Will a complete Scorpio rear end bolt into a XR4ti?

[timxr8]

They are definately spherical, both the original ones and the Graham Goode ones. The angle that the bearings can make is not very big, but it is big enough for the application. The movement of the arms is without any binding in the bearings through the whole suspension travel.

The Sierra was indeed never raced with 6 degrees, but the reason for this was that it was not allowed by the regulations. If I remember correctly the alternative pick up points on the RS500 are 60 or 70 mm further to the front than the original ones and I believe the regulations allowed an additional 20 mm on top of that. So that made a total of 80 or 90 mm (I would have to check a book to see what it actually was), which is not enough to make it into 6 degrees.

Where do you have the info from that 7.5 degrees would give better stability than 6 degrees? The racing period of the RS500 is a long time ago. It would be great to see some written down evidence on testing of such things. But in practice (on a road or hobby race car) I think it would be very difficult to notice the difference between a 6 and 7.5 degree beam, as the difference is really very small.

I had the emails backed up on my old computer, which my son knocked off my end table a month ago (he's 2) and that was the end of that old hard drive. The team was running one as of 10 years ago when I talked with them. They had been running the car for a few years, including on Bathurst. From what I remembered, they ran the 6 deg for a while, but wanted a little more geometry change in the back on corners. They extended the inner mount 80mm, which is about a 7.5 degree setup. I remember a 9 degree figure being the least the teams could do with the Sierra.

99% of us will not notice a difference of 1.5 degrees. The only reason is people throw the 6 deg beam as if Ford themselves did it and becomes near Dogmatic in Europe. It's much easier to just throw a couple holes 80mm apart on some steel and build off of that...which was my plan until I bought a 6 degree setup from MK (with Supra diff mounting). I'll probably still build another beam at the 7.5 deg angle, but we'll see if I can get this other project done.

I'm more concerned with the angle of the mounting pad for the bearing carrier. If the Scorpio is a different angle, that could cause some issues with a swap.

[Marc]

9 degree indeed also sounds familiar as being the max that was possible.

I don't really understand what you mean with "It's much easier to just throw a couple holes 80mm apart on some steel and build off of that..." The work needed to be done to make a 6 or 7.5 degree beam is the same, it's just that the holes are a bit further away with the 6 degree. Adding some holes 80 mm (or further) away on the subframe isn't the most difficult part. Extending the arms and making sure the geometry is still OK afterwards is more difficult.

I had my beam made to my own drawings and specifications, so I was free to choose any angle I wanted. But as far as I know the 6 degree would be best, as determined by Ford themselves back in the day. For track driving you might want a bit more camber change, although the additional toe change you are getting is not helping. But for a road car the 6 degree makes more sense as it also helps with straight line traction and tyre wear.