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I didnt want to mix up the threads by posting unrelated information so I figured I would start a new one.  This thread is for figuring out what works and what you find your truck likes.  

 

I did some more datalogging as of late and found that a more aggressive timing curve later in the rpm band, say 2500 + rpm, seems to pull harder up top.  Previous I was running tunes that maxed timing at 26*.  I took 2 tunes copied them and ran them back to back on the same stretch of road, same conditions.   I was not using wiretap for this so I will leave those details out

 

First Tune 29* max

Quote
Race 29*  
Number of Power Levels 6
RPM Limit 3700
Valet Mode  
Maximum Valet Mode Power 35
   
Timing Parameters  
Fuel Load Timing 1
Low PSI Timing Reduct 5
Timing Reduct Scaling 80
LightThrottle Timing Adv 1
Light Throttle Limit 35
Timing Equilzer  
1500RPM 16
2000RPM 19
2500RPM 24
3000RPM 27
MAX 29
Boost Level Fueling - CAN Bus  
0 PSI 88
1 PSI 90
2 PSI 92
3 PSI 94
4 PSI 98
5 PSI 102
6 PSI 106
7 PSI 110
8 PSI 114
9 PSI 118
10 PSI 122
11 PSI 126
12 PSI 130
13 PSI 134
14 PSI 138
15 PSI 142
16 PSI 146
18 PSI 150
20 PSI 150
22 PSI 150
24 PSI 150
26 PSI 150
28 PSI 150
30+ PSI 150

 

Second Tune 26* max

Quote
race 26*  
Number of Power Levels 6
RPM Limit 3700
Valet Mode  
Maximum Valet Mode Power 35
   
Timing Parameters  
Fuel Load Timing 1
Low PSI Timing Reduct 5
Timing Reduct Scaling 80
LightThrottle Timing Adv 1
Light Throttle Limit 35
Timing Equilzer  
1500RPM 16
2000RPM 19
2500RPM 22
3000RPM 25
MAX 26
Boost Level Fueling - CAN Bus  
0 PSI 88
1 PSI 90
2 PSI 92
3 PSI 94
4 PSI 98
5 PSI 102
6 PSI 106
7 PSI 110
8 PSI 114
9 PSI 118
10 PSI 122
11 PSI 126
12 PSI 130
13 PSI 134
14 PSI 138
15 PSI 142
16 PSI 146
18 PSI 150
20 PSI 150
22 PSI 150
24 PSI 150
26 PSI 150
28 PSI 150
30+ PSI 150

 

29v26..PNG

 

The interesting thing is the tunes are the same except for the timing above 2500 rpm.  If you look on the graph rpms hit that 2500 rpm mark at about line 20-21, each line is ~.3 seconds so 3 lines = 1 second.    You can see where timing jumps and also where boost jumps. 

 

Now keep in mind the graphs are not exact so take them with a grain of salt, but everything appears to show that the tune with higher timing up top gives faster time to 50 mph, and a faster ramp up of boost.  The higher timing tune appeared to reach 50 mph nearly 1 second faster.

 

as always studs are a good idea, but I am fairly sure anyone can run this timing above 2500 rpm.    If people are not blowing their heads off left and right with other tuners then there is no reason why this type of timing curve will hurt with the Quadzilla. 

 

 

Food for thought, open to other thoughts.

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That's a really interesting idea. Just for reference, do you know what the timing range is for common rail trucks? What kind of timing do those things need when they reach 4000 rpm? I know it's a different beast, but maybe the timing range from low rpm to redline will help identify timing requirements up high.

 

@Me78569 The quad would have to have control of timing at all times in this case, correct? During cranking, idling, etc. I'd be terrified of what would happen if I was WOT and the quad shut off, possibly adding 10 degrees of timing.

Edited by kzimmer

I think the CR trucks main injection event maxes at 19*.  The preinjection event can be up to 50*

Edited by trreed

1 tooth is 10* @Me78569. I am conflicted on the timing thing. I know Mike and the other modified vps physically build more timing into the pumps. But they also modify the displacement of the pump. An SO has made in the high 800s on fuel without any funny business. Just get the turbos moving fast enough and in the rpm range the vp works. That has always been the key.

  • Author

@jlbayes are you saying that given that the vp makes power in the 2k-2600 rpm area there may not be any need for more itming to make more peak power?  

I am not sure the timing is the limiter.

I had a chance to put on about 160km on the highway tonight. 100-200° drop in EGT cruising at a little over 70mph (650° give or take) and at WOT (quad Defuel set to 50 psi, 1000° max, settled down to °940 or less). Happy with that. WOT spoolup is great and very little smoke. 10psi to 50psi happens lightning fast. It's a beast. I just need a long highway trip at reasonable speeds to test mileage. Also need to dial in fuel and timing.

  • Author

can you shoot a video or two when you get time....   

 

all we need is time time time

On 27/11/2017 at 10:55 AM, Me78569 said:

@kzimmer

 

Try this.  I put the fuel limit back to what it was on 2.7.1 

 

 

Got my high idle back, thank you sir.

On 01/12/2017 at 7:24 AM, Me78569 said:

can you shoot a video or two when you get time....   

 

all we need is time time time

 

I'll try to get one soon. The wife needs the truck today so I gotta take the car out of town.

  • Author

@kzimmer Well it appears like @Carbur8tr is joining you at the 350 bar setup.  He is going to be running some 7 x .012's from DFI.  

9 hours ago, Me78569 said:

@kzimmer Well it appears like @Carbur8tr is joining you at the 350 bar setup.  He is going to be running some 7 x .012's from DFI.  

 

Excellent! If I decide to pull mine again, I'm going to set the pop to 350 bar. Truck runs great at 365, just that little quirk. With a manual I likely wouldn't even notice the quirk because of anti-stall.

Edited by kzimmer

  • Author

If I ever get back up in your area ( Crown Shred in regina is a client of ours) I will have to take your truck for a spin

I’m curious myself to see the result. I ran a set of Jacob’s 7x.012 vcos about 3 years ago now and they weren’t horrible but you definitely had to learn how to drive it (pre-Quad days). Not a setup I would let anyone drive unless I knew they had enough feeling in their right foot lol. 

 

Anyways, I ended up going with a set of 7x.012s from Chris set at 350 bar, 150 degree cone, sac. Debated a little back and back forth and decided with the higher timing and pop pressure that the pintle not coming into direct contact with the tip might help a little for preventing possible issues with cracking and stress. 

 

Again though, this is all precaution. I haven’t seen nor heard of any negative effects on some of the higher popped vco injectors, but regardless I like the thought of having a bit of overhead. 

8 hours ago, Me78569 said:

If I ever get back up in your area ( Crown Shred in regina is a client of ours) I will have to take your truck for a spin

 

Cool! I take my used oil and antifreeze to them. They have a second office close to where I work. 

 

Just keeper under 50 psi until I get a manual trans in, lol.

@Me78569 and @kzimmer I've been reading a bit and thinking that we might be able to take a different approach to the idle issue.

 

So what we have to work with:

1400-1600 bar distributed among 3 injection events due to the rotary design

467-533 theoretical max pop pressure say 10% inefficiency factored that lands us at 420-480 bar

Factor in pump age and you're probably even lower that that

Fuel injected can be modified by holding the solenoid closed longer allowing more fuel to fill the compression chamber in the pump 

 

With that in mind I think we can confidently guesstimate that our ceiling is somewhere in the area of 400 bar.  In my opinion this is not a realistic pressure but one that might be functional provided the pump is healthy and there was a way to either modify timing or off idle fuel to prevent possible stalling issues. 

 

 

 

My thought right now is that the off idle stalling is becoming an issue not because of the pressure the pump can provide, but maybe because the pump cannot accommodate quick enough for the larger amount of fuel required by the larger injectors. Because in the split second of you putting a load on the truck, the rotor is spinning at probably the lowest rpm it will ever encounter which will result in the physical movement of the rotor itself magnifying the problem and the lack of fuel potentially becoming an issue.  In theory more fuel will be needed in order to achieve the atomization necessary for the injection event.  

 

I guess a way to test this would be to put a hair of wiretap in when tps moves off of 0% when the truck is below 5mph and load is above X%.  The wiretap should hold that solenoid shut just a little longer allowing a little more fuel in the chamber.  Essentially you would be bumping the throttle a little before you accelerate but just that little bit might help eliminate the stalling.  All just thoughts but I'm curious to see what you think and if it might be possible.  

 

I'm still trying to find a technical document that has VP44 HO and SO data for exact numbers on the high pressure side.  Some of the links below point to a number anywhere from 1400-1600 which is why I used the numbers above.

 

https://www.dieselnet.com/tech/diesel_fi_pln.php

http://www.cumminsforum.com/forum/98-5-02-powertrain/1839897-bosch-vp44-101-a.html

https://www.bluechipdiesel.com/vp44diagnostichelp.html

http://dodgeram.org/tech/dsl/ISB/Vp44.htm

  • Author

first question I have is if we see a need for 350+ bar?    If we can define what the goals are then we should be able to say yes it is worth messing with 400 bar or no it isn't.

 

I think one thing we would need to know is how much duration is lost per bar as well.  At some point you will be better off running a smaller injector at a lower bar if the only goal is smoke control.  

@Carbur8tr very interesting thoughts. I think that makes sense. Let me ask you guys this, is increasing demanded fuel via canbus 0-4095 mechanically the same as using wiretap to keep the solenoid open? If so, we may have come full circle as @Me78569 experimented with canbus anti-stall a while back, lol.

 

It's important for me to note, that I put it in gear and don't touch the throttle, it won't stall. The RPM will drag down for a portion of a second, and then recover and idle normally, in gear. Now, the situation is worse if i'm idling in gear and stab the throttle on and off quick. If it does not stall, it also recovers fine. Now also, it seems to be *a little bit* worse on lvl 3 than on lvl 0. Still exists on lvl 0 though, but I did notice a difference. Whether it's an anti-stall via canbus or wiretap, depending on the mechanics of either, I think it can be resolved. But.... is it worth it? We may never know, haha.

  • Author

adding wiretap is like mutliplying the canbus signal by up to ~%30 

 

IE: canbus only 0-4095  if we add wiretap the upper limit extends to ~5300 but that 1200 of extra duration is done by bypassing hte psg.

Right so @kzimmer kinda touched on the direction of that and where I was headed.  I know that from past experiences the vp and ecm has not liked you messing too much under 1k and off idle so the thought process there is maybe to avoid that issue we can pull a little bit of wire tap in and see where that lands us.

 

Obviously we have to worry about resolution of the wiretap though and I'm not sure you can get that so might be a fruitless thought.

  • Author

I dont think we really have the resolution needed to add "just a touch" of wiretap at or near idle without unpredictable issues.  

 

I can VERY easily adjust the code to use the wiretap min setting regardless of TPS input and this would do what you are talking about.  

Also the debate on whether or not it's worth it is definitely something to consider here.

 

All of this is making the assumption that a larger injector can use more pop to clean up low end smoke, but there's obviously limits to all of this. 

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Welcome To Mopar1973Man.Com LLC

We are privately owned, with access to a professional Diesel Mechanic, who can provide additional support for Dodge Ram Cummins Diesel vehicles. Many detailed information is FREE and available to read. However, in order to interact directly with our Diesel Mechanic, Michael, by phone, via zoom, or as the web-based option, Subscription Plans are offered that will enable these and other features.  Go to the Subscription Page and Select a desired plan. At any time you wish to cancel the Subscription, click Subscription Page, select the 'Cancel' button, and it will be canceled. For your convenience, all subscriptions are on auto-renewal.