Originally Posted by TXGold
What are you seeing for sustained boost? I am seeing 23-24psi sustained and have 6.7.15.
Just a quick heads up, a lot of factors will come into play here. Not just tuning version. I see too many random values thrown out on forums, with not much background on what that value means, or how it can be interpreted to help someone reading the thread. So I'll try to steer it into a direction that may help a few people out.
1. Emissions equipment status
2. Power level
3. Barometric pressure
4. Engine RPM for this "sustained level"
5. Torque converter status
6. Coolant temperature
7. Ambient air temperature
Just a few things to keep in mind when looking at numbers! Thanks guys!
My 2011 F-250, DPF delete, 10,000 miles on the Odometer, 2500 ft elevation, Hot power level, Coolant 190, 80 degrees outside.
From a dead stop I will see max boost of 36psi if I watch it through the first 4 gears. The highest boost values will be seen at LOW rpm when the turbo vanes are closed a bit. Once the vanes open the boost will come down to 29-32 psi and hold there until the next shift.
Rolling into it, it depends on the TC status and engine RPM. TC locked, low RPM I will get 34-37 psi (load on the engine from the TC creates an ideal situation for building high boost numbers at low RPM). TC unlocked will yield max values 31-33psi. Once again, boost levels will drop in the higher RPMs as the variable geometry turbo opens and allow the engine to breathe (and keep the turbo from excessive overspeed).
Remember, manifold pressure is a restriction value and not necessarily a measure of horsepower or torque.