I 've post this picture of the injection rail, I 'm asking me a question is it really helpfull to change the fuel pump because the injection rail will still open at 3 bar (factory setting), so if we want more fuel we only need to change the spring by a longer one or increase the longer with a peace of metal like a ring pressure will increase in the rail, than after we will have more fuel during the injector bypass. Does anyone has change the factory setting?

There are aftermarket pressure regulators which have a screw to regulate the pressure which will be a straight fit for what you have. Alternatively, some folk carefully compress the regulator a little in a vice for the same effect.

BUT received wisdom (from folk who RR engines on a daily basis) is that at anything above 4 bar the spray pattern breaks up and/or the injectors tend to stick open.

If you really need more fuel, bigger injectors and a re-map are the better solution.

As for the fuel pump, it's not simply a case of what pressure it operates at, but what the fuel delivery is at that pressure. That's why a 1.1 Seicento uses a different fuel pump to a 6 litre BMW.

Hiya!

I would recommend upgrading the pump to the walboro 255, and use a pressure regulator, when we was tuning either my standard or Turbo B it was proving difficult to get the B to supply enough fuel.
Once I upgraded these the map was better and the B's more responsive.

PICTURES!!

I was looking into these but there seems to be multiple versions of these 255.
Any idea to find out what you got in the Bee?

please see
http://www.onlyfuelpumps.com/walbro-fuel-pumps/walbro-255lph-performance.html

Hiya Oli, the pumps are all the same, just maybe there's some difference in the wiring connections. All you will need is the pump and this will fit in your old fuel housing and floater.

If you can send a pic of your old pump (in the housing) and a close up of the connector, I'm sure they'll put you right.

Found an old pic of mine.
https://www.fiatforum.com/barchetta/138667-kc3-project-silver-10.html?p=1533684

Looking at the Walbro site they offer a replacement pump, is this the one you have KC?
http://www.fuelpumpsonline.co.uk/fiat-barachetta-18-16v-sris-fuel-pump-619-p.asp