Much like anything in life, our first track outing with the STi Killer proved to be bittersweet. While it was great to finally get the car out on track and get our baseline numbers, our day was cut short thanks to an ever-worsening fuel pressure problem and a sloppy shifter, which made for tricky 2-3 upshifts. Considering our '01 Camaro was built from a pile of rubbish, we are thankful our first-time issues were so simple and spent the last month telling inflated stories of our track outing to friends while casually working on fixing the last couple of bugs.
In regards to our fuel pressure problem, we found that the stock fuel pump, which we had found on the floor of Greg Lovell's shop, was, not surprisingly, on its way out. During our initial dyno tuning the air/fuel ratio was actually fine, if not a little rich, but during our first quarter-mile pass, we saw injector duty cycles of 118 percent and a 13.4:1 air/fuel ratio, which tipped us off to the fuel pressure problem. For those of you not familiar with the LS1 fuel system, a typical working setup should run 58 psi of base fuel pressure, where as ours was around 52 and would drop well into the 40s under mild acceleration. Luckily, Racetronix, a company you should no doubt be familiar with, offers one of the most comprehensive fuel system upgrade kits for a stock-style fuel system, and with a quick call we had a fuel pump kit and plug-and-play wiring harness on the way.
Along with the standard install, which you can follow along on the next couple of pages, we also went a step further and decided to wire a fuel pressure sending unit to our stock rail so that we could log fuel pressure, along with duty cycle, inside our stock PCM using HP Tuners. Fortunately, using HP Tuners, there are several ways to accomplish this, depending on your needs. Since we wanted a clean OEM look and we plan on logging fuel pressure on every lap, we chose to wire an Auto Meter fuel pressure sending unit (PN 2246), which we ordered from LM Performance, directly to our stock PCM, using the existing EGR input wiring. Obviously, in doing so, we would lose the ability to run an EGR system, so if you're in an emissions-stringent state and are worried about an issue, we recommend you wire your harness directly to the HP Tuners input box and record the 0-5 volt input that way.
With our fuel problems fixed we turned our attention to our unknown shifter assembly, which we replaced with a tried-and-true Pro 5.0 unit, which we ordered from Brothers Performance, who shipped the assembly and knob in a flash. Besides the obvious reduction in throw, improved ergonomics, and confident 2-3 shifts, the Pro 5.0 shifter base includes a positive stop mechanism, which means our D&D-built T56 will live a longer life, without premature wear thanks to overextended shifts. Compared to our fuel system install, the shifter felt like a walk in the park, but it is something we will be thankful for every time we hunt for that next gear. As always, we have documented the install on the following pages and once again, our good friend and master mechanic Greg Lovell of AntiVenom EFI was on hand to walk us through the process.