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Discussion Starter #1
I've got a 19 that's on a weight loss plan that does mainly city stop n go driving. Now I've been reading about exhaust back pressure (EBP) and turbo boost pressure (TBP) and people are saying that the EBP to TBP ratio should be close to 1:1 (i.e 17 psi EBP : 17 psi TBP). I'm using a SCT GTX and at cruising speed; EBP is roughly 25 psi but turbo boost is 5 psi. EBP when driving is always mid 20 psi and turbo boost is single digit psi. The low boost could be because I drive like a grandpa to help with mpg but anyways, is my EBP normal or is that too high?

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Your EBP reading isn't corrected for atmospheric pressure. Boost is.
 

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Subtract your BARO reading from the EBP reading. That will give the "corrected" EBP. It probably will not be exactly the same as Boost, but at normal levels, it should be fairly close.
 

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Discussion Starter #5
Some numbers from today:
EBP between 23 to 26
Barometric is 14.26 '
"corrected EBP" around 10 psi.
turbo boost is 3 - 5 psi.
"correct EBP" : turbo boost ratio is between 2:1 and 3:1. What"

Do I just take the barometric reading for what it is or do I need to correct it?

It would seem that the EBP would need to be around 17 to 20 psi for me to get a "corrected EBP" that would put the ratio at 1:1 but at normal crusing, 24 psi is the lowest it gets. Should I be worried about the backflow hurting mpg?
 

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You're fine.
 

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Try using a different scan tool (IE ForScan) to see the PIDs you want. This will give you a second opinion as to what your truck is reading at the sensors.
 

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EBP should be about 1.5 times the boost
Yeah - ForScan is the tool you need -- also sensor voltages is a more accurate representation of what is happening -- the PCM can use inferred values if a sensor is out of range, this throws the information needed to troubleshoot the problem out the window
 

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I suspect the readings on your monitor are quite a bit behind the actual values - purposely done that way for ease of reading
Listen to the turbo and watch the readout - can see/hear the difference
Would be nice to see EBP and MAP -- the boost is a calculated value anyways -- I'm not convinced it is as straight forward as MAP - Baro -- I think the "boost" term is more like the oil pressure gauge, just a feel good thing from Ford
Intake manifold pressure would be a more accurate measure of what people are asking when they look for boost -- Ford represents it as a "boost" in the output of the engine power

Manifold pressure along with engine timing and fuel rate would affect perceived "boost" -- the gauge on the dash is just an indicator that takes that information along with Fords voodoo code and points the needle at a number
 

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I need to get back to a CTS 2....ugh.....My previous one died, now using a nGauge since I had it on hand. I'll see if the NG has a MAP PID. I don't recall seeing the EBP.
I'm sort of hoping EDGE is going to release something newer with better options.
 

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No Limit Stage 2 with a Magnaflow outlet. At idle it's got a nice "thump" to it as well. There's still some "hair dryer" action while driving due to the VGT and tuning, but it sounds pretty good overall.
 

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I have been tracking MAP & EBP since I came across this thread earlier this week. I'll add the boost PID once I get a chance as a comparison.
The screenshot shows MAP & EBP at 1750 RPM. At idle MAP=14.6 (atmosphere) and EBP=17.1
766062
 
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