Exhaust Back Pressure

S

silvernblack6.0

slow6.0
Joined
Aug 12, 2008
Messages
33
Hey Gang,
I have an 03 with what seems to be a serious problem with EBP. If I run 04 software that uses the ebp sensor, the truck will only pull say 20 pounds of boost at wide open throttle, Ebp sits at 48 psi while this happens according to the scanner. Ebp, map, and baro match at KOEO. I have changed the sensor before with no change. If I run stock 03 programming that ignores ebp, the truck will pull thirty pounds of boost at WOT but is partially restricting the exhaust according to sound and egt numbers. The truck has 185cc injectors and an SS turbo. I was wondering if it is feasible to change to the 04 and up style ebp sensor plumbing and if that would cure the ebp reading higher than normal? Could I just replumb the tubing myself or do I need to switch the manifold and tubing? Any insight would help. Thanks for reading this.
 
My post probably won't help, but I've noticed that my 05 programming will only allow low twenties at WOT empty. The only time I can boost to 30 psi is pulling a trailer up a hill at freeway speeds.

Since these are load-dependent engines, your results might be skewed a bit at WOT empty.
 
I run the 06 software in my 05. Sometimes I run the 05 in my 05. Once I tried the 07 in my 05. Never tried the 03 or 04 in it though. Need to look at where the MAP sensor is being clipped. Also need to look at what the VGT duty cycle is being commanded instead of just relying on the sensor reading.
 
PSD Player,
what do you mean by where the map is being clipped? Where the gauge is being spliced in? Either way, boost is referenced off of the map sensor and also off of the tube running to the map sensor, one electronic and one analog. IDS matches both exactly, I can try and post a graph of the ebp, map, rpm, maf, vgt%, etc.. if you would like with the 04 tuning, and with the 03 tuning. I only have tunes in the 04 files, because nobody can seem to build an 03 tune that works right, so I only have stock 03 programming, nothing to modify for my injectors and larger turbo. Thanks for listening.
 
My 05 doesn't have a MAF sensor. Strange, huh? I wonder how other strategies would run on my truck? Hummm.
 
On the 03 there is a different table that is needed for MAF since it is being used for the new turbo learn procedure. EBP is inferred on that strategy as well. So its an educated guess. However. Since MAP can only go to 5 volts and is limited to 51psi. Then you are looking at EBP which is also limited to 5 volts and a certain PSI but its all done in kPa anyways. But lets concentrate at what is the VGT duty cycle being commanded for the SAME mass fuel desired. Understand?
 
Yes,
I understand. What pids would you like then? At what rpm, what throttle, etc.. and I will get it. For some reason, the shops wireless is down and I don't have the ability to give you a graph as of right now, but I can save it and then send it tomorrow hopefully or just link my laptop to the net real quicklike. Let me know what you want to see. Just mfdes and vgtdes or anything else? Thanks again.
 
MFDES and VGTDC vs APP and RPM. But since the files may have different ICP DSD and IPR DC commanded to get there you can only compare apples to apples if they are the same. This isn't so much one year vs another there are a ton of other things that will alter the end result.
 
would you like them to be with comletely bone stock programming since I can only have stock 03 programming? I will get them tomorrow, thanks again.
 
Doesn't need to be bone stock if its an issue between tunes. Compare the tunes.
 
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