Can I upgrade the Viperís fuel system?

There are ways to "re-manage" the fuel system, for those of you with modifications that are maxing out the stock fuel system.

You need (1) longer fuel injector duty cycle at the point where the car is lean; (2) more fuel pressure (with adequate flow); and/or (3) bigger injectors. The latter is usually indicated when duty cycle exceeds 80%. Practically, this is difficult in the Viper because (1) no one makes a tunable device to change duty cycle (you are stuck with "burned" chips or "flashed" PCM at best; (2) the regulator is in the fuel tank, so it must be removed and an external fuel regulator and associated plumbing added; and (3) bigger injectors without precise control will just enrich the mixture at all RPMs & engine loads, which is not very sophisticated.

Motec is the best computer controller at this time, but unfortunately the most expensive. There are other fuel management computers that can control 10 injectors. The drawback they have is that they are governed by a "batch-fire" program, and will not fire sequentially. Thus, too much fuel is wasted in the intake, and poor fuel atomization can cause deposits.

SVSi makes an entire fuel delivery system, which requires you to ship them your car.

One alternative to making the fuel system completely tunable to the modifications of your car is to have the intake manifold removed so that the rear ports can be utilized for a return system. Once the proper fittings are installed, a new return line to the fuel tank can be installed. Remove the factory in-tank pump, and install an Essex High pressure/high volume pump and filter assembly. The return line can be regulated by a single port fuel regulator via a vacuum line to the intake. This would solve all of your fuel problems and is the same configuration that the GTS-R cars have for their fuel systems.

Interesting to note: Team Viper has remarked that anything less than 30HP is a waste of money and lack of knowledge on re-programming the computer. The stock computer has compromises necessitated by Corporate policies and Governmental regulations that keep ultimate performance out of reach. Chrysler engineers have said that over 500 hp is available from the current engine with only electronic changes. The side benefit of this reprogramming of the computer is better performance without driveability compromises.

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