Right, regarding the versions....
First Alfa 33 that was produced, with the heater vents popping up from the dashboard, was the S1
Then came the second version of that car, which is known as the S2, with lower suspension, front anti roll bar (most S1's didnt have one at all) , alloy wheels, plastic dashboard with the heater vents in it rather than above it, different interior, power windows located where the gear stick is - rather than high up on the centre console of the dashboard.
Different wiring, different engine cams/valves etc etc.
Power output of the S2 was higher than the S1. Got 105 bhp rather than the 95 bhp out of the 1.5 ltr of the S1.
So I suppose its clear why its considered an S2 rather than a facelift.
Then, the S3 came up !
Production of that started late 1989, most of them were sold from 1990 onwards.
Now the S3 was a completely different 33 !
- Galvanized
- Interior
- Dashboard
- Factory A/C
- Power Steering
- Optional ABS
- Different front and rear ends
- Strengthened engine bay
- Different engine ranges, 1.4 carby, 1.5 injection, 1.7 8v injection , 1.7 16v injection
All of these S3 33's produced between 1989 and early 1993 were NON CAT and the 16v produced 137 bhp.
Also all of them came with BOGE front suspension with a 4 bolt top mount and cylinder type springs.
Finally, came the S3 built after the emission regulations started in 1993 ( actually the regulations started applying since 1992 but Alfa Romeo delayed it a year
)
So I suppose the CAT versions can be considered the "S3 Facelift"?
Those came with reduced horsepower - 132 bhp on the 16v
No AFM, just MAF in the ECU and a sensor on the inlet.
Throttle position Sensor instead of Throttle position Switch, different injectors, all with CAT and lamda sensors and FINALLY the SPICA front suspension with CONE type springs and 3 bolt top mounts, which allowed the car to sit higher and stiffer, reduced the bodyroll of the first S3's, but the car sat higher than a Landrover !
Problem with the CAT versions .....well "problem" ..... is Not so much the reduction of output (the 5 bhp less) as is the lack of feel and throttle response.
Believe me when I say.... there is A HUGE difference between the CAT and normal version of the S3.
So, to sum things up, IMHO, you either need to get a NON CAT 16v 33, OR a 1.5 Ti S2 !
Most fun guaranteed
Ideally, you could get the S2 (which is almost 150 Kg lighter), put a 16v engine in it out of an S3 (non cat), keep the gearbox of the S2 Ti (shorter) and POSSIBLY convert it into carbs !
Sorry for the long response