Fuel pressure regulators, was Re: Fuel pump questions

[Carl Summers]

bruce plecan wrote:
> 
> Maybe I should have asked this first, are you talking about the FPR for
> the injectors, or for a seperate fuel system for when the NOS in on?.
> If your running one pump, and two metering systems, I'd recommend using
> a large difference in system pressures, and two return lines.  Sometimes
> if the NOS step isn't too large, they use the NOS to hammer the FPR,
> in it's vacuum reference line to just run the pressures as high as
> possible.  I'd use a fuel pressure guage on both to make sure one wasn't
> robbing the other, or that you're exceeding pump capacity.  While that
> -10 looks large, you have a BIG hole to fill when the NOS fuel solenoid
> trips if you're running a big NOS, and it's better to have too much
> fuel around, rather than not enough, and have it sneeze.
>   Bruce    nacelp at bright.net

Nitrous is something I have played with for years,,,and tuning is still
misunderstood even by most "experts"(including NOS) in the performance
industry.  If you have ever bought a direct port kit from them,,you
should have noticed they have a reccommended jetting vs fuel
pressure...and it's somewhat correct(way too rich, but safe) but these
jets are for carbureted applications,,,,,when the nitrous is activated
on a carb app. the injection of nitrous causes the carb boosters to lose
"signal" which lessens the fuel flow out of them.......but in a FI app.
the fuel flow to the engine remains the same,,,(The only person at NOS
that understood this is no longer there) the fuel/nitrous/jet
requirement of a FI system is drastically lower than that of a carb
application.... ......and about the #10 line....if I remember correctly,
the Paxton pump is so high flowing that a large line is required so as
not to build backpressure at the pump and therefore eliminate
overheating of the pump and ultimate failure........ 

-Carl Summers