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Okay. Why do I see people posting that with 60 90 hp injectors they get better fuel economy then stock? I would think the higher hp rating the more fuel you would use. What are stock injectors hp rating?
2004.0 Dodge 2500 Cummins Stock, NV5600trans, South Bend single disk, Edge Insight CS, Smarty JR, MBRP 4" TBE, 104000+ miles
Ok I think I can answer this. The reason you see people talk about better mpg on bigger injectors is just like every other performance mod you hear about doing the same thing. It's about being efficient. If driven for better economy (keeping your foot out of it) then you can get better mpg because its running more efficiently. If driven hard I'd say you probably use more fuel than when driven hard on stock injectors because they simply don't put out as much fuel. That's the simple answer. Now as for stock injector HP. I can only assume that it would be zero when compared to performance injectors because they are giving you a HP rating over what stock already is. And be mindful that those ratings are not iron clad. They are estimates at best. Hope I answered your question
When changing injectors, or nozzles, you change the spray pattern. Particularly on the Common Rail motors, that can have a HUGE impact on efficiency. 3 nozzles holes vs 4 or 5 or 6 makes a big impact, too. It totally changed the flame front as the fuel burns. As the fuel is used more efficiently, then less is needed for the same power level. i.e. 150hp on a stock engine would use X liters of fuel per minute. On a more efficient 150hp level, that same motor with better injectors/nozzles, would use 5%-15% less fuel.
Just because the injector is now capable of letting more fuel in the cylinder, doesn't mean that injector is always letting that amount of fuel in.
Yes we are assuming that. They wouldn't be better than stock otherwise. And test have been done to show this so it's not really a assumption. All injectors are different so some are better than others but if been around vehicles especially diesels for and period of time you understand that that's just the way it is with parts. performance or not
So are we assuming that all 60/90ish HP injectors have more spray holes than stock? Or that they get a better spray angle?
Originally Posted by davis21
Yes we are assuming that. They wouldn't be better than stock otherwise.
You can't assume that, because it's not true. You call up pretty much any injector company and order 90hp nozzles or injectors for an 04.5-07, it's still going to have the 5 holes they came with factory. Same with your 03-04 or 07+ 6.7, still going to have the same 8 holes as factory there.
Really the only time you're going to change the number of holes is mixing things, namely the Motorsport nozzles which are a 7 hole design.
The same is going to hold true for the spray angle; 04.5-07 is 124*, 03/04 is 143*, and 07+ 6.7 is 146*. The Motorsport nozzles are 143*.
Do they change the angle a little? Possibly. It's not going to be from a 124* to a 143* for example, maybe a couple degrees or so.
There's a thread on here (Exergy vs Industrial) that has some decent info on the mixing of 143* nozzles in 04.5-07 trucks, but it kind of petered out.
I don't know anyone changing the number of holes on CR injectors. I'll go ahead and say no one does.
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