Ira Kaufman writes:
i must get that book but off hand i would say the didion setup as is causes
the trouble.as we see it is the same problem with the four or six.i suppose a diffrent rear setup instead of that triangle may be the answer.
I'm going to have to disagree with that. The single-point mounting of the DeDion's control arms in Ricart's design is not elegant only in its simplicity, but in removing all the basically irreconcilable differences found in any four-arm setup, and any unwanted steering effects as well.
Any four-arm design inevitably places torsion loads on the axle whenever there's a side-to-side difference in bump and droop, as does the stock 105 rear axle control setup, which uses a top link with no side-to-side leeway except what's allowed by the rubber bushes. A three-link + lateral locator avoids this problem, but there's still going to be some rear-axle steering. The triangle with pivot at the apex solves all of that, especially with the use of the Watts link to control lateral movement. It's a brilliant design, and reason enough for me to keep my Milano, even if I didn't like anything else about it! And it would absolutely have to be a feature of just about any Alfa-based project car I might contemplate.
As for driveline problems, one point of having a chassis-mounted final drive in the first place is to de-couple the suspension from the drivetrain. I think fiscal constraints kept Alfa's engineers from taking full advantage of this; a long torque-tube of sufficient diameter would have been quite expensive for a production sedan, and so they had to keep futzing around with the pieces they had in inventory until they'd made it work well enough.
Will Owen -- to be removed from alfa, see http://www.digest.net/bin/digest-subs.cgi or email "unsubscribe alfa" to [email protected]
