Am I being told the truth about exhaust upgrades?
#16
12-10-2004, 07:52 AM
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12-10-2004, 07:57 AM
#18
12-10-2004, 08:07 AM
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#20
12-10-2004, 01:15 PM
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#21
12-10-2004, 04:05 PM
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#22
12-10-2004, 04:59 PM
The exhaust back pressure is measured at the EP sensor that is at an end of a tube running off the exhaust between the exhaust manifold and the turbo. So if there is no or little back pressure measured at this point, the PCM will alter the variable vanes of the turbo to direct more exhaust on to the turbine blades for more boost.
The question that is unresolved at this point is whether modified exhaust downstream from the turbo will affect the back pressure readings at the EP sensor that is upstream from the turbo? There is some concern that a modified exhaust will reduce back pressure readings to the EP sensor and cause the PCM to adjust the variable vanes incorrectly not opening the vanes and potentially causing overspeed/overboost of the turbo. This is more of a concern at altitude.
The question that is unresolved at this point is whether modified exhaust downstream from the turbo will affect the back pressure readings at the EP sensor that is upstream from the turbo? There is some concern that a modified exhaust will reduce back pressure readings to the EP sensor and cause the PCM to adjust the variable vanes incorrectly not opening the vanes and potentially causing overspeed/overboost of the turbo. This is more of a concern at altitude.
Changing the exhaust effects how the ECM controls the vanes in the turbos resulting in under or over boost conditons. you are basicly trading minor inefficiency for more gross HP.
Last edited by Crash687; 12-10-2004 at 05:23 PM.
#24
12-10-2004, 06:00 PM
Originally Posted by SBV45
Crash687. on exhaust modification, I would be after better fuel economy and lower egt. Are the gains worth the changes in turbo operation?
just you may be shortening the life of the bearings in the turbo by over reving them.
Ford does not want you to modify the exhaust so that you buy the next latest great more HP and torque engine/truck combo. It also gives them a loophole to call you a moron for building up your truck without you taking responiblity for it. Ford gives you a warranty for the way the truck and engine was built not the way you modified it.
Your tech is an idiot. And evidently he needs to go back to Tech School and get Re-Certified..........
Last edited by Crash687; 12-10-2004 at 06:15 PM.
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