Yet Another Question... Dynojet PC-V, Wideband Controller and ECU Hack

Road Weazel

Registered
OK, the n00b has another set of questions. My bike is is a '99 and is set up with a Hahn Racecraft turbo set up, water injection and a variable pressure fuel regulator (40 PSI to 80+ on boost). I'm going to upgrade to the '05 ECU and rotor and get away from the 16 bit processor and PC-II. I'm building an ECU Interface Unit so I can hack the ECU but I'm only planning to remove the top speed limiter and change the timing (retard after 5K RPM and possibly advance below that). I want to use a Dynojet PC-V and Wideband with Autotune for the fueling. Autotune sounds like a good idea to me because I live at an altitude of 5,000' but work in the valley around 1,000'. I will have this dialed in on a dyno, with an A/F meter...
So, now that I've laid out the plan, DJ has a newer PC-V set up with a Pressure Input that can adjust the mapping based on the level of boost. Do I need that if I have the variable rate fuel pressure regulator that adjusts fuel pressure based off of boost? It seems somewhat redundant.
Thanx, guys. I'd appreciate your input.
Weazel
 
Your bike only has four injectors, total. The purpose of a rising-rate fuel regulator (FMU) is to vary fuel pressure according to the needs of a turboed or blown engine. Normally-aspirated, your injectors have enough "range" at 43 pounds of fuel pressure; on a turbo at 6 pounds of boost or above, they do NOT. Increasing the fuel pressure exponentially with boost-referencing enables your stock injectors to supply enough fuel on boost, it gives them extended range. Maxing out the injectors and pushing them towards 100% duty cycle without the FMU would lean the motor and do damage.
 
Thanx for the reply, Frank. I understand what you've explained. We ran into the 100% duty cycle running a B-King on e-85 with a PC-V. We could only control the primary injectors and just didn't have enough flow.
My question was whether I need the newer PC-V with the Pressure Input since I have boost-controlled fuel pressure.
Thanx! :beerchug:
Weazel
 
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