6.0.4 revisited

[MorganY]

so an HEUI sytem, on an 05+ 6.0 at 100%, injects fuel at 28,000psi? then why is injection pressure always brought up when talking about HEUI systems. doesn't sound right to me.

Garrett

(not trying to sh*t stir, or get anyone angry)

The injection pressure is always brought up because without a 3800+psi on ICP, the injection pressure at the TIP of the injector will drastically fall and you will lose horse power, even though you may have increased the capacity and nozzle size on your injector. Even with a 1000 psi drop in ICP you will see a 5-7k pressure difference of the fuel thats being injected at the tip, enough to lose horsepower from the lack of atomization. In more rare cases like myself, When ICP pressure is sustained 1800-2000psi lower than needed 3800 psi (even though its a only few thousand) that loss in pressure is drastically multiplied by a factor of 7 from the intensifier piston and plunger inside the injector ( "Even with 4Kpsi of oil in the rails and a 7:1 injection ratio the injector is probably only is injecting fuel in the low 20Kpsi area on a good day -HotRodTractor"). Think of the 6.0 injectors as a syringe. High pressure oil driving the plunger, and drastically multiplying the force being injected out of the syringe tip.

I currently maintain 2000-2200psi at the ICP sensor via voltage at WOT on a healthy, stock 05+ pump at max PW.. That puts the injection pressure at the tip LOWER THAN 14,000-15,4000psi, HALF of what the fuel should be injected at the tip. If I were to dyno the truck, with my injectors (210/100's), I would be surprised if it had 350hp in it at WOT, just from the fuel not being burned properly from lack of atomization. And let me tell you, it smokes like a freight train at WOT. Thick, thick unburnt, un atomized fuel coming out of the exhaust.

If ICP wasn't a big deal, there would be many guys running large conventional injectors on a stock oil system. Hence the reason the max conventional injector size on a stock oil system is 205cc's at max PW (Typically, RCD/MPD is said to have been able to push the limit on this)

The 6.4's common rail system would be the same concept, yet simpler, because the pressure at the rail, is pretty close to the pressure being injected at the tip due to the HPFP. If one were to add 100 over nozzles to their 6.4, without extra high pressure volume, the rail pressure (also injected at the tip) would be under 20,000psi (similar to 3000psi of ICP on a 6.0), and the truck would lose more power than it would gaining from the larger nozzles (assuming pulse width did not change).

 

[MorganY]

What I really want to know is, what are we referring to when we say a "190cc" injector... It can't be 190CC per injection, my guess is 190CC per minute, but then I wonder at what RPM...

This is above me......

The CC rating is the capacity the fuel injector can inject.

 

[Pizza pig]

Spot on Morgan!

 

[Hotrodtractor]

1) 190cc means that its total capacity is 190cc per 1000 shots if fully stroked out (Common rail injectors don't have a "capacity" they are just fed high pressure fuel from the rail as long as the injector is open).

2) Even with 4Kpsi of oil in the rails and a 7:1 injection ratio the injector is probably only is injecting fuel in the low 20Kpsi area on a good day - the dynamic pressure drop of the oil flowing just does not allow it to equate out so perfectly.

 

[MorganY]

1) 190cc means that its total capacity is 190cc per 1000 shots if fully stroked out (Common rail injectors don't have a "capacity" they are just fed high pressure fuel from the rail as long as the injector is open).

2) Even with 4Kpsi of oil in the rails and a 7:1 injection ratio the injector is probably only is injecting fuel in the low 20Kpsi area on a good day - the dynamic pressure drop of the oil flowing just does not allow it to equate out so perfectly.

Learn something new everyday, thanks! Can you post a link to your thread explaining the 6.0 injectors more in depth?

 

[TheReelMuhcoy]

All this talk about fueling.... The one thing that has crossed my mind multiple times that I am VERY excited for is the exhaust! Call me what you will but, I cant wait to see what these turbo's are going to sound like coming through a unrestricted stack. She will be a one of a kind, that's for sure.

 

[powerstrokin15]

with the way 6.4s sound I'd say it won't sound so great.... because if you change the turbos on a 6.4 it sounds soo much better. IMO it'll give off that vacuum sound.


Eric@HolderdownPerformance

 

[Hotrodtractor]

Learn something new everyday, thanks! Can you post a link to your thread explaining the 6.0 injectors more in depth?

I never really did a thread for the 6.0 sticks. There is one for 7.3 sticks - and the function is fundamentally the same. I'll dig out a link.

 

[Mdub707]

(not trying to sh*t stir, or get anyone angry)

The injection pressure is always brought up because without a 3800+psi on ICP, the injection pressure at the TIP of the injector will drastically fall and you will lose horse power, even though you may have increased the capacity and nozzle size on your injector. Even with a 1000 psi drop in ICP you will see a 5-7k pressure difference of the fuel thats being injected at the tip, enough to lose horsepower from the lack of atomization. In more rare cases like myself, When ICP pressure is sustained 1800-2000psi lower than needed 3800 psi (even though its a only few thousand) that loss in pressure is drastically multiplied by a factor of 7 from the intensifier piston and plunger inside the injector ( "Even with 4Kpsi of oil in the rails and a 7:1 injection ratio the injector is probably only is injecting fuel in the low 20Kpsi area on a good day -HotRodTractor"). Think of the 6.0 injectors as a syringe. High pressure oil driving the plunger, and drastically multiplying the force being injected out of the syringe tip.

I currently maintain 2000-2200psi at the ICP sensor via voltage at WOT on a healthy, stock 05+ pump at max PW.. That puts the injection pressure at the tip LOWER THAN 14,000-15,4000psi, HALF of what the fuel should be injected at the tip. If I were to dyno the truck, with my injectors (210/100's), I would be surprised if it had 350hp in it at WOT, just from the fuel not being burned properly from lack of atomization. And let me tell you, it smokes like a freight train at WOT. Thick, thick unburnt, un atomized fuel coming out of the exhaust.

If ICP wasn't a big deal, there would be many guys running large conventional injectors on a stock oil system. Hence the reason the max conventional injector size on a stock oil system is 205cc's at max PW (Typically, RCD/MPD is said to have been able to push the limit on this)

The 6.4's common rail system would be the same concept, yet simpler, because the pressure at the rail, is pretty close to the pressure being injected at the tip due to the HPFP. If one were to add 100 over nozzles to their 6.4, without extra high pressure volume, the rail pressure (also injected at the tip) would be under 20,000psi (similar to 3000psi of ICP on a 6.0), and the truck would lose more power than it would gaining from the larger nozzles (assuming pulse width did not change).

Maybe we need to have a mod move some of these posts to a new thread now... and sorry for the derail in advance guys...

So how does this affect the burn from a hybrid injector that runs an intensifier piston that is closer to 5:1 or in that area? Sure you can get all the fuel in, but in theory it will never burn as clean as a 7:1 stock style piston right? At least in theory... So instead of 28k psi (theoretical) we're at 20k psi theoretical. So if real numbers for 7:1 is low to mid 20's, we'll say 23k psi, the 5:1 hybrid may really only be 16.4k ish psi? (28k theoretical to a 23k real is a 82% value, so I used the same to go from 20k to 16.4k) Thoughts?

 

[Hotrodtractor]

Maybe we need to have a mod move some of these posts to a new thread now... and sorry for the derail in advance guys...

So how does this affect the burn from a hybrid injector that runs an intensifier piston that is closer to 5:1 or in that area? Sure you can get all the fuel in, but in theory it will never burn as clean as a 7:1 stock style piston right? At least in theory... So instead of 28k psi (theoretical) we're at 20k psi theoretical. So if real numbers for 7:1 is low to mid 20's, we'll say 23k psi, the 5:1 hybrid may really only be 16.4k ish psi? (28k theoretical to a 23k real is a 82% value, so I used the same to go from 20k to 16.4k) Thoughts?

There is a ton of this stuff in the 7.3 section that I typed up to describe this - but in a nutshell your are not really correct in your line of thinking. Pressure loss in a dynamic flow situation is a function of flow rate - since the injection ratio is less it takes oil flow to move the same amount of fuel. There are scenarios - specifically at WOT where the hybrid would have an actual higher injection pressure at the tip than the standard injector set up identically with all things equal other than the injection ratio.

I need to go look up that thread and post a link....

 

[TooMuch03]

Maybe we need to have a mod move some of these posts to a new thread now... and sorry for the derail in advance guys...

So how does this affect the burn from a hybrid injector that runs an intensifier piston that is closer to 5:1 or in that area? Sure you can get all the fuel in, but in theory it will never burn as clean as a 7:1 stock style piston right? At least in theory... So instead of 28k psi (theoretical) we're at 20k psi theoretical. So if real numbers for 7:1 is low to mid 20's, we'll say 23k psi, the 5:1 hybrid may really only be 16.4k ish psi? (28k theoretical to a 23k real is a 82% value, so I used the same to go from 20k to 16.4k) Thoughts?

That is why conventionals will typically make more power than equivalently sized hybrids, all else equal. I believe for the 6.0, conventionals are 7.1:1 and 1mm over hybrids are 6.2:1, If I am remembering correctly.

 

[TooMuch03]

There is a ton of this stuff in the 7.3 section that I typed up to describe this - but in a nutshell your are not really correct in your line of thinking. Pressure loss in a dynamic flow situation is a function of flow rate - since the injection ratio is less it takes oil flow to move the same amount of fuel. There are scenarios - specifically at WOT where the hybrid would have an actual higher injection pressure at the tip than the standard injector set up identically with all things equal other than the injection ratio.

I need to go look up that thread and post a link....

Please tell us more about this. I am very interested.

 

[TheReelMuhcoy]

This is a very interesting topic... Separates the boys (me) from men, in this world. If I have any say, leave this rant here in this thread for anyone reading up on how we came to the final conclusion of what injector to mate with these turbo's... And a little injector 101 class.

 

[Mdub707]

Jon, my vote goes for 190's of some sort too. 190/75's or 190/100's. I think that would be a good starting point to see how these turbos work. 190 is a popular size in the 6.0 crowd and still using a conventional injector.

 

[farmall99]

While the injector talk is informative, I think the flow of the turbos should be looked at instead of trying to compare HEUI to commonrail. What you need to find out is what CFM the stock 6.4 chargers put out and find a similar turbo(s) that flow similar, and size your injectors from there.

 

[Jwarren]

From what I have seen in the 6.0l is when ICP drops power loss is caused my no more than a lack of fuel. With the 7.3L the ECU has a injection PW multiplier based on ICP pressure the 6.0L does NOT!!! The 7.3L will add PW to make up for lower than desired ICP pressure. When a 6.0l looses ICP pressure PW remains the same and injector flow rate drops drastically.

 

[MorganY]

http://youtu.be/mr0GwKIHIcg

Go to 4:30, WOT run at 2000psi.

 

[Pizza pig]

What pw tune is that morgan?

 

[Jwarren]

http://youtu.be/mr0GwKIHIcg

Go to 4:30, WOT run at 2000psi.

You sure thats only 2000PSI ? Not saying its not, sure is getting fuel. When I was running 275/150's smoke seemed to clear up at low ICP.

 

[MorganY]

What pw tune is that morgan?

I don't remember the number exactly, Matt said it was maxed out.

Ya Jesse it looks like its getting fuel..but the truck falls on its face after about a half throttle, its only when you hit that third stage of the pedal. It won't even spin the tires like it used to with stock sticks or 190/75's. No seat of the pants feel anymore. 2.2 volts at the sensor sustained at WOT.