Quadzilla Adrenaline Economy and MPG

[TFaoro]

6 minutes ago, Mopar1973Man said:

That's what I just learned. 

 

Man, this is tougher than hell trying to figure out what is good and bad timing wise. The thing I am realizing still the Quadzilla holds timing fairly solid to one spot. True that lower timing numbers tend to build power faster. Higher timing number are better for efficiency. The weird part is trying to find the curve that works the best. Between the max timing table and the cruise timing setting is puzzle. Like I told you @Me78569 I've been limiting my travels to highway 55 mostly 55-65 MPH travel so I can figure out this mystery or puzzle. I will admit cruise boost pressure about 10 PSI is about optimal for normal highway driving (55-65 MPH) it kicks out just about the right time during grades. 

 

So I guess I need to fix my "Max Timing Table". more or less tweak it a bit. (Exponential growth 12% starting at 16)

1500 - 16.0

2000 - 17.9

2500 - 20.0

3000 - 22.4

Max - 25.1

Lower timing builds the boost faster (usually), but as you inject more fuel and have higher rpm you need higher timing to get the explosion to occur at the right time. 

 

4 minutes ago, Me78569 said:

I need to spend some time learning @AH64ID Timing calc stuff, just haven't had time to yet.  That should help figure out where timing should be at a given rpm and match that to a good MPG for that rev.  

 

 

really all comes down to trying to get the combustion in the right spot.   as revs increase the amount of timing needed to keep timing in that sweet spot increases.  

 

 

There's a lot about this kind of stuff I don't know haha,  I wish I could sit down and chat with someone smarter than me, but doubtful that will happen.

I hope John will give us some insight. The general "theory" should be the same for all diesels, but I'm not sure how specific he can be considering no one has seen VP timing until now. 

[Mopar1973Man]

So many things to consider. Cetane of the winterized fuel, intake air temperature, coolant temperature, RPM's, engine load, etc. I'm gaining on it but rather little feedback from the OBDLink or Quadzilla to tell if you're heading the right direction or not. 

3 minutes ago, TFaoro said:

Lower timing builds the boost faster (usually), but as you inject more fuel and have higher rpm you need higher timing to get the explosion to occur at the right time. 

 

 

But what happens if you injecting less fuel, lower engine loads? That's the weird part I'm not racing here just cruising. I know there is certain amount of advancement required between the speed of the crank and the explosion of the fuel. So say for example I'm turning mere 1,600 RPM (about 55 MPH), engine load below 20%. So this is lower in RPM, lower in engine load, less fuel injected, etc.

[TFaoro]

6 minutes ago, Mopar1973Man said:

But what happens if you injecting less fuel, lower engine loads? That's the weird part I'm not racing here just cruising. I know there is certain amount of advancement required between the speed of the crank and the explosion of the fuel. So say for example I'm turning mere 1,600 RPM (about 55 MPH), engine load below 20%. So this is lower in RPM, lower in engine load, less fuel injected, etc.

Exactly what you need to think about. So WOT at 1600rpm should have more timing than light cruising at the same rpm. If you inject too soon the explosion happens early and decreases economy.

There's a flip side to that though. Less fuel lowers the compression within the cylinder and makes the fuel ignite later. So you need higher timing to make the explosion happen at the right time. That would be for really light load (Hopefully I'm saying this right as it did come from John)

[Mopar1973Man]

5 minutes ago, TFaoro said:

Exactly what you need to think about. So WOT at 1600rpm should have more timing than light cruising at the same rpm. If you inject too soon the explosion happens early and decreases economy.

There's a flip side to that though. Less fuel lowers the compression within the cylinder and makes the fuel ignite later. So you need higher timing to make the explosion happen at the right time. That would be for really light load (Hopefully I'm saying this right as it did come from John)

 

 

That was my thought. This why I'm not a huge fan of the Fuel Load Timing because of it backward to what you just said. It retarding timing at low loads and advancing fully at 100% engine load. Using the info from @Me78569 about Smarty wanting 20* of timing I started a bit high and working my way back slowly. The thing is still there is also the factory of nozzle size too you and @me78569 are much larger than me so more timing would be required vs myself being you need more timing to convert the fuel and to ignition. This why I kept pulling down and retarding from what I'm seeing.

 

Being my exponential curve worked really well on my fuel curve I'm going to try it out on the timing side. Last few have been rather linear growth rate +2 or something of that sort. Now trying exponential.

[Me78569]

which is why Cruise State timing is useful.  The quad will automatically turn fuel load timing to 0 / disabled, then switch to using cruise state timing only, which is generally higher timing than your "performance" base curve.  

 

So if all the qualifiers for cruise state are met we ignore everything but cruise state.  Best of both worlds.

 

The Quad literally sets EVERYTHING to 0, except cruise timing, when cruise state is sensed.  

 

 

They live in different realms and don't talk to each other lol

 

If you like I can build you a tune that inverts fuel load timing when in cruise state only ?

Edited February 17, 2017 by Me78569

[TFaoro]

23 minutes ago, Mopar1973Man said:

That was my thought. This why I'm not a huge fan of the Fuel Load Timing because of it backward to what you just said. It retarding timing at low loads and advancing fully at 100% engine load. Using the info from @Me78569 about Smarty wanting 20* of timing I started a bit high and working my way back slowly. The thing is still there is also the factory of nozzle size too you and @me78569 are much larger than me so more timing would be required vs myself being you need more timing to convert the fuel and to ignition. This why I kept pulling down and retarding from what I'm seeing.

I think this is the opposite of what you're saying haha. 

So at very low load the timing is up high, then as you load the truck it retards timing in that middle range, then when load comes up high (lots of fuel) the timing increases again. At least that's how I think it works. Nick correct me if I'm wrong please. 

 

I do agree, you will need significantly lower timing than me. For reference mine is happy at 20.5* at 70mph, which is right about 2K rpm. I would expect mine to like about 22 at 75-80mph which I think is around 2300rpm. I've yet to drive the truck on the freeway since all of these updates though. 

[Me78569]

@TFaoro Mike is saying that when cruise state is enabled fuel timing should work inverted to perfomance mode.  I think it makes sense haha.  in an effort to keep mpg while keeping the truck moving you would want to decrease timing as load increased and increase timing when load dropped.  This change effectively gives us a full steady state timing table and a performance timing table based on 3 + axis

 

We have to remember that cruise state normal timing are 2 different lines of the code they cannot intersect.

 

attached is a spreadsheet that shows what mike wants. Change a2-c2 to fit the situtation and that's what is needed.

 

 

Book1.xlsx

Edited February 17, 2017 by Me78569

[Mopar1973Man]

Just to confirm @Me78569...

 

In cruise state...

 

 we should see timing advancement during period low engine loads. Then as load increases then the timing should retard. Based on the boost pressure setting remain in 

 

Then if it kicks out to performance mode...

 

Keep the current fuel load timing you have now. Where timing retards with lower engine load but advances with high engine loads. 

[Me78569]

I still have to kick out of cruise state if Quadzilla load spikes.  that's the only way I can know for sure that there is a change happening, no other sensor input will tell me that the driver / cc is requesting more power.  If boost stays low it will jump back into cruise state after 3 seconds at the new cruise timing, if load is increased then cruise timing will drop, if load decreases cruise timing will increase.

 

If boost comes up above the limit then cruise timing is not re-enabled and your base timing cruise is active along with performance fuel load timing, IE more timing at high load and less at low load.  

 

 

 

 

[Mopar1973Man]

I've got a lot of canyon roads that have mild up or down grades. So mild that I can keep the boost well below 10 PSI but the load can vary 10-20% typically. So like for example if the truck is traveling flat ground and the encounters a light down grade that engine loads is reduced 5% it would be nice to push like 1* more timing. Or if the reverse happened like a small knoll hill timing would retard say 1*. 

 

Would be different if I lived in Texas where everything is basically flat and then the whole set cruise timing would be fine. But then there is folks like me that live in the mountains with rolling hills and highways where a fixed timing isn't optimal. Watching stock vary up and down as small changes of load occur but Quadzilla basically holds timing to RPM that's it. So if cruise control is set then RPM doesn't really change much but engine load and boost pressure do.  

[Mopar1973Man]

UPDATE!

 

I've now added a exponential growth calculator to my Excel sheet so no longer do you have to wander back and forth to calculate fuel maps or timing map curves. The spreadsheet is on the first post of this thread.

Edited February 18, 2017 by Mopar1973Man

[Mopar1973Man]

Today I made a mistake and left my performance tune up and forgot to change before going home. It netted me 23.1 MPG when I hit the door tonight. No bad. Here is my data log from the OBDLink. This is my last log in the pile, 62.08 miles of logged MPG. OBDLink data logs and saves all the files to the tablet and I can pick and choose the files I want to look at. Also talked to Spencer about that and he'll see what he can do about adding that into the logging feature. 

[dripley]

I get my best mileage with the Comp on 5X3 on the highway. My best is 22.3 pure interstate run. Prior to the comp about 20.3. No logs to back that up just my feeble memory.

[Mopar1973Man]

What I'm finding out is the steeper the fuel curve is the better the MPG will become. Timing isn't so much of the picture but the CANBus fuel curve is more important. 

[Me78569]

@Mopar1973Man was this hand math or odblink ?   

 

If you canbus fueling is more aggressive your OBDlink will show higher mpg, as it uses some caluclation of fueling per load to get mpg.  If you decrease the pedal movement needed then your load reduces and calculated mpg goes up also.  Same way as the overhead computer.  

 

 

I have not found any difference in mpg based on canbus fueling with my testing.  But I could be missing something.

[Mopar1973Man]

Returned back to Boise today made a cool even 24.0 MPGs...

[Mopar1973Man]

Well gang... I've touched 24.0 MPG on this last run back to Boise, Idaho.

 

 

I do need to back down my timing more again the idle misfire is back again.  I'm going to change up my timing curve on this performance tune some to see if I can resolve the misfire at idle.

[Mopar1973Man]

Crap!! Well that went out the window. I did a fill and verified the offset and there is about 18% error. So the hand math is 19.90 MPG and the ONE Mini showed 23.9x MPG. So I've recalibrated again. I was really hoping for good number. They are improving but slower than expected. Almost 20 isn't ugly.

 

OBD link is up to 106% volumetric efficiency. 

Edited February 22, 2017 by Mopar1973Man

[TFaoro]

58 minutes ago, Mopar1973Man said:

Crap!! Well that went out the window. I did a fill and verified the offset and there is about 18% error. So the hand math is 19.90 MPG and the ONE Mini showed 23.9x MPG. So I've recalibrated again. I was really hoping for good number. They are improving but slower than expected. Almost 20 isn't ugly.

 

OBD link is up to 106% volumetric efficiency. 

Until you set a tune and run a couple tanks through it, I don't think you'll be able to get accurate readings from your OBD. I saw the same thing from my SGII.

[Mopar1973Man]

Being all the miles I've got to do I'll get my few tanks in pretty quick. At least right now I'm getting close to accurate feedback for the OBDLink now. I'm using the same fuel station every time.