Every car seems to be a bit different in how the hood/bonnet closes and opens, the level of effort to do same, and the amount of tension wound up in the torsion bar.
The strap performs no active duty: it is there to prevent the hood from flying further back then necessary and doing damage in the process. The actual position of the open hood should be controlled by the the detent in the plastic block mounted on the body, and how the torsion bar rests in same.
On mine, I think I have some excess torsion in my bar: I have to gently guide the bar out of the detent when opening and closing as it seems to have some lateral forces wanting to have it snap towards the engine.
However, when it is opened, the bar rests in the detent (those were my photos noted by Muf)nicely; holds the bonnet up without effort, and the strap is relatively taught.
Michael Salemi
1969 280SL
Signal Red w/Black Leather
Restored