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C6 Corvette: How to Port and Polish the Throttle Body

Throttle body porting and polishing. Yeah, you can do that at home. Read on to see how.

By Nick Vaughn - February 12, 2015

This article applies to the C6 Corvette (2005-2013).

Some people have said that porting and polishing should be left to the professionals. For some that may be true, but for you? Well, after you read these steps you may give it a shot. Porting and polishing your C6 throttle body isn't as difficult as you might think. In fact, it could be one of the easiest and quickest ways to improve your car's response times and toss some quick additional horsepower under your hood. Take a look through this article to learn what it takes to port and polish your Corvette.

Materials Needed

  • Dremel tool or die grinder
  • Grinding stone(s) and various sanding drums or hand-held sanding paper grits
  • Metal polishing compound
  • Green and red Scotch-Brite pads
  • WD-40 penetrating oil
  • Throttle body gasket
  • Eye protection

These steps assume that you have already removed the throttle body from the engine. We will show you how to port and polish the throttle body after you have already cleaned the inside of any oil buildup, removed the butterfly, shaft, and linkage.

(Related Article: How to Remove Your Throttle Body - CorvetteForum.com)

Step 1 – Prepping

Apply WD-40 penetrating oil to the throttle body walls to prevent oil and metal shavings from sticking together. Apply a small coat to the grinding stone as well.

Figure 1. Throttle body before port and polish.

Pro Tip

Tape around the shaft to help ensure that no metal shavings get into other areas of the throttle body. These may cause premature wear of the bushings or bearings.

Step 2 – Grinding

Using the grinding stone, smooth out the interior walls of the throttle body bore, so it is even with the walls. Start with the edges. If there are some rougher and uneven edges, use a sanding drum for your rotary tool to further smooth out the throttle body walls.

Figure 2. Grinding stone for throttle body.

Pro Tips

  • Take your time and slowly sand out the walls as uniformly as you can. You can always remove the material, but you can't put it back on.
  • Varying grits of sanding drums can remove more or less material. Finer grit sanding drums and sanding paper are recommended because they can prevent removing too much of the material too quickly.

Step 3 – Sanding

Remove additional minor imperfections by wet-sanding the throttle body walls. Do this by applying water to a finer grit sanding drum, which prevents the material from gumming up. Continue sanding with a green Scotch-Brite pad followed with a red pad. Keep applying water to keep the dust off and removing fine particles. The outcome should give you a clean, smooth surface.

Pro Tip

If necessary, use the Scotch-Brite polishing process on the throttle plate. It usually does not have rough edges and might not have to be worked over.

Step 4 – Polishing

Apply a metal polishing compound and polish the walls of the throttle body. This will clean and remove anything left behind during the grinding and sanding steps.

Figure 3. Throttle body after port and polish.

Pro Tip

Mothers make a good polishing compound, but there are many options out there. Follow the directions on the container for best results.

Step 5 – Reassembling the throttle body

Install a new throttle body gasket when putting the throttle body back into the engine. Also, peen the screw threads or apply Loctite thread sealant on the other end to ensure they don't come out.

Featured Video: Porting and Polishing a Throttle Body

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