17-08-2012, 12:07 PM
That shouldn't improve economy - that just proves how bad the thermal efficiency of an XUD9 is!!!
That increase in boost pressure will just stop more heat being transferred to the head and ... Theoretically lower boost pressures would improve economy since there'd be less pumping losses....
Remember a DT is 21:1 compression ratio, with an added 8psi of boost... If you had that on a HDi, the thermal efficiency would be through the roof, it'd be amazing, but it's not needed, it can drop the pumping losses massively by not needing such a high CR. Another reason a HDi should be getting better efficiency than they are.
That increase in boost pressure will just stop more heat being transferred to the head and ... Theoretically lower boost pressures would improve economy since there'd be less pumping losses....
Remember a DT is 21:1 compression ratio, with an added 8psi of boost... If you had that on a HDi, the thermal efficiency would be through the roof, it'd be amazing, but it's not needed, it can drop the pumping losses massively by not needing such a high CR. Another reason a HDi should be getting better efficiency than they are.
