Upgraded stick on a stock truck?

[6speedsd]

I need to replace a couple injectors here soon. Thought about upgrading while I was in there. Considered 155 or maybe 175's with stock nozzles. Truck is basically stock, with the exception of intake/exhaust and a mild tune from IDP(aggressive street). No studs, factory fuel, stock turbo. I know either of those options would be smoky, and a little hot, but I could clean that up with a tune. Basically I'm curious if either option would be worthwhile on a stock truck. Everything I've read about 155's says they aren't worth it with stock charger, and to just go 175's. but what about the fact I'm not studded or running an upgraded fuel system? Too risky?

The truck is my DD. It tows quite a bit during the summer months (lawncare), but its not huge weight. 5-6000lbs I'd say. I'm not looking to make a high HP truck. Just a reliable towing DD, and not lose any mpg. If I'd be fine running either, I'd rather go that route when I have it apart, but if its just too risky, ill stick with stock remans.

 

[Breaking Habits]

155/30 would be great for what your doing. Truck would have a lot more low end. I wouldnt bother with an injector upgrade with stock nozzles. Just my perspective

 

[jdgleason]

:whs:

Realistically, you'll want some kind of a fuel system as well.

 

[6speedsd]

My understanding is that bigger nozzles just allow the fuel to dump faster. But if you don't run around with your foot buried in the skinny pedal, why would you need it to dump faster? I have never had my truck at WOT, and never see a reason why I would. I mean I don't putt around like grandpa, but I definitely don't beat on it daily either.

I'm not that knowledgable on injectors, so if my reasoning is off, just excuse my ignorance!

 

[jdgleason]

My understanding is that bigger nozzles just allow the fuel to dump faster. But if you don't run around with your foot buried in the skinny pedal, why would you need it to dump faster? I have never had my truck at WOT, and never see a reason why I would. I mean I don't putt around like grandpa, but I definitely don't beat on it daily either.

I'm not that knowledgable on injectors, so if my reasoning is off, just excuse my ignorance!

More fuel in a smaller window is (in theory) good for smoke and temperature control, to a point.

 

[Evan ogre44]

:whs:

 

[6speedsd]

Hrm, seems like it would be just the opposite. I guess things aren't always as they seem.

 

[jdgleason]

Look at it this way.

Say you have 155cc of fuel and it takes you 2us pulsewidth to empty the injector. If you can inject that same 155cc in a window of say, 1.8us, the combustion event is quicker, but will produce the same power, as long as you are able to burn the fuel.

Numbers are in no way accurate, but you get the idea.

 

[TooMuch03]

More fuel in a smaller window is (in theory) good for smoke and temperature control, to a point.

Yes and no... More fuel in a smaller window also means higher cylinder pressures, without necessarily seeing any bump in power, at low rpms. If the main use of the truck is for towing or mild street performance, the additional peak horse power that is compromised by using a stock nozzle will not be noticed. Also, in theory, at low rpm, the smaller nozzle should allow for the engine to make more torque because of better fuel atomization allowing more of the intake charge to be utilized. All in all, you aren't looking at much of an increase in injector capacity, the stock nozzles will be just as capable of making power as a 30% or 50% nozzle would be, based on what the OP wants to do with the truck. It would be a totally different story if he was talking about putting a set of 205s in or something.

:whs:

I would like to thank you for providing so much useful information to this thread.

 

[jdgleason]

More fuel in a smaller window is (in theory) good for smoke and temperature control, to a point.

Yes and no... More fuel in a smaller window also means higher cylinder pressures, without necessarily seeing any bump in power, at low rpms. If the main use of the truck is for towing or mild street performance, the additional peak horse power that is compromised by using a stock nozzle will not be noticed. Also, in theory, at low rpm, the smaller nozzle should allow for the engine to make more torque because of better fuel atomization allowing more of the intake charge to be utilized. All in all, you aren't looking at much of an increase in injector capacity, the stock nozzles will be just as capable of making power as a 30% or 50% nozzle would be, based on what the OP wants to do with the truck. It would be a totally different story if he was talking about putting a set of 205s in or something.

That's why I said in theory. Either way, tuning can tame a correctly sized nozzle back to limit heightened cylinder pressure...

 

[Pizza pig]

155 with a stock nozzle will smoke less down low, but smoke more up top. Other way around with a 30% nozzle. The crazier you go the more risk of breakdown there is. I would recommend 155cc with the stock nozzle, with the stock charger and good tuning, it runs great! The added torque down low is great for towing and its far more budget friendly. I have a guy that tows 15k daily with 155cc and stock nozzles and an 03 turbo and he absolutely loves it, made a huge difference for him.

I have towed a few times our landscape trailer 5-6k in landscape stuff(18ft pequa trailer with 3 scags on it. 1 turf tiger, 1 pro v, and a hyro pistol grip, 3 trimmers on the rack, 2 backbacks in the bed with a tool box, and 3 guys) With 75%, 100%, and 150% nozzles. No issues, so be confident with what ever choice you choose!

 

[TooMuch03]

That's why I said in theory. Either way, tuning can tame a correctly sized nozzle back to limit heightened cylinder pressure...

I agree. The tuning will have a big role in making the truck perform at its best. I am not disagreeing with the fact that larger nozzles on the same sized bodies will make more power. My point is that that power increase is not seen until beyond say 3500 rpm (just throwing a number out there), so for this DD, tow truck build, there will be no benefit, IMO, to upgrading nozzles, other than to replace worn out stock nozzles.

Look at it this way.

Say you have 155cc of fuel and it takes you 2us pulsewidth to empty the injector. If you can inject that same 155cc in a window of say, 1.8us, the combustion event is quicker, but will produce the same power, as long as you are able to burn the fuel.

Numbers are in no way accurate, but you get the idea.

Like you said in this post. The big variable will be if the air is there for complete combustion of the fuel. If the truck has a stock turbo, the longer pulse width required with stock nozzles may be beneficial to allow more air to contact the fuel meaning more complete combustion, also in theory. Of course, the smaller nozzle will mean a compromise in high rpm power, due to the limited pulsewidth, but since we are only talking about 155s, it shouldn't be a huge difference.

 

[jdgleason]

Lol were on the same page

 

[6speedsd]

155 with a stock nozzle will smoke less down low, but smoke more up top. Other way around with a 30% nozzle. The crazier you go the more risk of breakdown there is. I would recommend 155cc with the stock nozzle, with the stock charger and good tuning, it runs great! The added torque down low is great for towing and its far more budget friendly. I have a guy that tows 15k daily with 155cc and stock nozzles and an 03 turbo and he absolutely loves it, made a huge difference for him.

I have towed a few times our landscape trailer 5-6k in landscape stuff(18ft pequa trailer with 3 scags on it. 1 turf tiger, 1 pro v, and a hyro pistol grip, 3 trimmers on the rack, 2 backbacks in the bed with a tool box, and 3 guys) With 75%, 100%, and 150% nozzles. No issues, so be confident with what ever choice you choose!

That's exactly the answer I was looking for. As I said, this is my DD. I use it to commute and to tow. My concern was whether I'd risk the stock HG with the increased cylinder pressures from bigger sticks. Yea, anything over stock will risk the HG, I know that. That's why I asked opinions. I don't want it to be smoky, or get hot while towing. That's why I figured stock nozzles would be better.

What about the stock fuel system? Will it flow enough to feed 155's?

 

[6speedsd]

I Of course, the smaller nozzle will mean a compromise in high rpm power, due to the limited pulsewidth, but since we are only talking about 155s, it shouldn't be a huge difference.

I'm not worried about high rpm power. As I said, my truck will never see high rpms. I have no reason for it. I will gladly sacrifice top end power to gain low end. Low end is where I use my truck.

 

[Pizza pig]

The stock fuel system should be plenty sufficient for that setup. The fuel pump can handle the volume, but the factory regulator is sub par at best. I do recommend a regulated return setup (this deletes the factory regulator) and keeping the stock pump. Do you have gauges to monitor fuel pressure and egt and best? I suggest you do so you know whats going on before you go any further.

 

[6speedsd]

Gauges will be coming before injectors. Just haven't gotten around to ordering a set yet. Been waiting on tax time.

I've checked FP by hand, but no permanent gauge yet. Blue spring is on the to do list as well.

As I said, I'm in lawncare, so budget is really tight over the winter months. I have plenty of plans, but budget doesn't allow them most of the time.

 

[6speedsd]

FWIW.... Thinking about going with a set of Warrens 155's with stock nozzles. Talked to Pat a bit the other day about them. Seen a lot of good reviews about his upgraded sticks.

Any of y'all using his?