I think there are a whole bunch of factors the feed into that, HP-Factory have an explanation on their website:
http://www.hp-f.com.au/how-to-read-a-dyno-graph/
You really should be looking a the percentage increases and apply those to the factory flywheel figures.
So in my case: 227/201=1.13 * 184KW = approx: 207KW
Peak torque: 750/700 = 1.07 * 580nm = approx 620NM
These numbers are not to far of other reports for tuned WK2 CRD's
Hope this helps.
Gus