CSF High-Performance Dual Engine Oil Cooler Kit for DE5 Acura Integra Type S / FL5 Honda Civic Type R

The CSF High-Performance Dual Engine Oil Cooler Kit for the DE5 Acura Integra Type S and FL5 Honda Civic Type R is engineered to solve one of the platform’s most critical limitations: inadequate factory oil cooling that leads to dangerously high temperatures during spirited driving and track use. With FL5 testing revealing stock oil temps exceeding 275°F (135°C), CSF developed its first complete engine oil cooler system to deliver a dramatic improvement in thermal control for both stock and modified vehicles. This dual-cooler setup provides exceptional heat rejection, consistent lubrication stability, and increased reliability under the most demanding conditions, all while giving the engine bay an aggressive motorsport-inspired appearance. Designed for enthusiasts who push their cars hard, this kit sets a new benchmark for FL5 and DE5 oil cooling performance.

Design & Engineering

• CSF approached the development of this engine oil cooler kit with two primary challenges. The K20C1 engine lacked any factory provision for an external oil cooler, and available space in the FL5’s already crowded front cooling stack made placement difficult. Since mounting a cooler behind the grille would add unnecessary heat load to the intercooler, condenser, and radiator, and upgraded intercoolers only worsen this issue, CSF determined that the sides of the bumper were the optimal location. Limited airflow in that area required the creation of purpose-built ducting to ensure proper cooling performance. With airflow addressed, CSF built the system around its compact universal dual-pass oil coolers, using two units to provide maximum cooling capacity. Paired with Superstrasse CPE-lined stainless steel braided lines and DYME Pro / Spec quick-release fittings, the kit offers industry-leading serviceability and durability.
  • Two dual pass high-performance oil coolers
  • CPE lined stainless steel braided lines
  • DYME Pro / Spec quick release fittings
  • Billet sandwich plate with 175°F – 195°F (80°C – 90°C) thermostat
  • Oil temperature reduction of up to ~15°F (~8°C)
  • Carbon fiber bumper vents
  • Laser cut mounting brackets
  • Approximately 7 quarts (6.6L) overall oil capacity
  • Pair with the FL5 Performance Radiator for maximum cooling performance

Oil Coolers

• At the core of the FL5 kit are two 13″ x 4.5″ (33cm x 11.5cm) dual-pass oil coolers run in series for maximum heat rejection. These bar-and-plate coolers feature CSF’s Aero-Flow bar design, which reduces weight while maintaining exceptional strength, flow, and durability. Unlike tube-and-fin designs that are vulnerable to track debris, CSF’s rugged construction and fully TIG-welded cast end tanks ensure reliability under intense conditions. Each cooler is pressure tested to 120psi, and the 40-degree feed-and-return fittings are engineered for optimized flow and reduced pressure drop. These are the same coolers used by Honda Racing Corporation for the FK8 TCR program, and CSF is already collaborating with top teams such as Precision Racing LA for upcoming FL5 touring car efforts.
  • Bar / Plate core offers strength and durability
  • 100% TIG-welded construction tested to 120PSI
  • Smooth 40-degree feed / return fitting design
  • Dual pass flow for additional cooling
  • Oil capacity increased by over 2 quarts (2 liters)

Pressure Drop

• Adding an oil cooler to an engine that did not originally include one introduces the risk of oil pressure drop due to increased system restriction. CSF’s testing revealed a slight pressure reduction after installation. While acceptable for street use, it warranted a solution for track-driven cars. Switching test vehicles from the factory 0W-20 oil to a higher viscosity 0W-30 or 5W-30 restored optimal pressure levels and ensured consistent performance in high-load scenarios.
  • At Idle Operating Temperature:
    • Stock with 0W-20 Oil: 20PSI (1.4bar)
    • CSF Oil Cooler with 0W-20 Oil: 15PSI – 17PSI (1.0bar – 1.2bar)
    • CSF Oil Cooler with 0W-30 or 5W-30: 20PSI (1.4bar)
  • Straights on Track:
    • Stock with 0W-20 Oil: 70PSI (4.8bar)
    • CSF Oil Cooler with 0W-20 Oil: 50PSI (3.4bar)
    • CSF Oil Cooler with 0W-30 or 5W-30: 67PSI – 69PSI (4.6bar – 4.8bar)
  • Cornering on Track:
    • Stock with 0W-20 Oil: 59PSI (4.1bar)
    • CSF Oil Cooler with 0W-20 Oil: 47PSI (3.2bar)
    • CSF Oil Cooler with 0W-30 or 5W-30: 56PSI (3.9bar)
  • Highway Cruising:
    • Stock with 0W-20 Oil: 75PSI (5.2bar)
    • CSF Oil Cooler with 0W-20 Oil: 55PSI (3.8bar)
    • CSF Oil Cooler with 0W-30 or 5W-30: 70PSI (4.8bar)

Lines, Fittings, and Thermostat

• CSF collaborated once again with DYME PSI to integrate their motorsport-grade quick-release hose and fitting technology. These Pro / Spec fittings support tool-free clamshell operation, withstand up to 10,000psi, and dramatically reduce installation and maintenance time. DYME PSI hydraulically crimps each fitting to Superstrasse CPE-lined 304 stainless braided lines built to CSF’s exact specifications. Oil flow is managed by a billet aluminum thermostatic sandwich plate that installs in the factory oil filter location using an M20 x 1.5 adapter. It supports the OE filter or a larger 70mm unit, begins opening at 175°F (80°C), and is fully open by 195°F (90°C). A pre-plugged 1/8 NPT port allows the addition of aftermarket oil temperature sensors for more precise monitoring.
  • Fittings:
    • Forged 6061-T6 aluminum body
    • 180° swivel adjustment
    • Dual Fluorok FKM seals
    • Chemical and heat resistance up to 401°F (205°C) continuous operation temperature
    • Secure and permanent crimp-on connection for high-pressure systems
  • Lines:
    • 304 stainless steel reinforcing braid and polyethylene top braid
    • Burst pressure of over 2000PSI
    • Suitable for up to 302°F (150°C) continuous operation temperature
  • Sandwich Plate:
    • Billet aluminum construction
    • 175°F – 195°F (80°C – 90°C) thermostat
    • Accommodates OE filter or others up to 70mm in diameter with a M20 x 1.5 thread
    • 1/8 NPT pre-plugged port for temperature sensor

Ducting & Vents

• Ensuring proper airflow to the side-mounted coolers presented a major engineering hurdle. Mounting coolers behind the grille would overload the main cooling system, while relying on leakage airflow around the intercooler was insufficient. Using brake ducting was dismissed due to its impact on braking performance. CSF developed dedicated carbon fiber bumper vents designed via CFD to direct ample airflow to both oil coolers. Constructed from pre-preg carbon, these vents follow the lines of the FL5 for an OEM-plus appearance. Additional louvered fender vents allow hot air to exit efficiently, further enhancing cooling performance.

OE Fit & Finish

• Leveraging industry partnerships, CSF sourced motorsport-quality carbon fiber to ensure exceptional fit, finish, and durability. The vents are track-tested, bolt on without double-sided tape, and include cut templates for precise installation. Templates are also provided for international FL5 models equipped with PDC sensors, maintaining full factory sensor functionality. While some kits avoid bumper cutting, none match the airflow or cooling efficiency delivered by CSF’s engineered solution.
  • Motorsport-grade pre-preg 2×2 carbon fiber construction
  • OE level fitment and finish
  • Provides optimal airflow to the oil coolers versus kits with air deflectors from the center opening
  • Instruction include cut out templates for easy install with motorsport grade hardware (no tape)
  • Laser-cut louvered vents for airflow into the wheel wells

Replacement Windshield Washer Reservoir

• To accommodate the oil cooler and ensure proper airflow within the right-hand bumper area, CSF engineered a low-clearance replacement windshield washer fluid reservoir. This redesigned bottle integrates seamlessly with the factory pump and filler neck, maintaining a clean, OEM-style appearance in the engine bay while creating the necessary space in the bumper for the cooler assembly.

Dyno Testing

• For independent validation, CSF worked with MotoIQ to gather third-party test data. Using dual sensors at the oil filter housing for accuracy, MotoIQ performed nine consecutive dyno pulls to establish baseline heat soak, followed by identical testing with the CSF prototype installed. Ambient temperature differed by only 0.5°F, yet the CSF kit consistently reduced oil temperatures by an average of 9°F (5°C), with a maximum observed temperature of 222°F (105.5°C). These results were achieved even before the addition of the fender liner vents. While dyno testing provided valuable baseline comparisons, real-world track testing demonstrated far more dramatic temperature reductions under extreme conditions, validating the effectiveness of the full system.

Features

• Two CSF high-performance dual pass oil coolers
• Bar / plate core offers strength and durability
• 100% TIG-welded construction tested to 120psi
• Smooth 40-degree feed and return fitting design
• Dual pass flow for additional cooling
• Oil capacity increased by over 2 quarts (2 liters)
• Motorsports grade AN lines with patented quick release fittings by DYME PSI
• 304 stainless steel reinforcing braid and polyethylene top braid
• CNC billet machined sandwich plate with 175°F – 195°F (80°C – 90°C) thermostat and 1/8 NPT port for aftermarket oil temp sensor
• Pre-preg carbon fiber bumper vents for maximum airflow and cooling effect
• Laser cut louvered fender liner vents to improve the airflow path and promote heat extraction
• Replacement washer fluid bottle compatible with factory washer motor
• Includes all brackets and hardware
• Includes installation instructions and templates
• 2-year limited warranty

Applications

• Acura Integra Type S: DE5 | 2023-present | K20C1 2.0L I4 turbo
• Honda Civic Type R: FL5 | 2023-present | K20C1 2.0L I4 turbo

Notes

• CSF recommends the following oil weights depending on application:
  • Light Track Duty and/or High Performance Street: 0W-30 or 5W-30
  • Heavy Track Duty and/or Dedicated Race Builds: 0W-40 or 5W-40

About CSF

The Racing & High Performance Division of CSF Inc. is dedicated to designing and producing the world’s most advanced, efficient, and dependable cooling solutions. CSF offers a broad range of state-of-the-art cooling systems, with over 250 distinct applications. These include high-performance all-aluminum direct-fit radiators, intercoolers, and oil coolers, as well as bespoke manufacturing tailored for racecars, power sports, off-road vehicles, marine, and industrial applications. Every cooling solution from CSF is meticulously crafted to ensure optimal engine temperature management, even in the most rigorous driving scenarios. With a legacy spanning over 50 years and more than 40 million cooling units distributed worldwide, CSF is widely regarded as a luminary in the industry.