Hi, does anyone know if any company makes, or has made, overdrives to fit an Uno?
Namely the 1.7D...
Namely the 1.7D...
Technical Overdrives?
- Thread starter edessex
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Technical Overdrives?
I would be amazed if anyone has. If you think about where it would have to fit on the gearbox, it would need quite a bit of engineering for the unit, let alone the controls and the packaging in the almost non-existent space. In fact, as yours is a diesel and has the C510 box, it would need a new casing completely.
Being obsessed with gearboxes recently, I can make suggestions to help you. You already have one of the tallest gear sets FIAT put in the C510 box, similar to the last turbo boxes.
There are two things you can do:
1) Put the tallest 5th gear pair on the box you can get. I reckon it is 0.767:1 and can be found on a few boxes. Search for P/N 46767951 on ePer to get an idea. You could buy the pair of gears for £120. The job could be done with the gearbox in the car and really isn't that hard to do at all as you don't have to separate the whole gearbox to access the 5th gear pair. You basically take off the end cap, undo the 5th gear selector rod bolt, select a gear and the 5th manually, unstake the two nuts holding on the 5th gears and take them off.
2) Go about making your own box to get a really, really tall 5th. UT box with it's higher ratio layshaft is a good start. Think some Bravos have even taller ratio. I can sell you a whole stripped UT box in excellent condition if you like. You need to be pretty mad to do this in my opinion.
From my calculations it sounds like you will be doing about 3300RPM at a true 70MPH (perhaps nearer 80 indicated). With a 0.767:1 5th, you would do 3000RPM.
There are two things you can do:
1) Put the tallest 5th gear pair on the box you can get. I reckon it is 0.767:1 and can be found on a few boxes. Search for P/N 46767951 on ePer to get an idea. You could buy the pair of gears for £120. The job could be done with the gearbox in the car and really isn't that hard to do at all as you don't have to separate the whole gearbox to access the 5th gear pair. You basically take off the end cap, undo the 5th gear selector rod bolt, select a gear and the 5th manually, unstake the two nuts holding on the 5th gears and take them off.
2) Go about making your own box to get a really, really tall 5th. UT box with it's higher ratio layshaft is a good start. Think some Bravos have even taller ratio. I can sell you a whole stripped UT box in excellent condition if you like. You need to be pretty mad to do this in my opinion.
From my calculations it sounds like you will be doing about 3300RPM at a true 70MPH (perhaps nearer 80 indicated). With a 0.767:1 5th, you would do 3000RPM.
OP
OP
Cheers guys, I had a feeling that there wouldn't be any mass-produced overdrive units, but thought it worth asking!
Although I can handle a fair few mechanical tasks, I have never tried playing with gearbox internals... seems a tad daunting.
I was only really after improving fuel economy without severely editing anything...
Already at 50mpg, will have to stay with that!
Although I can handle a fair few mechanical tasks, I have never tried playing with gearbox internals... seems a tad daunting.
I was only really after improving fuel economy without severely editing anything...
Already at 50mpg, will have to stay with that!
Defo worth asking, still might be true, time moves slowly in the Uno section...
Fitting an overdrive would be harder than fitting the 5th gears. But a 300RPM drop at 70MPH is perhaps not worth it if you don't already have the parts.