Taller Final Drive ratio

[Bjorn Nilson]

Switching the shift mechanism to a cable system might not be a bad idea.

How do the gear ratios / final drive in the C510 compare to those in the Ritmo box?

I am mentally preparing for it. The C510 would be more durable for sure. Rebuilding the shift mechanism, clutch hydraulics and engine support might be worth the effort. This would be an operation much like what's required for a K20 swap?
Final drives in C510 (UT Mk2) and Ritmo are the same; 3,588:1. Whatever approach I go for will result in almost same result. See the comparison sheet in my firs post.

 

[lidox19]

Bjorn,
This guy in the UK has converted his X to a Punto GT engine and gearbox and has converted the shifter to cables using an MGF selector.

solving gear linkage when fitting Uno Turbo in my X1/9 | FIAT X1/9

Anyone done the conversion and fitted a Uno Turbo engine into an X1/9 with the Uno Turbo gear box and got pictures on how the solution on making the gear linkage work on the car. As the Turbo gearbox has the linkage on top of the gearbox and the X1/9 in the front of the engine? I've been told...

www.fiatforum.com

Regards
Andy

 

[Steve Hoelscher]

I am very happy with the result of my UT engine build. It works well on track and with X1/9 5 speed gear box/gear ratios I can keep it within maximum torque range 4-7000 rpm in most situatons. However, this is mainly a street car so I am looking for making the final drive taller, more like standard UT 3.588:1 instead of X1/9's 4.077:1.
I also have an UT Mk2 gear box but it doesn't fit the UT Mk1 (or X1/9) engine. -The input shaft/splines differs.
I have an idea to move the final drive from the UT box to the X box. But does the pinion and crown wheel from the UT Mk2 box fit in the X box? I also read in the forum that pinion/crown wheel from Ritmo/Strada/Regata would work? But they have the same ratio as X? I've been searching the web for Final Ratio Gear Kits, but all I've found are shorter than stock 4.077:1, most likely best for tuned, high revving X1/9's and hill climb.
I am also thinking about having a Torsen diff made for VAZ Samara. But that will require some modifications a described at https://www.villevieri.com/egbox.htm .Has this been done by any member in the forum?
Any feedback would be appreciated.
EDIT: Forgot to add the UT/X ratio comparison sheet that may be of interest:
View attachment 37512

I should note that the X1/9 5 speed came with three different gear sets. It appears that the above chart only utilizes the '79-'80 gearset. Although there isn't significant difference in them.

I have looked at the Abarth unit and concluded it wouldn't fit an X1/9. However, I didn't have the opportunity to inspect the internals. If somebody had one I would love to get a chance to do a thorough evaluation of the internals.

 

[Dr.Jeff]

I have looked at the Abarth unit and concluded it wouldn't fit an X1/9.

That's unfortunate but pretty much expected. Good to know either way, thanks.

 

[hotx19]

Hey guys
I have been using a c510 gearbox in my x19 uno turbo race car for some years now
It's a great box it handles the 300hp my engine makes very nicely
I previously destroyed 5speed x19 and uno turbo boxes at a low boost setting
The gearbox is very cheap in Australia my variant came from a Alfa 147
I fitted a quaife lsd too it before use
The gear change is custom cables and a ksport shifter
The clutch centre splines has too be changed too suit the larger input shaft
X19 5speed shafts are used and the lower engine mount is slightly modified too suit the gearbox
A punto gt clutch slave cylinder is used with standard x19 master too give a nice light pedal
The gearbox is much nicer too use than the original gearbox very smooth and quick thru the changes

 

[Bjorn Nilson]

I have been using a c510 gearbox in my x19 uno turbo race car for some years now
It's a great box it handles the 300hp my engine makes very nicely
I previously destroyed 5speed x19 and uno turbo boxes at a low boost setting
The gearbox is very cheap in Australia my variant came from a Alfa 147
I fitted a quaife lsd too it before use
The gear change is custom cables and a ksport shifter
The clutch centre splines has too be changed too suit the larger input shaft
X19 5speed shafts are used and the lower engine mount is slightly modified too suit the gearbox
A punto gt clutch slave cylinder is used with standard x19 master too give a nice light pedal
The gearbox is much nicer too use than the original gearbox very smooth and quick thru the changes

This is exactly what I need, and what I am aiming to do. I am stuck in manufacturing the cable and clutch hydraulic mechanisms on the gearbox. On my box a couple of tabs has been cut off, and mount/frame for clutch hydraulics is missing as well as the "up/down' lever for selecting gears:

If possible, please post more detailed pictures that could help with solving my mechanism problems.
I also realize that the lower engine mount will require a minor modification, but you mentioned X1/9 shafts has been used. What shafts are you referring to?

 

[hotx19]

I will take some more pics tomorrow after work for you

 

[kmead]

I will take some more pics tomorrow after work for you

Thank you that would be greatly appreciated. This dovetails nicely with a thread we have started which is around alternative transmissions to mate to the SOHC.

Thanks

 

[Dr.Jeff]

Yes, this is more in line with what I was referring to in the other thread (that @kmead refers to).
@Bjorn Nilson, I'm pretty sure he was referring to the axle shafts.

So my next question would be what newer engines, with better heads and other design improvements/performance, came with the C510 box?

 

[MikeHynes]

Hey guys
I have been using a c510 gearbox in my x19 uno turbo race car for some years now
It's a great box it handles the 300hp my engine makes very nicely
I previously destroyed 5speed x19 and uno turbo boxes at a low boost setting
The gearbox is very cheap in Australia my variant came from a Alfa 147
I fitted a quaife lsd too it before use
The gear change is custom cables and a ksport shifter
The clutch centre splines has too be changed too suit the larger input shaft
X19 5speed shafts are used and the lower engine mount is slightly modified too suit the gearbox
A punto gt clutch slave cylinder is used with standard x19 master too give a nice light pedal
The gearbox is much nicer too use than the original gearbox very smooth and quick thru the changes

What broke on the 5speed and uno turbo boxes?

 

[hotx19]

What broke on the 5speed and uno turbo boxes?

I will get some photos but basically it wold rip the teeth of 3rd gear not once but 3 or 4 times
It even did it in 4th gear on the dyno during a power run
I was very much over it then I did the c510 swap and haven't had an issue

 

[hotx19]

Very hard too get good pics
Hope these help

 

[Bjorn Nilson]

Very hard too get good pics
Hope these help

Many thanks. Is your gear mechanisfrom an AR 147? Would be difficult to find something like that at the junkyards in Sweden. My box is from an UT mk2 and it differs slightly. And as seen in my previous post I don't have the mechanisms. A complete box should look like this:

It is hard to see on your pictures, but it looks like your gear selector levers work in a different direction?

 

[MikeHynes]

I will get some photos but basically it wold rip the teeth of 3rd gear not once but 3 or 4 times
It even did it in 4th gear on the dyno during a power run
I was very much over it then I did the c510 swap and haven't had an issue

Yikes! Do you know how the c510 gears differ? Are they larger?

 

[kmead]

Many thanks. Is your gear mechanisfrom an AR 147? Would be difficult to find something like that at the junkyards in Sweden. My box is from an UT mk2 and it differs slightly. And as seen in my previous post I don't have the mechanisms. A complete box should look like this:
View attachment 46060
It is hard to see on your pictures, but it looks like your gear selector levers work in a different direction?

Yes from the looks of it. The one cable is acting on the counterbalance rather than the OE lever, you can see where the mount for the OE cable comes over the left end and would interact with the lever, he came around from the engine side. The other cable I can’t really tell the routing but it looks like it uses the normal lever.