That's the way I understand it but basically I don't know much. Also Nate, what you said above to try the other chip to compare before I buy duals LOL. Tony might have it dialed in better,

On my scan gauge I have it cycling eight different readings. When I took it off the cycling and just use scan I have DC% & ICP on so once again I'm not looking at PW. When you say 'farther the injectors stoke' and 'running the injectors longer', this is PW, right?

haha, It might be Tony's heavy tow mode, not hot tune if I'm running out of oil. I know, you want me to get duals to test them, LOL. Maybe I just should get hybrids and stay with the T500. Who knows?

Before I got home that night it was pitch dark and the camera was still showing the Geo. It was a fuzzy black and white but still good enough to tell if there was a problem.

 

I was wondering if someone would bring up hybrids.

 

Yes, PW is how long the IDM is commanded to fire each injector. Basically as the intensifier piston strokes down, more oil has to fill the injector to continue driving the intensifier piston. So the longer you hold the injector solenoid, the farther the intensifier piston will stroke, therefore you need more oil to drive the piston in order to inject more fuel. The farther you stroke the piston, the farther you stroke the plunger. The farther the plunger strokes, the more fuel comes out of the nozzle.

That is why a 160cc A code would require more oil than a stock 98cc A code. The intensifier piston is shorter in the 160 so that it can stroke farther to push the plunger farther to inject more fuel. It will use the same amount of oil as stock until it is commanded to fire long enough to inject more fuel than stock, therefore stroking the piston farther than stock.

The reason hybrids use less oil per CC of fuel is because while they use the same intensifier piston as a regular A code, they use the larger plunger and barrel of the B code injectors. The plunger and barrel is on the fuel side of the injector. With the larger plunger and barrel, for every mm the intensifier strokes, the plunger is forcing more fuel down and through the nozzle than the smaller plungers and barrels could. So, since the injector will inject more fuel per mm of stroke, you ultimately get more fuel out of the nozzle for the same amount of intensifier piston stroke. So more fuel for the same amount of oil required to run the injector.

A larger nozzle would also require more oil because the larger nozzle allows the injector to empty faster. If the injector is emptying faster, it is stroking the intensifier piston faster. That means it has to fill the injector with the same amount of oil as it would with a stock nozzle, but it has to do it in less time. Sometimes MUCH less time.

I'm tired and fixing to go to bed, so hopefully that all came out right and makes sense. Lol If anyone sees any errors, let me know. I could have misworded something and I'm not a professional injector builder. Jim would be more capable of answering any questions relating to the witchcraft that happens in an injector.

 

With hybrids you'd need to wastegate that turbo to be safe. I don't need you to test the duals for me anymore Glenn. I was just worried at the time we were doing our builds that the T500 wouldn't keep up with mine as the modded 17 was setting a code. It does, so I'm good, as I'm not going with any bigger injector, unless it was maybe a stage 1.5, but not until I need a full rebuild on mine.

Looks like your choices are:

Leave it as is and stay out of the hot tunes too much.
Switch to more oil, one way or another.
Put in hybrids and wastegate the turbo.
Go smaller on injectors and put in stage ones or 1.5's.

You can probably tell which idea I don't like.

 

Darin, I will get you over your fear of bigger nozzles one way or another. Lol. Stage 1.5s... Ha!!

 

Thanks for that explanation Travis. I couldn't find fault with it but my knowledge is lacking. It seems like I'll never get this just right but I don't know if there is a 'just right' pulling that train. So far I believe Tony's heavy tow tune is the best, that is if he can smooth out the cruise. I'm a cruise freak but I travel long distance and just like it.

If I go with #3, that will be next winter project. #2, I could maybe squeeze in the next month before I leave. #4 would help my EGT's and yes, I can tell which idea you don't like but the idea I'll probably have to go with, #1! Thanks for your input!!

 

No real fear Travis, just don't see the need for a tow vehicle. If a guy can't tow in the max hp tune, and has to have it de-tuned or stay in a low power setting on the chip, what is the point? It's just a tow vehicle, nothing else. I'm happier than a shark at a penguin party with mine, so I don't see any big changes. Also, as you know, bigger injectors = bigger oil = bigger turbo = more money than I want to spend. I have my hotrod and I'm putting the motor together in a couple weeks.

 

If I saw 2800 psi on my scanner under WOT, towing, whatever, I'd be tickled to death and carry on my merry way.
The increase in power, fuel flow, or whatever, going from 2800 to 3200 psi is barely measurable on the flow bench. Well, ok, it is measurable, but it's barely worth mentioning there's even a difference.
2800 psi is SWEET in my opinion. If you were seeing 2600 psi, maybe I'd be concerned. 2400 or lower I'd say you need to look at larger HPOP, or go with Hybrids. 2800 psi? Sounds fine to me.....

Glenn, I'd leave your set-up alone and just enjoy the scenery.
If it bugs you and you really want 3200 psi at a lower dc all day long, then consider Stage-2.5's. Those are a great compromise for Stage-2's without the oil requirement. 200cc/30% Hybrids. Sell your set and build another because your Stage-2's really aren't worth converting to 200/30%, dollar wise.

The bucking or whatever you described at 3k rpm's I would guess is an issue on the top oil side of one of the injectors. It probably can't respond and flow quick enough and the result is a skip in injection from time to time during the oil controlling events. If that makes sense. We can usually see this on a flow test, but not always. It could even be a poor solenoid not able to grab the Armature plate. Could be many things but my money would be on an injector issue of some sort.
It's best to identify which injector is causing this and swap it out.

 

Thanks Jim, I think I'll enjoy the scenery. LOL

You lost me when you say: "you really want 3200 psi at a lower dc all day long, then consider Stage-2.5's." Bigger injector and have more hpop at the same time?

I've only put 14K on those injectors and you put all new solenoids on, at least that's what I remember.

Thanks Jim!

 

That all makes sense. I guess I don't know the range of PW. I was thinking that at 2400 rpm vs. 3000 rpm that there would be 300 less injections per minute per injector, but apparently the PW must be a more significant contributing factor.

So what is the range of PW?

 

On mine it's between 1.1 to 1.7 ms, unless coasting downhill then it goes to 0.4 ms.

 

Yes, with these Hybrids which are 200/30%. They can flow more fuel than Stage-2's, but the 30% nozzle restricts how quickly they empty. They are a great towing injector still capable of around 400 hp like a Stage-2, but with much less stroke there is no need for lots of oil behind them.

What I meant by them not being worth it is, by the time you cover the cost of the Hybrid P&B's and new 30% nozzles, you're not far from just building a new set. If this interests you, shoot me email or pm, I can't discuss pricing in the forums. With pricing I can better explain what I mean.

PW varies constantly. Idle it's around 1.5 +-, and the max will depend on the injector. Stage-1's are around 4 ms max, Stage-2's are around 3 ms max (Larger nozzles empty quicker dropping required ms.)
Make sense?
RPM has no real play in the PW. You can run any PW at any RPM (there are actual limits, but for sake of argument let's say there's not). This is the trick to tuning, knowing what works.

 

Just to touch on that a little bit also, the hybrid plungers and barrels and the 30% nozzles is the reason the 200/30 would require less oil. The hybrid plunger and barrels will inject more fuel per mm of stroke than the A code P&Bs. That means you'll inject more fuel for the same amount of stroke as you had before. Now with the 30% nozzles, it won't stroke the intensifier piston as quickly, so you won't need to fill the injector as quickly. That probably won't make any sense either, but I hope it does.

Jim, off the top of your head, do you know how quickly a 160/100 empties @ 3000psi ICP?

 

Thanks Jim, I didn't realize the 2.5's were hybrids. Time is getting close to us leaving for our yearly 'half year' trip so maybe next winter. I appreciate all your input!

 

We typically don't use 100% nozzles on our Stage-2's, but the 160/80% empty real close to 2.5 ms. (I looked it up, I was a little off in my earlier post)