Not sure if you knew but there was a version of the Biturbo called the Racing, so this car has a Racing engine and not a racing engine if that makes sense. The standard engine in a 2.24v would be a 2 litre 24v with around 245bhp, engine code AM475. The Racing was a more sporting version of the 2.24v and is considered to be the holy grail of Biturbos. The engine (code AM490) had some significant differences including forged pistons, new crankshaft, lighter con-rods, different camshafts, different ECUs and different turbos and developed 285 BHP. Only 230 Racings were made for the Italian market only, they look fairly similar to the 2.24v but were only available in black or red and had a few minor detail differences.
The 2.24v on Ebay definitely has the Racing engine as its written on the cam covers, an awesome powerplant and much cheaper than a genuine Racing which are now going for big money.
http://www.autoscout24.com/Details.aspx?id=260518880&cd=635523458750000000&asrc=st