There is no actual answer to that question except for as much pressure as you can to prevent the chain from jumping the sprockets, but not too tight as to wear out the guides. (There is no xx ft-lbs. etc.)
Here are the instructions from an actual race manual from Suzuki Japan:
Camshaft Chain Tensioner
_Ê_ Replace the cam chain tensioner with the kit tensioner to decrease the flutter of tensioner.
_Ê_ Apply the engine oil to the tensioner rod, O-ring and tensioner body, insert them into the
tensioner body. (Our Brock’s Performance tensioner is pre-lubed)
_Ê_ Check to see that the tensioner rod turns freely in the body.
_Ê_ Install the tensioner on the cylinder block with the tensioner rod is fully pushed back.
_Ê_ Turn the tensioner rod in with a screwdriver until it becomes hard to turn.
_Ê_ Turn the crankshaft clockwise forcing lightly to the tensioner rod with twisting force to
take up any gap and tighten the locknut.
Never forward the tensioner rod forcibly, this will increase mechanical loss of the
tensioner and may damage to the chain guide. The cam chain tensioner must be adjusted at every race , when road racing.
For drag racing, we check it frequently @ every 10 passes, by rotating the engine by hand forward and back to feel for exesive movement. Minimal ‘slack’ may be felt, but excessive slack can cause the chain to jump timing and lead to engine failure.