Forum:
Ive got a 1981 F50 with the 2.5 diesel and 4 spd gearbox. Its great for around town and offroad but maxes out at around 90kms/hr on the hwy. I want to take the scat on a few trips which will involve some distances on highways with 100-110 speed limits. Driving out here at those speeds can be dangerous as well as tedious so I'm interested to know if theres any practical options. Ive read a few topics on this forum and there seems to be a few options discussed eg replace with 5spd box, change transfer gears, new diff gears? Not sure which is an option for me and the associated costs and risks.
Simplest option is to find a
Simplest option is to find a 5 speed box. I can't speak for your local market, but in the UK some of the last F50's came with 5 speed. It's a straight swap if you have the propshafts as well. An F20 box will also do if you cange the bell housing (4 bolts). An F75 box will fit but the prop flanges are diffrent, however the sliding joint in the pros of both vehicles ar ethe same spline, so these can be hybredised and balanced in needs. Main prob is you end up with no hand break a F50 keeps it's on the raer of the transfur, while the F75's is on the rear whels.
As for diff ratios the F50 is the higher option, with F20 being lower. A standard F50 will pull 31 tyres though, so that is an option for raising gearing.
The different transfur ratios I belive only count with F70-85 modles. I think The F20-65 are all the same.
Any veiws expresed in this thread by me are purely from my own experience, and (sometimes) falible memory. Hope my comments help, but please don't take them as gospel.
Thanks for the reply. Im
Thanks for the reply. Im going to get a set of 31 tyres and see what a difference they will make (According to an online tire calculator I'll see roughly an 11% improvement in speed at the same revs). I have a set of 215/75/15 Kuhmos on at the moment which I think is about an inch smaller in rolling diameter than standard (16 x 6.00) which isn't helping. 31 tyres are very common here and there are 2nd hand sets available everywhere. So I'll get a used set to check them out. If this gets me by I'll be happy as the current 4spd box is in fantastic condition- no slop, easy changes, no noise.
1981 Daihatsu Scat F50
Gold Coast Australia
Just an update on this should
Just an update on this should anyone be interested. I fitted 31x10.5x15 tyres on the weekend. Cruising speed is much improved. It will sit quite comfortably on average of 95kms/hr for a couple of hours. The bigger tyres also provide a bit more dampening over the rough tracks. Engine has enough torque to handle the tyres so its now a bit quicker of the mark.
1981 Daihatsu Scat F50
Gold Coast Australia