Race cars in
AO Silver Member
Join Date: Oct 2007
Location: South Africa
1st off the Diesel 5 speed box is not the same platform as the 5 speed petrol boxes, the only similarity is the bolt pattern to the engine block. The Diesel 5 speed shares the same platform as the 6 speed box. The mods are slightly prohibitive to go that route... I did the 6 speed (2.5 gear internals) conversion on my race cars and it was A LOT OF WORK.
In the 5 speed boxes gears 1 - 4 is all in one section of the input / output shafts and difficult to swap about. The 5th gear is a bit easier to swap, so yes 5th gear of the 2.0 on a 1.6 box makes more sense.
EDIT: 5th gear is the same on the 1.6 and 2.0 - the difference comes in with the Final drive ratio. 1st gear on the 1.6 is shorter AND the bigger final drive ratio on the 1.6, making it significantly shorter than 2.0 1st gear. If you want to restore the longer 5th gear - you need the 5th gear from an Uno Turbo of 0.875:1 (they where popular in SA) - even the Fiat 20V coupe has the same 5th gear, just a shorter final drive - making overall ratios longer. I would fit the 1.6 box and live with the slightly short 5th gear
Last edited by Gertie; 08-01-18 at 08:32.