injector/injector pressure

[DownunderGTiR]

say if i plan on going for 450hp
should i keep my fuel pressure at 3bar or pump it up to 4bar? which would be more optimum? cause i read that

" BAR = 59 PSI Running at 4 bar is better than running at 3 bar. Here is why, you can get more WHP from your inj at 4 bar, there is no xtra cost for a 4 bar program from JWT, you get better drivability at 4 bar because of better fuel atomization and you car will do better at the emmisions station becasue of better fuel atomization."

is this reconmented?

as for injector size which should i go for?
if i was to run 3bar/4bar at 85% duty cycle? is there a better choice?

600cc @ 4bar (694cc) @ 85% @ 0.5BSFC = 449bhp
700cc @ 3bar @ 85% @ 0.5BSFC = 453bhp

if i was to go for the certain fuel pressure and injector size what would be the reconmented brand/size regulator to look out for?

Lastly what size fuel pump would i need in order to complete all this?

just want to clear some thing up and much sure before i hand over my hard earn dollars to someone.

Did i miss out on anything?

thank you

Hai

 

[ashills]

.5 bsfc is a little low u should maybe work the figures out using .6
a set of 800s is probably safest then you have some room to keep 3bar rail pressure and not be near the top of the injector duty as alot of pumps lph drop massively when u up the pressure so by the time u put upt 2 bar of boost to 3 bar u can see the sort of pressure you'll be getting
the only plus point to 4 bar rail pressure is some injectors atomize a bit better if u are worried about emissions for mot etc

 

[MarkTurbo]

Keep the fuel pressure at 3 bar and get a set of bigger injectors, a small tweak on fuel pressure isnt too bad but going to 4 bar will put a lot of extra strain on the fuel system and is just a bodge for not having big enough injectors in the first place as far as im concerned ;-)

 

[boucherie]

rather than start a new topic i thought it best to add to this one!

il soon be getting my new engine and il be looking at running a 'safe' 400bhp, as ive got 800cc injectors already will i be alright with the stock fuel regulator or do i need to look into getting a new one and what seems to be a good easy to use choice?