Robert Q Posted January 30, 2002 Share Posted January 30, 2002 I am considering using Cossie Yellow fuel injectors on my 2.0 16 XE and have noted in DT catalog they are 311 cc/min which seems about right. What I don't know yet is the Resistance or the Bosch part number. Has anyone else tried these before or have any spec. or part number info. All comments greatly appreciated. Thanks Robert Link to comment Share on other sites More sharing options...
EFA Posted January 30, 2002 Share Posted January 30, 2002 Robert Are you using grouped or sequential injection, what horsepower do you intend to get and what fuel pressure do you intend to run??? The part number is on the injector body - last 9 digits identify the injector specs. Post that number here and I'll give you the details. Fat Arn The NOW PROVEN R500 Eaterid=red> See the Lotus Seven Club 4 Counties Area Website hereid=green> Link to comment Share on other sites More sharing options...
Robert Q Posted January 30, 2002 Author Share Posted January 30, 2002 Arnie, Thanks for the post. I don't have the part number for Cossie yellows that's one thing I'm trying to find out, so I can possitively ID the flow rate and resistance. Cheers Robert Link to comment Share on other sites More sharing options...
oilyhands Posted January 30, 2002 Share Posted January 30, 2002 I use them on my Atmo Cosworth, cant remember the number.. they run at 4 bar and are at 80% duty cycle running batched injection on a 250BHPish output. Oily Link to comment Share on other sites More sharing options...
Chelspeed Posted January 30, 2002 Share Posted January 30, 2002 Normal Vauxhall practice is cream injectors (standard Vauxhall) until about 250bhp then they run out of flow (and even then you need to run 60psi pressure or something like that). More power than that and you need to change to greens which are OK to silly power, 290bhp or so. Forget the part no's. Link to comment Share on other sites More sharing options...
oilyhands Posted January 30, 2002 Share Posted January 30, 2002 The yellows are the 3 OHM resistance type and needed an inline resistor to function correctly with the Emerald ECU. Oily Link to comment Share on other sites More sharing options...
Robert Q Posted January 31, 2002 Author Share Posted January 31, 2002 I would not expect the cream (744) injectors to work above 220-230 BHP based on a number of engines I have seen. The Yellow seem a good bet, however the low resistance is a bit off putting. Cheers Robert Link to comment Share on other sites More sharing options...
EFA Posted February 1, 2002 Share Posted February 1, 2002 Graham/Robert The Cream injectors are good for far more than 220 -230bhp - at 3 bar they are rated at 52.75 bhp on an 100% duty cycle. To illustrate this SBD run 60psi on creams in their 252bhp engine on an 85% duty cycle. Running a larger injector with a duty cycle shorter than 75% at max power gives poor disperstion and vaporisation of the fuel low down so running large injectors reduces the smoothness of idle and throttle response, particularly in grouped injector setups. So big injectors are a bad thing if you do not require them. In theory the creams can produce over 300bhp as the fuel pressure is increased - some drag racers allegedly run up to 8 bar on their fuel rails. For a street car, the other components restrict sustainable fuel pressure to about 5 bar (72.5psi) - Running cream injectors at 100% duty cycle at 5 bar would theoretically give 355bhp. Interestingly the Caterham in tank pumps I have tested in VXI (not JPE) and the engine K cars is only good for 50 - 55 psi sustained measured at the fuel rail. There are some other factors which influence the calculated power output such as brake specific fuel consumption BSFC which varies depending on the efficiency of the head and the type of induction system used. In reality the creams can deliver high 200's bhp outputs as they do in my engine, the advantage of running the high duty cycle (up to 93% in my engine) being better torque and low end drivability. Most injector actually max out at about 95%, so the most facinating thing is that a few cars (particularly performance Japanese cars for the North American market) on the market run an injector duty cycle greater than 100%. I have not yet figured out why..... Fat Arn The NOW PROVEN R500 Eaterid=red> See the Lotus Seven Club 4 Counties Area Website hereid=green> Link to comment Share on other sites More sharing options...
EFA Posted February 1, 2002 Share Posted February 1, 2002 Graham/Robert The Cream injectors are good for far more than 220 -230bhp - at 3 bar they are rated at 52.75 bhp on an 100% duty cycle. To illustrate this SBD run 60psi on creams in their 252bhp engine on an 85% duty cycle. Running a larger injector with a duty cycle shorter than 75% at max power gives poor disperstion and vaporisation of the fuel low down so running large injectors reduces the smoothness of idle and throttle response, particularly in grouped injector setups. So big injectors are a bad thing if you do not require them. In theory the creams can produce over 300bhp as the fuel pressure is increased - some drag racers allegedly run up to 8 bar on their fuel rails. For a street car, the other components restrict sustainable fuel pressure to about 5 bar (72.5psi) - Running cream injectors at 100% duty cycle at 5 bar would theoretically give 355bhp. Interestingly the Caterham in tank pumps I have tested in VXI (not JPE) and the engine K cars is only good for 50 - 55 psi sustained measured at the fuel rail. There are some other factors which influence the calculated power output such as brake specific fuel consumption BSFC which varies depending on the efficiency of the head and the type of induction system used. In reality the creams can deliver high 200's bhp outputs as they do in my engine, the advantage of running the high duty cycle (up to 93% in my engine) being better torque and low end drivability. Most injector actually max out at about 95%, so the most facinating thing is that a few cars (particularly performance Japanese cars for the North American market) on the market run an injector duty cycle greater than 100%. I have not yet figured out why..... Fat Arn The NOW PROVEN R500 Eaterid=red> See the Lotus Seven Club 4 Counties Area Website hereid=green> Link to comment Share on other sites More sharing options...
Peter Carmichael Posted February 1, 2002 Share Posted February 1, 2002 A duty cycle of more than 100%. That I would like to see. Some sort of quantum effect that invents more time, I presume. Wormholes and the like. The 95% thing is down to latency. The solenoid valve in the injector takes time to react, so when you get above 95% in a high-revving application the injector never has time to close. Link to comment Share on other sites More sharing options...
oilyhands Posted February 1, 2002 Share Posted February 1, 2002 I think the reason drag engines use such high fuel pressure is that the pressure is referenced against the inlet tract rather than the atmosphere, its not unusual with supercharged engines for them to be running 2-3 of boost.. this brings the net fuel pressure down to more like 5 bar.. The theoretical power available from an injector will vary widely with the RPM where peak BHP is made at higher rpms the injector latency is higher as a percentage of overall duty time available since it is firing more often. Oily Link to comment Share on other sites More sharing options...
EFA Posted February 1, 2002 Share Posted February 1, 2002 Peter, It exists on some Isuzu cars I know - they run 103%.... Fat Arn The NOW PROVEN R500 Eaterid=red> See the Lotus Seven Club 4 Counties Area Website hereid=green> Link to comment Share on other sites More sharing options...
Robert Q Posted February 1, 2002 Author Share Posted February 1, 2002 Arnie, Agree with your comments about not useing to big an injector than required, that's why I'm not attracted to the 803's. Looked at the SBD price list today for their 252 kit, it says they use 803's - maybe because it bumps up the sale value then ! I know you can flow more fuel through the creams at higher pressure, but I did not know anyone that had tried it yet. If they work reliably at higher pressure fine because I won't want to buy new ones then assuming the rest of the system can cope with more PSI. Don't Bosch recommend 3 bar, does this mean they may become intermittent or unreliable at higher pressure ? Robert Link to comment Share on other sites More sharing options...
oilyhands Posted February 1, 2002 Share Posted February 1, 2002 It's common practice to run higher pressure than manufacturers recommendations, looking at my injector list the recommended pressure vasry from 2.0 bar to 5.0, these are all standard OEM installations so I dont think upping the fuel pressure a bit is going to do any harm provided your pump and fuel rail can take it. The 1.8K SS has the FPR tweaked to deliver higher fuel pressure and iron out a weakening off at higher RPM. Oily Link to comment Share on other sites More sharing options...
Chelspeed Posted February 1, 2002 Share Posted February 1, 2002 When I ran the SBD 252bhp kit it used cream injectors but had to run a higher than normal fuel pressure of 60psi (virtually exactly 4 bar) to get enough fuel in. The duty cycle as Arnie said was about 85% at some sites. Steve said he thought 85% was a maximum duty cycle that he'd like to use, I didn't ask why I'm afraid. So he has now changed the 252bhp kit to use the green injectors and returned to a more normal fuel pressure of 50psi (3.something bar). Thats why I said previously that about 250bhp was a maximum for cream injectors. Link to comment Share on other sites More sharing options...
8vastra Posted February 1, 2002 Share Posted February 1, 2002 The Vaux creams also have a very restrictive needle type outlet. makes fuel delivery a bit useless beyond a certain pressure. try the late astra gsi Bosch blue injectors or the turbo ones, they have a pepperpot holed design which gives a better delivery and a bigger flow. Link to comment Share on other sites More sharing options...
8vastra Posted February 1, 2002 Share Posted February 1, 2002 oh, but they are only rated at 370-375 cc per min, so may not be enough for ya!! :D Link to comment Share on other sites More sharing options...
kjp Posted February 2, 2002 Share Posted February 2, 2002 Please draw me a picture to help understand how an injector can be on 103% of the time??? KenP Link to comment Share on other sites More sharing options...
Chelspeed Posted February 2, 2002 Share Posted February 2, 2002 It's clearly a relativistic effect. As the Vauxhall engine cars are so quick they must be affected by the theory of special relativity. Time dilation means that although they are only open 100% of the time, relative to the car, they are actually open 103% of the time, relative to an observer at rest. Obvious really. The same effects can be seen with the red shift, well actually the fluorescent yellow shift. Whatever colour a tuned Vauxhall engined car starts off painted it always ends up looking fluorescent yellow. Spooky or what? Link to comment Share on other sites More sharing options...
kjp Posted February 2, 2002 Share Posted February 2, 2002 ah,there I go again, allowing myslef to be constrained by the laws of Newtonian physics, how silly of me. Thanks for putting me straight!! KenP Link to comment Share on other sites More sharing options...
EFA Posted February 2, 2002 Share Posted February 2, 2002 Have you been drinking the methanol again Graham??? 103% is true but as I said I neither know how or why. Talk to Isuzu. I believ the Piazza Turbo is one of the affected cars if you can find one whihc has not disintegrated... and maybe tyhe M100 Elan (Isuzu engine....) Fat Arn The NOW PROVEN R500 Eaterid=red> See the Lotus Seven Club 4 Counties Area Website hereid=green> Link to comment Share on other sites More sharing options...
oilyhands Posted February 3, 2002 Share Posted February 3, 2002 There must be some confusion over terminology surely, you simply cannot have the injector open for 103% of the time. Perhaps the injector opportunity time used in the calculation is net of the latency... and the injector time is expressed as a percentage of this, meaning that the injector never fully closes.. Oily Link to comment Share on other sites More sharing options...
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