Originally Posted by Jarkko.Männistö
cant you chance the fuelling system another way ?
you have 1350bar system , chance that to new version 1600bar ..
that should give you around +20 - 25% more fuel .
the pump chance should be easy, as they both use belt.
and if 140-150hp cars can be mapped to 200hp, and with other mods they can be around 210-220hp. then add there this 1600bar system, and you have fuel for at least .....
its sounds funny, that you can get power with 1.9 16v diesel, but not with 2.4 10v .
also is funny, that 16v gearbox can handle 480nm, but 10v only 400nm.
and was it that 2.4 20v 175hp jtd, that cant handle almost nothing more, or the gearbox will broken.
is there anything, that can be done to the gearboxes on these cars? I mean the engine sound is so much better, and if you can get 250hp with 16v, then why not 300hp with 2.4 jtd 20v 175 .. ?
i think you are a little mislead...
first the HighPressure Pumps are both driven by belt but:
the newer ones are electronic controlled via ECU - they have at least a low and one High Pressure Output - where the old ones are simply high pressure all day... next thing is the diameter of the belt driven gear it's not shure this is exactly the same on all 5 Zylinder engines...
Increasing railpressure does not increase the amount of fuel in the same way, it is way less! Reson for this is the drag you have on your fueling system - the higher the pressure - the higher the drag which is limiting maximum throughput.
Take the Walbro fuel pump for example:
it has an output of 255liters / hour on with 0 Bar pressure - output drops dramaticly as pressure raises - i know first hand - got one installed to my windscreen washer jets and thrust me it's no were close to 255l/h with that small diameter of the washer hose... (it's still quite a thing on the washers ^^)
those CR Pumps are expensive as hell, for reasons named no way plug&play and the increase in fueling would be quite limited - it is best to remove all bottlenecks in the Fuelings system first.
Changing the Fuel Pump would be needed once the Stock System can't deliver the asked pressure any longer. (Big INjectors + loods of boost + high rpm!)