Reading an old performance car road test of a A610 the other day, the article stated the increase in power of the A610 over the GTA, was due to an increase in capacity, from a longer-throw crankshaft. And bigger valves and increased boost from the Garrett T3 turbo.
According to the A610 manual, it does indeed run more boost than the GTA. Now, I've seen it mentioned in discussion on this forum, that the GTA turbo is already running close to it's upper boost limit, in standard tune. So, does this mean the A610 turbo is of a different spec, or is it exactly the same as the turbo used on the GTA?