APR Intercooler Kit for Audi S4 / S5 (B9)

The APR Intercooler System is a massive front mounted upgrade that dramatically reduces intake air temperature (IAT), minimizes heat soak, and provides increased performance! The system is an easy to install, direct bolt-on design, that is recommended at every stage of performance

• Dramatically lowers intake air temp (IAT)
  The factory intercooler reaches dangerously high IAT levels, even on the stock ECU!
• Massive frontal surface area and core volume
  3.125″ x 5.75″ x 28.25″ – 162.4 in² frnt. & 507.62 in³ volume – OEM
  2.250″ x 16.2″ x 22.00″ – 356.4 in² frnt. & 801.90 in³ volume – APR
• Highly effective core design
  Bar-and-plate core with staggered and louvered fins.
  Rigorous testing determined core style, fin density, and size.
  Low pressure drop + highly effective cooling = high performance!
• Smooth cast end tanks
  Engineered for low turbulence/restriction and maximum flow.
  Organically shaped to promote airflow across entire core.
  Pressure tested to prevent power robbing boost leaks.
• Easy to install
  Simple plug-and-play design with no trimming or drilling necessary!
• Designed by engineers with lasers
  With the best equipment and smartest engineers, it just works!

Testing:
APR’s engineers tested each intercooler in a multitude of tests to show the impact the APR intercooler has on intake air temperature. The following tests were conducted with a 2017 S4 using the stock ECU calibration on 93 octane fuel and no other modifications. Ambient conditions during the stock intercooler tests were 72.8°F and 98.4 kPa with 78.7% relative humidity. Conditions were similar later in the day during during the APR Intercooler testing with 78.4°F and 98.5 KPa with 62.8% relative humidity. This gave the APR Intercooler no added advantage over the stock system during the tests.

Design:
Unfortunately, to the untrained eye, many intercooler designs appear the same. However, effectiveness of the system and overall performance are greatly determined by several key metrics. Alloy selection, end tank design, construction type, fin style, fin density and overall core dimensions must be analyzed and balanced accordingly to deliver class-leading performance. While the OEM’s goal is to create a lightweight, easy to manufacture and inexpensive to produce, cross-platform design capable of supporting factory power levels, APR’s intercooler must be capable of supporting more than factory output. Achieving this goal took a multi-step approach focused around intercooler core selection, end tank design and install location.

Core Size:
APR’s Engineers also paid close attention to the balancing act between core effectiveness, pressure drop and space for end tanks through core sizing. With the core too small, pressure drop decreases dramatically, but typically results in a core incapable of effectively cooling. Likewise, with core size too great, pressure drop can increase, resulting in the turbocharger working harder. However, more importantly, with no space for appropriate end tanks, utilization of the core and overall effectiveness of the system diminishes rapidly, negating the benefit of the larger core. APR’s engineers were able to balance each of these characteristics to deliver maximum performance.

The APR system increases frontal surface area by 119.09% and has a 58% larger core!

Compatible models

• AUDI S4 B9
• AUDI S5 B9