V-One S Racer:
There is a theory that by using a longer fuel line you'll get more run time... I can't see myself getting any more than 10 seconds . It also S-L-I-G-H-T-L-Y lowers the fuel pressure because the fuel has to travel further. I got sucked into making my fuel line longer, but it only caused fuel delivery problems, I make mine as short as possible (within reason) now.
The pressure line can affect your engine's tuning... but it's sorta complicated . Basically, the shorter the pressure line, the more fuel pressure there is and it causes a richer setting and vice versa . It doesn't have as much of an effect as changing the needle settings though.
Most people i see like to run a slightly longer then normal fuel line.
as if your end up upside down waiting for a marshal, u have less chance of stalling while upside down, as long as u dont rev the engine
what i have been told on pressure lines is (numerous places on the net say the same)
if you run a shorter pressure line, it keeps the pressure equal, so if you back down on throttle, so does the pressure.
but with a long one, it spaces the pressure waves out more, so when you enter a hairpin the pressure is higher then normal and fuels the engine, so when you open the throttle out the other side, it should jump out quicker, as long as it doesnt start to flood.
its all personal preference.
but i'd run the pressure line the same length as in the book, and some more length then normal on the fuel line.