Engine/Transmission (1998.5 - 2002) Do I need injector upgrade?

[ctdodgeram]

So many posts about injectors or a box. What if you already have a box?



What will injectors do for me now?

 

[BFC]

Short answer, more horsepower How much is up to you but then you might need more goodies to keep EGT's down and enoug fuel to get to them.



Glenn

 

[jwilliams3]

Yes,

I would go ahead and get something in the 100hp area.

Your dually needs the extra low end to get it rolling!!



--Justin

 

[Bigsaint]

No doubt, if you want more power, go up a couple of steps in regards to the injectors. Keep it sane since you are pulling that big 5th wheel, maybe try stage/step 2 injectors. You will smoke with heavy throttle and low boost but that will clear right up once the boost is up. Just keep an eye on those egt's if you have the stock HY turbo.



IMHO, you are much better off making the bulk of your RWHP with the injectors, rather than pushing the envelope with a high end box and small injectors. With the larger injectors, you can have the same power you have no with the Blue Chip box set lower, easing the strain on the pump. When you want to play, you will now have more power.



Scott W.

 

[andrewkoperdak]

I went injectors first. I am not sure what the previous post meant by " a dually needs low end". Injectors are not low end. A box is low end at it changes the injection time, as you already know. Injectors follow what ever mod you have or if you are stock they follow the stock fueling curve. I am stock and have Stage 3 100 HP injectors. My power comes on when the turbo has spooled up and hangs on till about 2600 RPM. If I lay into it I can have a smoke trail that will kill all the insects in the surrounding counties. Since you have a box you would get an amazing amount of power if you also added injectors. Without a box I am at 285 hp and 617 lb ft of torque with 30 psi boost. You would have significantly more! I limit my boost to 30 psi even though it will make more. I don't want to prematurely wear my engine out.

Andy

 

[jwilliams3]

Andy,

"Your dually needs the extra low end to get it rolling!! "

Duallies are also alot heavier and I think 100hp injectors are only the beginning for a vehicle with such weight to make a significant difference in performance in my opinion.



What I mean by that statement is exactly what I stated, fueling curves from injectors follow stock with no box, I totally agree so when you get the bigger injectors hence your low end has just increased.



When I installed just 275's I noticed a greater low end when driving around town.



--Justin

 

[RSnaith]

Originally posted by jwilliams3

What I mean by that statement is exactly what I stated, fueling curves from injectors follow stock with no box, I totally agree so when you get the bigger injectors hence your low end has just increased.



When I installed just 275's I noticed a greater low end when driving around town.

I'm going to second your opinion, Justin. Most timing/fueling boxes don't do much (if anything) below 1400 RPM. More aggressive injectors will tend to boost bottom end, as they follow the stock torque curve, but at higher torque levels.



I am going to disagree with the 100HP injector recommendation, though. I've found off-idle bottom end to be as strong with 80 HP injectors, and even RV275s give a dually good help down low (I ran 275s for many miles on my 01 3500).



Rod

 

[andrewkoperdak]

Justin & Rod,



Sometime ago I was in a thread and everyone in it told me that a box changed low end performance. They also mentioned that boxes "shock" your driveline in the lower RPM ranges. becuase the bring the torque and hp up so suddenly with timing changes. My timing is un-altered. I went with injectors so that my power comes up gradually and strong.

Yes my 1100 RPM torque is higher but if you had one of the boxes that makes approx 100hp I think you would have higher numbers sooner. I do have more umph at the low end but it doesn't come on strong till my turbo is spooled. 1400 is still a week RPM for me. 1700 I can move mountains.

I am not trying to make an arguement. Simply trying to understand how we shifted logic over the months and why.

Andy

 

[RSnaith]

Hey Andy,



I wish I'd been around a while ago to chime in on that thread. Keep in mind, what I'm about to spew out here is simply opinion and info gathered from my own observations over the years.



Most timing and fueling boxes will provide a "shock" at the RPM where they begin taking effect. The reason for this sudden kick in the pants feeling is that the box is providing enough fuel/timing advance to build RPMs quickly. As well, the torque curve will now tend to rise steeply to 1750 - 1850 RPM, and then begin to level off. However, this shock usually doesn't start until 1400-1500 RPM, which is where the box truly begins to take effect. If you were able to get dyno numbers down at the 1100 - 1200 RPM area, I suspect you'll see numbers very close to stock levels, as the box has just barely started operation, if it has at all.



Injectors, on the other hand, will tend to be a smooth curve that follows the stock curve (assuming you don't have a fueling box attached). This smooth curve will tend to cover the fact that you are indeed making more torque at 1200 RPM than you would with a fueling box or stock.



Personally, for the best drivability, I feel a mild set of injectors (RV275s, Stage 2's) coupled with a fueling box is ideal. The injectors provide some bottom end fill, reducing the "shock" when the fueling box really starts to pour it on. Your result will be a torque curve that is steep to 17 or 1800 RPM, then gradually climb to 2400 RPM or so, before letting down.

 

[Opz01]

Originally posted by ctdodgeram

So many posts about injectors or a box. What if you already have a box?



What will injectors do for me now?

This is a good question, I have two answers that come to mind.

1. Initally I used a box similair to yours. (50% is a high setting. ) And several fellow Cummins owners had the same opinion... That running a box with stock injectors is harder on your injector pump than running that box with aftermarket injectors.

2. Power!(My favorite injectors for towing and throttle response thus far is DD2's. ) The box and injectors do complement each other at making horsepower.



Opie