Australia 2009 track query

I've managed to find a 2009 Melbourne track to use which isn't perfect but it's good enough but there is one curious problem which I wondered if any track makers might have an answer to. - I run the game with a quickrace percentage of 20 which in other Melbourne tracks means the race is over 12 laps, but with the 2009 track for some reason it calculates 8 laps! does anyone know if and how this can be changed - hope someone can help

inspect the S1CT01.DAT file through the cmagic4 tool

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RELEASE => Physics (under FIA Technical Regulations)
MagicDatas? Setups? Pit Stop Strategies? Track Specific Performances? Up2Date GP?
Power Torque Curve? Where's this stuff? All download is available at ..

ok thanks for the quick reply - is it just a case of replacing the laps value in the gp4info file or are there other things to change? -- i'm just asking because i've checked a couple of other Melbourne dat files and they both have various other information labels but no track has the same set of labels - just don't want to mess the track up!