Been following this conversation - Thanks! Reliability (with a little more power) is where I want to go with my 2003 SD. Great info all the way guys!

 

Great info as usual from Tugly & Pocket....but to the original poster

What do you plan to use the truck for? Dedicated tow vehicle? Daily driver? 1/2 & 1/2?

 

Like Rich said.....this has been a very reliable towing & daily driver setup for me the past 8 years / 90K miles. 175 cc single shots with stock nozzles, similar to the 160's with stock nozzles.

Swamps 175 Single shots, Stock HPOP , van turbo & regulated return, in tank & prepump mods.

 

The truck is for general purposes, mainly work and enjoyment...i have a construction trailer that can gross 10k, and i'd like to be able to pull that and dump trailers around no prob with decent mpgs. i would like some extra power for messing around. my buddy has a 99 cummins with some minor mods that he thinks has a million horse power and i'd like to put him in his place someday, haha. i do plan on doing road trips in the future, possibly pulling something.

 

I love my 175/stock injectors but i think after i get my 38r on i might go with bigger nozzles just not sure what to go with to have good towing manners

 

For towing, larger nozzles have a huge advantage........... IF and I mean IF they are tuned properly.

The bigger nozzles allow for more fuel-per-time. So you can immediately see where this goes if you increase pulse width too much. You end up with a lot of fuel, a lot of power, and a lot of smoke.

But the advantage also comes in that fuel-per-time. Now you have the availability of more useable power at higher RPM's, where you spend the majority of your time really working the engine when towing anyway. At low RPM cruising, it doesn't matter, since it takes very little real horsepower to pull a trailer behind you on flat ground and no acceleration. But when tackling a mountain pass with a load behind you, the truck is going to drop down a gear. This is where bigger nozzles really shine.

Smaller nozzles require more time to inject a certain amount of fuel. As I've mentioned earlier, your injection window shrinks as RPM's climb. If you drag out your pulsed width to the max amount of time of that injection window (or often more), now suddenly you have a very very very hard time keeping EGT's under the danger zone. This is where "tow tunes" come into play, because really you're just shrinking pulse width down to the point where you aren't exceeding that injection window. But by doing so, you're cutting power.

Larger nozzles allow much more fuel to be injected in a much shorter time. So now instead of cutting back the pulse width because you've exceeded the injection window, you're still way inside of that window with room to spare. At the same time, you're injecting more fuel in that shorter time frame, so you have more power on tap to accelerate up that mountain, or just maintain speed. All the while the EGT's are much lower than compared to smaller nozzles.

The trick is to limit the pulse width to allow the injector to work as designed, rather than plugging away at trying to get as much pulse width as possible. That's all controlled with the tuning.

When I'm pulling up a mountain I'm sitting at a little under 2ms of pulse width. Stock nozzles would need about 4ms or more to try and keep up, but I'll just keep pulling away while their EGT's go through the roof and their motor goes into thermonuclear meltdown. I struggle to go past 1100 degrees with TT and quads in the back all the way up to 11,000 ft.

 

bigger nozzles it is

 

238/100s will do what you want with correct tunes and a few extras.

 

So i'm thinking 238/200s...

 

200 nozzles are hard to keep tuned and can be picky. I would have it live tuned for sure.

 

Are they that much harder to tune than the 100% nozzle?
After reading some posts from Golfer who works for swamps, had me leaning to either 30% or 200% nozzles
http://www.powerstrokenation.com/for...=165985&page=2

 

Anybody who's ridden along on a live-tune knows it's not a simple matter.

Be wary of taking a couple of numbers lightly. 100% can be tuned remotely to be "tolerable", but it generally requires live tuning to get the truck to behave like a stocker at idle and with cruise control. Even with that, you're not going to have legal emissions (the truck will stink and haze when cold, and it will not be as clean as the stock injectors at any time). 200% nozzles can be live-tuned to be tolerable, but kiss stockish manners on the cheek before it turns for the door. Even after live tuning, the truck will be on the edge - and if so much as one injector goes out of balance (which fire hoses can do), you're chasing it down the rabbit hole.

I turn to Pocket to confirm/deny that one - he tunes his own 250/200s.

This is not the time to think "Well if more is better, then I want more more". Yes, bigger nozzles are cooler (in more ways than one), but just going stage 1s is cooler than stock, with much more power. My stage IIs are on the verge of needing serious upgrades to the truck to allow full fueling. I have about $6K - $7K under the hood and in gauges to monitor the added power, plus $4K in the transmission. 250/200s will need more more mods (read - money). Joey needed $15K worth of mods (on his engine alone) to accommodate his big sticks, and he still blew a head gasket - no small feat on a 7.3L.

I'm not trying to talk anyone into or out of anything, I'm saying Stage 1s and Stage IIs make plenty of power, but one of those takes a lot of money to support. Going beyond that means you seriously preload the Buck$Zooka - or prepare to park the Powerstroke between patch jobs.

 

Here's a quick overview on nozzle behavior and what to expect:

30% - not much of a difference from stock. Might give you a bit of a torque increase down low, especially when using tuning designed for stock nozzles. If the tuning is aggressive, you'll see a bit more smoke at times.

80% - nice improvement over stock, super easy to tune, good idle, very nice manners, runs strong and gives you a good power band. A solid performer and top choice for most people. Highly recommended for mild builds. Tuning can be nailed remotely in just about any instance.

100% - can be hit or miss, depending on the extrude hone process used. When done correctly, they are a little harder to tune than 80%, and give you a bit broader power band. When not done correctly, they are nearly impossible to clean up the idle and can be your worst nightmare. Caution is to be used here, live tuning highly recommended.

200% - what is considered to be on the verge of daily driver capable. Can be difficult to dial in the tuning, especially idle quality. Provide an extremely wide power band all the way up well past redline. Live tuning is pretty much required at this point, and must be done in the hands of someone very capable.

300% and above - almost entirely used by race/sled pull trucks. Persistent tuning required, almost always a haze at idle. Perfect for those trying to break well over the 600hp mark, but disastrous for just about any average Joe trying to turn into a daily driver without lots of professional assistance.


To the OP: for what you describe as your goals and the size injector you want to use, I would personally recommend 80% nozzles. I haven't seen you mention really getting to know any specific tuners, and I don't know how close in proximity you are to any of them. So based on that alone I would stick to the 80%. In the end it will make your life easier and give you less grief and headache.

200% nozzles are really nice, and seem like a low-hanging fruit that everyone should just grab and go with, but the tuning aspect is tricky. I'm just an amateur tuner. I understand the theories and all very very very well, but the application to specific tuning programs and software is not at the professional level. I do enough to get by with my own truck, and have tuned only a handful of other trucks just to learn for myself. Most have turned out good, some not so good. Like I said, I'm not a pro.

I do have one friend running 80% nozzles. His was actually the very first Super Duty I tuned that had single shots. It took several tuning sessions for me to get the learning curve down, and then a few more sessions to dial it in. But once I got it down, I haven't touched the tunes since. He's been using those same tunes for about 3 years now, and can tow up a mountain pass in his race tune without so much as looking at his EGT gauge. The idle quality is almost bone stock, and the truck starts right up even on the coldest mountain winter days. He loves the way it runs, and I think you'll also be just as happy with 80%.

That's my 2 cents.

 

Good summary guys. I've read this before and just though I'd put it out there for the OP. Good luck in what you do and please report back on what you decide and how you like it. It's always nice to talk about injectors and there tuning manners.

 

Pocket just gave an excellent description of what I chose for our Excursion in these two paragraphs. I need to save it for future reference. I really enjoy driving the Excursion with this setup, SOTP feels @ 50 hp stronger than my pickup with swamps 175/0. The guys here on FTE helped me decide on this setup and I can't thank them enough. I still owe them a steak dinner & a beer........