Delivery hose to regulator correct?

[eichh]

OK im in the process of putting on some quick disconnect fuel lines. I was taking notes as to what line goes where and I the return line is hooked to the regulator is that right? (bottom arrow) It seems like the delivery would go to the regulator first. Also what is the tiny vacuum tube on top (top arrow) some of the smog stuff was taken off when I bought it, does that need to be plugged or just left open?

Thanks

regulator by erik.eichhorn, on Flickr

[Howie]

OK im in the process of putting on some quick disconnect fuel lines. I was taking notes as to what line goes where and I the return line is hooked to the regulator is that right? (bottom arrow) It seems like the delivery would go to the regulator first. Also what is the tiny vacuum tube on top (top arrow) some of the smog stuff was taken off when I bought it, does that need to be plugged or just left open?

Thanks

regulator by erik.eichhorn, on Flickr

The open nipple is a vent to atmosphere, the arrow on the regulator shows direction from the pump.

[eichh]

so it does go from the pump to the throttlebodies to the regulator then back to the tank.

[Speeddog]

so it does go from the pump to the throttlebodies to the regulator then back to the tank.

Yes

[eichh]

thanks

[Roaduser]

on cars we traditionally hook up the regulator diaphragm backside to vacuum. is there a known reason why the ducatis are tuned without a vacuum on the regulator?

[Howie]

on cars we traditionally hook up the regulator diaphragm backside to vacuum. is there a known reason why the ducatis are tuned without a vacuum on the regulator?

Some cars use the pressure regulator as a mixture control device.  The vacuum hose will usually come from a manifold vacuum source.  Low vacuum (acceleration, full load), higher fuel pressure, more fuel injected into the cylinder. High vacuum (idle, decel and cruise), lower fuel pressure, less fuel injected. 

[Roaduser]

yeah thats how i understand it too. but i was wondering why they tune the bikes without a load parimeter in the tune. without a varied fuel pressure or a mass air flow/pressure sensor on the manifold i dont know how the engine management can tell the load on the engine and thus fuel acordingly for moments of extreme load. if there was a load variable parimeter in the tune or a vacuum varied fuel pressure wouldnt we get better response under extreme load by having a more accurate tune then simply revs vs throttle position they currently have?

the reason i ask is if i was to get a custom map, and hooked a manifold vacuum to the regulator before hand, would i get better throttle response down low and under extreme load?

sorry bout the thread jack, its a question ive asked my self before but never voiced and this thread prompted me.

[Howie]

Throttle position and RPM indicates load.  As a modification your idea has possibilities but you would need a way to control the vacuum and a lot of dyno time.