Fuel System

• S. African CIS fuel pump, same size as CIS3 pump but 1" longer. Stock 80q filter system.

•SX Performance fuel pressure regulator

•All lines and fittings Aeroquip in -6

• -5 tube-nuts to stock, rigid fuel lines

• Custom fuel rail using extruded rail stock, -6 fittings on each end.

• Lucas/RC 500cc injectors (about75% bigger than RS2)

• 20v/Digifant injector inserts replace the CIS inserts

• Intellitronix Fuel pressure gauge and sender

• Custom programmable 034EFI ECU EFI using TPS, air and water temp, 02, MAP, and RPM (click here for more info)

Ignition System

• CIS3 Igniton system with 5-window hall sender and ignition ECU. Timing set at 15d BTDC, load input from 034efi system to calculate ingition advance or retard based on load.

Crane Capacitive Discharge ignition ecu and coil. The Crane box intercepts the stock pulse from the CIS3 ignitions system and boosts theoutput while increasing the # of charges from the coil. For example the stock ecu will fire the coil for up to 20 degrees of crank rotation in one long pulse. What happens is that the first 5 degrees of crank rotation result in a powerful spark, but as the coil discharges the mJ output decreases resulting in a tapered off charge. The Crane in turn intercepts the stock ignition trigger and created multipe, higher voltage and mJ charges to the coil, the Crane can fire the coil up to 20 times per charge, or once every degree of crank rotation! Not only does this result in a more powerful spark, but the coil fired multiple hotter sparks than just one tapering off spark. The idle is smoother with the Crane and ignition problems with high boost, high hp applications are limited. The Crane coil is a much more powerful unit than any of the stock Audi coils, it can deliver up to 600v of high current spark.


Well, this is the whole point of this project, right! OK, so hopefully you understand the "framework" or ŇsystemÓ that this fuel system will operate within. It is critical to have a free flowing intake and exhaust track when upgrading a car for the 300+hp range. I honestly feel that using the components I am using now, there is no reason, from a power standpoint, that this car can not crank out 500 hp with the proper tuning. Longevity may be an issue of course, but with the lack of restriction and unlimited programming capability, how much power do you want?

Also, many feel that the 10v cars suffer from lack of high RPM performance, and that the 20v motor is needed. I would argue that the problem with the 10v cars has more to do with CIS than anything. One of the greatest differences I have noticed so far is amazing high RPM performance, much better than before. Let me list some of the advantages to going programmable EFI as I have done:

• Unlimited tuning potential, no "chips" to burn or change, all changed to fueling can be done driving down the road with a laptop sitting next to you. Whether it is 100 hp or 10,000 hp will not matter, you are only limited by airflow and injector size. Fueling will never be a concern again, even an Audi Motronic system is going to require chip programming to accommodate performance increases.

• Non-linear fuel delivery where it relates to RPM. In other words, CIS is either rich or lean from idle to redline, aside from the effect of the Differential FPR, there is no way to manually tune the system to be richer at high RPM and stoich at idle (unless you are one of the few programming whizzes).

•Increased accuracy and efficiency, no "pooling" up of fuel like in CIS.

• The best fuel atomization possible, CIS is really like a carburetor, there is very little atomization of fuel from the injectors. Also, there is an endless assortment of EFI injectors to choose from.

• No intake restrictions in the form of airflow meter or even Mass Airflow Sensor (though one could be used if you really wanted)

• Create more room in the engine compartment by eliminating CIS fuel lines and airflow box.

• Tuning a CIS system for high horsepower requires Band-Aid after Band-Aid to run properly.

• Installation is relatively easy, a simple harness is constructed and the stock ECU is left intact to control ignition duties. Great for the "electronically limited".

• Welcome to modern engine management! It has been almost 10 years since CIS has been used in an Audi!

My goal was to get rid of the "CIS" system and replace it with the EFI system. Since in the normally aspirated cars (CIS, CIS-E, and CIS-3) have essentially separate fuel and ignition systems (only really sharing the water temp. sensor). The whole fuel system can essentially be removed and the ignition system never really know is, this is even applicable in the turbo KH/MC cars too. As mentioned earlier, a DIS ignition system is in the works. For what its worth, the stock ignition system with knock sensing isreally good. One of the nice things about this system is that it can count timing pulses to fire the injectors using the factory hall sender in the ignition distributor. This is only possible in NA vehicles with the 5-window distributor, the turbo cars have only 1 window and will need an external timing wheel.

So, gleefully I pulled the CIS system and prepared the engine compartment for modification. A few harnesses will need to be made, the biggest for the fuel injectors, another for the TPS, water and air temp and O2. There were simply run through the firewall to the ECU mounted behind the glovebox. I left the stock water temp sensor on the top of the water outlet alone, and added another water temp sensor with 14x1.5 threads to the back of the head that was plugged from the factory. The TPS was the stock VR6 unit, I had to incorporate the stock idle switch for the ISV to work properly. The air temp is located in the IC outlet, but could have replaced the cold-start injector too, which I just plugged with a plate. I used a generic Bosch 4-wire O2 sensor, only $55 retail. Other CIS sensors remain unplugged such as the potentiometer, DPR, cold start, and full-throttle switch. For now the check engine light is on because of these, but I will incorporate the proper resistance to let the CIS-ECU think that sensors are still there.

The fuel system turned out really well with all the -AN fittings, it is nice to work with parts that are so standard and available compared to some of the metric stuff. I chose Aeroquip because they were a little cheaper than EarlŐs was. www.racehose.com has a great selection of Aeroquip, and www.amstreetrod.com has a great selection of EarlŐs. Tube nuts work really well for incorporating to the stock hard fuel lines, the biggest problem is getting a hold of a 37 degree flaring tool- I had to buy one new for $150.

The fuel rail is held in place by welded mounts on the intake manifold. The SX FPR is also a work of art; rated at over 1000hp, it is extremely adjustable and reliable. Audi 20v injector inserts screw right into the head and replace the CIS injector seats, a real treat when I discovered that a few years ago! Boost is controlled manually by spring stiffness in the stock wastegate, but I may go to an electronic system in the future just to easy tuneablilty. After everything is installed, and fuel leaks are checked for, set the ECU to a baseline calculation and get the car running. After realizing that the car was not starting because it was too lean, I readjusted inputs and the car fired right up! Within 10 minutes of driving and tweaking, I had the car running well across all RPM! The first thing I noticed was how strongly and smoothly the car ran (especially at high RPM), reminding me of the way an injected America V8 runs and pulls. Some blame the 5 cylinder for being unbalanced and rough running, but I am realizing it has more to do with the fuel system than the engine itself. Please email me with any specific questions, and if you are interested in doing a similar conversion.

I am making available ECU's to those who are interested.

Click here to see an overview and specifications of the ECU

Click here to see an overview of the Supplementry ECU

Fuel and Ignition System