Water Injection

Water Cooled Combustion

Besides the Miller cycle, cooled exhaust gas recirculation, and variable compression ratio, the injection of water is a ‘hot topic’.

To evaluate the benefits in fuel consumption and power output and to study the feasability of this technology, FEV thanks Audi AG for the great support that allowed the realization of the project.

The result: Torque, maximum power output and hence acceleration of the Audi TTS Coupé base vehicle are increased significantly while fuel consumption is reduced.

Focus on shortest possible time until start of series production: FEV decided to realize the water injection via port water injectors as this solution offers the highest probability for short term series production implementation

Results At A Glance

Significant improvement in performance compared to base production variant:

• + 18 % max. torque
• + 10 % max. power
• + 20kW/l @ Lambda = 1
  Up to + 30 kW/l @ Lambda = 1 possible with higher water consumtion
• Up to 4 % fuel consumption reduction
  in Lambda1 region with base compression ratio
• Up to 12 % fuel consumption reduction
  in region where enrichment demand is eliminated

Water consumption (depending on driving profile):

• 1 % (moderate) to 10 % (sportive) of fuel mass

Compared to the base calibration torque and maximum power could be increased significantly, while fuel consumption was lowered by up to 12 percent.

FEV's Scope Of Services