How to get my 650ccs to work as 550ccs via fuel pressure? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

xpl2007 · 10-24-2007, 11:04 PM

I know stock sr20det fuel pressure is 43.5 with vacume off. How would i make my 650cc work like 550cc?
Lower fuel pressure? If so how and what formula?
Tweak SAFC II? Dont want to tune with SAFC II just yet, would like to start at fuel pressure..
thanks

DOOK · 10-24-2007, 11:06 PM

buy the correct injectors

B Love · 10-24-2007, 11:28 PM

It doesnt matter you are jeff. jeff doesnt use 550cc injectors only 650 and above because he is jeff

cdlong · 10-24-2007, 11:51 PM

it's 36.8 psi if you want to go that route, but at lower pressures you might start to have problems with atomization and spray pattern. use what ever you're using to tune for 550cc injectors and change it to 650. or just take ltd's advice.

xpl2007 · 10-25-2007, 12:08 AM

Thanks!
Thanks B Love... lol
With 550 there is little to no tune I have 650cc .. Mines ECU Stage 3 takes care of it..
How did you figure out 36.8?

Quote:

Just looked at my paper work from the 650cc injectors and they are flowing at: 652,635,635,652..
It says 43.5 psi would be 643cc
40 psi 617cc
35 psi 577cc
30 psi 534cc

Ill do 40 or little less maybe... Then SAFC II Tune for now thanks. Always safe on 100 octane!

NiSmOKnIghTsRBS14 · 10-25-2007, 01:30 AM

sell the 650s and buy 550. good luck

s13coupedrfter · 10-25-2007, 11:52 AM

Pressure does not equal volume and like cdlong said you will has atomization and spray problems

xpl2007 · 10-25-2007, 01:28 PM

I got the print out and it says it safe to do so??? Ill call them.

xpl2007 · 10-25-2007, 01:43 PM

Nismo 550 injectors run at 615 so im good at 40psi it dosnt affect the spray as much any lower will idles and runs fine. Just called and talked with DeatschWerks...

10-24-2007, 11:04 PM	#1
xpl2007 Zilvia FREAK! Join Date: Apr 2007 Location: Newport Beach Posts: 1,490 Trader Rating: (15) Feedback Score: 15 reviews	How to get my 650ccs to work as 550ccs via fuel pressure? I know stock sr20det fuel pressure is 43.5 with vacume off. How would i make my 650cc work like 550cc? Lower fuel pressure? If so how and what formula? Tweak SAFC II? Dont want to tune with SAFC II just yet, would like to start at fuel pressure.. thanks __________________ http://zilvia.net/f/traderratings.html?u=57636 If i sold you something or gave you it for free post here! Thanks!

10-24-2007, 11:06 PM	#2
DOOK Post Whore! Join Date: May 2007 Location: Land of Milk and Cookies Age: 42 Posts: 7,552 Trader Rating: (3) Feedback Score: 3 reviews	buy the correct injectors __________________ <------ Grumpy Old Asshole MY REVIEW THREAD: Ltdnismoracer4=DOOK http://www.zilvia.net/f/showthread.p...ltdnismoracer4

10-24-2007, 11:51 PM	#4
cdlong Nissanaholic! Join Date: Jun 2003 Location: Colorado Springs Age: 44 Posts: 1,865 Trader Rating: (0) Rides Gallery: cdlong Feedback Score: 0 reviews	it's 36.8 psi if you want to go that route, but at lower pressures you might start to have problems with atomization and spray pattern. use what ever you're using to tune for 550cc injectors and change it to 650. or just take ltd's advice. __________________

10-25-2007, 01:28 PM	#8
xpl2007 Zilvia FREAK! Join Date: Apr 2007 Location: Newport Beach Posts: 1,490 Trader Rating: (15) Feedback Score: 15 reviews	I got the print out and it says it safe to do so??? Ill call them. __________________ http://zilvia.net/f/traderratings.html?u=57636 If i sold you something or gave you it for free post here! Thanks!

10-25-2007, 01:43 PM	#9
xpl2007 Zilvia FREAK! Join Date: Apr 2007 Location: Newport Beach Posts: 1,490 Trader Rating: (15) Feedback Score: 15 reviews	Nismo 550 injectors run at 615 so im good at 40psi it dosnt affect the spray as much any lower will idles and runs fine. Just called and talked with DeatschWerks... __________________ http://zilvia.net/f/traderratings.html?u=57636 If i sold you something or gave you it for free post here! Thanks!

10-24-2007, 11:28 PM	#3
B Love Zilvia Addict Join Date: Apr 2007 Location: California Posts: 889 Trader Rating: (3) Feedback Score: 3 reviews	It doesnt matter you are jeff. jeff doesnt use 550cc injectors only 650 and above because he is jeff

10-25-2007, 01:30 AM	#6
NiSmOKnIghTsRBS14 Zilvia Junkie Join Date: Jun 2007 Location: SoCal Posts: 426 Trader Rating: (4) Feedback Score: 4 reviews	sell the 650s and buy 550. good luck

10-25-2007, 11:52 AM	#7
s13coupedrfter Zilvia Addict Join Date: Aug 2005 Location: Socal Posts: 839 Trader Rating: (8) Feedback Score: 8 reviews	Pressure does not equal volume and like cdlong said you will has atomization and spray problems