Hi all,
Need to get hold of the some injectors for the duratec. I have a set of the standard duratec bosch injectors but I gather these are not quite up to
the job.
So what do people suggest?
We're going to use the standard rail, it will be running on 45mm throttle bodies and initially will be using standard cams, though there is a
likelihood that they will be upgraded in the future.Therefore would like to future proof for this. For race regs we also need to run at standard fuel
pressure. I have an idea where I need to be in terms of flow rate but don't really know the best place to get them from, I understand some people
buy them from the states due to the favourable prices.
Any help appreciated
Cheers
Andy
[Edited on 7/3/11 by andylancaster3000]
Not as simple as it seems :-) IF you understand exactly what's involved.
Not saying to avoid it, just that this an entirely New can 'o worms... tread with adequate knowledge.
To increase fueling You have the choice of:
1) a higher fuel rail pressure
2) a wider injector control pulse
3) a larger injector
OR any combination of the above With caveats (as always :-)
#1 requires the ability to competently reprogram the ECU
#2 requires the ability to competently reprogram the ECU
#3 requires the ability to competently reprogram the ECU
Notice a trend?
1) A higher rail pressure means reconfiguring the Injector pulse, for appropriate fuel delivery. (The old setup is no longer appropriate as a major
variable has been forcibly altered ).
2) Altering the injector 'on' time' effectively increases fuel delivered... all else being untouched.. needs a reprogram to effect
this change though
3) A larger Injector ALSO requires a different 'signal pulse'.
Why? Because larger injectors are slower to open and close.. true. (this why Serius Hi perf engines have 2 small injectors rather than one big/clumsy
slooow one :-)So previous ECU fuel injector timings are wayyy off.
Betcha the Sales kid didn't mention that?
OR you could do like most.. just buy 'Big Uns' and then wonder why the result is less than expected :-)
[Edited on 7/3/11 by Bare]
Thanks for your response. I am aware of the points you make. However my requirement for larger flow rate injectors comes from having to maintain
standard rail pressure (3 bar), I want to maintain the standard fuel rail setup - I have some standard injectors but with the expected engine output
these will be right on (if not beyond) the allowable duty cycle and finally not being able to run secondary injectors. So the only real option is to
up the injector size.
Andy
Go for the cosworth green injectors from burton power, listed in the duratec section
http://www.burtonpower.com/parts-by-category/fuel-system/fuel-injectors/pr6647.html
You wont be able to import them cheaper that that (I know, I tried 
)
Other than that, they are standard length, bosch injectors with 14.5mm o-rings I would go for around the 300cc/min mark to future proof.
There is not much information in the Burtons listing. Flow rate standardised at 3 bar is less than minimum needed. What impedance are they? Omex ECU
doesn't like low impedance injectors in practice regardless of what omex might say about ballast resistors. Don't know about other
ECU's. Supplier also needs to be able to give details of injector opening rates against voltage for compensation table. Etc.
I would talk to whoever is going to supply or has supplied your ECU for advice on suitable injectors.
They are standard, high impedance (12-14ohm). The opening times etc are all close enough to the standard ones to make no difference to the mapping.
You'll find the same for most high impedance injectors. They will be Bosch injectors and either Cosworth or a quick Google will give you the
specs if you are really that bothered.
Standard duratec injectors are around 180cc/min and are maxed out at 240bhp. Those at 310cc/min are more than adequate for 300bhp NA. I ran 600cc/min
in mine and they were too much to get a really smooth idle. If I was doing it again I would have gone for ones around 400cc/min for 300bhp
supercharged.
Others to look at are Siemens Deka's.
David, when you say the standard injectors are rated to 240bhp I assume this is if the rail pressure is upped above the standard pressure? For the
forseable future we will be on the standard camshaft so I'm wondering whether we could get away with the standard ones.
Thanks for the link to the burton injectors. I've also seen some ford racing ones on ebay (USA) that I thnk would be suitable. I think they are
120-130UKP. Are these likely to come in more expensive than the burton ones by the time import duties etc have been paid for?
Cheers,
Andy
Here is a list source of Injectors you could fit.
But I'm surprised by your 300cc requirement .. that's a wee unit in my experiences.
However try a wrecker for a (gasp!) used Saab injectors almost free for the 'oem' sizes that nobody actually wants.
Injector information
Stock injectors on Saab 9000 1993
Brand: Lucas
Mfd. p/n: d5162EA
Imp: 15.9 Ohms
Flow: 286g C7H16 @ 3 bar / 60s (~408 cc/min)
Stock injectors on Saab 9000 1994-1998
345 cc/min @ 3 bar fuel pressure
Static Flow Rate: 31.6 lb/hr @ 43.5PSI = 239.4 g/min = 349 cc/min (+/-4%)
Dynamic Flow Rate 2.5ms pulse width @ 100Hz: 6.68 mg/pulse (+/-6%)
Coil Resistance: 16.2 Ohms (+/-0.35 Ohms)
Physical Dimensions: EV1 Body Type
Connector: Minitimer (Bosch EV6)
Possible upgrades can be:
Bosch -968 “Green Giants”
465 cc/min @ 3.8 bar fuel pressure.
413 cc/min @ 3.0 bar fuel pressure.
Siemens
Deka 630 cc/min @ 3.0 bar fuel pressure.
Static Flow Rate (GAS): 62.7 lb/hr = 646 cc/min = 474 g/min
Dynamic Flow Rate 2.5ms PW @ 100Hz (GAS): 20.2mg/pulse
Coil Resistance: 12 Ohms
Gain: 0.11ms/mg
Offset: 0.055ms
Turn on time @ 14VDC: 1.14ms
Turn off time: 0.85ms @ 600KPa
Factory Tolerance: +/-6 %
Spray Pattern: Cone (4-Hole)
Connector: Minitimer (Bosch EV1)
Siemens
Deka 4 875 cc/min @ 3.0 bar fuel pressure.
Static Flow Rate (GAS): 80 lb/hr = 875 cc/min
Dynamic Flow Rate 2.5ms PW @ 100Hz (GAS): 18.6 mg/pulse
Coil Resistance: 12 Ohms
Spray Pattern: Pencil
Connector: Minitimer
Bosch
EV14 920 cc/min @ 3.0 bar fuel pressure.
Static Flow Rate (GAS): 88 lb/hr = 920 cc/min
Coil Resistance:12 ohms
There are more :-) but certainly wayyy beyond the capacities of a Duratek
Seriously suggest a remap of your ECU injector pgm to 'suit' or you ..will... be running 'whatever' non oem injectors at well
below their potential. Regardless of claims to the contrary.
G'luck .
[Edited on 7/3/11 by Bare]
Yes with pressure upped they will work upto 240bhp ish. Standard pressure is good up to 200bhp or so.
I used the siemens ones bare has listed, they were too much for low revs but they worked ok. Only ran at 60% flat out with 300bhp at 12AFR.
People like to fit huge injectors, but theres no need. Just boasting factor. You will never see more than 300bhp from an NA duratec, so you dont need
anything bigger than 300cc/min
I imported a few sets from the states, by the time they got here they cost nearly as much as buying them here to be fair. You'll save about £25
on a set importing them.
Bare, I know you are new, but most people on here have enough knowledge of fuel injection and engine set up to know you need to remap after changing
any part of the system....
quote:
Originally posted by flak monkey
Yes with pressure upped they will work upto 240bhp ish. Standard pressure is good up to 200bhp or so.
I used the siemens ones bare has listed, they were too much for low revs but they worked ok. Only ran at 60% flat out with 300bhp at 12AFR.
People like to fit huge injectors, but theres no need. Just boasting factor. You will never see more than 300bhp from an NA duratec, so you dont need anything bigger than 300cc/min
I imported a few sets from the states, by the time they got here they cost nearly as much as buying them here to be fair. You'll save about £25 on a set importing them.
Bare, I know you are new, but most people on here have enough knowledge of fuel injection and engine set up to know you need to remap after changing any part of the system....
mine's not fully tuned yet but I'm reaching 100% duty cycle on std duratec injectors @ 3.5bar with AFR 11.0 
maybe I'll try running them at 4.0bar
it's a stock engine with 42mm gsxr throttle bodies
[Edited on 13/7/11 by radom]
quote:
Originally posted by radom
mine's not fully tuned yet but I'm reaching 100% duty cycle on std duratec injectors @ 3.5bar with AFR 11.0
maybe I'll try running them at 4.0bar
it's a stock engine with 42mm gsxr throttle bodies
[Edited on 13/7/11 by radom]
Just out of interest I did a 'theoretical calculation' for 180cc injectors:
Assuming 4 cylinder engine
80% duty cycle which I believe to be the normally recomended maximum
you will flow 34.56l/hr
UK petrol has an energy content of 9.7kwh/l so this is 335kwh worth of energy
For a non turbo engine you can work on about 40% max efficiency, so if your engine has low frictional losses, well set up etc you will end up with:
=134kw = 178 bhp
At a realisitc 35% efficiency for a properly set up engine probably can do more like 160bhp. Of course you could go for a higher duty cycle etc (at
100% duty and 40% efficiency =225bhp)......
Turbo engines can have up to 50% efficiency which would give 168kw/223bhp at 80% duty cycle.
Within reasonable limits the flow through an injector is proportional to the fuel pressure, so if the injectors flow 180cc/min at 3 bar, you'll
get 198cc at 3.3bar and 216cc at 3.6 bar. You may get leakage through the 'off' injector if you exceed the manufacturers rated pressure
though.
using 80% duty cycle, 4 cylinders, and you should have an efficiency between 35 and 40%:
efficiency 35% 40%
240cc injector 200bhp 239bhp
270cc 235 268
300cc 260 297
630cc 545bhp 625bhp!
from which we can work out that flaks 630cc injectors/300bhp engine would have been at about 300/625 of 80% duty cycle, at max power (approx 38%
duty), and at a very low duty cycle at idle!
Regards
Hugh
quote:
Originally posted by Nitrogeno25
At what rpm are you seeing 100% duty cycle?
Well 11:1 it's a little rich...
here are injectors we list
id say the "green giants" 2nd from top. inexpensive and pretty good too, give nice control at low rpms.
atspeed fuel injectors LINK
- colin.
quote:
Originally posted by atspeed racing
here are injectors we list
id say the "green giants" 2nd from top. inexpensive and pretty good too, give nice control at low rpms.
atspeed fuel injectors LINK
- colin.
Bosch green giants are very good, i would go for them!