dsberman94
Well-known member
you guys should hear non working vgts with 6.0 manifolds. soooo BA. its rediculous. theres more of a grumble than my 7.3 when the stacks are on.
VGT off?
- Thread starter Stroked777
- Start date
powerstroked08
Active member
I haven't tried that, but if you set your desired bp for that rpm the vgt is going to adjust the vanes within its set parameters(max,min duty cycle) to achieve that number. Now if the bp is going higher than the desired number the vanes will continue to open up until they get to the minimum duty cycle set limit(h&s tunes are 7% I think) Now if you turn off the vgt the vanes will be all the way open to my understanding, but you will have a laggy truck. Now thats not a huge deal but you can just set your minimum duty cycle to 1-2% instead, and set your desired ebp to say 60(at high rpms)and keep your quick spooling characteristics and have the same open vanes in the high rpms to keep your ebp as low as if you had the vgt off. Does this make any sence?
Stroked777
New member
I know it's gunna be laggy on the street but what I'm saying is will it maybe help with sled pulls and racing? Seeing that you could possibly keep the drive pressure and boost at a 1:1 or close to that becuase the vanes will stay open the entire time and driving the atmo the entire time or will the vgt still being there cause the ebp to go higher than boost pressure. Sorry in trying my best to put this idea down from my head lol
Stroked777
New member
I might be misunderstanding what your saying, but maybe I'll give what you said a try
Usually what i do is just command a lower back pressure than normal if thats the drivability you are going for
What you can do is adjust the back pressure to be lower say above 2100 rpm so in most driving situations you are making normal boost but as soon as you hit 2100 the vanes open and make the turbos basically go to least back pressure possible
The turbo vanes follow back pressure most, i wouldnt worry about the vane position too much untill you have adjusted desired back pressure
What you can do is adjust the back pressure to be lower say above 2100 rpm so in most driving situations you are making normal boost but as soon as you hit 2100 the vanes open and make the turbos basically go to least back pressure possible
The turbo vanes follow back pressure most, i wouldnt worry about the vane position too much untill you have adjusted desired back pressure
Stroked777
New member
So what your saying is 2100 and below the turbos would operate normal, and then above 2100 it would open the vanes right up and all exhaust energy would go to the atmo?
What would that entail? Keeping the tables the same and the. Above 2100 Rpms change the desired back pressure to what number? Or would I have to you with it
What would that entail? Keeping the tables the same and the. Above 2100 Rpms change the desired back pressure to what number? Or would I have to you with it
powerstroked08
Active member
What Dustin said is a good way to go about it. You can have a normal ebp table until like he said 2100 and then play with your ebp to manipulate the vanes.
Stroked777
New member
And in theory it should drive the atmo harder if you open those vanes up if tuned right?
powerstroked08
Active member
This is how I have observed the vgt behavior. Say your cruising and the ebp is at 15psi and the duty cycle is at 85% but your "desired" ebp table is commanding 20psi your vgt will start closing the vanes to get the ebp to meet the "desired" pressure. So the vgt will continue to close the vanes until it hits the maximum duty cycle to acheive its desired pressure of 20psi. And on the flip side of that, if your ebp is at 50psi and your duty cycle is 15%, but your ebp table is only commanding a desired pressure of 40psi. Then your vanes will start to open to a lower% to get the ebp down to the set or desired psi. It will continue to open the vanes until it hits the minimum duty cycle limit(mine is set at 2%)
powerstroked08
Active member
So I would think if you play with your ebp like Dustin said at 2100 or so rpms to be low enough and you have your minimum duty cycle set to maybe 1-2% then once the rpms hit 2100 and the ebp gets up some the vanes will basically open to their limit and just drive the atmo. I think anyhowLOL
Stroked777
New member
Reading back thru the thread I saw when you were talking about ratios. I don't know I got a bad sensor or what but on my mini max on a few occasions the past few days in 5th tc lock I was able to hold the pedal just right where it would say 25 psi and 21 on ebp. I didn't know that was possible but I had to let off because is was accelerating pretty quickly, but it read that for a few seconds before I let off
set it to a low, but realistic number. I would say if back pressure desired was around 40psi it would drive good and still open the vanes fast enough to let the turbos keep up to the back pressure so to speak.
2100 was just a number i through out, honestly 2500 rpm is probably more realistic for a tune you would use on the street. What i would do is drive a little and kinda pay attention to what rpm the back pressure starts to get high and use that as a guide to when you want to start triming back. Give the ECM and turbos enough time to react, so work your way into it before that number
So say 2500 rpm is when you would like 40 psi back pressure, start tapering from 50 psi at about 2300 and then at 2400 45 psi ect. Mainly so there isnt an abrupt change in the tables making the vanes bounce hard if you find yourself riding that fine line at half throttle or something
powerstroked08
Active member
You know Dustin, this is why you can't sell your 6.4. We need you to keep on playing with your truck and sharing the knowledge! We can't lose one of our guru's!
LOL i wouldnt say that, this stuff will be retained information, but i will admit it is fun to build a tune just to try and go run it and see how it acts, and make sure that the tables DO what you want them to do. I have a feeling my truck wont sell anytime soon
powerstroked08
Active member
Agreed! I have played with a bunch of tunes and it is pretty cool once you get the results you want! But there have been way too many times I didn't get the results I was shooting for:fustrate: I guess 1000 horse isn't going to happen on stock fuel!LOL Maybe I just need more shiney things under the hood. Or maybe some stickers!
ointlaugh: Anyhow I hope to see your truck in diesel power again soon!AllGo'N'Show
New member
Got the VGT loaded and Brandon's trans file with some slight changes, love the new sound at idle much better than the jet engine. Only went around the block a few times to get some points programmed so can't comment there yet. Thanks PSA
powerstroked08
Active member
Cool man! Let me know what you think of it.
travisH3
New member
Ok so after watching the video on page 3 of this thread i want this done. I emailed gearhead about getting his tunes because i really want different trans tuning. my 6.0 had gearhead tuning and didnt shift at set speeds. it shifted depending on load and throttle i think and if i wanted to unlock the tq converter i could tap the brakes and it would unlock. my 6.4 doesnt do that. who can I talk to that may be able to get me a trans file that will work along with VGT off until 1k rpms. I know with MCC your supposed to be able to write it your self but i just dont want to have to bug someone on the forums to help me. id rather just get it done and load it up and enjoy it. I like the H&S engine files, they do fine for me id just like a better trans file like my 6.0. i love that sound at idle! thanks for anyones help, i appreciate it.
TD-5
Member
TravisH3 PM'd me for some info on the changes I made to the VGT tables. As I can't attach pictures to a PM, I'm posting them here along with a recap of discussion. The pictures are screen shots of the tables,
First set are Vane position control, First picture is my changes, then H&S, & factory settings for comparison.
Second set are of desired back pressure, again my settings, then H&S & factory for comparison.
Keep in mind the changes must be made to all the tables, 3 tables for Vane position control, & 12 for desired back pressure.
Along with getting rid of the hairdryer sound at idle, I was also looking to see if there was any efficiency improvements by lowering the back pressure. the original 50% reduction I made across the tables made the truck laggy & smoke.
The settings I have installed now for Desired EBP are a 10% reduction across the tables & 0 below 1000 RPM with a taper in towards 600 rpm at the higher torque values.
The Vane position settings are 10% reduction across all the tables & set to 2% below 1000 rpm. The reason for 2% vs 0 was the minimum duty cycle ( travel ) for the vanes is set at 2% & there was some discussion about having the command exceed the minimum duty cycle and what effect that might have on the actuator & or vane linkage wear.
I didn't drive the truck much after making these changes as I took it off the road for the winter to do some upgrade work. I still haven't got it finished yet due to unforeseen delays in parts & my job getting in the way.
However, the driving I did get in I can say there was no perceived change to performance from the 10% reduction in the tables, & the hair dryer effect is gone at idle like in the video. As far as any gains in efficiency (mileage), I can't say as I didn't drive it enough.
If your just looking to eliminate the hair dryer sound at idle, just make the changes to the tables below 1000 rpm.
NOTE: any changes you make are at your own risk, I have a very basic knowledge of all this tuning stuff, & this is just what I tried. I am by no means an expert !
First set are Vane position control, First picture is my changes, then H&S, & factory settings for comparison.
Second set are of desired back pressure, again my settings, then H&S & factory for comparison.
Keep in mind the changes must be made to all the tables, 3 tables for Vane position control, & 12 for desired back pressure.
Along with getting rid of the hairdryer sound at idle, I was also looking to see if there was any efficiency improvements by lowering the back pressure. the original 50% reduction I made across the tables made the truck laggy & smoke.
The settings I have installed now for Desired EBP are a 10% reduction across the tables & 0 below 1000 RPM with a taper in towards 600 rpm at the higher torque values.
The Vane position settings are 10% reduction across all the tables & set to 2% below 1000 rpm. The reason for 2% vs 0 was the minimum duty cycle ( travel ) for the vanes is set at 2% & there was some discussion about having the command exceed the minimum duty cycle and what effect that might have on the actuator & or vane linkage wear.
I didn't drive the truck much after making these changes as I took it off the road for the winter to do some upgrade work. I still haven't got it finished yet due to unforeseen delays in parts & my job getting in the way.
However, the driving I did get in I can say there was no perceived change to performance from the 10% reduction in the tables, & the hair dryer effect is gone at idle like in the video. As far as any gains in efficiency (mileage), I can't say as I didn't drive it enough.
If your just looking to eliminate the hair dryer sound at idle, just make the changes to the tables below 1000 rpm.
NOTE: any changes you make are at your own risk, I have a very basic knowledge of all this tuning stuff, & this is just what I tried. I am by no means an expert !
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