Turbo Brake Function?

[bballer182]

I've had two LBZs now that will not follow my commanded vane position no matter what I do. Command is 100% at 0-5mm3 and 34psi boost. Also changed B2231 and B2232 to always enable boost control. Doesn't do what the tune calls for and vane position isn't as steady. Both trucks have the 6128 op system.

Dan-
you shouldn't have to change 2231 or 2232. factory setting is ok for turbo brake. I have asked Ross once before to edit the table descriptions. They are a little confusing. The end result should be that the ECM will NOT try to control boost, (ignoring the boost table) and referencing the vane table only.

Did you edit the max vane table too by chance!

[dansdieselp]

I'll try upping it a little on the next truck and see if that works. Thanks for your input.

[Boost]

Are the vanes strong enough to turbo brake the truck? Silly question but I am picturing a small turbo slowing down a huge truck... the idea is strange to me at first. Also, is there any undesired effect say in heat buildup due to the backpressure? I ask because I increased idle vane position on an LBZ for better response and desired sound. Thanks.

[bballer182]

Are the vanes strong enough to turbo brake the truck? Silly question but I am picturing a small turbo slowing down a huge truck... the idea is strange to me at first. Also, is there any undesired effect say in heat buildup due to the backpressure? I ask because I increased idle vane position on an LBZ for better response and desired sound. Thanks.

There is no ill affect. It is a factory tuned feature on the medium duty kodiaks and topkicks.

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[Boost]

Thanks!

[Boost]

So I'm wondering, why are there J-brakes available that go in the downpipe, are they stronger? And the last of the "4500"s they were LLYs right? Not much use looking at their factory turbo brake parameters when setting up an LMM to tow a motor home and use the turbo brake?

[bballer182]

The exhaust brakes that were the flapper valves were use up to '06 (true LLY's) the '06 model year MDs actually had LBZs in them but detuned and re-RPO'd for the MD's as LLYs and they use toggle switch to flip the ECM into a separate set of tables that was never released to us. And same goes for the LMM MD's. So there are no parameter for you to even look at to see what they were doing. Sorry man.

[dansdieselp]

Tried another LBZ and same result. No turbo brake or open vanes at idle. Can't figure it out.

[bballer182]

Tried another LBZ and same result. No turbo brake or open vanes at idle. Can't figure it out.

If you want Dan, you can e-mail me the tune and I can see if i can find any reason why it would be working...

Justins@molalla.net

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[Drake_Lawdawg]

I know this is an old thread, but how do you get the vanes to only do this while operating in T/H mode? On the LMM it looks easy but the LBZ I can't find a way???