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155/50s or 175/stock with WW II

11K views 10 replies 5 participants last post by  MurderedStroker 
#1 ·
Hey guys, I've been doing a bunch of reading lately on trying to narrow down which injectors I should get. I'll be running the stock turbo on my 04 with a Wicked Wheel II.

I have found a lot of info the 175/stock injectors but not much on the 155/50s.
I'll most likely end up getting them from Warren. I don't tow at all and will eventually be pairing this with the atlas 80 tune. (I'll also be doing studs, ect. when I buy these injectors also.)

Just don't want to be disappointed with 175/stock on the upper rpms, and also not sure what would pair best with the WW II.

Looking to have a fun/strong DD.

Any input or info would be greatly appreciated!
Thanks! :icon_ford:
 
#2 ·
I heard it's not even worth doing the 155/50. The stock nozzle is big enough for 155. When I have to do injectors I was going for a 175/50 or 75.

I am by no means an expert this is just want I have gathered and understood from looking around on this website. If your only 155 just use the stock nozzle and save money.
 
#3 ·
I was under the impression that a 155/stock was fairly pointless? :dunno:

Though a 175/50 or 75 would be nice (power, ect) I do believe it would be too much fuel for my application. That's why I have narrowed down to the 175/stock or less. Unless someone thinks I would be able to run a 175/30, but I believe that would still be fuel heavy.
 
#4 ·
There is a lot that goes into injectors sizing... a lot will depend on whos tunes you are running and what your PW is in your tune. If your tuner runs a limited pulse width (like 2.2-2.3ms) then you will not see very many gains with 175/stock or 155/stock. But if the run a higher pulse width (like 2.5-2.7ms) then a 175/stock will make more power and run cleaner than a 155/30...


Here is a little more injector info that might help and point you in the right direction.

Think of an injector as a giant needle syringe from the doctor.

The first number (155cc, 175cc, 190cc etc...) that is how much fuel the injector can hold. Kind of like how many cc's fluid you can hold in the syringe from the doctor. (in 1000 full complete shots)

The second number (stock, 30, 75, 100, etc...) that is how big the nozzle size is over stock. Basically it is how much faster the fuel can be dumped over stock. Think of this as the needle gauge (size of hole in the needle). The bigger the gauge the more fluid you can dump in the same amount of time.

HPO, ICP, ETC... this is how much oil pressure you have behind the injector. This could be symbolized by how hard you press the syringe with your finger... or hard hard you bang it with a giant hammer The harder you hit it then the better your injection pressure and faster you dump fuel.


PW, Pulse width, 2.4ms, etc... this is how long the injector pulses for, or how long it has to dump fuel. This is kind of like how long your finger can push on the back of the syringe. The longer you push the more fuel comes out.





So why not just upgrade the size of the injector body (155, 175, 190) without upgrading the nozzle size... Well there is only so much time to dump all the fuel. If you keep the smaller nozzle size and put more fuel inside the body of the injector then you need more time to dump the fuel.

Why can't you just open up/lengthen the pulse width long enough to dump all the fuel... well there is only so much time to play with. You don't want to advance the timing too much because that can cause increased cylinder pressures and increases the chance of blowing your motor.

So why not just put the largest nozzle possible? Is there a problem with dumping too much fuel? Well the pulse width can only be adjusted so much. You can't just turn off the fuel. With too big of nozzles you will be dumping way too much fuel when cruising and towing. This will cause much higher egts under normal driving conditions and possibly slight hazing under light acceleration.




So at a low rpm, with enough ICP, the pulse width opened up all the way then a 175/stock will dump just as much fuel as a 175/100... but you really have to open up the pulse width to dump 175cc with stock nozzles.


With all that said. You could essentially get a 175cc injector with a 30% nozzles. At full pulse width you will be able to dump all of the 175cc of fuel. But if you back off the pulse width through tuning you can dump slightly less fuel. Like 155cc or 135cc(stock)


On the other hand if you put a 150% nozzle on a 175cc injector (175/150) then at full pulse width you will still only dump 175cc of fuel. You cannot just turn down the pusle width because we don't have access to the tables. You have to adjust other parameters to try and manipulate the pulse width. Basically you will not get 175/150 to turn down enough to run very well. They will be hot and smokey and less efficient. you cannot get a 175/150 to run like a stock injector and still have power and driveablity up top. With larger nozzles you will be dumping fuel more like pouring a bucket on a fire. This results in a slower less controlled, less efficient burn. What you want is to atomize the fuel. (most pressure possible through the smallest nozzle) That would be like using a mister to equally spread out the fuel over the fire. The burn would be quicker, more controlled, and equally spread out. Thus resulting in more power. This is why many people with 300/150 injectors have a hard time with egts and hazing when driving around. There is just no way to turn down the fuel enough to run right and still have descent power up top.



So 155/50 would run smokey, have high egts cruising, and make less power than 175/stock assuming that you use a tune that runs a higher pw.


Does that help or confuse more?



PS... I am a Warren Diesel dealer. Let me know if you need any help or need any pricing
 
#7 ·
Great explanation of it of it all.

Now here is a question I have had in my head... How does the size of the injector and nozzle work with the altitude someone operates in? I wonder this because it is very common here in CO for people to re-jet their gas motors, small engine equipment as well, to smaller jets to work with the thinner air here. With that being said, if someone gets a larger turbo up here, would they not need as bigger of an injector/nozzle as someone closer to sea level?
 
#5 ·
^^ Thanks for that. It explains a lot.
 
#6 ·
Well that cleared it up for the most part, I think I'll re-read that a few times to make sure I understand haha.

But, assuming you tell the tuner what injectors you are running, per say 175/stock, they will obviously do there best in tuning them for the best performance for that specific injector, in this case as you stated, a larger pw?

I suppose I like the idea of 175/stock as you can add nozzles later, tho I do not intend too. I just want an injector that will run fairly well with the stock charger & WW II, and not be a smokey mess.

I will probably end up sending you a PM with some more questions.
Thank you both for your responses.
 
#8 ·
tuners will do their best to accommodate your mods. Some tuners work better with some mods and some tuners work better with others. I can tell you that my most favorite tune right now is my SPD from TSD and I run it for my DD... but I would not run their tunes on 175/stock. That is because the way that Chris writes his tunes tends to favor larger nozzles. Chris actually told me that he sees ZERO difference between stock injectors and 175/stock on the dyno with his tunes. That is because of the way he writes his tunes. When I had 175/stock injectors and ran my SPD tune... the truck felt like it had stock injectors in it. But if I ran gearhead, erics, or jesse's tunes then the truck ran like 175cc injectors. That is why I recommend different tune writers depending on which mods someone runs.


just fyi... 175/stock will be too much even for a stock turbo with the WW2... heck... even stock injectors on a race tune can be too much for the stock turbo with a WW2. You can always turn down your tuning to accommodate... or you can run a stage 1 turbo or stage 1.5 DIY. Here is a link talking about our new DIY stage 1.5 kits. Send me a PM if you want more info

http://www.powerstroke.org/forum/6-...906-wpe-kc-diy-turbo-kits-testers-needed.html
 
#11 ·
I was very intrigued by the 1.5/2.5 DIY kits, definitely something I would be interested in doing for my truck. I feel like the more I read these forums the more my bank account is crying... :hehe:
 
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