Do you guys want a place for MCC tuning

[6.4stroke]

This is very interesting even tho I have a sct the controllability in this software is overwhelming. I might screw with this software

 

[Dzchey21]

No you will have to change all the back pressure tables to make that happen.

What do you consider high back pressure?
The back pressure deviation tables will only change whether or not it throws a code if the back pressure doesn't match desired.


Another thing you need to check is see if the vanes are going to 7% at wot. If they are try changing the tables to 2% and see of.that helps.

Before pulling rail.pressure or pulse width back I would pull timing back first that should take some back pressure out as well as lower cylinder pressure

 

[B585Ford]

No you will have to change all the back pressure tables to make that happen.

What do you consider high back pressure?
The back pressure deviation tables will only change whether or not it throws a code if the back pressure doesn't match desired.


Another thing you need to check is see if the vanes are going to 7% at wot. If they are try changing the tables to 2% and see of.that helps.

Before pulling rail.pressure or pulse width back I would pull timing back first that should take some back pressure out as well as lower cylinder pressure

The highest I have ever let it get was 68 and I let off with 2 different "Woops" moments where I saw 71 and 72. I am on a stock valvetrain and truck is a DD so I know my numbers (if only for a few seconds) are conservative. Of course, my EBP readings are true EBP (not absolute). That is why I thought just doing the desired EBP might not work (the program is only calling for 50 and I am seeing 70 and still climbing.

Again, I appreciate your advice. For now, I am going to try cutting the vanes back to 5% and see where that gets me (along with cutting the desired EBP). If that helps, I will try cutting them down to 2% if needed. Thanks for confirming the deviation tables just tells it when to throw a code.

Messing with the timing kind of scares me. I definitely feel like I have a complete grasp on what is "safe" timing. I guess if it comes down to it, I would just cut 1 degree at a time. Hopefully, that won't be necessary. In OD (I don't usually go much over 100 MPH), I don't run into the issue because the RPMs aren't high, but in 4th and especially 3rd, EBPs do become an issue.

 

[Dzchey21]

Well one thing i havent totally varified is that back pressure is in absolute or in actual psi, from what my truck does it looks like its psi and not absolute. 68psi of back pressure really isnt that high, considering boost is prob around the 50 psi range, your just about 1:1

IF you retard the timing you cant hurt much, getting into advancing the timing is where you can run into issues

 

[B585Ford]

Well one thing i havent totally varified is that back pressure is in absolute or in actual psi, from what my truck does it looks like its psi and not absolute. 68psi of back pressure really isnt that high, considering boost is prob around the 50 psi range, your just about 1:1

IF you retard the timing you cant hurt much, getting into advancing the timing is where you can run into issues

I can say with 99.99% certainty that H&S does subtract out the barometric pressure (usually around 14.7 or so). I assume the tables are true readings also. You are correct, depending on a few factors (mostly what gear/rpm), I am in the 50s on boost when I see the high 60s so it does maintain close to 1:1, but wouldn't I be risking floating the valve if I go above 70?
BTW thanks for the input on retarding the timing....that makes me feel a lot more comfortable.

 

[B585Ford]

Just an update...today's testing was mostly a bust. I got busy with having to do some stuff around the house and then it rained. I did get to try cutting Desired EBP by 10% in the higher RPM/Throttle ranges as well as cutting vanes back to 5% in those same ranges. It does seem like I made a little headway because when I ran on "Wild" in 4th gear, I peaked at about 68 psi (I use to hit 70 if I didn't let off). At that time the roads were damp (it hadn't rained in about an hour) so testing was still limited because I had to watch or would I break the tires lose when I floored it. I went back and dropped some of the EBPs by another 2 in the higher RPM/Throttle ranges and cut the vanes back to 2%. The roads were decently wet when I tried to re-test it so I couldn't keep it floored (all testing was done on the Interstate) because I kept breaking the tires lose and kicking out the a@s end. I know I could have put in 4 wheel drive, but I am trying to get apples to apples comparisons since I am still learning what a change in each parameter does. Hopefully I will get some time tomorrow to try again. Based on the numbers I was seeing, I think I am going to have to cut the fuel a little bit to get where I want to be in the "Hot" mode...I will start by trying to retard the timing first. BTW I had already cut the cut the RP by 200 and didn't go back and reset it back to baseline, but it is still commanding 26,600.

 

[B585Ford]

Now I have had the time to test the new combination (lowered EBPs by another 2 and cut the vanes back to 2%). If it did improve anything, I can't appreciate it. My EBPs went to the high 60s and were climbing fast when I let off. I think I have found the limits with what adjusting the vanes and reducing the Desired Back Pressure can do. So now I guess I will move on to retarding the timing. The tables for timing aren't what I expected. Based on what is listed, I am guessing the Negative numbers represent advanced timing (injecting earlier)...is that your impression? Assuming that is correct, I will want to move the numbers in the positive direction (i.e., less negative) right???

 

[Dzchey21]

correct, the max timing file should see like -18 degrees which is actually 18 degress of timing, what i would do is look at the max timing you see when the ebp gets up where you are uncomfortable and back it down probably 1 full degree at a time, test, watch back pressure and timing at the same time. To me your back pressure doesnt seam that high, but i understand your concern. have you tried just running a wild instead of hot tune?

 

[B585Ford]

Thanks for confirming and I appreciate the tip on backing down at the levels where problems begin.
Yes, I have ran Wild and I dont experience EBP issues on it except in the exact right conditions...and that is only in 3rd gear. I guess I am guilty of being diesel junky...I want all...tons of power, great towing (I don't tow on hot), and reliability. Work and family is keeping me pretty busy but hopefully I will get a chance to give the newest changes a try soon. Again, thanks for all of your help!!!

 

[Dzchey21]

No problem.

You may also just back down the pulse width a little bit too, if you look in the tables there is a big jump between wild, mild and hot

like 1500 us 1800 us and 2160 us... you may consider turning wild to 2000 us and mild to say 1900 and see what that does as well. help keep the smoke down anyway and less fuel driving the turbos.

 

[B585Ford]

I have been studying fueling so that I can reduce the PW. Got a few questions. Do you have any idea where there are 20 different tables called “Main Inj. Mass Fuel Commanded Configuration…/Temp…”? They all have the same numbers!!!! These tables list Torque on the x-axis and RPMs on the Y-axis. It appears to me that this table is basically telling you the fuel flow rate in liters per hour divided by 10 (actually mm^3 per second which I think is microliters per second ) at certain RPM and throttle position with the throttle position actually being determined by expected torque. Then I look at the tables listed as “Injection Duration …..Power setting”. The x-axis is RP, the Y-axis is fuel flow rate (again in mm^3 per second). Here’s where I get confused…I am use to hearing PW values somewhere between 1.6 and 2.3. Since PW does vary on a tune based on throttle position and a number of other factors, how exactly is a PW calculated…i.e., is the max PW on a given tune PW??? Or is the PW calculated based on an industry standard (certain PRM, temps, etc)??? The reason I ask is because the numbers in these tables are not listed at 1.6-2.3. Are these the tables I should be adjusting? If so, why aren’t those values within the 1.6-2.3 range?

 

[Dzchey21]

Yeah sorry


Your looking for injection pw in us which is read as 2168 or 2.168 Ms

So look for numbers like.that you are going to see numbers based on rail pressure so.at say 24600 the number will look like 2186 on hot 1898 on wild 1535 on mild and 1300 on stock.

Basically only look at the own number at 24600 psi the rest of the graph will only be part throttle then look at your mm3 and look st that about 100 -110 mm3

It's hard to look at because there are lot of.parts on that graph that the truck never hits so some.of the pw numbers are huge and others are way small but just remember you won't hit 26000 rail at 30 mm3

 

[B585Ford]

Yeah sorry


Your looking for injection pw in us which is read as 2168 or 2.168 Ms

So look for numbers like.that you are going to see numbers based on rail pressure so.at say 24600 the number will look like 2186 on hot 1898 on wild 1535 on mild and 1300 on stock.

Basically only look at the own number at 24600 psi the rest of the graph will only be part throttle then look at your mm3 and look st that about 100 -110 mm3

It's hard to look at because there are lot of.parts on that graph that the truck never hits so some.of the pw numbers are huge and others are way small but just remember you won't hit 26000 rail at 30 mm3

Thanks for the clarification....I thought the decimal might be off, but when I was seeing numbers like 3462, I thought that can't be right. In any case, it will probably be the weekend before I can try the next round. BTW after your question about Wild, I decided that I am going to try to raise the PW on Wild instead of knocking down the Hot tune. Thanks again.