I've only just managed to get a copy of this and it was nice to see such a comprehensive article on the Biturbo.
Here's my entry for the error spotting warm beverage prize (apologies but you did ask):
Whilst you are correct in saying that the Biturbo engine was based on the engine fitted to the Citroen SM, this was in turn derived from the Merak engine, in fact a prototype Merak Biturbo was built and can be seen at the Panini Maserati Collection in Italy. It is rumoured that the Merak engine was itself derived from the V8 fitted to the Bora etc but with 2 cylinders lopped off which goes some way to explain the slightly unusual 90 degree configuration on a V6.
The Chrysler Maserati TC didn't have anything in common with the Biturbo, it was basically a posh Le Baron with some aspects assembled and trimmed by Maserati. The tie in was something to do with Lee Iacocca - he and Alejandro De Tomaso became friends when Iacocca was at Ford. De Tomaso was developing the Pantera which used Ford engines and was sold through the Lincoln Mercury dealer network in the USA. Iacocca later moved to Chrysler and then approached De Tomaso to collaborate once again, this time in a rather less successful capacity. The engines on the early cars were a 2.2 litre 4 cylinder and were built by Maserati hence the name on the cam cover but Maserati had no part in the design, they were derived from a Chrysler unit, supposedly with some involvement from Cosworth. Later cars used a Mitsubishi V6. The bodies were assembled by Innocenti, another company owned by Alejandro De Tomaso. It is interesting to note that once again Maserati and Chrysler are together as they both now form part of the FCA Group.
It was good to see that you didn't fall for the hype regarding power figures for the Karif but the performance figures you quote, whilst commonly seen, are somewhat an urban myth. The story goes that Alejandro De Tomaso wanted the Karif to make a big impact with the press when it was launched and the cars made available to journalists were "massaged" for additional power. These press cars had somewhere around 285 bhp and the performance figures commonly published relate to these press cars. It is rumoured that these "massaged" engines didn't last very long. The production cars had the same engine and power output as the standard export 2.8 engine so around 250 bhp for the non-catalysed version and around 225bhp for the catalysed version, so the commonly published 0-60 time of 4.8 seconds only applies to the early press cars with the higher output engines. Supposedly the high output engine was available on request but it came with a huge number of caveats and the same warranties were not offered, as a result there was a minimal uptake on this option. There is a small section in the owners' manual with regard to the optional high powered engine which gives instructions on additional maintenance and care required.
The power figure quoted for the Ghibli Cup is perhaps slightly low, Maserati claimed 330 bhp at launch.
The photo of the interior on page 68 mentions that the Racing used Koni electronic suspension. In fact all models had this suspension system from 1989, it was first made available with the launch of the 2.24v and was also fitted to subsequent models such as the 222 4v, 418v, 4.24v, 430 4v, late Spyders etc all the way through to the Ghibli II. It was however a no cost option to delete this and have conventional suspension. The interior photo you have on this page is not from a Racing - a Racing would have a full leather interior in either grey or black, the interior in the photo has alcantara bolsters in a different colour to the leather centres and is probably the interior of a 2.24v. The Racing would also normally have grey dashboard inserts rather than wood although perhaps 5 or 6 cars out of the 230 Racings built were specced with the wood finish.
You're correct in saying the Racing was "the hottest of the lot", but only just, the export version, the 222 4v was very similar in performance with only 4 bhp less and is actually far rarer with only 130 built compared to 230 Racings. The 4 door 430 4v was also pretty close and rarer still.
Production of the Shamal was never stopped and restarted, this only occurred with the Ghibli GT and Quattroporte IV after Ferrari took control in 1996, by which time Shamal production had finished. The factory was shut down and production lines were modernised before production started again, the Quattroporte IV was heavily revised with a number of updates and became the Evoluzione, controversially some aspects of the interior were cheapened, the Lassale clock was replaced with a cheap digital clock and some of the interior wood trimming was deleted. The 2.8 version was dropped from the UK market and only the 3.2 V8 Evoluzione was available here, the 2 litre and 2.8 litre versions continued in Evoluzione form for other markets. The Ghibli received a few minor updates and quality control improvements and a further couple of hundred or so cars were built. You can identify a post Ferrari take over Ghibli by the high level 3rd brake light which was fitted to the top of the rear windscreen, pre-Ferrari takeover Ghibli GTs have the 3rd brake light mounted at the base of the rear windscreen.
Anyway, I sound like a proper pedant and overall it was a very nice article, and it was nice to see an attempt to dispel a lot of the myth surrounding the Biturbo era cars. Yes the early cars were a bit rubbish but every year they were revised and updated and when Maserati finally introduced fuel injection and improved their quality control they became excellent cars. Unfortunately it all came a bit late for the US market where they still have a terrible reputation which is largely unfair. Perhaps it would also have worth mentioning the continuous development of the Biturbo engine, in the mid 1980s they built a version known as the 6.36 which featured six valves per cylinder and used some patented technology on the valvetrain. They managed to extract more power from 2 litres than contemporary Ferraris were managing from 3 litres
It is interesting to note that Maserati remain in a state of denial and embarrassment with regard to the Biturbo era, whenever you see an official event with the launch of a new model, Maserati will wheel out some of their past masters in the lineup, but never a car from the Biturbo era. If you look at this photo of the factory for example you will see past models proudly displayed on the building but where is the Biturbo?