Join Date: Aug 2008
Location: Newtownards, N.I.
Car Year: 2009
Car Model: XC diesel
Diesel engines are driven off a number of IQ ( injection quantity) tables. Smoke, boost, altitude, gear position, rpms, torque, driver request. All are compared, and the lowest mg/stroke wins. Truly DBW.
Your problem isn't the torque curve on the dyno, but the fact that it isn't the same as the curve in first gear- which is lowered to protect the drivetrain. Also you need to confirm that the ECU has the latest software as each incarnation has had radically different available torque at the clutch biting point around idle rpms.
I'm bemused tho why you are quoting torque at the wheels? The engine is in fact performing as per spec...
edit: I should add that you'll find the same response from all modern sub-2l diesels. The protection of the DPF and DMF from overloads is a universal concern. Torque below idle rpms destroys DMFs, excess fuel before boost builds kills DPFs.
2009 SH XCdiesel 6MT