarket intercoolers, HKS carefully balanced cooling performance with turbo response.
Massive Core Upgrade
Factory intercooler dimensions:
645 × 145 × 80 mm
HKS R Type:
645 × 205 × 105 mm
That means:
- approximately 41% taller
- approximately 31% thicker
- significantly larger internal air volume and heat-transfer surface area
New Multilayer Core Technology
Instead of simply making the core bigger, HKS uses a multilayer bar-and-plate design optimized for both cooling and airflow.
Advantages include:
- stronger construction for high boost
- improved thermal conductivity
- lower pressure drop
- excellent durability
- more efficient heat rejection
The internal fin geometry is designed to maximize contact between compressed air and aluminum while minimizing flow restriction.
Pressure Loss Engineering
A common misconception is that larger intercoolers always improve performance.
If airflow slows excessively, turbo lag increases.
HKS minimizes pressure drop by optimizing:
- internal fin density
- air passage geometry
- end tank design
- flow distribution
This preserves turbocharger response while increasing cooling.
End Tank Design
The cast aluminum end tanks are engineered to:
- distribute airflow evenly
- reduce turbulence
- eliminate dead zones
- maintain equal airflow across the entire core
Uniform airflow means every section of the intercooler contributes to cooling.
Why Cooler Air Makes More Power
According to the ideal gas law:
Lower temperature → Higher air density
Higher density means:
- more oxygen molecules
- more fuel can be burned
- higher cylinder pressure
- more torque
- improved combustion efficiency
The result is stronger, more consistent performance.
Heat Soak Resistance
The factory intercooler can lose efficiency after repeated acceleration or track laps.
The HKS intercooler’s larger thermal mass absorbs and dissipates heat more effectively, helping maintain:
- stable intake temperatures
- consistent ignition timing
- sustained power output
- reduced ECU intervention
This is especially valuable during track driving or repeated high-speed pulls.
Performance Benefits
Compared with the factory intercooler, the HKS unit typically provides:
- lower intake air temperatures
- improved mid- and high-RPM power
- greater resistance to heat soak
- more stable boost performance
- enhanced reliability for tuned engines
Exact horsepower gains depend on the tune and supporting modifications, but the larger benefit is maintaining power consistently, not just increasing peak output.
Installation Notes
HKS designed the intercooler as a factory replacement for 2020-on GR Yaris models.
Important notes:
- Vehicles equipped with the factory intercooler water spray require the optional 13999-AT001 water spray bracket.
- For GR Yaris models produced after the 2024 update, HKS specifies compatibility requirements including the appropriate piping kit.
Best Supporting Modifications
For maximum performance, pair the intercooler with:
- HKS intercooler piping kit
- High-flow intake system
- Performance downpipe
- High-flow exhaust
- ECU calibration
- Upgraded turbocharger (for higher power goals)
Together, these upgrades improve airflow throughout the entire induction system.
The Verdict
Engineering Rating: ⭐⭐⭐⭐⭐ (10/10)
Cooling Capacity: ★★★★★
Heat Soak Resistance: ★★★★★
Turbo Response: ★★★★☆ (well balanced despite larger size)
Reliability: ★★★★★
Track Performance: ★★★★★
The HKS R TYPE Intercooler Kit 13001-AT008 is one of the finest OEM-fit intercoolers available for the GR Yaris.
Rather than chasing peak dyno numbers, HKS engineered it to deliver lower intake temperatures, reduced pressure loss, and sustained performance during prolonged high-load driving, making it an outstanding choice for spirited road use, track days, and high-power GR Yaris builds.
