TBH I'm not sure. I'd guess at a combination of a re-map, different cams, bigger valves and/or high comp pistons. Other tuning tricks of the trade may also have been used to good advantage. 147bhp was very nice though and also very useable. All the above is a long winded way of saying 'I don't know'. I know .... I'm rubbish!!
While a lardy sports-tourer by modern standards, I find that 147 bhp allows the horizon to come to me as fast as I can process - wouldn't want anymore. Superb engine DS
Had my 2000 model DSSA model on the dyno back in the day, was putting out 130bhp at the rear wheel with only a race can, didn't think it was too shabby on the track either.
