APR 3.0 TFSI Supercharger Coolant Performance System

APR is pleased to present the second iteration of the Coolant Performance System (CPS) for the Audi 3.0 TFSI Engine.


Through extensive motorsport testing in the Grand-Am Road Racing series, and high boost pressure testing utilizing a larger supercharger, APR’s engineers were able to significantly improve the 3.0 TFSI’s supercharger cooling system. The updated system not only improves performance, but also improves overall engine reliability by keeping components well within their desired operating temperatures.

From the factory, the 3.0 TFSI’s supercharger features dual air to water heat exchangers mounted inside the unit, which are responsible for lowering the intake air temperature before it reaches the combustion chambers. As air moves through the heat exchangers heat transfer occurs, cooling the intake air while heating the coolant. The coolant is then pumped through a circuit shared with the engine’s cooling circuit and across one front and one side mounted radiator. As air rushes across the radiator, the coolant’s temperature is reduced. The cooling system’s pump circulates coolant back through the supercharger and the process recurs.

The problem with this system is that after only a few moments of spirited driving the cooling system becomes overwhelmed and lacks the ability to reduce the coolant's temperature. This is made worse by the fact the cooling system is shared by the engine’s cooling circuit, which can easily raise coolant temperatures beyond 100°C. As a result, the system’s effectiveness decreases, intake air temperature rises, power decreases and reliability drops.

The APR Coolant Performance System takes a multi step approach to increasing the cooling system’s effectiveness, resulting in a system capable of delivering increased performance and reliability.



The APR CPS system separates the engine and supercharger cooling circuits. In doing so, coolant temperature drops significantly and instantly improves performance. The CNC machined, black anodized reservoir proudly displays the APR logo and mounts conveniently in the engine bay with the included bracket.


Hot coolant from the supercharger’s heat exchangers is pumped through the front mount radiator and OEM side mount radiator. As the coolant passes through the unit, it’s cooled and circulated back through the supercharger’s heat exchangers. By increasing the frontal surface air an impressive 138%, the larger unit increases the heat transfer coefficient, which quickly and effectively lowers coolant temperature. Additionally, the larger radiator increases the thermal capacity of the system.


The cooling system’s thermal capacity plays a critical role in lowering the average coolant temperature across the entire system. By increasing coolant capacity an additional 4.2 liters with the APR CPS coolant tank, colder coolant is pumped into the supercharger’s dual heat exchangers. As a result, more heat is transferred to the coolant system as hot intake air passes over the exchangers. This directly translates to more consistent power, even under demanding situations.

Coolant Separator Kit Installed Installed Detail Radiator Radiator Radiator Radiator Radiator ADS Kit Coolant Tank


APR conducted grueling, back-to-back testing to determine the effectiveness of the upgraded cooling system, compared to the same vehicle equipped with the factory setup. The starting intake air temperature (IAT) measured at idle was brought to an identical, and consistent, 35.5°C before conducting the tests. Six, back-to-back, twenty-one second sweeps on the dyno were conducted with a five second cool down time between each run.

After the first sweep, the factory system allowed the intake air temperature to rise 50% higher and by the final pull was a blazing 87.50°C. Consequentially after only the third dyno pull, the ECU intervened and began protecting the engine by attempting to reduce the intake air temperature. The supercharger bypass valve opened, bleeding boost pressure back into the intake tract, lowering the overall system IAT. As such, the results were skewed by not allowing the system to experience the hottest operating conditions during each run, but still proved the system was not up to the task. Power suffered dramatically.

Switching to the APR CPS system, the differences were immediately noticed. After the first sweep, IAT’s were 15.75°C less than stock at a steady and reasonable 55.5°C. During each of the brief, five-second cool down periods between sweeps, the system’s recovery rate increased, as the coolant and intake air temperature rapidly decreased. The system remained consistent between each pull, only slightly increasing in temperature. By the final pull, IAT’s were only 11°C hotter than the initial pull. The ECU never intervened to reduce power as it did with the factory cooling system, and was still 21°C cooler than stock.

Vehicle Application Guide
Make Models Transmission
Please note some cabriolet models may require modification to the coolant tank mounting location.
Audi B8 S4 6MT & S-Tronic
Audi B8.5 A4 & S4 6MT & S-Tronic
Audi B8 S5 6MT & S-Tronic
Audi B8.5 A5 & S5 6MT & S-Tronic
System Type System Part Number Price(税別)  
Complete APR Coolant Performance System MS100068 ¥400,000 
Partial Coolant Separator Reservoir MS100065 ¥75,000 
Partial Radiator and Coolant Tank MS100066 ¥380,000 
ADS Requirement ADS (Audi Drive Select) Dynamic Steering Auxiliary Cooler
Required and only applicable for vehicles with the ADS system.
MS100032 ¥50,000 

APR Tuned

Phone: (092) 883-9222 Fax: (092) 883-9213 Address: 1-18-3-101, Ikinomatsubara, Nishi-ku, Fukuoka, 819-0055

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