Bored out throttle bodies

[cuckoo]

hi just enquiring if it is worth the money to get a 70mm throttle body how much more petrol would it use versus hp thanks

[Mark]

better throttle response thats about it. 70mm is too big but because the whole intake isnt 70mm i think its max 69mm

[QIK62C]

who does boring now ??

[greenfoam]

I've pulled my throttle body apart a few times lately for a bit of porting, but I haven't bored it out, just reshaped it a bit and cut back the shaft. Still it would be fairly easy to bore one out to a larger size any machine shop would do it for you but then you need to make a new and perfectly round butterfly, that might not be so easy. The stock one should flow around 500cfm anyway and that's allready more than the engine can breath going flat out

[greenfoam]

Oh yeah, here's my thottle body adpater and throttle body, I've been paranoid ever since I looked at this picture did I forget to clean out the metal shavings from the last grind I did? which was the brass screws hanging out aftet I cut back the shaft, I know I cleaned the adapter after taking the pictures but well... Anyway too late now if I did forget, because I've been driving it for a week, lets hope brass is really as soft as it seems : ). All I've done with the TB is cut off the edges that are at the front and back and blend the front edge to a smooth curve, gave the butterfly half an edge and cut back the shaft, did a dodgy job of that because I left it all bolted together, held open the butterfly with one hand and held the die grinder in the other at 20,000 rpm heart in your mouth stuff that is and yep I did end up taking a chunk off my thumbs knuckle (nothing that wont grow back) but the TB was ok! : ). So the two leasons for the day are, wear gloves and make double triple sure things are clean before going back on the car

[greenfoam]

I missed out on buying a really cheap TO4B turbo today on ebay by 2 dollars and a couple of seconds, blah! oh well maybe next time