SELF Re bore 75mm TB to 80mm
After market throttle bodies have qouted an increaese of 'up to 13kw, if used with additional cold air intake'. I am thinking of reboring my Gt TB to 80 mm this weekend. The OD of either end is 80mm +, so why can't the 'butterfly' area be 80mm? Aftermarket TB's are 80 mm and clain large kw output over standard. As the gap between TB air inlet and butterfly shaft bearing is approx 3 mm each side, meaning if I rebore inlet there is approx 0.5 - 1mm each side for inlet to bearing separation, am not sure if this is enough. Also will butterfly jam open, making 'fly by wire' throttle jam full on? I will make a new butterfly at 80mm d, and have calculated a taper of about 5 - 7 mm to compensation for the new diameter. Has anyone done this and are my taper calculations correct? If I am wrong, no prob, at least I tried to enhance the induction system over the standard spec...., and Ill just have to buy a new TB to make my oil burner standard again (over 1 l per 1000km).
Please only reply if you have tried and succeeded, or tried and failed.