See [link=http://www.prme.nl/forum/viewtopic.php?t=54]my report[/link] on my forum for complete MTW TD75 tests
This engine hauls much like a 40+cc

35cc
Data sequence: prop; muffler;rpm; header Lcm; header IDmm; remarks
mejzlik 18x10;3271 ;7200; - ; - ;original MVVS 3271 side muffler
mejzlik 18x10;3W-2;7600;20;22; original mvvs header with 3W muffler
3W 18x12 mod;3W-2;7200;20;22; Foil and blade shape modified
3W 18x12 mod;TD75K;7600;20;22; Foil and blade shape modified
3W 18x12 mod;TD75K;7050;30;25; CHT 156°C
3W 18x12 mod;TD75 ;6750;30;25; TD 75 has longer internal header
3W 18x12 mod;TD75;7250;25;25; header still too long for TD75
3W 18x12 mod;TD75K;7420;25;25; CHT 160°C
3W 18x12 mod;TD75K;7650;20;25; CHT 170°C more power than 22mm header
3W 18x12 mod;TD75;7550;20;25; Header still slightly too long for TD75
Menz-S 20x8;TD75;7050;20;25; Excellent pull
Mejzlik 20x8;TD75;7470;20;25; Excellent pull
Mejzlik 18x10;TD75;7830;20;25; The shorter header is a little noisier