With the introduction of the 2.0T FSI Audi changed to the fuels of what we understood of fuel injection in their cars. Direct injection was something that was for diesels not for petrol’s and some of the numbers involved were a little mind blowing. The 1.8T that has become the best friend of the Audi owning masses normally had a fuel pressure of around 3BAr and maybe to the heady heights of 4Bar with a uprated fuel pump. The TFSI change our understanding of fuel pressure completely with pressures of over 130Bar that’s over 1900psi. The reason for this massive increase in pressure was due to the fuel now being injected directly into the combustion chamber. The electric fuel pumps that have been the basis for supplying fuel in most modern cars is simply not up to the job of these new high pressures. The solution was to go back to mechanical pumps that are driven directly from the engine. In the case of the TFSI its driven by three lobs on the camshaft which is turning at a rate of 1.5 times that of the engine. This means that the faster the engine turns the more potential fuel there is available to meet the demand of the engine. At lower RMP there simply isn’t enough fuel for many of the higher output conversions to work properly.
There have been many after market fuel pumps come and go over the last few years but there have also been many faliure with these and some tuning comapnies have given up fitting them all together. What has been need was a high quality pump that increases the available fuel in the critical low-mid end of the power range without the problems that have been associated with the uprated fuel pumps.
APR seen to have a solution. The quality of these pumps seems to be very good and while I’m sure someone will tell me of a car that has had a problem I can report of lots of problems with some of the others. All reports I have had from tuning companies using the APR pump, sware by them as the prayer answered about uprated fuel pumps for the 2.0T FSI with non of the fuel contamination problems or failures that have been seen in others.
The increase of volume in the APR pump has been increased by 40% over the stock item helpping to tackle the problem of fuel starvation in the critcal rev ranges. You can clearly see this in the graphs that APR are using to claim the improvements with below.
To give an idea of the tolerances involved, the final surface finish on the piston inside the fuel pump is so critical that it can be damaged by touching them with bare hands. The tolerances between the piston and the new barrel the piston rides in can only be measured by a multi-million dollar machine which uses air volumes to measure the part clearances to within microscopic levels.
The components used in the APR pump are also of a high caliber. The piston and barrel of the new pump are made of a certified and heat-treated bearing-grade stainless steel and have a special diamond like coating. The seals used in the pump are made of a high performance, filled polymer with a high modulus spring to retain the seal forces throughout the life of the product. The cross section of the seal is also of a proprietary design to maintain integrity over many years of use.
APR FSI pumps have been track tested since 2006 with several hundreds of thousands of miles of combined usage. Each APR pump starts out as a brand new OEM pump and is then modified with the new components by APR and undergoes a rigorous testing process on our high pressure fuel pump tester. Once a pump passes our standards it is serialized and shipped to the customer.
The APR fuel pump tester is a key element in the APR fuel pump production process. With the fuel pump tester we are able to perform several tests to ensure every pump is working to the high standards we have set for it. First the fuel pump tester allows us to perform the critical initial break-in of the new pump. By bringing the pump up to the full operating pressure, we can confirm that the seals in the pump are properly installed and not leaking. We are also able to verify operation of the fuel pump selenoid to ensure the fuel is being injected at the right time and in the right amount. Finally, a performance test is performed to make sure that the pump output is within specifications. This level of quality control ensures a lifetime of worry free miles with an APR FSI high pressure pump.
To ensure flawless drivability the APR 2.0T FSI fuel pump requires APR engine management recalibration to allow for the increased size of the APR fuel pump. If you already have APR software installed this recalibration upgrade is free, otherwise it needs to be purchased separately. Currently, some APR Stage II clients will be able to take advantage of increased horsepower and torque up to 25hp and 35lb ft with APR fuel pump specific engine management performance recalibrations.
When it comes to a critical component that can mean the difference between winning a race and not finishing at all, motorsport teams must use the best components available. Motorsport teams around the world have put the APR High Pressure Fuel Pump though brutal and demanding testing and have proven again and again the reliability and performance you can expect from each and every APR High Pressure Fuel Pump. The initial success of the R-GTI and APR’s own motorsport team have lead other noteworthy teams around the world to rely on APR.