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d240t2 · 03-04-2003, 07:11 AM

(new flow/old flow)=(new pressure/old pressure)^.5

So...you need to know the new pressure...

[(new flow/old flow)*old pressure ^.5]^2 = new pressure

=[270/370*43.4^.5]^2 = 23.1psi. PJ got it right!

And absolute pressure in the rail doesn't matter...only differential pressure. At idle, you will pull ~8psi of vacuum, so pressure in the rail is only going to be ~15psi, but that doesn't matter since differential pressure between rail and manifold is still 23.1psi. Still...nobody knows how good the atomization will be at that low of a pressure.

What do you hope to gain by doing this? You basically will just have 270cc injectors in the end...you won't be able to put out more fuel on the top end!

And all the Nissan regs are the same fuel pressure...so you'll be fine. Most FI cars run off of that same fuel pressure...but some don't.

Dennis

03-04-2003, 07:11 AM	#12
d240t2 Zilvia Member Join Date: Mar 2002 Location: Atlanta, GA Age: 44 Posts: 205 Trader Rating: (0)	(new flow/old flow)=(new pressure/old pressure)^.5 So...you need to know the new pressure... [(new flow/old flow)old pressure ^.5]^2 = new pressure =[270/37043.4^.5]^2 = 23.1psi. PJ got it right! And absolute pressure in the rail doesn't matter...only differential pressure. At idle, you will pull ~8psi of vacuum, so pressure in the rail is only going to be ~15psi, but that doesn't matter since differential pressure between rail and manifold is still 23.1psi. Still...nobody knows how good the atomization will be at that low of a pressure. What do you hope to gain by doing this? You basically will just have 270cc injectors in the end...you won't be able to put out more fuel on the top end! And all the Nissan regs are the same fuel pressure...so you'll be fine. Most FI cars run off of that same fuel pressure...but some don't. Dennis Last edited by d240t2; 03-04-2003 at 07:19 AM..