Air Suction
Adhere to the following instructions if the engine air-suction is to be modified:

• To ensure the functionality, standard parts, such as filters, tubes, suspensions (oscillating insulation), etc., must to be mounted according to the same specifications as the standard model.
• The clean-air side and the connection maintenance indicator must not be modified.
• It is not permitted to the change the installation conditions in the area of the inlet port.
• The flow velocities in the intake range, in front and inside the air intake, must not be increased. Do not confine the unrestricted cross section.
• The water separation of the engine air-suction may be impaired even by small modifications in the area of the suction opening (e. g. the radiator grill). Therefore, modifications in this always require a permission of the responsible department.

• Use only original Volkswagen components for modifying the exhaust system.
• Length and mounting position of the flexible metallic hose between exhaust manifold and exhaust pipe must not be changed.
• The unrestricted cross section of the exhaust pipe behind the sound absorber must not be reduced.
• Pipe bend max. 90°
• Avoid additional pipe bends.
• Bend radii 2.5 d.

• Minimum distance to plastic lines, electrical cables and spare wheels:
  200 mm for exhaust systems without shielding,
  80 mm for sheet shieldings,
  40 mm for sheet shieldings with additional insulation.
• Additional shieldings are required:
  • In the area of operating devices
  • in the area of modules, attachments and installations , if they are not made of heat-resistant material.

Cooling:

The cooling system (radiator, radiator grill, air ducts, coolant circuit, etc.) must not be changed.
A sufficient throughput of cooling air must be ensured.

• Keep the air intake of the radiator free
• Do not place any warning signs, plaques or other decorative parts in the area in front of the radiator.

Provide additional cooling devices for modules, devices, etc., if the following conditions apply:

• Operation at outdoor temperatures above 35°C.
• If the vehicle is standing and high continuous power is drawn off

Disk brakes

• The cooling must not be impaired by spoilers below the bumper, additional wheel trim panels or brake disk coverings, etc.

Preparation 2nd heat exchanger

• At backfitting of a heat exchanger, it is important the bleed the cooling water system completely:
  
  heater output:8,7 kW
  air-mass flow: 360 kg / h
  volume flow: 1500 l / h
  
  the additonal heat exchanger from the T4-selection can be recommended.