LBZ: Will making a variable vane turbo brake in efi harm anything?

[Jasondt2001]

I haven't noticed that on any of the truck I have put this one, but thanks for sharing - I'll keep a closer eye on them from now on.

yeah, I'll be sure to check my oil more frequently now - I've never seen a problem and I check mine frequently.

Have you guys noticed increased oil consumption on the turbo brake feature? On mine on a high rpm decel I can see white smoke coming out a little bit pretty hard to notice though, the only way I found out was a buddy was following. With no oil leaks anywere my truck will use about 2 quarts in 5000 miles with the turbo brake feature. I have mine tuned to work anytime the throttle is released because I hate using the brake and there is lots of hills where I live.

Not sure about the oil consumption part, but I did notice smoke under the same conditions.

I tow during the day, but, I've noticed no white smoke, I'll look harder, thanks for the heads up!

 

[Jasondt2001]

i know the converter doesnt control it, but while cruising on the highway at say 70, i am at 2000rpm. if i have the main tune modded every time i let off the throttle to slow a bit the turbo brake would function because the converter holds it at the rpm. understand? i may be splainin' it wrong.



on my main tune, i have the rows 0-15 mm3 in the min/max vain table set to 10. this way at very low throttle it opens up the vains for less engine braking. then beyond that i have modded vain tables to where i saw it best built boost. and cleared up smoke the best. i have it all changed in the main tune, just need to flash it in and give it a try.

Yes while you're on the freeway if you've commanded it to come on at 2000 rpm (Like me) and you're doing 70 with the tq locked and let off nothing will happen... If you stomp it to 80 to get passed someone and then let off it feels like the damn brakes are on and it'll pull you back to legal limits quite quickly.
IT all depends on where you put the enabler. I've finally just put it at 2200 rpm to come on and will downshift manually when towing, or just use a strict tow tune and have that in when I know I'll be pulling something with a lower RPM value to enable it.

 

[Cornell]

Oh you do it a bit different than me guys...

I adjust my max vane tables up to where I command it in my target tables. For me it works great - but as Dustin said, if I command 99.5 (my usual) I only see a MAX of 99.2 in the log.
I think if you command the minimum table at 0mm3 in the main tune you'll have the turbo brake on ALL the time, but, if you tell it the max vane in the main tune, and the commanded where you want it it would work like mine, and mine works great.

If you guys want, I'll post my tune and my stocker it so you can see it.

If you would post up your stock tune and the modifid turbo brake tune that would be awesome, I modified my target boost at all altitudes and didn't notice much difference in deceleration, I didn't have any weight behind me though.

 

[Jasondt2001]

Stock Turbo Tune Changes

Here ya go guys.
I also included the script for the stock tune to the turbo brake tune if needed.
That's the .txt file enclosed, the two .tun files are the actual tunes you can compare in efilive

 

[JoshH]

When I do the brake function I don't do anything to the boost tables. I set the max, min, and target vane tables to 100 at 0 and 5 mm3 from whatever RPM I want it to be active and up. Works great. I have seen 100% every time I have logged it and only when I let off the throttle and the RPMs are above what I have it set at.

 

[Cornell]

if you could post up your stock and modified turbo brake tune that would be awesome. I modified my desired bosst levels at all altitudes last night from 0-10 mm3 from 1800 to 3400 rpm and I didn't notice much of anything in deceleration

 

[Jasondt2001]

I did, go back 2 posts

 

[stacks04]

okay guys, it works in the dsp tow tune i have. if anybody is interested in it i will post up all i did to make it work. :hello:

 

[McRat]

I wouldn't worry about hurting anything.

Our motorhome (LMM) has a factory turbobrake switch, as do some other Kodiaks.

It is very aggressive in slowing down a 17,500lb MH. Even on the steepest grades you don't need brakes.

 

[Jasondt2001]

if you could post up your stock and modified turbo brake tune that would be awesome. I modified my desired bosst levels at all altitudes last night from 0-10 mm3 from 1800 to 3400 rpm and I didn't notice much of anything in deceleration

If empty, it's there but not as good as with a load behind you - also make sure you're in tow haul mode... you'll feel it with the TQ converter locked.

 

[Jasondt2001]

I wouldn't worry about hurting anything.

Our motorhome (LMM) has a factory turbobrake switch, as do some other Kodiaks.

It is very aggressive in slowing down a 17,500lb MH. Even on the steepest grades you don't need brakes.

Thank you! I've really enjoyed it! :hug:

 

[Cornell]

If empty, it's there but not as good as with a load behind you - also make sure you're in tow haul mode... you'll feel it with the TQ converter locked.

I musta skipped over it lol, been posting from my phone all day :rofl: I had it in tow haul and had it in manual mode to keep rpms up to try and feel it more but no luck. When I get home I'll check out your tune to see what I did wrong

 

[LBZ]

T/H and 8000lbs behind me going through the Rocky Mountains, I notice it-big time!! It will build about 10-12lbs when it's working above 2500rpm.

 

[LBZ]

Could the smoke be from a failing turbo or valve seals I wonder?.....

 

[rcr1978]

Could the smoke be from a failing turbo or valve seals I wonder?.....

Possible, I thought about it for a while but figured it could be numerous things Crank case vent, turbo seals, ect... But I think without the turbo brake feature the oil consumption is gone. Maybe since there is no combustion taking place in the cylinders I wonder since the lack off pressure somehow the oil is getting past the rings since basically there's a firehose under there trying to cool the piston off. This may be a far fetched but who knows. How does the keystone ring function does't it need pressure to help seal the cylinder?

 

[Cornell]

Works like a charm now thanks Jason

 

[Jasondt2001]

Good news!!

Works like a charm now thanks Jason

Awesome!! glad I could help! :hug:

Now you need to play with the vane table down low to get the 'rumble/deep throaty' idle :happy2:

 

[Cornell]

If empty, it's there but not as good as with a load behind you - also make sure you're in tow haul mode... you'll feel it with the TQ converter locked.

Awesome!! glad I could help! :hug:

Now you need to play with the vane table down low to get the 'rumble/deep throaty' idle :happy2:

I had the Lb7 idle in all summer then I switched up my tune a bit and forgot to change the tables down low again, maybe i'l remember to do it after worrk today

 

[raceghost]

Resurrecting another thread I cam a cross with great info. My question is this. I am trying to build 1 tune to rule them all... Have done it with rally cars, now trying to do it with diesels. Since I am new to the exhaust break for towing, and trying to understand the way the VVT can control it, is there a chance, say, you romp on it up the freeway ramp as an example, push it to 3500 RPM and then let off in a quickness and all of a sudden set the exhaust break off? ANy thoughts of where this feature added in to the 1 tune to rule them all, could cause risks or issues? I dont know how to explain what I see or think I see as a risk here, just questioning the exhaust or turbo break within a performance tune. I see you guys are putting them in the DSP5 tunes and it sounds like they are in all 5 now, so I have probably answered my own question... However, the last post within this thread was over 9 years ago I think, and a lot of seat time and trial and error has gone on since that last post, so maybe some new info going on?

ALso besides adjusting the Vein Tables, any other tables need adjusted for this feature?

I checked out JasonDT2001's uploads of his tune file, but then realized they are for an LBZ and I am an LLY so not sure how to actually set this up on an LLY. ANyone want to give me a hand? Or point me again in the right direction?

Thanks in advance,

 

[LBZ]

I always built it to come on above 1200 or maybe 1400rpm and it won’t slam on. Takes a second or two for the ring to move the vanes to the 98% closed position. But it will come on if you coast.

IIRC it is only the vane tables you change