Below is an image from the excellent Comp Cams website here
Technical Specs & Information along with a summary of the types of change one sees when changing item 10 in Camshaft Diagram below, the "Intake to Exhaust Lobe Separation".
I used to own an Acura Integra Type R which had a cam shift mechanism (VTEC) that came into play at 5200 RPM, this number because the EPA test cycle actually does not test above 5200 RPM and I suspect this may have something to do with Porsche changing the cam advance curve at that point - maybe because they don't need the natural EGR effect to pass after this? Also the improved torque in what would otherwise be a peaky engine is a nice touch.
The wide lobe separation at idle I suspect is to improve idle quality as well as to decrease cranking compression.
Camshaft Diagram Showing Lobe Separation Angle
1) Max Lift or Nose Lobe
2) Flank
3) Opening Clearance Ramp
4) Closing Clearance Ramp
5) Base Circle
6) Exhaust Opening Timing Figure
7) Exhaust Closing Timing Figure
8) Intake Opening Timing Figure
9) Intake Closing Timing Figure
10) Intake to Exhaust Lobe Separation (LSA)
Tighten (smaller LSA number)
Moves Torque to Lower RPM
Increases Maximum Torque
Narrow Power band
Builds Higher Cylinder Pressure
Increase Chance of Engine Knock
Increase Cranking Compression
Increase Effective Compression
Idle Vacuum is Reduced
Idle Quality Suffers
Open Valve-Overlap Increases
Closed Valve-Overlap Increases
Natural EGR Effect Increases
Decreases Piston-to-Valve Clearance
Widen (larger LSA number)
Raise Torque to Higher RPM
Reduces Maximum Torque
Broadens Power Band
Reduce Maximum Cylinder Pressure
Decrease Chance of Engine Knock
Decrease Cranking Compression
Decrease Effective Compression
Idle Vacuum is Increased Idle Quality Improves
Open Valve-Overlap Decreases
Closed Valve-Overlap Decreases
Natural EGR Effect is Reduced
Increases Piston-to-Valve Clearance