DSP5 haters discussion/argument/fight/etc

TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
15,595
1,843
113
Mid Michigan
The new model Duramaxes always seem to bring out arguments like this. Been that way since the LLY came out.

We'll see what we'll see on the L5P.
 

LBZ

Super Moderator
Staff member
Jul 2, 2007
9,903
149
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B.C.
Some of you guys must not be towing 30k.. :hug:



Or definitely not towing 10-15k through the mountains in the middle of winter when it’s -20.
Sure a guy could flash a tune in but when a one leaves Calgary and it’s 45 degrees you don’t really think about the temp 3 hrs away when you and 3 buddies are loading up the sleds for the weekend!!
 

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
3,485
467
83
Central OH
I guess Mark should have tried to talk me into one of these single master tunes instead of a dsp

Oh and the single 80mm turbo having a progressive power band :roflmao:
 

gmduramax

Shits broke
Jun 12, 2008
4,072
248
63
Nor cal
Sorry for the derail I’m just bored. But if anyone in the NorCal area wants to go for a ride to see how violent and shitty an LMM runs with an 80mm on a single tune just pm me. It’s just sad all these people paid good money for a truck they can’t drive around.

These L5P numbers have me contemplating selling my truck for one, unless I can get those heads to work on my LMM I just might.
 

2004LB7

Well-known member
Dec 15, 2010
6,944
2,119
113
Norcal
There are several legitimate reasons to have a true DSP5 switch:

On a mileage tune for running empty you can get away with a little more timing than a tow tune run under load, and it will help the mileage. On VVT trucks you can also open the vanes at cruising mm3 to help the mileage when not under a load. Those things would both not work well while towing heavy loads.

Running on a high power tune will mean that you use less throttle input when driving conservatively, such as while towing. With light throttle comes earlier shifts, earlier shifts while towing will get you under the turbo. On a lower powered tune you will have to use more throttle while towing, effectively raising the shift points and making the truck tow nicer. Sure I can manually shift at a higher RPM, but many customers don't want to manually shift their automatic and why should they have to. Some people get annoyed by a turbo brake except when they are towing, so having it only on the tow tune is nice.

While racing if you are not full throttle (for bracket or what the track can hold) you are also going to have a lower shift point and a hard time staying consistent for bracket/index racing. A switch lets you run a tune that will run the number while WOT with shifts at a consistent RPM.

A low power tune for if someone else drives your truck is nice. A high idle tune is convenient for low speed cruise control (towing a camper through an RV park without your foot bouncing on the throttle), jump starting someone, warming up your truck or cooling off the interior faster, etc.

Except for when towing you will be running in a different part of the map vs when running empty so you can still have your towing/milage tune together. It just takes logging to see where it runs for the different loads. Same applies for the turbo vanes.

As for the shifts, they should always be consistent with a single tune as the throttle input will always match the same shift rpm. If you are changing it in a DSP tune you may need to allow time to the trans to adjust/learn. Best to leave it once it has adapted

I can see its use in racing or sled pulling, etc

If you have a touchy throttle, especially while towing, you need to make adjustments to your tune

For warming up, this can be done in the tune or on the elevated idle settings. Cooling off, if you are referring to the engine, that should be in the tune also. If you are talking about the A/C then yeah, maybe useful. I think the LB7 has a table for this too
 

monster50iii

Member
Dec 5, 2014
329
6
18
I'm not a tuning professional by any means, but I run more aggressive fuel pressure, boost, and less timing in my tow tune vs the rest. A guy could make a single tune that does it all, but I feel there will be compromises one way or the other.
 

DAVe3283

Heavy & Slow
Sep 3, 2009
3,724
292
83
Boise, ID, USA
I guess coming from a LB7 (fixed single) I didn't think about the benefit of being able to turn a tow brake on and off. That would be cool.

All I've ever tuned is LB7s, but I have found that more timing doesn't mean more mileage. Once I hit somewhere in the 6-9 degree range (SACs seem to like a hair more timing), fuel economy stops going up, it just gets louder. Fuel pressure, on the other hand, does improve mileage. I tend to run pretty aggressive fuel pressure curves, and have always been able to make a single tune that gets good unloaded mileage without getting too hot towing, since the timing isn't through the roof. But higher fuel pressure can shorten fuel system life, so that's a tradeoff.

Having a tune make more power at a given throttle percent will effectively alter shift points, if you drive based on a constant acceleration rate, not a constant throttle. But the way I handle that is get the tune where the throttle is smooth, predictable, and progressive (not linear!), then adjust the normal and tow-haul shift points so it drives nicely. It helps if your converter is matched with your turbo/cam setup, of course. Trans shift points matching your power band and throttle curve makes all the difference in how nice a big single turbo rig is to drive.

As a side note, it might be nice to split the "to DSP or not 2 DSP" discussion into its own thread, since it doesn't really apply to the L5P tuning (yet?). But there is some good info / entertainment here, might as well let it keep going IMO.
 

JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
13,699
751
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Texas!!!
So you can tell me you have never been caught off guard spinning your tires when you’re rolling into it, because the boost hits in the rain, snow, or ice? I feel you can make the throttle as progressive as you want our power band still won’t be progressive. And for someone that’s not used to it or worse yet only driven vehicles with traction control it’s dangerous IMO. Of course I might be a little bit biases since my wife could’ve easily been killed in her accident due to her lack of throttle control.


Sent from my iPhone using Tapatalk
Not that I can recall. I have spun my tires in the rain and snow before, but that is because I was trying to accelerate as fast as traction would allow. I was slowly easing into the throttle until I broke traction, and then backed out. I could have easily done the same thing with a stock tune under the same conditions. Stock LBZ turbos are pretty predictable on boost, and even the 76mm single on the shop truck is pretty predictable and easy to drive. As a matter of fact, I don't even have a switch on that truck, and I drive it all the time on the tune that ran in the 10s at 128 mph. I would be happy to let anyone go for a ride in it if they are close by.
 

tkniss

New member
Apr 25, 2012
25
0
1
Or definitely not towing 10-15k through the mountains in the middle of winter when it’s -20.
Sure a guy could flash a tune in but when a one leaves Calgary and it’s 45 degrees you don’t really think about the temp 3 hrs away when you and 3 buddies are loading up the sleds for the weekend!!

Yep, but gotta add a couple things. Try leaving the truck on the max effort tune when it is more like -35 outside. Even being plugged in all night doesn't help. Oh sure, it starts right up but have you ever listened to a max effort tune Duramax just idling or driving at these temps. Now lets hook up 10-15k behind and head to the mountains. I turn mine down to stock if for nothing else than my ears and stress level. It might not be hurting anything but that is not what it sounds like.
just my two cents.
 

gmduramax

Shits broke
Jun 12, 2008
4,072
248
63
Nor cal
Yep, but gotta add a couple things. Try leaving the truck on the max effort tune when it is more like -35 outside. Even being plugged in all night doesn't help. Oh sure, it starts right up but have you ever listened to a max effort tune Duramax just idling or driving at these temps. Now lets hook up 10-15k behind and head to the mountains. I turn mine down to stock if for nothing else than my ears and stress level. It might not be hurting anything but that is not what it sounds like.
just my two cents.

Interesting isn’t that what ect and iat multipliers are for :spit:
 

GMC_2002_Dmax

The Still Master
I just traded out my 2016 Denali LML for a 2019 Denali L5P.


My initial impressions after driving a 100% STOCK LML for almost a year is that the L5P is a big improvement IMHO.


I have owned or driven them all, owned new a 2002/LB7, 2007/LBZ and driven a ton of LLY and LMM and have also owned a 2012/LML - Tuned/SOTF, 2016/LML BONE STOCK.


IMHO I would delete an L5P, remove some of the limiters, get it to about 500 honest RWHP and around 1100 for TQ, Max the TCM Line PSI out and leave it as a single tune.


The trans should live and it will last a good long time.

The guys that want to spend $5k on ECM Tuning, $1k or so on TCM Tuning, $4.5-$6K on a full built trans, plus a downpipe/install labor, under-hood pipe kit/intake, and a full exhaust, IMHO you are approaching north of $12K to delete a truck and do what has been done to previous years.


Granted a lot of guys build a trans, do a under-hood delete anyways, but the stock truck is pretty healthy by stock truck standards, I have not towed with mine yet, but on tip in and stabbing it I can tell its better than a 50-60HP LML deleted tuned truck just stock.

I have my spare ecm and tcm.........so we shall see what I decide to do.


:eek:
 

Dozerboy

Well-known member
Jun 23, 2009
4,892
470
83
TX of course
The "I need a DSP5 switch" starter pack



Hey I need some better pictures than that! How my supposed to copy your top secret squirrel tuning if they’re all blurry... oh well I’ll just enter the highest value allowable in those tables and should be good to go.


Sent from my iPad using Tapatalk
 

tkniss

New member
Apr 25, 2012
25
0
1
Interesting isn’t that what ect and iat multipliers are for :spit:

Lol. Yep, but haven't seen many 800hp trucks with anything resembling anykind of iat multipliers. And even with a winter front, good luck seeing ect anywhere near 185 while cruzin into the -35 wind at 60mph
I have three lbz's: One single turbo, one dual turbo and a triple turbo. All tuned by different, reputable tuners. All the trucks have proper working t-stats and all react pretty much the same to -35 :cold:

sorry guys, my posts (or me ) got screwed up
 

THEFERMANATOR

LEGALLY INSANE
Feb 16, 2009
3,890
43
48
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ZEPHYRHILLS, FL
Well I have a dsp2 and happen to really like it. I only have an lb7, but have found the 2nd tune quite handy, at least for my application. My drivetrain and frame in my burb is not up to the power of my daily driver tune when I add 8-10K pounds to it of travel trailer, gear, generator, and the rest. So I have a dsp2 that I use basically for tow/haul mode. I even started to hook it up to a relay triggerred off of the tow/haul indicator so it cuts the power back when towing to protect my drivetrain/frame, but I have found on wet/icy roads it was nice then to cut the power back as well, so I left it on a switch. With mine, when it comes on boost, it either squats and goes forward, or pops up in the back and goes right around. And it's one thing to get a pickup sideways, but it's a different story when you do it in a suburban.

For vgt trucks, I actually liked the dsp5. I really only needed 4, but the 5 was there. It was nice having a stock/valet tune, milage tune with lots of timing and no boost, a daily driver/performance tune, then your tow tune with turbo brake. And yes, I've built up single tunes that did 3 of those in one, but there is always trade offs in those kinds of tunes.
 

Chavez91

People Go Outside?
May 30, 2012
139
2
18
Heh. Wouldn't you like to know
I just traded out my 2016 Denali LML for a 2019 Denali L5P.


My initial impressions after driving a 100% STOCK LML for almost a year is that the L5P is a big improvement IMHO.


I have owned or driven them all, owned new a 2002/LB7, 2007/LBZ and driven a ton of LLY and LMM and have also owned a 2012/LML - Tuned/SOTF, 2016/LML BONE STOCK.


IMHO I would delete an L5P, remove some of the limiters, get it to about 500 honest RWHP and around 1100 for TQ, Max the TCM Line PSI out and leave it as a single tune.


The trans should live and it will last a good long time.

The guys that want to spend $5k on ECM Tuning, $1k or so on TCM Tuning, $4.5-$6K on a full built trans, plus a downpipe/install labor, under-hood pipe kit/intake, and a full exhaust, IMHO you are approaching north of $12K to delete a truck and do what has been done to previous years.


Granted a lot of guys build a trans, do a under-hood delete anyways, but the stock truck is pretty healthy by stock truck standards, I have not towed with mine yet, but on tip in and stabbing it I can tell its better than a 50-60HP LML deleted tuned truck just stock.

I have my spare ecm and tcm.........so we shall see what I decide to do.


:eek:

Ehhh..... You'd be surprised... Did the dummy solenoid mod @ about 7k miles... It's at 21k when I pulled the trans just before tuning a few months ago and the clutches were already smoking... And that's at stock. Don't think line pressure will save these. We will see though.... Pulling it in the coming week or so to build it. We will see how bad 2 1400 ft/lb pulls did and tq backed down to 1280 for the past month has treated her.