technical discussion of injectors

[RM]

if you put on tips on our bosch injectors how does that increase power? if you're cruising down the road and you're ecm is calling for say 10k from you're cp3 and its putting this out and theres 10k at you're injector how is any different shape on the tip of you're injector going to help. when the ecm calls for the tip to lift the duration and volumn will be the same or is the duration the same and the hogged out tip going to give you more volumn? where is the chamber for the next shot of fuel at in the injector? does the performance tips raise the full torque rpm? or lowers it. any one have dyno graphs to compare. is a 06 injector a 8 hole tip with what degree of angle for the piston bowl? is all a performance tip have done to it is a very clean holes in tip or is the chamber around tip enlarged. if its just cleaned up holes like a lot of the pictures ya see how long running a stock tip with all the small micron crud running thru it will it take before its a performance tip? im attaching a couple of pictures i hope they give enough detail the first is a cutaway of a 05 and the second is a picture of a bosch hpcr injector i think its internals are the same just configured different

 

[sag2]

The tips have larger holes so for any given pressure it is going to flow more volume. The ECM does not know the size of the tip, only that it is calculating a pressure and pulse width for a stock flowing injector.

The new 6. 7 has tuned injectors like the VM diesel and the Mercedes diesels. You have a flow number stamped on the injector and you have to tell the ECM the number or it won't start.

 

[RobertP]

exactly a higher flowing nozzel will need more volume to creat more pressure, which will give more power.

 

[RM]

exactly a higher flowing nozzel will need more volume to creat more pressure, which will give more power.

at a steady state of throttle wont a performance nozzle need more volumn to keep the same pressure which will get you smoke. the ecm wants its same pressure so it will increase volumn but you all ready had enough to give you that speed so wont that just make smoke?

 

[cclark746]

I was sure that aftermarket nozzles changed the angle and sprayed a finer mist to improve atomization. The fact that your running the same pressure and volume is obsolete because your using your the same amount of fuel but using it more efficiently.

 

[RMalone]

Don't forget the ECM can back off duration to compensate for more volume from pressure or larger holes. I also think the ecm is determining pressure and duration from throttle postition. So if you are just cruising at 70mph the ecm will back off pressure and/or duration to maintain the power required. Or perhaps your foot isn't as close to the floor when running aftermarket nozzels. I am not real sure.



Aftermarket nozzels do add MORE fuel as well as improving atomization and efficiency. You just aint gonna get another 100hp without adding more fuel. I don't think all of them increase efficiency either. I get lower milage from aftermarket sticks, that doesn't mean my right foot isn't the culprit though. While highway cruising, milage is about the same, but running around town I lost at least 1mpg.



Ps the pics of injectors sure don't look like the sticks in my 04. 5.

 

[MCummings]

Your foot is only telling the ECM what you want to do. More power.



Take a 400HP motor, that idles at 1,000RPM and redlines at 5,000RPM (for mathematics sake),



If you puch your foot down 25% percent, you are not telling the computer, I want 25% of available fueling, although that would be awesome for performance, that is not how it operates in this new age of diesels.



Instead you are asking the computer to give you 25% of RPM, then the ECM decides, based on RPM, Boost, Engine temp, Rail Pressure, and a few other criteria, how much to open the injectors to achieve 25% RPM. (Which would be 2,00RPM) Once you are 2,000RPM, the computer starts pulling back fuel to maintain that RPM setting. It's doesn't matter how big the injectors are. You could have one hole injectors, and the ECM might have to hold them open 50% of the time just to maintain the RPM, or you could have 45 hole injectors and hold them open . 001%. The result is the same. 25% pedal, equals 25% RPM.



The ECM makes adjustments based on certain inputs to achieve the desired result.



THis is why you can put an "EZ" on the truck, and it will "make more power".



One, the ECM sees alot more boost before there is actually any. The ECM being a "robot" doesn't need to reason with there being 15PSI of boost at 1,00RPM, it just reacts accordingly. Lots of fuel.



Two, the rail pressure plug fools the ECM. Say the ECM is asking for 10k PSI. Well, the EZ turns around and tells the computer... Nope. . Only 8,500 PSI here... so the ECM doesn't reason, it reacts, and starts pumping more fuel.



So, your ECM is going down the road thinking you have 8,500PSI and 15psi of boost, and it's trying to pump more fuel, but in reality, you have 10k+ rail pressure, and 0 Psi Boost. Tap the go pedal, and the ECM cranks teh injectors open to get the RPM you want thinking that it is not smoking, and that everything is okay.



Instead, you have turned true signals into lies, and the ECM is Happy, and so are you because you are getting what you wanted. More power.



Any box that plugs in, does this.



So do injectors. The ECM thinks to open injectors x amount of time, and that weould equal x amount of power, however, when they are open x amount of time, they are actually flowing more fuel, making more power, but the ECM is happy,, and so are you.



Merrick

 

[Rotty]

A little more technical engineering here,

Do the injectors run on 12v or something different?

How much current does it take to open an injector?

What is the max repetion rate?

How long does it take to open an injector?

How long does it take to close an injector?





Curious here.....

Kevin