Alpha Performance Audi B8.5 S4 & S5 Boost Cooler System
Audi B8.5 S4 / S5 Boost Cooler System
The Alpha Performance Audi B8.5 Boost Cooler System is a great addition to your S4/S5 whether your car is stock or modified. The system features a large, high efficiency heat exchanger located at the front of the car, an additional reservoir that holds over a gallon of coolant and a high flow pump which runs complementary to the factory pump. Whether you live in a warm region of the world, enjoy long spirited drives in the mountains or run long sessions at your local track day, the S4/S5 Boost Cooler will keep your intake temps low, maintaining your 3.0 TFSI supercharged engines maximum output.
As with all Alpha Products, everything needed to install the system is included – bolts, fittings, lines etc. Best of all, no drilling or modifications to the car are required, it’s a 100% bolt on affair.
The ‘Core’ of the System
The most important part of an efficient heat exchanger system is the core, skimping here could mean the overall performance of an ‘upgraded’ system might be worse than stock! The OEM unit is a single pass design with a core area of 156in^2. Our Alpha core is a high quality, triple pass unit where the coolant makes three passes through the heat exchanger vs competing cooling kits which use a single pass design. The core is made in the UK with a fin area of 417in^2, almost three times the surface area of the stock core! For added durability the fins are hemmed for strength, able to withstand abuse from road debris.
Increased Coolant Capacity, Decreased Heat Soak
The hand fabricated Alpha coolant reservoir acts as a large heat sink to keep coolant temperatures low and stable. With over a gallon more coolant on board, it increases the cycle time of the coolant in your S4/S5 allowing it to dissipate more heat before being recirculated, working as a large thermal reservoir, keeping the horsepower-killing heat soak at bay.
Pumping Up the Power!
To give you the best possible performance and keep the coolant flowing efficiently through the larger Alpha heat exchanger, we added an additional high flow brushless pump to run in conjunction with the OEM brushless pump. The combination of the two pumps allow a very high flow rate to keep the fluid moving and maintains that flow rate at higher pressures giving you the assurance your car will stay cool in hot climates, extended track sessions or everyday driving. See graph below for pump data.
The Devil is in the Details:
To provide your S4/S5 with the best cooling system on the market we thoroughly tested multiple variations of the Alpha Boost Cooler System. We tested divorced and non-divorced systems finding that divorcing the system showed no real gains, only added complexity. We found the stock pump stops flowing at 8psi so we added an additional brushless pump to support running higher pressure and maintain flow. Data log after data log was recorded and the results analyzed until our engineers were completely satisfied.
All testing/logging was performed on our Dynojet dynamometer doing 1st through 5th gear pulls with conditions and ambient air temps equal.
Post Intercooler Air Temperature:
This graph shows the difference between stock VS Alpha air temperatures after the air has passed through the intercooler, cooler air means more horsepower!
Post Intercooler Coolant Temperature:
This graph shows the difference in coolant temperature between the stock system and the Alpha Boost Cooler kit after the coolant has passed through the intercooler to cool the air charge. Lower temps mean the car can maintain maximum output!
Pre Intercooler Coolant Temperature:
This graph shows the ability of the Alpha system to pull more heat out of the cooling system. Notice how the water temps stay more consistent with the Alpha Cooler. If the heat rejection was the same between the stock and Alpha system, the lines would trend the same.
Heat Rejection of Air:
This graph shows heat rejection of OEM versus Alpha Performance system. Heat rejection is a perfect indicator of how the system performs because the starting temperature does not affect the data. The Alpha system has significantly greater heat rejection throughout the run and rejects more heat on deceleration allowing for quicker cool down time.
- High Quality Triple Pass Heat Exchanger
- Hand-Fabricated Reservoir
- Brushless Coolant Pump
- 4 Ply Heavy Duty Silicone
- Brushless Pump Plug-in Jumper Harness
- All Hardware Needed for Install
- Factory Coolant Tube
- Much Better Heat Rejection vs Stock
- No Loss of Horsepower from Heat Soak
- Car Runs Cooler all the Time
- Cooler Intake Temps
- Increased Efficiency of the OEM Intercooler
- No Drilling or Modification to the car Required – 100% bolt on!