The first quote (link here
) is from the auction text here
, which seems to follow Simon Moore's descriptions. The second one (link here
) I wrote 3 years ago -- and I learned quite a bit since then.
I'm convinced that the notion of "Porsche designed the front suspension" is incorrect. This notion sounds too much like outsourcing. In several sources, Busso and Fusi (and others) describe it as Dubonnet, Dubonnet/Porsche or even Dubonnet/Porsche/Jano suspension. The last term is probably the most accurate. One of the best descriptions seems to be embedded in Busso's comments in "La 6C2500: un'analisi severa" in Tito Anselmi's book "Alfa Romeo 6C 2500" (published in 1993), where he describes some technical aspects of the front and rear suspension, and also mentions that the 6C 2300B front suspension was "prepared towards the middle of 1934" (that is, before the German cars won races, the first of which was the Coppa Acerbo in Pescara in August of 1934).
According to Busso and Fusi, the front suspension is clearly based on Dubonnet's patent portfolio (Dubonnet had patents for both the trailing arm principle as well as spring and shock absorbing system, applied for in the 1929-1935 time frame). Alfa first used the Dubonnet system on some P2 racing monopostos as well as on the Bimotore, and changed and evolved on these cars and then the 6C 2300 B and the 8C 2900. I believe that Alfa under Jano, driven by market forces and, according to Busso, the "impatient" Scuderia Ferrari, already worked on the Dubonnet system several months before the collaboration with Porsche started. Where the house Porsche (that is, most likely, Porsche's engineer Karl Rabe) comes into the picture is for steering geometry: Porsche had several patents for linkage between steering box and steering rods, and specifically one patent that relates to the steering rods being attached to a lever that is mounted in the center of the frame and so corrects steering angle and toe-in according to suspension travel, which certainly has been used on the 6C 2300 B and 8C 2900. In essence, Porsche's steering geometry patent is an application of three-dimensional trigonometry with radii in multiple planes -- today, relatively easy to do on a computer, but quite complicated and elaborate when one has to do it by hand. Porsche later also patented the use of two independent torsional rods for the Dubonnet front suspension (instead of helical coil springs), which was used in the Volkswagen Beetle.
According to Busso, Porsche was also involved with geometry of the rear axle (not the suspension), where steering angle and toe-in were corrected according to the travel of the swing axle. IMO, it's also conceivable that some of Porsche's involvement may have been with the gearbox, both in terms of synchronisation of gears as well as shaping the geometry of the gear rings between the differential and the swing axles.
Several rumors seem to exist with respect to partial payment in cars, but none of the ones I heard relate to an 8C changing hands. At the time Porsche was involved, the 8C 2900 had not even been considered as a production model -- so, forget about that notion. But the rumor of payment "in kind" may have a different context: Total annual production of Alfa Romeo in 1935 was 91 cars, only 10 in 1936, and 270 cars in 1937. Money was tighter than tight -- so it's conceivable that payment took some other form than cash, but given the low production numbers, payment in form of a car may have been a little bit too rich. I don't remember where I read that Anton Piëch, Porsche's son-in-law, drove a 6C 2300B, in which he brought an Adler rear axle to Alfa for studying before the axle was shipped to New York, and that his car was changed to 6C 2300 B Pescara specs. IMO, it is conceivable that some of these upgrades were not at full price and may or may not have been partial payment (or maybe just for road testing of the engineering work?).
It should be noted that Busso's comments in "La 6C2500: un'analisi severa" seem to have a somewhat bitter undertone (although my Italian is not that good to be sure) when he mentions that the Volkswagen Beetle introduced in 1939 had "close similarities" with the Alfa front and rear suspension, so much so that "the geometries were practically the same" as that of Alfa's, which leads is to another rumor: That Alfa's work concerning the rear axle was given to Porsche as partial payment (for Porsche to use) -- which would make the relationship between Alfa and Porsche to look more like a joint venture than an outsourcing contract. Given Busso's words, this seems to be a valid possibility, but I haven't seen any evidence of it (and I don't know what exactly the scope and the terms of Porsche contracts #63 and #69 were).