Lb7 can anybody check this tune

Vmyrhaug

2003 lb7sac45 35" 20x12 fjallasport flares
Mar 6, 2016
177
6
18
41
Norway
2003 lb7 120k miles
the truck is probably tuned
can anybody tell me what they think of this?
i read this tune out of the truck today.
stock trans
3.73 gears
33" tires
banks cold air intake.
banks big head wg
4" exhaust
 

Attachments

  • lb7stock.tun.zip
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  • alistock.tun.zip
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2004LB7

Well-known member
Dec 15, 2010
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doesn't look like a very good tune. nothing particularly bad but the PW has been increased a lot. enough to destroy a stock transmission real fast

also the maf and boost codes have been disabled. probably because they didn't rescale them to adjust for the increased boost and airflow at higher HP and it popped codes

No timing, airflow or maf, boost, throttle or torque adjustments.
 

Vmyrhaug

2003 lb7sac45 35" 20x12 fjallasport flares
Mar 6, 2016
177
6
18
41
Norway
Thanks. It have been like this all time i've had it. I had it for 6 years. 5th gear slips on wot.
But i saw the gear ratio in trans was 4.10. But its 3.73.
I had it on dyno. Only 300hp on wheel.
Will it perform better with a good tune?
 

2004LB7

Well-known member
Dec 15, 2010
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seems to be the way Alison set it up. everything in the tune including tables we don't have access too also reference it. likely because it had it setup with 4:10 for there normal customers and when GM decided to use it, it was easier to tweak other parameters than all of the stuff related to it being 4:10

if you think about it, the transmission doesn't really know what is in the rear end. all it is looking for is the pulse per rotation matching up. but if they have a ton of tables all calibrated to 4:10 and they want to use it on something else, then change the pulse per rotation and maybe things like shift timing. all of which they would likely do anyways even if it was used on a 4:10 axle
 

DAVe3283

Heavy & Slow
Sep 3, 2009
3,727
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Boise, ID, USA
Thanks. It have been like this all time i've had it. I had it for 6 years. 5th gear slips on wot.
But i saw the gear ratio in trans was 4.10. But its 3.73.
I had it on dyno. Only 300hp on wheel.
Will it perform better with a good tune?
A good tune can do better than 300HP easily on a LB7. This is the one I run on my Suburban and ran on my truck before I built the motor: https://www.duramaxdiesels.com/forum/threads/no-logic-3-0-175-hp.42711/

You can do over 500 HP on a stock LB7 if the CP3 is healthy and you want to roll the dice on if your rods survive.

I'd recommend getting the transmission built before you put a stronger tune in. The one I linked will roast a stock transmission pretty quickly if you're heavy on the throttle. But with a built transmission, it's a great setup, tows well, etc.

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Vmyrhaug

2003 lb7sac45 35" 20x12 fjallasport flares
Mar 6, 2016
177
6
18
41
Norway
A good tune can do better than 300HP easily on a LB7. This is the one I run on my Suburban and ran on my truck before I built the motor: https://www.duramaxdiesels.com/forum/threads/no-logic-3-0-175-hp.42711/

You can do over 500 HP on a stock LB7 if the CP3 is healthy and you want to roll the dice on if your rods survive.

I'd recommend getting the transmission built before you put a stronger tune in. The one I linked will roast a stock transmission pretty quickly if you're heavy on the throttle. But with a built transmission, it's a great setup, tows well, etc.

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i flashed the tune you linked. wow, the car wake up.
yhank u very much for this tune, did some adjusment on it.
adjusted down fuel pressure att wot, adjusted down fuel pressure at light load from 1500-2000rpm, its started to rattle a little with tune.
adusted down main fuel table a little, maybe trans will live.
but a very nice tune.
also adjustet speedo, was 9% off in my "stock" tune

also adjusted shift points in al5. adjusted below 50% tps. and now rpm isnt above 1500rpm on daily driving light load.
still some fine tuning in al5 tune, but is working very well now.
 

TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
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That NoLogic tune is a good one. Dave did very well on it. :)

Vmyrhaug, once the trans starts to limp, theres not much you can do to save it. Start planning for a rebuild.
 

DAVe3283

Heavy & Slow
Sep 3, 2009
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Boise, ID, USA
Glad you like the tune. What altitude (elevation) are you at? I mostly run 2500-6500 ft (750-2000 m) and have never noticed it rattle. I go to sea level from time to time and it is louder, but I wouldn't say louder than stock. Interesting it makes yours rattle.

I'll have to think about that. If lowering rail pressure helps, that's moving the center of the injection event back. You might try knocking a degree of timing out of the timing table where it rattles instead. I was somewhat aggressive on timing in the highway/cruise ranges to maximize fuel economy. It might be a bit more than yours likes. You could also play with pilot injection to try and quiet it down. Or what you did should be fine too, but it might get better mileage to bring the pressure back up and dial the timing down. You could try both and see.

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Vmyrhaug

2003 lb7sac45 35" 20x12 fjallasport flares
Mar 6, 2016
177
6
18
41
Norway
Glad you like the tune. What altitude (elevation) are you at? I mostly run 2500-6500 ft (750-2000 m) and have never noticed it rattle. I go to sea level from time to time and it is louder, but I wouldn't say louder than stock. Interesting it makes yours rattle.

I'll have to think about that. If lowering rail pressure helps, that's moving the center of the injection event back. You might try knocking a degree of timing out of the timing table where it rattles instead. I was somewhat aggressive on timing in the highway/cruise ranges to maximize fuel economy. It might be a bit more than yours likes. You could also play with pilot injection to try and quiet it down. Or what you did should be fine too, but it might get better mileage to bring the pressure back up and dial the timing down. You could try both and see.

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I've noticed that redusing fuel pressure give"softer" ignition. On this i did not reduse much. Only a little.
Also checked ign timing. Did som smal adjustment there, but not more than 1 degress..
The rattle can be from fuel quality here in norway. I see winter fuel is less rattle on warm engine.
Also need too turn up boost pressure smoke free up to 80-90% throttle.


Altitude here is 600m over sea level ( 2000ft)

Transmission have limped 4 times in 5 years now. I know i have too build it.
But, it still works...
 

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
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Central OH
Anyone else confused why we needed to look over this tune file, when he seemingly has a decent understanding of how it all works anyway?
 

DAVe3283

Heavy & Slow
Sep 3, 2009
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I'm guessing he is new to the Duramax, and was curious if it seemed reasonable.

If I bought a VW TDI, I'd probably be doing the same thing on a WV forum if I found an aftermarket tune in the ECU. Because while I understand tuning software, I don't know what's normal or safe for those engines.

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2004LB7

Well-known member
Dec 15, 2010
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I've noticed that redusing fuel pressure give"softer" ignition. On this i did not reduse much. Only a little.
Also checked ign timing. Did som smal adjustment there, but not more than 1 degress..
The rattle can be from fuel quality here in norway. I see winter fuel is less rattle on warm engine.
Also need too turn up boost pressure smoke free up to 80-90% throttle.


Altitude here is 600m over sea level ( 2000ft)

Transmission have limped 4 times in 5 years now. I know i have too build it.
But, it still works...

be aware, you cant "turn up" boost pressure on the LB7. it is a fixed vane turbo. the best you can do is modify the waste gate to raise the pressure when it opens. other than that, try to get the boost table to match as much as possible to the actual boost in order to limit codes
 

DAVe3283

Heavy & Slow
Sep 3, 2009
3,727
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Boise, ID, USA
be aware, you cant "turn up" boost pressure on the LB7. it is a fixed vane turbo. the best you can do is modify the waste gate to raise the pressure when it opens. other than that, try to get the boost table to match as much as possible to the actual boost in order to limit codes
Exactly, he will need a boost increase valve of some kind (which I mention in the forum post where I share the tune). The expected boost tables are already dialed for the PPE boost increase valve, but since the LB7 MAP sensor is only like a 2-bar sensor, it just ends up being mostly maxed out, so it probably won't throw an over-boost code no matter what. It should still catch under-boost though.
 

Vmyrhaug

2003 lb7sac45 35" 20x12 fjallasport flares
Mar 6, 2016
177
6
18
41
Norway
be aware, you cant "turn up" boost pressure on the LB7. it is a fixed vane turbo. the best you can do is modify the waste gate to raise the pressure when it opens. other than that, try to get the boost table to match as much as possible to the actual boost in order to limit codes
Wg pressure is now 20psi.
What i ment with turn up boost pressure is adjust wg pressure too 28psi. I have a bank big head in there, so, a little adjustment will be perfect.
 

Vmyrhaug

2003 lb7sac45 35" 20x12 fjallasport flares
Mar 6, 2016
177
6
18
41
Norway
Anyone else confused why we needed to look over this tune file, when he seemingly has a decent understanding of how it all works anyway?
The tune file from dave was awsome. Just some small adjustment for me.
And now with some small adjustment, and small adjusment on light load shifting points in trans, it now runs perfect.
 

Vmyrhaug

2003 lb7sac45 35" 20x12 fjallasport flares
Mar 6, 2016
177
6
18
41
Norway
Exactly, he will need a boost increase valve of some kind (which I mention in the forum post where I share the tune). The expected boost tables are already dialed for the PPE boost increase valve, but since the LB7 MAP sensor is only like a 2-bar sensor, it just ends up being mostly maxed out, so it probably won't throw an over-boost code no matter what. It should still catch under-boost though.
I'm going to adjust the banks big head wg first. But before that i need to mount a boost gauge in the car.
Iv'e mesured 20psi in dyno before. But i will adjust it too 28psi.
 

DAVe3283

Heavy & Slow
Sep 3, 2009
3,727
296
83
Boise, ID, USA
I'm going to adjust the banks big head wg first. But before that i need to mount a boost gauge in the car.
Iv'e mesured 20psi in dyno before. But i will adjust it too 28psi.
That should work great. I didn't realize the Banks Big Head was adjustable. That's much better than using a increase/bleed valve.

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