1000cc injectors to big ???? - GT-R Register - Official Nissan Skyline and GTR Owners Club forum

banzai g · 11th July 2008, 05:13 PM

Im wondering is 1000cc injectors to big for my engine !!!?
Im running a trust 2.7 ,trust t517 turbos,tomie cams ,nismo inlet , Large single nismo pump etc !!!!! Car was running 610hp @1.3 bar before rebuild ! My car is mainly a road car ,with maybe the odd quarter mile !
It wont be run at top boost all the time.
I was wondering would i be better down sizing to 800cc's or that ???

tweenierob · 11th July 2008, 08:09 PM

DO NOT!!!! buy 800s dude.

1000cc perfect, a common misconception is that bigger injectors mean more fuel usuage on low load. IT all depends who maps it

Rob

banzai g · 11th July 2008, 09:27 PM

Fair enough Rob !!!!! Saying your goin be the man that maps it !!!!!!!

GT-R Glenn · 11th July 2008, 09:59 PM

Teenierob is spot on
The computer tells the injector how long to open ,so if its tuned right , it will only need to be open x% to get the right a/f ratio irrespective of injector size.
Bigger injectors I think give a different pattern at high % openings.
800's would be fine for 600 650 even up to 800hp but theres no reason you couldn't run 1000's.
It will make sweet f**kj all difference.
Yoda ran 1000cc injectors with 380awkw's no issues at all.

Piggaz · 12th July 2008, 12:24 AM

Only problem i see is that u fuel pump wont be able to supply enough fuel for the 1000's at big duty cycles. However... if you aint using the large duty cycles you wont have a problem

GT-R Glenn · 12th July 2008, 02:22 AM

Thats true if he was going to max or anything near max the injectors but he alrready said 600's hp.
So whats that, 60% duty ...Something like an 044 wouldnt even be breaking a sweat.

tuRBy · 12th July 2008, 08:19 AM

I run 1000cc injectors and the fuel useage is excellent at low rpm and low load

R.I.P.S NZ · 12th July 2008, 09:11 AM

I use 1000cc inj on nearly every engine we build, there is no problem getting them to idle nice etc,

Rob

Madden · 12th July 2008, 10:48 AM

I have just installed 1000cc's in mine and my idle is sky high. On idle i have AFR's of 11.4 and if i lean it out it starts to missfire? I have played with the lag times and get the idle lower but it starts missing. I put in Rc engineering injectors and i cant find lag times for them anywhere.

Any idea's?

DarkChild · 12th July 2008, 12:36 PM

Madden,
Apparently the lag time on these RC injectors is 1.1 milliseconds. I just got a set of 1000cc ones too.

markM3 · 18th July 2008, 11:07 AM

I heard and would appreciate tuners comments that the smallest injector for the power was best as it gave better fuel vaporisation??

Is this true or total rubbish?

On the F40, when Ferrari developed the catalysed one, they changed the spray pattern of the injectors and found the car produce more power (up from 478 to 515bhp (reported by R&T mag I think).

Cheers,

kismetcapitan · 18th July 2008, 11:24 AM

I'm wishing I had 1000. My 720s are pushed to the ragged edge - 90% duty cycle, 4 bars base fuel pressure to squeeze out more flow.

In fact, I think I'll add that to the must-buy list. My fuel system surely can handle them - I've got twin Apexi pumps. I'd like to reduce fuel pressure to stock 3 bars base. I suspect that lower fuel pressure = more fuel pump life.

SamuraiSam · 18th July 2008, 02:55 PM

Quote:

Originally Posted by markM3

I heard and would appreciate tuners comments that the smallest injector for the power was best as it gave better fuel vaporisation??

Is this true or total rubbish?

Absolutely false. Whoever said that has no idea how fuel injectors work. Better fuel vaporization is great, but near perfect vaporization can be achieved with 1600cc injectors without any issue whatsoever. The end result is not due to injector size-by-pressure, but rather nozzle design. Buy modern Denso, SARD, Bosch, RC injectors, and you won't have any issues. Buy sh*tty rebored/enlarged injectors from Venom etc and you will be up sh*t creek.

SamuraiSam · 18th July 2008, 02:57 PM

Kismet, lower fuel pressure will not mean more fuel pump life if you are sending the fuel pump battery voltage as you should be (you should have eliminated the factory voltage regulated fuel pump controller circuit). If you use a fancy controller circuit hi-load bypass then maybe you could very slightly increase pump life with lower pressures. The other issue with low pressures is poorer atomization as there is less 'force' behind the fuel to force it through the nozzle in a mist pattern so you will get poorer and poorer atomization (necessitating a non-linear 'sharper' increase in fuel injector pulsewidth compared with the "expected" correlation of slight pulsewidth increase) as line pressure is lowered.

Run 38 or 43psi whichever your car comes with.

markM3 · 18th July 2008, 03:21 PM

Thanks for clarifying Samurai Sam

11th July 2008, 05:13 PM	#1 (permalink)
banzai g GTR Register Member Join Date: Jan 2007 Location: bushmills northern ireland Posts: 418	1000cc injectors to big ???? Im wondering is 1000cc injectors to big for my engine !!!? Im running a trust 2.7 ,trust t517 turbos,tomie cams ,nismo inlet , Large single nismo pump etc !!!!! Car was running 610hp @1.3 bar before rebuild ! My car is mainly a road car ,with maybe the odd quarter mile ! It wont be run at top boost all the time. I was wondering would i be better down sizing to 800cc's or that ???

11th July 2008, 08:09 PM	#2 (permalink)
tweenierob GTROC Member Join Date: Aug 2003 Location: herts Posts: 1,738	DO NOT!!!! buy 800s dude. 1000cc perfect, a common misconception is that bigger injectors mean more fuel usuage on low load. IT all depends who maps it Rob __________________ Off to Dubai to map some R35's, 599.3hp and counting www.trracing.co.uk OSGiken 3.0l T51 back on... 3 track days before christmas

12th July 2008, 08:19 AM	#7 (permalink)
tuRBy GTR Register Member Join Date: Feb 2006 Posts: 547	I run 1000cc injectors and the fuel useage is excellent at low rpm and low load Last edited by tuRBy; 12th July 2008 at 08:26 AM.

12th July 2008, 09:11 AM	#8 (permalink)
R.I.P.S NZ GTR Register Member Join Date: May 2004 Location: Rotorua NZ Posts: 2,195	I use 1000cc inj on nearly every engine we build, there is no problem getting them to idle nice etc, Rob __________________ R34 GTR: Quickest street trim skyline in NZ, 9.7 @ 137 on 1st test pass, first meeting in the UK, 10.4 @ 144. 240z, WRH8.71 / 162 @ 2 bar, stock crank, full street trim 1972 240z, RIPS RB30, quickest/fastest Jap street car in NZ 8.71/162mph 2 bar, No NOS, street tyres. RB engine building, alloy and stainless fabrication, affordable skyline tuning and high capacity repowers, worldwide shipping arranged. e-mail rips@inspire.net.nz www.ripsltd.com

18th July 2008, 02:57 PM	#14 (permalink)
SamuraiSam GTR Register Member Join Date: Oct 2007 Posts: 390	Kismet, lower fuel pressure will not mean more fuel pump life if you are sending the fuel pump battery voltage as you should be (you should have eliminated the factory voltage regulated fuel pump controller circuit). If you use a fancy controller circuit hi-load bypass then maybe you could very slightly increase pump life with lower pressures. The other issue with low pressures is poorer atomization as there is less 'force' behind the fuel to force it through the nozzle in a mist pattern so you will get poorer and poorer atomization (necessitating a non-linear 'sharper' increase in fuel injector pulsewidth compared with the "expected" correlation of slight pulsewidth increase) as line pressure is lowered. Run 38 or 43psi whichever your car comes with. Last edited by SamuraiSam; 18th July 2008 at 03:00 PM.

11th July 2008, 09:27 PM	#3 (permalink)
banzai g GTR Register Member Join Date: Jan 2007 Location: bushmills northern ireland Posts: 418	Fair enough Rob !!!!! Saying your goin be the man that maps it !!!!!!!

11th July 2008, 09:59 PM	#4 (permalink)
GT-R Glenn GTR Register Member Join Date: Nov 2002 Location: Waiuku NZ Posts: 1,220	Teenierob is spot on The computer tells the injector how long to open ,so if its tuned right , it will only need to be open x% to get the right a/f ratio irrespective of injector size. Bigger injectors I think give a different pattern at high % openings. 800's would be fine for 600 650 even up to 800hp but theres no reason you couldn't run 1000's. It will make sweet f**kj all difference. Yoda ran 1000cc injectors with 380awkw's no issues at all.

12th July 2008, 12:24 AM	#5 (permalink)
Piggaz GTR Register Member Join Date: Sep 2002 Location: Sydney, Australia Posts: 756	Only problem i see is that u fuel pump wont be able to supply enough fuel for the 1000's at big duty cycles. However... if you aint using the large duty cycles you wont have a problem

12th July 2008, 02:22 AM	#6 (permalink)
GT-R Glenn GTR Register Member Join Date: Nov 2002 Location: Waiuku NZ Posts: 1,220	Thats true if he was going to max or anything near max the injectors but he alrready said 600's hp. So whats that, 60% duty ...Something like an 044 wouldnt even be breaking a sweat.

12th July 2008, 10:48 AM	#9 (permalink)
Madden New Users Join Date: Nov 2004 Location: Berkshire Posts: 2,078	I have just installed 1000cc's in mine and my idle is sky high. On idle i have AFR's of 11.4 and if i lean it out it starts to missfire? I have played with the lag times and get the idle lower but it starts missing. I put in Rc engineering injectors and i cant find lag times for them anywhere. Any idea's?

12th July 2008, 12:36 PM	#10 (permalink)
DarkChild GTR Register Member Join Date: Nov 2004 Location: Kuala Lumpur, Malaysia Posts: 327	Madden, Apparently the lag time on these RC injectors is 1.1 milliseconds. I just got a set of 1000cc ones too.

18th July 2008, 11:07 AM	#11 (permalink)
markM3 GTROC Member Join Date: Jan 2008 Posts: 199	I heard and would appreciate tuners comments that the smallest injector for the power was best as it gave better fuel vaporisation?? Is this true or total rubbish? On the F40, when Ferrari developed the catalysed one, they changed the spray pattern of the injectors and found the car produce more power (up from 478 to 515bhp (reported by R&T mag I think). Cheers,

18th July 2008, 11:24 AM	#12 (permalink)
kismetcapitan GTR Register Member Join Date: Nov 2005 Location: Seoul Korea Posts: 6,396	I'm wishing I had 1000. My 720s are pushed to the ragged edge - 90% duty cycle, 4 bars base fuel pressure to squeeze out more flow. In fact, I think I'll add that to the must-buy list. My fuel system surely can handle them - I've got twin Apexi pumps. I'd like to reduce fuel pressure to stock 3 bars base. I suspect that lower fuel pressure = more fuel pump life.

18th July 2008, 03:21 PM	#15 (permalink)
markM3 GTROC Member Join Date: Jan 2008 Posts: 199	Thanks for clarifying Samurai Sam

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