August 2010 Fuel System
Finally had to fess up and install a upgraded Fuel System. I ran for 2 years with a Kenny Bell Boost-A-Pump to decrease the Injector Duty. It worked, gave me about 5%. Enough to keep it a bit more safe at 95% vrs 100%. This was prior to the GT28 installation. So out came the BAP and in came the full fuel upgrade. I decided on Injector Dynamics ID1000s, FIC fuel rail. Pre-made Parker Teflon -6AN lines. 2 new Denzo 950-0155 (stock) fuel pumps.
I also removed all the pins from all the connectors and made new wires and new pins. So the Pigtail from the fuel tank top connector to the BP1 connector are all new. I did not want to cut and splice for the 2nd fuel pump. I wanted the +12v wires to be red. I did the same thing inside the fuel hanger/canister. You can see this in the last 3 pictures.
The wiring and theory is unique to most set-ups. The stock FP ECU is controlled by the car’s main computer. Main purpose is to only run the fuel pumps when the engine is actually running. A Major safety thing. The other function of the ECU to FP ECU is running the FP at 9v up to 4000 rpms, then 12v above. This is done by the main ECU sending a 2v signal to the FP ECU telling it to pump out only 9v up to 4000 rpms. The the main ECU sends a 4v signal to the FP ECU to raise the voltage output to 12v above 4000 rpms. So I built a electronic circuit board using a “comparator” integrated circuit tapping off the ECU 2v to 4v signal. The function is to have a “reference voltage” to one side (I used 3v). When the input voltage is less than 3v, the circuit remains inactive (running stock 9v operation). But when the output voltage goes to 4v, it fires the circuit on, which then turns on a 40A relay. This relay then sends 12v to my new 2nd fuel pump. The basics here is that I am running on 1 stock fuel pump, totally stock in form from FP to the filter under 4000 rpms. Above 4000 rpms, the 2nd fuel pump is brought on-line to supply the extra fuel pressure needed under heavy loads. This serves a dual purpose. One, the 2nd FP is never running unless I am under boost or load. So things are quieter. Two, it is safer not having the 2nd FP running. Three, the car runs better because it is running at 9v which isn’t overpowering by increased fuel flow.
Injectors and final hose routing/installation is not finished. Will post when finished. When all done, I will install the Vipec, and a GM flex fuel sensor and convert to E85. Which is the driving force for this larger than normal fuel system upgrade.
Previous installation was using a BAP (Kenne Bell Boost-a-Pump) Although it did a good job reducing my injector duty, it did’nt do well enough. (I think it dropped maybe 6-10% overall) I used a triggering method off the stock FP ECU. When the FP ECU received the 4.0v trigger signal at 4000 rpms, it triggered the BAP to boost up the FP voltage to 16v. This way it wasnt running at full 16v unless I was over 4000rpms. Below that, car ran stock at 9.0v.