Hello Matt

Thanks for yours answers
We uses an APC 18x10 for breaking. But we will try APC 19x11 or 20x10,5.

Friends of mine Stéphane uses on his Temptation (personal design) equiped with RCGF 32 cc : APC 20x10,5 (7200 t/mn), APC 20,5x10 (7000 t/mn) with tuned pipe;
Eric on his Initial (personal design) equiped with RCGF 32 cc : APC 18x12 (7800 t/mn), 20x10,5 (6900 t/mn) with Hatori header and muffler.