I've just bought the car and haven't done the mods myself - they were done by Brodie Brittain Racing in Silverstone. Car was delivered brand new from Amersham Motors so mods were done in 1994/5. As far as I can tell engine mods were restricted to the top end - ported and polished heads, re-profiled valves and seats, raised compression ratio (not sure to what but it will run on normal unleaded so it can't be that high). It was also fitted with non-standard cams but I have no idea what spec they are except that they were done specially for this car and were not 'off the shelf'. The car is quite 'drivable' with reasonable power/torque at low revs, though not as good as standard. Engine really kicks above 4000rpm, rev limit set somewhere above 8000rpm but I haven't explored above that out of mechanical sympathy. Dyno plot shows peak at around 6700rpm. ECU was re-mapped so suit the engine mods. Bottom end wasn't dismantled so still standard 2.5 litre and, presumably, not balanced, hence my reluctance to rev it madly. Exhaust is a custom stainless system (including manifolds) with DTM rear box and straight-through cat replacement.
Rest of car - lowered 60-70mm (absolutely rigid - I'm changing to Eibach springs VERY soon before my teeth fall out) with Koni adjustable struts, larger anti-roll bars front and back, 17" wheels with 215/40ZR17 tyres, Forza cross-drilled, grooved and ventillated front disks.
I also have a Porsche 911 3.2 Carrera and the Alfa is considerably faster (so the Porsche is going!). It has alledgedly topped 160mph on a German autobahn but I'm not sure how accurate the speedo is at that sort of speed. I'd estimate 0-60 at around 5-6 seconds, and that's without abusing the clutch too much. The car is fabulous to drive with the exception of the ride quality and poor clearance, both of which will be sorted by the new springs.
In terms of cost the invoice for the car from Amersham Motors was about £29k in 1994. That was £17k retail plus mods plus new car tax and 'on the road' charges so the mods must have been around £8-10K. Glad I didn't pay that! This included a lot of development work including track testing so similar mods should be rather cheaper now that there is more expertise available on these cars/engines.
I wouldn't say that the car is a 'nutcase' car but it certainly attracts attention (currently stickered-up as a replica of Tarquini's '94 touring car but I may not put up with that for long!). It is perfectly useable every day - the interior is standard (leather) and little refinement has been lost (suspension excepted) so creature comforts are all present and correct.
I suspect that I'll learn more about the modifications that have been made to the car as I drive it and 'investigate' it. I have some pictures but I think I need to put them on my website before I can provide links here - is that right?
I'd be interested to hear from anyone who's heard of this car or knows anything about it - registration M405 RUD in Rosso.