Tow tune

[Walkerbk]

Hey everyone, first post here but I have been tuning my ls base race car for a while and have been running 11s now over my old low 13s.

I am debating on whether or not to tune my 05 cummins with a 48re myself or pay firepuk. I rebuilt the engine and transmission myself less than 5k miles ago and have a stock turbo with 60hp sticks.

My thought is that I should reduce the injector pulse width at idle and leave the rest.
Plug everything into the timing table and then copy and paste.

The two things I am not sure about is 1, what is the difference between the 50/50 split. What would be the point of changing that to a 70/30? 2, what is the difference between a tow tune and a street tune? Timing and more fuel to make it hotter?

I will be in the future upgrading the turbo or maybe going compound.

[Walkerbk]

So I reduced injector pulse width by 5% across the board for now. disabled torque management, and adjusted a few other parameters. let me know what you think of the timing and the injector PW.

I dont want to save the tune until I feel comfortable with it (i.e. I dont want to pay $100 and then have to pay another $400 to have someone else tune it). Tell me what yall think about this as a base tow tune. I do not have a EGT Gauge yet but it is on the list of things to get in the near future. BTW, I do not tow often but when I do it is heavy (12-15k trailer weight)
inj PW.JPGtiming table tow tune.JPG

[JohnnyK05]

Why do you want to reduce pulse?

[Walkerbk]

1. It smokes at idle pretty good. Like a nice haze.
2. 60hp injectors are from what I have read are 30% larger than stock so I only reduced 5% in hopes to reduce the haze while keeping over stock power.
3. Without a egt gauge I don't want to push to much fuel before I get that.
I however have not tried this tune yet so... please let me know what you think.

[crakrz]

Why is it smoking at idle? I would have thought that it should have an over abundance of air at idle rpm's and should not smoke at all. The only time you would want extra fuel is at high demand from your right foot.

[Walkerbk]

It has a lot less air at 0psi than it does at 10+psi.

I can add the inj PW back. What do yall think of the timing for towing?

[crakrz]

"It has a lot less air at 0psi than it does at 10+psi."

Yes that is an obvious math calculation. But what I was suggesting is- a diesel engine with no active throttle body restricting air is always drawing in the maximum amount of air that it can at all times. So it is probably somewhere around AFR of 30:1 or even up to 50:1 at idle. Normally at high loads and depending on the engine design and efficiency, you will not start seeing smoke until you are below 18:1 or thereabouts.

If you are seeing smoke at idle where your injection amount is so small, this points to a mechanical issue or injection timing so far out that it is not getting effective combustion of the fuel.

[Walkerbk]

Makes since. Turbo is pushing all needed air, more fuel at idle=more heat=more air... if there is to much the computer should dial it back to keep rpm at the set rate. I did just adjust the valves the other day and have not been able to drive it that much since, but I know that it smoothed out the idle a little, maybe that will help reduce smoke. They were really loose across the board. So set PW to stock keep timing... how do I adjust the waistgate to increase boost. I have read that you increase the duty cycle but am not certain that I need that in a tow tune and am not sure as to what to change it too.

Seeking of AFR... how are you guys plugging a egt gauge into hpt? I was thinking of just a cheap probe and then a converter box as the one below. This way I can data log egts.
http://m.ebay.com/itm/Adafruit-Analo....c100408.m2460

[JohnnyK05]

Correct me if I am wrong. This is a rebuild 5.9L with 60hp injectors, stock turbo and stock tune? How hard has the engine been worked so far? These engines like to be worked to seat in. Who's injectors? There shouldn't be hazing at idle but I have experienced similar issues with 60hp injectors if you are talking about light hazing at idle. My truck is an 05 with 60hp injectors so you have my curiosity on this one.

[Walkerbk]

Correct, light to moderate work out. I just last weekend bought a trailer for it which is a 30+ gooseneck weighing around 4500lbs. Drove about 200 miles going 70 most of the way. I do still have a light blow by but it has been reduced greatly since the first start.

Injectors are 60hp DAP remanufactured. Which I know remanufactured injectors tend to have problems, but I have also heard a lot of good about DAP. I will try and do a injector balance test if possible. It wouldn't let me do it last I tried, but that was before sending in the tuner to be "fixed". As I said earlier to, adjustin the valves has smoothed the engine out, it might have reduced the haze. I was just looking at it and couldn't see anything in the dark. I will try to get out and get her warm some time today and check.

If you have an 05 with 60hp sticks, how is towing and egts?

[Turbo_Mike]

Here's my advise/definitions:

Stop thinking about timing like a gas engine. Timing is when the fuel is injected in. Nothing more, nothing less.
More timing makes better N/A power, better MPGs, more engine noise, less EGT typically.
Less timing makes the turbo spool, increases EGT, and can make soot.
50% means the injection event is evenly balanced before and after TDC of the piston.
Combustion happens when it happens, timing doesn't affect it that much.
A tow tune is a tune with limited fuel that you can be at high throttle and high load for a long time and not overheat or melt the motor.
A performance tune has a lot more fuel in it so it makes a ton more power but the engine will overheat/melt if you have that much fuel in it for long periods of time at high load.
Fuel is power and torque.
Boost is kind of like nitrous. More boost allows more consumption of available fuel. Higher boost at same fuel = lower EGT because more fuel is burning in the engine and less is going out the exhaust.

[Walkerbk]

So then it makes since that I reduce my pulse width with larger injectors for towing. I will be getting a egt gauge soon which will help a lot with tuning. I'll take a look at some street tunes and what kind of PW and timing they are running. I'll be towing again this weekend so I am hoping to load everything in and see how it goes.

[Walkerbk]

Well, I went to load the tune into the truck and it is saying the vehicle is not licensed. I compared the vin with licensed vehicles and it is, and it is the "stock" tune downloaded and modified so I don't know why it's doing this. I emailed hp tuners about it. Hopefully this will get figured out soon. When I did my ls tune, it went so smooth and now this.

[Dom_c13b]

At idle I like to set timing at about -2*, that seems to be the quietest the truck will run. In the cruise range I like 4-10* depending on injector size. Top end around 18-22*. In between in the spool up ranges I run down to -5 to -10*. That's for a tow tune. Also Injection duration you should leave fairly stock for most of the table. Maybe -5% across the board but probably not even that. For power add some in the 100MM3 and above range, maybe 5-10%. for a heavy tow tune I run around 2000uS duration, for a lite tow/daily tune I run around 2400uS. Pressure needs to be smoothed out a lot, in the cruise range I dip down to about 15k psi, WOT about 23.5k psi, idle 6-8k psi. Boost, adjust the minimum duty cycle to 70% and forget about it.
That's a real basic run down on getting a base tune going.

[Walkerbk]

finally got it figured out, the operating systems did not match up with the "stock file" and got it taken care of somehow. It smoked about the same at idle and then it smoked a lot more through highway speed. I did not like having that much smoke so I plugged everything into the timing calculator (attached) and got the timing that is in the attached tune. I have not loaded the tune yet though, I will do it tomorrow morning and try it prior to leaving for work.timing adjusted.hpttiming calc.xls

[Walkerbk]

I might just remove the post injection event from the stock tune and leave it at that. I do not want to chance my new $10K engine towing heavy since I do not yet have a EGT gauge.

[Dom_c13b]

you only had 2* of advance at 3000rpm. That will certainly be very unfavorable. The new table looks better.

[Walkerbk]

Do you think that it is safe to gross 25k with that timing without a egt gauge? If not I am just going to run a modified stock tune (remove post injection event, reduce inj PW 5% at idle, waistgate min duty cycle at 70%, a few other things)

[B00STJUNKY]

Do you think that it is safe to gross 25k with that timing without a egt gauge? If not I am just going to run a modified stock tune (remove post injection event, reduce inj PW 5% at idle, waistgate min duty cycle at 70%, a few other things)

Why exactly do you wish to remove injector pulsewidth at idle? And how do you plan to do that?

Idle is controlled by a PID loop which takes your desired idle RPM setpoint, and constantly makes small fueling adjustments to maintain a steady idle RPM, which will require a certain average quantity of fuel (let's assume your truck idles at around an average of 25 mm3, which ends up being around 1000 uSec of duration with a rail pressure around 50 mPa). If you decrease the injPW map in the section of the map that would correspond to idle values by 5%, then that 25 mm3 at 50 mPa which used to result in 1000 uSec at idle would now only result in 950 uSec, which would directly affect idle (causing it to be lower than desired), which would result in the PID loop adding more mm3 to compensate for the lower than desired idle (up to the point that you would pretty much end up at the same duration as you had before dropping 5% out of the injPW map).

I mean, it could end up decreasing duration a little bit after all the corrections are applied, since increasing the mm3 rate often times puts the pressure map at a little higher mPa. But in the end, you're still going to be injecting the same amount of fuel as you were before, whether that quantity is derived via lower pressure and longer pulsewidth, or higher pressure with shorter pulsewidth.

[Dom_c13b]

Like Boost Junky said, I wouldn't worry too much about your Idle Pulse. If anything add a little Rail pressure in the idle range, Bring it up to 7500 or so and see if the smoke goes away. 7500psi, -2* timing works pretty good. And yes you will be fine to run that timing table with just about any weight.