BIG A CODE INJECTORS?

[FARMBOY22]

Originally Posted by 907dave

Agreed!

That is probably a question better suited for an injector builder, or someone with some time on a flow bench.

Sorry I am no help.

Hey I like a good debate as much as anyone. If nothing else it was still fun.

I'm still curious though.

[FARMBOY22]

The whole reason I brought it up is that I'm pretty well at the mechanical limit of of my stock engine. I want to lay out a plan to have a engine with an efficient tune at 350-375HP I can tow heavy with truck and trailer grossing 30,000lbs+ heavy, but still have a tune at 450-475HP that I can play with. For reliablity reason that's as far as I want to go as I don't want to fill the block or fire ring the heads and may be pushing it there? I'm looking to get a new HPOP anyways as mine will only hold about 1800PSI on a full throttle 60 to 90+ MPH run in OD on a 3% uphill grade with the Edge race tune and will set SES light in about 4sec.

[F-127]

Although somewhat sore on the subject(only cause I spent a pretty good length of time writing a post earlier today... only to be interrupted a few times... then being logged out automatically... attempting to post... then finding out I needed to resign in and have my work disappear), I'll try again.

I'll agree, the definitive break point on when an A code is better or a hybrid is better is certainly left to the injector builders, and even they might have difficulty coming up with the answer. I'll give my thought, if your going for the HP(or under) of what a 160cc/100% A code injector can provide, go for it. If your shooting for more HP than that, then hybrids are probably the way to go as you're probably building a 'performance' engine to have a high HP(and RPMs usually).

Situation asked, if your looking for a 200cc/100% injector and utilize the size of the injector often there are probably two situations:
Go with a 200cc/100% A code(if found), and a HPOP upgrade
Go with a 205-238/100% hybrid, HPOP upgrade not always needed

The hybrids may cost more, but if you use the total cost for injectors and the HPOP upgrade when using an A code, that route would probably be higher. If A codes are more efficient, how long before the increased efficiency of the A code would pay off?

I don't know for sure, but I ran 238cc/100% Rosewood hybrids in my 97 for quite a while and I averaged 15 MPGs with all my driving. I was fairly happy because some other side notes include: lifted, oversize tires, a non-streamlined bumper and even having some fun with it often. I even had a high of 17.9 mpg. I'm not sure how much better an A code could have done.

Now into some injector 'theory', some may already know parts of what I'll say, but I'll cover more for others. Some 'theory' is what I've read, as well as some of my own. With the combination of A code and B code parts we have the hybrid injector that flows more fuel volume per oil volume(but reduced pressure) when compared to the A code. See part details here.

The heart of the discussion: (which may have already ended)


Areas A,B,C referenced from image.
General accepted thought, lower HPs=A code, higher HPs=hybrid. Here's my attempt at explaination. At higher HP more RPMs are usually utilized. At some point the need for the intensifier piston movement is so fast, that the oil can't flow through area B and into area C fast enough. A pressure drop occurs over the intensifier piston when compared to the rail pressure(area A) and fuel injection pressure suffers. Raise the rail pressure to flow through B faster? Can't go much higher or the poppet valve will float. Another option? Hybrids, by flowing more fuel volume per oil volume, area C needs less expansion in a hybrid than the A code for equal fuel amounts. The fuel injection pressure drop is then somewhat less with the hybrid at higher RPMs. This giving the advantage to hybrids at higher HP. This is a thought on why hybrids, although "supposed" to inject at lower pressures than A codes, might actually inject at higher pressures in certain situations.

Is what I said above right? Not sure. Have I been 'inside' injector? Unfortunately not. Do I have more injector thoughts? Yeah, this is probably enough for one time though. Didn't really feel like entering debates on PSN, a little more friendly here. What's it mean when you answer your own questions again?

[cj45lc]

This really good, I don't know a doggone thing about these injectors but I feel like I'm starting to understand a little. I've got it in my head that I would like to go with a hybrid on my stock truck to keep from having to go bigger with the HPOP or turbo. Or would a single shot be the way to go, I pull 250-300 bales of hay a few times a year & usually have a 9-10k horse trailer hooked up otherwise. No more than I know about the deal I'll probably talk to some of the folks I trust (Bill-Cody- Marty) before I do anything. One thing for certain I know whose tunes will be in my truck.

[FARMBOY22]

If your more curious about the injectors check out the "selecting right injectors for a 7.3" thread in the FAQ section. It's what opened my eyes to begin with.