noxperpetua wrote:
Hallo..was wandering if a kite used with 27m lines and 23 bar could be fast in the window as a kite with a 26m lines with a 20 bar - i own a rpm 10m and use with it a 23+3m lines and standard 20 bar...(i'm 210 lb -97kg -start going with rpm with 17-18 knots).now i just bough a turbine 17 with 27m lines and 23 bar...was thinking to leave the 3m line extention and always use 27m - 23 bar with rpm if wind not pics up more then 20knots..after great fun with 23m lines ...
any one have tested this or is a good phisic with some good mathematic formulas???

It does not work that way, and a formula can never apply here.
If you have longer lines, the kite can be flown more "around", thus you can kite in less wind when marginal conditions.
If you have shorter lines, this is not possible anymore - but it does not matter in "normal" winds - only if underpowered.
But the short lines will feel like the kite races across the window - giving it a very different feel because of this, and it will feel much more "on/off".
Some like this, others hate this.
The kite will not turn faster, nor slower - with different line lengths.
Only a slight delay if REALLY long saggy lines...
Bar length is a very subjective matter - as actually you dont get the kite to turn faster with a longer bar, but it can feel like you can - especially if your hands are close together.
With big kites you NEED a longer bar though, simply because of the max throw needed.
You will not be able to feel any difference from 26 to 27meter line length, such small changes does not matter.
But your 17m2 will be way slower turning than your 10m2 of course - even if you have a longer bar on the 17m2, and you will most likely use it underpowered too now and then.
So my advice:
Go with 27m lines and the 23" bar for the 17, always.
And then you can use 23m lines and the 20" bar with your 10m2, and maybe on rare occasions use the 23+3=26m2 if not sufficient power and you dont want to rig the 17m2

Peter