Just read this ina review of the S3:
"I just presumed they�d use the 3.2 litre V6 in the A3 as that already produced 250bhp before they started tinkering with it. Not so. In fact they plumped for a 2 litre four-cylinder motor that derives its 265bhp from being turbocharged to within an inch of its life.
What this means is that while the S3 goes like hell � 0-62mph in 5.7sec � the quality of that performance is nothing like as endearing. The car suffers from turbo lag, which often means there is a considerable pause between your right foot requesting a gob of power to squirt past a long lorry and it actually arriving. In that time a less powerful but normally aspirated car such as the A3 3.2 quattro would already be on its way.
And while the V6 A3 howls sweet six-cylinder music, the highly stressed four-cylinder motor in the S3 sounds anodyne at low revs and increasingly harsh as the needle sweeps around the dial. I wonder how many people will think it worth paying the extra �760 that the S3 costs over the A3 3.2 quattro when its less responsive and refined engine gives a mere 15bhp extra. "
original article is HERE
Is this such a radically different engine to the Audi conversions - I’m guessing it must be but would be interested to hear from someone who knows.