Hey guys. I see countless posts about boxes. Pressure, timing, and duration - it seems they all have their potential downsides. I don't see much talk about injectors here. What are their potential downsides, or why is it that when someone wants 60-80hp they go to a box?

 

no offerings for 600s injectors yet.

 

I'm talking about 3rd gens in general. I have a 305/555

 

Most injectors need a box too...or they have a surge. For less than 100 hp, boxes are more cost efficent. Over 100 hp, there are many ways including injectors + pressure boxes.

 

I'm just looking for something I can stay within safe egt's with, not damage my engine, get a gain my 48RE can handle and is noticeable to the seat of the pants meter... I have a scotty 3 and 4" exhaust, gauges are ordered a while ago but backordered from Genos . I've read Doug's box comparisons but can't seem to decide which method is the least evil on the truck..

 

The good thing about injectors is that it is as close to the stock fueling/power curve as you can get. But the downside is more $$$ and EGT's. I dont think that stock you could manage EGT's with just injectors, (unless you went with some very mild EDM's). I would think that a piers bomber lite turbo with a good set of injectors and a boost fooler of some sort would yeild the results you would want for about 1100-1200 dollars or so but also at the cost of some down time. This is why the majority of poeple go with a box, Its cheaper, easier, and really no down time.

 

Cheaper and easier doesn't always equate to best in my book. I'd rather something that was less damaging to my truck's engine. I'm just not sold on the safety of increasing rail pressure or extending the duration..

 

You might want to read about how injectors are honed out. I caught the info from Larado Diesel's web site. I
I too would like to do the best for longevity of the engine without destroying the reliablity of the truck. Spend more now so I won't be down later..

 

You are so right on the Cheaper/easier thing. DD is taking their TTPM with 100 hp injectors and turbo and making a very smooth 500 hp daily. I have made 450 hp with my current set up but I also cant (shouldnt) drive it like this on a day to day basis.

As for the duration/pressure/timing thing, people have been doing this for a long time without troubles for a long while now. The EZ on level 4 I think is 26500 psi. About 3000 psi from the break off safety limit. While the Banks 6 gun is 27,000 plus psi, And dont we usually afiliate Banks with undestructive safe mild horsepower?

 

Who is to say that even though it's under the factory pop off limit that it's not wearing out the injection equipment and adding undue stress to the system, hurting longevity? I don't want my cummins to last 100k, I want 300+K...and yes I'll keep it that long.. Anyway my impressions have always been that injectors are the closest to stock everything, aside from a bit more fuel...seems safest to me... It just appears the aftermarket injector scene hasn't come around as quickly as the boxes have..

 

What is damage is caused by opening an injector longer?

 

Isn't that where a lot of heat comes from? I guess mechanically you're not pushing anything harder, but I read that VA 3.2 sure makes things toasty.

I would like to see more on those EDM injectors. Who was talking about those recently?

 

I'm not exactly sure, but it seems that by opening the injector longer, the fuel is being injected later, when the piston is in a slightly different position than Cummins or the ECU intended. I'm not sure if that is a bad thing or not.

I'd like to see more injector options come out!

 

One other thing to remember about pressure boxes is they aren't running the pressure at max (26K+) all the time. The rail pressure varies depending on throttle position and RPM. Theoretically, if you added some sort of pressure/timing box and didn't get on it very often, then you probably wouldn't be adding much more stress than running stock WOT. The FSM shows the pressure to vary between 300 - 1600 bar.

300 bar = 4,351.1321402 pound-force/square inch (PSI)
1600 bar = 23,206.0380812 pound-force/square inch (PSI)

I am also interested in injectors in addition to my Quad box. Are there any true EDM's out yet for the 305/555? I have found plenty of extrude honed ones, but no EDM's.

-Muzzy

 

So far the only person offering EDM injectors is Don M, and he's saying that he's still several months out on releasing them for the 3rd gen trucks. He has a few sets that are being tested with very good results, however.


That is very true. Doug originally pointed this out in several threads that if you change injector duration without the benefit of added timing, you are, in effect, retarding the timing.