The Tornado (and TNT) suffers from too much voltage drop on the battery cables during cranking. This
results in sluggish cranking and contributes to the resetting clocks problem.
The existing cables are each 1m long and use 8mm˛ wire. The total resistance is 0.005 ohms, which causes
a 0.625V drop if the battery can deliver 125A. That's 78 W that's not spinning the engine.
Not hopeless, but half that is better, and of course when the engine is hot, the starter will draw a lot
more current (~200 A). Then the drop is closer to 1 V and you've lost 200 W just in the wires.
Due to the restricted space under the battery, an additional 8mm˛ cable set was added, rather than replacing
the existing cables with 16mm˛. There is space to add another set if desired, for a total of 24mm˛, but that
is probably over-kill.
The terminal bolts need to be longer, to accommodate the extra lug. M6 x 15mm worked for me, but depends on
the lug thickness.
The positive cable is 1000 mm long.
The negative cable is 800 mm long.