Considering the many hundreds (easily around that number if not more when you consider GIAC/APR/REVO on a worldwide basis) of cars running Stage 2+ with 130Bar requested i think its fair to say the rail pressure isnt the issue.
After all the pumps were designed to run at this pressure all the time. Id like to think they would have been tested to run at a higher pressure without failing. Maybe Keith @ APR could elaborate on what the pressure test range is for the APR pumps. Id be pretty confident its higher than 130Bar though.
Interesting read here
Hi guys, this is a copy of a post I done for another Forum as this has been asked before, and a few people have been asking this to us by Email etc recently. The botton line is, if you already have an Autotech or KMD pump supplied by us dont worry.
We stopped supplying pump internals some time ago now so some text below is a little out of date but will give you the 'history' so to speak.
JKM appreciate that some people would like to know more about why we have made the switch from KMD & Autotech TFSI fuel pump internals over to the complete APR pre built and tested unit.
Where we have been using KMD/Autotech internals I will detail what process we have been going through for each fuel pump prior to sending it out to a customer, so you will get a feel for the process that needs to be run through by JKM to ensure that the pumps are of sufficiently high quality to sell to a customer.
After receiving the fuel pump internals from the manufacture (say for example KMD) we first check the machined parts for known manufacturing problems by measuring and a general visual inspection – any problems here and the pump internals are rejected.
We then hand assemble the parts together and with a light lubrication between the piston and bore, the clearance and general feel is assessed. The internals are then hand assembled into a test fuel pump body - any problems here and the pump internals are rejected.
Assuming that all is good on the above, we can then begin an up rated fuel pump internal build into a brand new OEM pump.
Cleanliness is paramount here as any debris etc will ruin the piston shaft. This is something that we only do in an extremely clean environment to ensure the utmost quality.
Once the fuel pump is built, we then move onto the next main step – Testing.
To ensure that each TFSI fuel pump that we supply is of the highest quality we have been testing each pump built by JKM, on our own TFSI car.
Therefore every time we build a new pump Kates nice new shiny MK5 GTI is pulled apart and the test pump is installed for performance testing under load. Following the install we analyse each fuel pump in detail.
We will look at the fuel pumps Quantity Valve differential angle, Total Compression volume, Fuel pressure and more – again comparing the results against known good units.
With our experience of these pumps it is possible to analyse the results and detect possible problems with internal clearances as a result of machining tolerances, but this is a very complex area. If we suspect problems we will remove the fuel pump, disassemble and inspect it again – any problems found here and the pump internals are rejected.
Following all of the above, assuming that the built TFSI fuel pump is functioning correctly, we will remove the fuel pump from our test car, seal it into a bag and box it and send out to the customer.
The main reason we have chosen to swap from KMD/Autotech is that the above is very costly to us (time wise) to get a good pump together. We have sometimes had to build 3 pumps to get 1 good unit.
We appreciate quality engineering, which APR provide with their fuel pump,
Our equivalent of the APR test rig, is our own MK5 Golf GTI engine and our diagnostics knowledge.
APR does have a superior hardware design, changing much more than just the piston and bore. The complete internals are re-engineered, right down to the balanced seal rings and main spring assembly. This design puts less stress on the rear balanced seal than the other pump solutions – the APR pump design is along the same route as the OEM pump only obviously containing larger internals for increased fuel volume.
APR route out bad pumps themselves during testing at their own facility, and the pumps have even been used by VW Motorsport on the VW Scirocco GT24 which won the ADAC 24h Race without any fault.
For those interested more information on this can be found here: http://forums.vwvortex.com/zerothread?id=3855643
JKM will only bring to market the quality items. If we find that the quality of an item is not acceptable we will first try and work with the supplier for a solution but ultimately if we would not be happy to use the product on our own car we will not sell it to a customer for use on their car.
For JKM the up rated internals route (only) is too inconsistent from the manufacturers.
APR provide a quality fuel pump out of the box, and the customer is in the knowledge that there will be no issues.
The APR pump can be bought in 2 ways.
1) An outright buy of an APR pump, where by you can remove your stock TFSI pump and retain it somewhere safe and simply install the APR pump. This route costs £624+Vat excluding postage back to you.
2) The second route is a core exchange but this can take up to 6 weeks to complete this process, where by if you send us your TFSI pump we will send it to APR for YOUR pump to be modified at the APR headquarters , this route costs £509+Vat excluding postage back to you and you are responsible for postage of your pump to JKM intially. However it does take a long time to complete this process due to the international shipping involved.
More information is at the following link: http://www.jkm.org.uk/performance/tfsipumps.htm
For those customers already with a JKM built KMD or Autotech pump, you do not need to worry as we have done the above testing process on your pump to ensure you have a good unit.
I hope this helps clear up the questions in this area and hopefully you will appreciate why we have made the switch to the APR unit.
For those who wondered, our own car does use an APR fuel pump but the K04 conversion car that has been on long term testing (27,000+ miles) has been, and is still using a KMD pump without fault due to the above testing process that we have performed.
Keith
JKM initially started supplying high volume/pressure 2.0 TFSI fuel pumps to customers in 2007. We have tried and tested many of the solutions available to the market. JKM have tested items that replace the fuel pump internals only (larger and stepped piston desing) and the APR design (larger but constant diameter piston as per the OEM Hitachi design).
Following long term reliability testing feedback JKM are now only supplying APR TFSI fuel pumps for 2.0 TFSI applications as we believe that APR has the most superior mechanical design.
The APR fuel pump design replaces more than just the piston and bore. The piston diameter is increased along with the complete re-engineering of the pump internals to suit the high volume design. This design approach will drastically reduce the possibility of fuel to oil mixture during the service life of the fuel pump.
Pump overview - Constant Diameter piston - Stepped Piston
Newly designed components are used throughout, such as a larger spring energized seal for a leak tight operation alongside a Diamond like Piston coating increasing surface hardness for a highly reliable operation.
In order to maintain the Highest Quality Standards all APR Fuel pumps are built at the APR facility in Alabama USA, where they are put through an aggressive post build testing process - ensuring that when you get an APR fuel pump, its reliability is without any question.
Therefore with Quality and Reliability in mind, JKM are now only supplying the APR High Pressure fuel pumps for 2.0 TFSI cars.
Fitting instructions for APR Fuel pumps can be found here. JKM do offer an installation service at £55.00+Vat - (£66.00 Including Vat)
APR testing regime/facilities
http://www.goapr.com/products/fsi_fuel_pump.html
This is what your paying your extra money for.
