Custom Quadzilla Tuning R & D Thread

[trreed]

I think this is gonna depend on the truck again. My truck doesn't have any issue with 26* at 85 mph, but I average 17.5 mpg at those speeds.  I start to see negative torque issues above that.  Who knows how it would react to the ability to have 40*?

[kzimmer]

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 November 29, 2017 by kzimmer

[trreed]

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

Edited November 29, 2017 by trreed

[jlbayes]

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.

[Me78569]

@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?  

[jlbayes]

I am not sure the timing is the limiter.

[kzimmer]

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.

[Me78569]

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

 

all we need is time time time

[kzimmer]

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.

[Me78569]

@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.  

[kzimmer]

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 December 7, 2017 by kzimmer

[Me78569]

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

[Carbur8tr]

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. 

[kzimmer]

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.

[Carbur8tr]

@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

[Me78569]

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.  

[kzimmer]

@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.

[Me78569]

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.

[Carbur8tr]

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.

[Me78569]

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.