I have built a gti PF head on my 90 ps engine and the thing runs like the sow and the one with the long gearbox:4. gear 6400U/min =200 km/h. Vmax in 5th gear approx. 220 km/h. I only planned the canopies and then the head. does anyone know why the thing is going so well. yes and there I would have another question: from about 5500 rpm he no longer pulls like in the lower range, can the manyicht lie on the too small exhaust system? is gti standart, but looks so thin.