It’s a shame things have gone backwards with bi-modes
I know you are referring specifically to the Class 800's and 802's. But not the Anglia Class 755's.
It seems that the 5-car Class 802's deliver from around 9.4 to 8.4hp at the rail - as the traction output ramps down.
The 9-car units being that bit heavier are slightly less 8.8 to 7.7hp/ton at the rail.
Obviously even less if an engine is out.
For comparison a 2+8 HST would deliver 8.6hp/t at the rails.
The Anglia Class 755 4-car bi-modes offer an exceptionally high output at appx 13.4 hp/t to the rail in diesel mode. That explains 0-60mph in 45 seconds in diesel mode!
The 3-car 755's have only half the power and must be delivering appx 7.9 hp/t, and that is reflected in their 0-100mph times in diesel mode - which are similar to a 2+8 HST!
For comparison a Class 222 Meridian unit offers around 11.9 hp/t at the rail (based on traction output downgrading in recent years since their introduction)