Let's discuss larger nozzles and idle quality

Powersmoker

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Yes, an emulator is really the best way to go for tuning any sort of aggressive setup. I can make more changes in 60 seconds than I could in 60 minutes using the the "tune and burn" method. It's the ONLY way to do "live" tuning.

I'm still interested in your new emulator :poke: :evil

Me too!



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CurtisF

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As for idle quality, it's a balance between hazing and smoothness. If smoothness is all you desire, set the idle ICP at 400psi.

DONE, lol.

I don't mind a slight bit of chop, but mine is a bit over the top. Plus I can watch other trucks with as big or even larger nozzles idle way smoother than mine, and with no haze to go with it.

Even on these videos I can "hear" that hollow chop out of the exhaust. It's unmistakable, but looking at how smooth the engine idles and hearing less of that romping is what I'm after. My idle chop can at times get to the point where the truck is idling like it's got a lope idle tune in it. Ok, maybe not quite that bad, but you get the point. :lame2: It just ain't smooth in the least bit.
 

Charles

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I don't mind a slight bit of chop, but mine is a bit over the top. Plus I can watch other trucks with as big or even larger nozzles idle way smoother than mine, and with no haze to go with it.

Even on these videos I can "hear" that hollow chop out of the exhaust. It's unmistakable, but looking at how smooth the engine idles and hearing less of that romping is what I'm after. My idle chop can at times get to the point where the truck is idling like it's got a lope idle tune in it. Ok, maybe not quite that bad, but you get the point. :lame2: It just ain't smooth in the least bit.


Set your idle ICP to 500, set the idle timing to ~6 in the seal-level/altitude map.

Get ahold of your pw map and make sure it's not acting like waves coming into shore with any big ridges or anything making the pw cycle like crazy.

Get ahold of your MFD table and make sure it's not doing anything like that either.

Check the fuel limit vs rpm map and make sure you don't have a big cliff or ridge right near idle doing that.


There are a few things that can hang one up, but once all those sorts of things are exhausted, and you verify that it's not running ICP up and down or pw up and down, it's time to think about nozzle VOP, over gap, cylinder compression and the like.

Or just drive.
 

CurtisF

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Update....

I've had a lot of good advice here in this thread, and I also had support via emails, phone calls, and PM's. That in of itself just goes to show that there are people out there willing to help others with tuning. Thanks guys! Without this input, I would not have made this progress in such a short amount of time.

The result.... the tweaks I ended up doing weren't much, but they made a huge improvement. Now that I look back, the changes were super easy and things I completely overlooked. The truck now idles much better when warm, and even the warm starts are easier since it settles into a smoother idle faster. In a nutshell the ICP at lower RPM's was lowered a bit, but ramps up quicker as the RPM's come up. The PW map has been reworked so that it's a bit lower off the bat, but ramps up a little faster than what I had it before. Base idle speed was raised, and the ICP while cranking was lowered. The rest of it regarding timing, multipliers, etc was all left alone. I actually tried it out with my PW table unchanged, and the other tweaks, and the idle was instantly better there too.

So it wasn't anything huge, but rather some minor tweaks. The bump in base idle speed was something I tried a long time ago, but gave up on it mainly because I had other stuff out of whack at the time. The ICP I had ramping up just too fast too soon, and it was choppy at idle and at times coming just off of idle (and even returning to idle).

At this point the truck is much smoother. Still needs a few very minor tweaks, but it's never idled this good with these injectors before. I'd say it's pretty close to a stock OBS truck at idle now.

Again thanks for the help guys!
 

CurtisF

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Set your idle ICP to 500, set the idle timing to ~6 in the seal-level/altitude map.
I've got it lower. On my truck it clatters even at idle if I ramp the timing up that much.

Get ahold of your pw map and make sure it's not acting like waves coming into shore with any big ridges or anything making the pw cycle like crazy.
Actually my PW map was pretty even flowing. The overall changes I made weren't much. I did find that the flatter I tried to make it, the worse the idle got.

Get ahold of your MFD table and make sure it's not doing anything like that either.
I keep going back to the stock MFD table. Every time I make changes to it, I never like it.

Check the fuel limit vs rpm map and make sure you don't have a big cliff or ridge right near idle doing that.
Good to go there too.


There are a few things that can hang one up, but once all those sorts of things are exhausted, and you verify that it's not running ICP up and down or pw up and down, it's time to think about nozzle VOP, over gap, cylinder compression and the like.

Or just drive.
Well the little tweaks I did do made all the difference in the world. And as good as the truck runs anyway I wasn't suspecting any mechanical issues.
 

Strokersace

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Good to hear Curtis.

Subbing this one too. My idle isn't smooth at all once warm and often "hiccups" coming back down to idle after driving at speed. This is with my Hypermax A-code stage 2.5's w/ .010 nozzles. Always has a haze from the tailpipe.

However, I'm running stock pcm programming because my trans is stock. Once specific tuning is in play, then this may all change. Great to see advances in this stuff though.
 

TARM

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Strokersace,

You are running a stock power level tune specific for your injectors or you are literally running stock tuning as in what the PCM has on it?
 

Strokersace

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Literally stock tuning!! 1997 pcm code TDE-1

I should clarify that the idle isn't bad by any means, it's just not as smooth as I'd like it to be. I notice that it idles smoother when cold than it does after it's warmed up after driving.

Truck runs really good and has good power for the stock tuning. Just don't want to put a chip in it and fine tune it until I have a trans that will hold up to the power. Would rather just do the chip once.
 

Charles

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What idle icp did you end up with?

What idle rpm did you end up with?


Oh, I forgot my injection offset is all 1's, so that makes my timing suggestion null and void for you if yours is actually being utilized with real values.

With the ICP being low for idle, yet being brought up when you need power, I found it far better to have ICP come up with fuel, rather than rpm. If it comes up with rpm the truck will tend to "drive itself" as rpm climbs, requiring you to let off the pedal a little off the top of each gear, and then get back in it again coming off a shift as the rpm falls and the truck falls on it's face a little. If the ICP has a very shallow slope in the direction of rpm, and a very steep slope in the direction of fueling I have found that to provide the engine with a lot of balls for lack of a better word. It accelerates based on your foot, not all wishy, washy doing it's own thing and falling off on shifts. If the ICP is based primarily on pedal, then on a shift the truck actually bullies the trans a little, instead of the other way around because as the rpm falls, the ICP stays largely the same, which keeps the power solid through the shift.

I'm not saying that you're not doing this, but I just remembered something in your post about ICP coming up with rpm, and figured I'd throw my .02 in there on that. Without fail, having rpm control ICP has made everything I've done less stable, and less fun to drive.
 

CurtisF

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What did your idle PW and ICP end up at?

What idle icp did you end up with?

What idle rpm did you end up with?
I haven't datalogged my truck yet with the new changes, so I'm not entirely sure where the idle PW is actually ending up at. But as always I can set values how I want, and the truck does its own damn thing when it feels like it. That's the one thing I've noticed about the PW table. I can almost set whatever values I want, it doesn't care. I get more changes out of that table if I adjust the curve or slope of the fueling, how quickly it rises and falls... or doesn't.

For example, my last two major tuning adjustments before starting this thread had two entirely different PW tables, but much of everything else was identical. In both cases, the PW at idle rested at around 1.45ms, even though the tables had completely different values. But the idle characteristics were both different, how they came off idle as well as how they came back to resting idle after driving. Also warm starts were affected, as a flatter PW table had a harder time settling into an idle after cranking.


Currently the idle ICP is down below 450psi, down from my other files of close to 530psi. Base idle speed is up to 750 RPM's.


Oh, I forgot my injection offset is all 1's, so that makes my timing suggestion null and void for you if yours is actually being utilized with real values.
Mine is also set to 1's across the board too ;)

With the ICP being low for idle, yet being brought up when you need power, I found it far better to have ICP come up with fuel, rather than rpm. If it comes up with rpm the truck will tend to "drive itself" as rpm climbs, requiring you to let off the pedal a little off the top of each gear, and then get back in it again coming off a shift as the rpm falls and the truck falls on it's face a little. If the ICP has a very shallow slope in the direction of rpm, and a very steep slope in the direction of fueling I have found that to provide the engine with a lot of balls for lack of a better word. It accelerates based on your foot, not all wishy, washy doing it's own thing and falling off on shifts. If the ICP is based primarily on pedal, then on a shift the truck actually bullies the trans a little, instead of the other way around because as the rpm falls, the ICP stays largely the same, which keeps the power solid through the shift.

I'm not saying that you're not doing this, but I just remembered something in your post about ICP coming up with rpm, and figured I'd throw my .02 in there on that. Without fail, having rpm control ICP has made everything I've done less stable, and less fun to drive.
And I was having a bit of issue with ICP climbing rapidly as RPM's came off idle, but not coming on with the fueling. The result was a choppy feel at light throttle. So some of that has been pulled back a bit. Now I can watch my ICP gauge in the cab climb more with fueling rather than with RPM's.
 
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Charles

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My ICP at low pedal positions is damn near flat with rpm. Rpm changes the ICP by just the slightest amount, and then, only really coming right off idle. For the remainder of the range, it's damn near unphased, making the engine drive with a lot of control over the vehicle and the trans. It basically doesn't give a damn what the trans does.... it's going to make ____ power as long as my foot stays steady.

That is of the utmost importance to me on a preferential note. I want a truck that accelerates evenly as long as my foot stays planted in one spot. I cannot STAND to drive a truck that accelerates on it's own like a runaway, and then falls down on a shift. It makes the shifts very uncomfortable and generally makes the engine feel like a little bitch. On a side note.... when this is happening you can forget about tuning the trans in. Nothing you do will make the shifts smooth. Conversely, with solid ICP through the shifts, you can run the line up until the tires are spinning on the shifts and it will be smooth as silk...

On Edit:

Here's an ICP map from my 550 that I had on webshots:
2251939120082519711S600x600Q85.jpg



Notice how the ICP is flat and stable from 800rpm down to 550rpm (smaller bubbled area). That won't let it get into a cycle if the rpm starts to swing. The rpm can climb from 750 all the way to 800, or drop all the way to 550 and the ICP will not flutter, so long as MFD remains the same. Which it won't, but at least you don't get compounded bs like you would if both were changing and fighting with one another. Imagine the engine lulls a little, so the MFD goes up, running the ICP toward the back of the map (increasing pressure) while the ICP is already headed toward the right (lower rpm) where if you had a ridge there you would be incurring double increases in pressure, which would quickly push the rpm up even with pw constant, which would fall back into the trough, causing a lull, yada, yada, yada..... next thing you know you've got a topfuel D9 sitting there idling...


As for what I was talking about above.... notice on the map how at very low MFD, the ICP is basically unchanging as rpm climbs (larger bubbled area). All it's really doing is accounting for the shrinking injection window and keeping the power consistent.

That is what makes cruise control super smooth, and gives the engine tons of balls. Believe it or not, keeping the ICP DOWN as rpm climbs is what makes an engine strong. Because when it ramps way up, you have to lift out of the pedal to maintain your acceleration rate, then when the shift is underway the rpm drops, and the ICP falls on it's face.

If you watched my ICP gauge during shifts you would see it just sitting there in one spot as the truck ran through the gears. I'm just saying.... that MAKES a truck, IMO. You get all the other stuff good, and that will make the truck have so much balls.
 
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907DAVE

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Oh, I forgot my injection offset is all 1's, so that makes my timing suggestion null and void for you if yours is actually being utilized with real values.

You know that is a time based map so setting to 1 does not completely void the map. Timing will still be increased by 1ms regardless of RPM, so at 3400 RPM you are still increasing SOI by over 20* when its set to 1.
 

Charles

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You know that is a time based map so setting to 1 does not completely void the map. Timing will still be increased by 1ms regardless of RPM, so at 3400 RPM you are still increasing SOI by over 20* when its set to 1.


Yes.

Null and void was with respect to anyone with a full table trying to make use of my suggestion based on that 1ms advance I have. Most people have a wildly changing, and usually much more aggressive table, making the value I quoted to be a starting point no good.

I'm not sure why Curtis' truck seemed harsh with a 6 if his offset is also 1's though.
 

CurtisF

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Here are some videos I shot of my truck. First one is warm idle after a long drive, so you can see/hear the idle quality and I even have a tailpipe shot so you can see it doesn't haze at idle. It's still not perfect, but it's a huge improvement. Second on is daily driving normal acceleration and deceleration coming to a stop (so you guys can hear how it goes back to idle). Last is the same DD tune with me getting on it from a stop and going WOT to about 60 mph. This tune is the exact same fueling at WOT that netted me 310hp at the rear wheels on the dyno.

http://www.youtube.com/watch?v=eNnIzdOYUSs



http://www.youtube.com/watch?v=pMRp7MamhvA



http://www.youtube.com/watch?v=nNFFSyyTReI
 

CurtisF

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By the way, I live at about 6,000 ft elevation, and I'm hoping that tune passes emissions testing.
 

CurtisF

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I'm not sure why Curtis' truck seemed harsh with a 6 if his offset is also 1's though.
I don't know either. I'm at 4 right now with offset flatlined at 1's across the table. 6 is just too much clatter, sounds way too advanced.
 

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