I haven't got to load my tune for adjusting this yet, did you also see a decrease in crusing egts?

 

<-- shame on this guy


My H&S EGT module crapped out about a month ago and I have been too lazy to order a manual gauge and install it. I know I know

 

I haven't noticed any significant increase in EGTs.

 

Also, when you have changed the min and max maps for the turbo, has this affected the exhaust brake when the truck is cold and warming up? i.e. does the exhaust brake still come on when the engine is cold to help warm the engine up?

 

The exhaust brake still works as normal.

It however doesn't come on automatically when the engine is cold it never did before either. All the engine does is idle up to 1000rpm on its own. You can manually activate the exhaust brake though.

 

Loaded my tune for this today. Gotta say I love the new sound and it does better around town. I did a WOT run and got 32psi boost and 50psi drive with the min and max set to 0 and 2 respectively. It needs some work in a few areas to help with high loads and low rpm, but I'm happy with the initial results!

 

can someone post a map of a turbo that has been loosened a bit for cruising speeds?

 

Is this similar to what the draconian guys are doing with the "5.9CR" modofier? Forcing the turbo to operate more like a fixed vein turbo and it ,in turn, gives u a more throatyer 5.9 sound? Cause my experiences running that tune was a bit of turbo lag and higher egts? I liked the sound and all but for me it was not worth running for the sacrificed turbo spool and egts creepin up a lil more than I like to see. And I was wondering is the higher egts due to the turbo not spooling as fast and therefor not being able to blow out the hot exhaust gases faster than the truck is creating them? Or am I way off haha? Just trying to understand how this is all coming together. And the benefits of tuning and running the turbo differently?

 

This is what I'm currently running.

I have a max of 6% at the higher end of the map because that's where it was with the no ATT tunes before and that always worked well for me.

It's zero on the low end to reduce load and also for the sound. In my experience if you set the entire map to zero the turbo won't quite spool very good on its own. In my testing it would require a lot of fuel and heat just to get 30psi out of it. I have found though it doesn't need much help so my map is capped at 6 and it works great.

Cruise egts are about the same as before and mileage seems to be about the same. As far as response goes under normal driving it is no different and under heavy throttle from a stop there is a brief lag but not bad at all.

Keep in mind to run a more open vgt tune like this you need to have more fuel come in sooner to help spool it. I will discuss this more later.

 

Are you running modified min closed/atmospheric/compressed turbo maps as well or just this one map? If so, mind posting them?

 

Thank you for that!

I'm just going to try opening mine up a bit on The low end, I don't want that common rail exhaust note and drone, I like how the vgt keeps that to a minimum, just want to reduce drive pressure a bit.

 

I got to drive my normal route from Klamath Falls to Bend with my turbo tune and saw some good results.

Stock turbo parameters: Cruise control set to 63mph, ~1775 rpm, boost 4psi, Back Pressure 4-5psi, EGT's 610-630*, fuel quantity 34-36mm3.

Turbo only 3% closed: Cruise control set to 63mph, `1775rpm, boost 2psi, back pressure 2psi, EGT's 640-660*, fuel quantity 30-33mm3.

This shows a small decrease in engine load by opening up the turbo during cruising conditions. I plan to keep running this and refine it some more and see if there is any measurable fuel mileage increase.

 

"Don't take this the wrong way, or as an insult... I'm just gonna be straight to the point with this section"

You guys need to be careful adjusting something that obviously none of you understand. The numbers your entering into this map don't correlate directly. They correlate to a different map that your not giving control over.

So 6 actually means more like 30%... 10 means 50%....

"This table converts the commanded Turbo Vane Position to an actual position sent to the VGT controller."

This is the description for a map that you can't see but need to understand what your actually doing.

6 on the top end is a ton btw. Your drive pressure is going to be quite high. I'm trying my best to stay out of these because I've spent the last 2 years testing all this to get to where I am. But some of this I'm going to chime in on to keep you from breaking something. I plan on leaving my MCC thread as it is (Barely basic in comparison to what's actually needed to write a tune). But honestly, ya'll need to be careful. Some of the stuff I've seen in this "SUB Forum" is down right scary...

You also don't need any help from the vgt to fully spool the turbo. And you don't need anymore fuel than you have either. 34lbs isn't hard to do with a 1 or 0 in the final columns...

 

Thanks for the thoughts dave. I understand a community looking to truly understand things you have spent a great deal of time learning puts you in an awkward spot. With that said I appreciate you jumping in to provide your guardrail guidance at the least.

 

Nice results rodram2002. I wish I had a drive pressure reading, that sure takes the guess work out of it.

 

As always we aprechieate the expertise.

I tuned mine based off mcc descriptions and working within the values that were there from factory. Thus in my mind I felt it was safe, unfortunetly as Dave said we don't always see the full picture. I'm glad you shared your experience once again.

 

Here's a screen shot of what it looks like in efi. Its a completely seperate table that uses the values you enter in the min/max tables to correlate to a % of closure on the vgt actuator.

BigCE, your turbo might be like mine on my truck and weak, so squeezing down on it isn't killing drive pressure. But throw it on a good clean turbo and you might see a nice 2.5:1 spike in the 70-90psi range. Do that a bunch of times or do it one time with a little bit of a cold motor and your now putting a new hg in...

 

Here's a screen shot of what it looks like in efi. Its a completely seperate table that uses the values you enter in the min/max tables to correlate to a % of closure on the vgt actuator.

and you can edit that map? that's awesome. Oh how I dream of the day 2010+ EFIlive comes out. Course I had my 2003 and learned dont get my hopes up.

 

I need a drive pressure guage I guess

 

Thank you for that map Dave. I assume that is true for all 6.7's? That will come in very handy for tuning. I am now very surprised at what the stock tuning does command for turbine vane position.

 

Its easy to make the assumption that a 1 isn't 1%, 10 isn't 10%, if you do your own testing. (measure the difference at idle for example...)

I do not know for sure what the direct correlation is. But I can tell you my maps look nothing like ya'lls, H&S, or stock do. Mine are completely different and its a result of hours and days of testing different ones. There is a lot to be had with the turbo on a stock truck.

You guys need to figure out a way to data log.

 

Wow that's amazing

 

Dave, do you know which turbine maps are for when the exhaust brake is turned on or off?

 

I haven't found any that react that way yet. You can literally zero out all max & min maps with no effect on the eb.

But at the same time I haven't tried to enter neg numbers either. Never know, alot of the 4th gen tuning has neg values where the 3rd gen didn't. So maybe zero isn't zero..

THe problem is data logging. or the lack there of. That's why I said you guys need to get some data logging going.

We did it the old fashion way, but it literally took months to get to where we had a viable product. And even then, last week we found two issues. A flutter when you are on flat ground in the upper gears with just the slightest bit of throttle input and some trucks need more smoothing on the accel maps like jerrods. Well, jerrods is the only one I've ran into so far that needs it... Which is really weird in itself.

 

Thank you sir! I just noticed that controlling the turbo from the turbine maps will still activate the EB even when it is turned off. I has only made turbine maps 1 and 2 for EB function thus far.

 

Has anyone played with when it is "active"? I have a friend that asked me to make the EB active automatically when it starts so its on when he remote starts in the winter. I dont think its possible though.

In other words, EB "on" as default when started...

 

Would be great to see more discussion about this.

Just because I love the sounds, I've wondered for years - if you could tune the VGT to be more open how would it sound. Well I went for today, and I'm anxious to do more with it. Starting with 0% max/min across the board - performance needs improvement but the sound is so much cleaner. Definitely doesn't make up for 2nd gen envy, but I think there's probably hope for an improved exhaust note with good performance. I don't dislike the sound of my truck with regular tuning, but at some points the VGT just sounds so restricting.

At 0% VGT on H&S "tow" I have to really get on the throttle to build any boost at all and I think I only see 5-10lbs max under 2K rpm, and about 20 max at full throttle. I'm going to introduce a small amount of VGT back into the tune.

 

At 0% VGT on H&S "tow" I have to really get on the throttle to build any boost at all and I think I only see 5-10lbs max under 2K rpm, and about 20 max at full throttle. I'm going to introduce a small amount of VGT back into the tune.

BigCE has tested this extensively, I believe he fuels a little more down low to get it moving.

RE: sound - Assuming you talking about the "5.9L" sound, its pretty straight forward:
1) Make entire Turbo MIN map values of "0" (all 4 maps)
2) Make entire Turbo MAX map values of "5" (all 4 maps)

I bet you may have already figured it out. All the above does is give the turbo a little wiggle room to tighten up for spoolup. I have ran it, and yeah its louder. As opposed to maps like the above, I just used those small values near zero load area of the maps so I get the sound at idle or off load, but good spool up otherwise.

Make sense? Fun and addicting right?!

 

So I figured out that if you drive the exhaust brake with only the first minimum closed position map, the EB will function when turned on and only when turned on.

Here are what my maps look like. I am having good results with this thus far. The EB stay right at 60psi of back pressure or below.

Tommy-If your friend wants that EB on all the time, a crude way of doing it is the drive the closed position in all the minimum closed position maps.

 

I'm confused are you saying the min and max maps actually influence the Exhaust Brake?

 

Yes. By forcing the vanes to a closed position by adjusting these maps, you can make the EB stronger and you should be able to turn it on all the time. If you set the minimum closed position for 0 fueling to a higher level on all the minimum position maps, then the turbo must close down when you stop fueling.

Not sure if I made it any more clear.

 

Well I have had a few beers so I am predictably lost.

I don't understand how you can set both maps to zero and have the EB still function. Now your saying these maps still influence the brake. Don't get me wrong I believe you if you have a drive pressure gauge you have more info than I do.

I have my maximum braking torque maps increased slightly I just assumed these were the only maps that had any correlation to the exhaust brake.