LBZ: General Limiting tables ETC mods

[Dozerboy]

I was hoping to discuss the LBZ limiting tables since I haven't seen much about them. Here are the tables I have modded and how. Don't ask why some of what I have done is based on what others have done. I would like to hear what others do and what defiantly not to do.

B1113-14 Torque Based Fuel For Altitude: All the multipliers below 1 where raised to 1 other then the 4800 RPM row

B1117 Maximum Fuel Quantity vs RPM: 200 in the cells to fuel up 4400RPMs

B1122 Torque Fuel Limit RPM Conversion: I left the 880,1000 RPMs row stock and raised the 1-0.91 rows to 120, 0.88-0.83 to 115, 0.80-0.75 to 110, the 0.73-0.54 I left somewhat stock other then the higher RPMs I used the highest value GM used stock.

B1118-19 Maximum Torque 1,2 vs RPM: 885.7 to fuel to 4200RPMs

B1128 Barometric Pressure Torque Limit: 600RPMs was left stock and the rest was set to 815

B1014 Pressure Maintain Fuel Limit: 125 was continued to fuel to 4000 RPMs

B1015 Desired Flow Vs Current: The last values was set to 0 and the 2nd to last was blended in

B1018-19 Pressure Control Max Duty: Max was set to 100% minimum to 0

Thats the gist of it. Here is my stock tune that has the mods done that I build my tunes off of.

 

[Dozerboy]

Nothing? Not even a "you stupid moron your going to f something up doing that" I guess thats good

 

[McRat]

To make things really confusing, not all the limiter tables really do anything. Best tactic to take, is to change about 5 limiters, test it, then change 5 more.

Limiter tables that have a scalar (1 to 0), you normally change to 0 to stop the limiter, not 1. If the scalar is 0, the table isn't used.

 

[McRat]

Desired flow versus current is not a limiter, it's a "guess" scalar. The CP3 is closed-loop programming. But it needs a start point, and that what B1015 does. Adjusting the last value to 0 is fine. Some OS's have 0 others have 400. Not sure 400 isn't already WFO.

 

[Mike]

Be careful, you may no longer have an engine rpm limiter with the adjustments you've made? Depending on b1115 b1116 b1102 etc.

 

[Dozerboy]

Thanks Pat I'll go back and do some expermenting.

Mike I still have B1117 set to 0 at 4600RPM+ and B1118 at 140 at 4600+, but I will check and see.

One thing that bothers me a little is the Torque Based Fuel For Altitude tables. The worse that I think could happen would be over fueling at higher altitudes, but I dropped the boost there so that isn't an issue. Med altitude I didn't change to much, but high altitude a few cells are as much as 20%.

 

[Mike]

Always wondered why dropping boost at a higher altitude was done. Seems more boost is need for the slight oxygen changes as elevation is increased.

What rpm do you take the engine to?

 

[JoshH]

Always wondered why dropping boost at a higher altitude was done. Seems more boost is need for the slight oxygen changes as elevation is increased.

Because there is less air to build boost with. You'll overspeed the turbo if you try to build the same boost at 10k feet as you do at sea level.

 

[Mike]

Good point Josh.

But on a stock tune with stock perameters, the rpm wouldn't be a problem. At that, with out the oxygen the turbo wouldn't spin anyway?

 

[JoshH]

You lost me.

 

[Mike]

Airplanes require higher pressure ratio turbos to fly at 20000 feet than close to sea level. Is the boost higher, lower or the same?

We are at 4000+ feet here. Taking a stock truck and duplicating rwhp to match that of sea level required raising the boost. Could be other ways but.....

Back on topic.... Sorry about that.

 

[Dozerboy]

What rpm do you take the engine to?

My shift points are set for 3500 in T/H WOT on the street. I haven't done any pulling yet, but I think I may shift at ~4000.

 

[Mike]

My shift points are set for 3500 in T/H WOT on the street. I haven't done any pulling yet, but I think I may shift at ~4000.

Cool.


I hit cancel t/h and didn't put the lever in D it was in 3 and the pedal on a truck. Holy hell, couldn't let off the throttle fast enough. Rpm kept on going.....

 

[Killerbee]

The best way to break the turbo, is to go to 11000 ft, and run it at 38 psi.

B1115 is not accurately commanding torque. Have you all logged torque? It is reported up to 150 high compared to the table values.

 

[Mike]

The best way to break the turbo, is to go to 11000 ft, and run it at 38 psi.

B1115 is not accurately commanding torque. Have you all logged torque? It is reported up to 150 high compared to the table values.

Yes, we know torque is only a reference and means squat.

 

[Killerbee]

That's not what I am saying. I am saying that EFILive is broken for the LBZ, beginning with B1115. The torque that is referenced from that table, is not being reported by the dma PID. It is way off. That is the basis of my remark, not to condescend.

Then again, if you know an explanation that I have missed, I will even put up with ego to learn it. :hug:

 

[Mike]

I know nothing, Ole Shultz, gotta love him.:angel: