I've ported TB's for years. Mostly Fords, some Chevy and now my 2015 Ram. I've also port and polished Superchargers, intake plenums and such.
If you're new to it, definitely get something to practice with.
I use an die grinder. The electric 1/4 die grinder from harbor freight does really well. If you have an air tank, a pneumatic one works great too. Then I use several flapper wheels from 40, 60, and 80 grit. The 2" x 1 1/4" work good. After that I use a Dremel with a 120 flapper and then finish it off with some 400 grit polishing/buffing wheels.
If you want to keep the stock idling and no issues, you have to go the venturi route. And it's the same as most of these other vendors do. If you want something all the way through, you have to upgrade the throttle plate/blade.
For most, if you look in your TB, you'll se a hump or a step up. That's what I shave down so it matches the inlet start of the TB. The 40 grit will knock it down pretty quick. BUT, so that you don't interfere with the idle quality, I mark (thin tip permanent marker) the location the blade rests at. That's the area that I don't touch with the 40, 60 or 80 grit. Cause once you do, could have issues or need to step up the blade size.
Once I get that hump down with the 40 grit, I move to the 60 grit to help smooth out what the 40 grit left. I'll also hit the back side of the TB. with this, I put a think black line around the opening so that I know how much to grind out. once that black ring is gone, i'm done. But do that same on the back side and don't touch the area where the blade sits. Once those are done, I step up to the 80 grit. Once that's smooth, now it's Dremel time with the 120 grit. Now...the 120 takes a lot longer to eat up aluminum but please know that if you leave it there too long, it'll eat it. So becareful. With the 120, I will go over the areas where the blade sits but very little and fast. The majority of the time is smoothing out the 80 grit from the majority of what I ported.
Once that feels super smooth, I move onto the 400 grit buffer wheel, still with the dremel. Now with this, I use a in and out motion and will go over the area where the blade sits too. This is to make it smooth as glass. Since these wear out quickly, I usually use 5-6 of them or until i'm satisfied on how smooth it feels.
But, as I said, buy a used one off ebay or junk yard to practice. The 40 grit flapper won't eat it out so fast that you have a hole or anything but you don't want to eat out a section that has a bit divot now. The aluminum bits I use for a superchargers or such, now those can eat through aluminum like a hot knife through butter. Those...you don't use on TB's.
But for less than $80-100 bucks, you can have everything you need to port TB's for all your vehicles or future vehicles.
