porting my wastegate hole

[Turbo6Smackdown]

I'd like to do this, while my turbos off. I know everyone says 'use a dremel' but it seems to me that the hole would never come out round then. it doesnt have enough precision. I hear the hole (stock turbo) is 7/8ths, and usually ya port it out to about 15/16ths. The easiest way it seems to me, is to just take a 15/16ths inch drill bit, and drill it. done. centred, even, smooth, AND the absolute correct diameter.
Has anyone done it this way?

 

[BlackBandit]

If you just run a drill through it and the puck isn't centered on the hole you might lose seal on one "side" of the hole. If the turbo's off why not just take it to a machine shop and have them drill it out based on the carbon marks left by the puck? That's what I would do. HTH james

 

[Turbo6Smackdown]

i had a grinding wheel ya put in your drill motor, that was a HAIR bigger than the hole. I just threw it in there and grinded till the wheel went thru. I couldnt have opened it a 32nds more. maybe a 64th. good enough for me. my 'lipstick print' it made, was centred. so im good to go on that. thanks.