Truck Forums - HOW-TO port your throttle body...

I FOUND THIS ON THE INTERNET!!!

Porting your the throttle body is a simple way to pickup some extra horsepower and if you already have some simple tools, it's super cheap. All you need is a dremel (or similar cutting tool) with some cutting bits, some sanding rolls, various grit sandpaper, and some quick dry metal filler of some kind (optional).
Here is a picture of the stock throttle body that we'll be working with. Our goal is to open up the area in front of the throttle blade including the front lip. You can also fill in the huge cut out area at the top (optional).

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First off, you need to mark the throttle body at the blade with a marker so you be sure not to go past the blade into the backside. This is VERY IMPORTANT. If you go too far and it will not allow the throttle blade to seal and cause idle problems.
If you also plan to modify the throttle shaft (optional), you will need mark the shaft at each end where it goes into the body, like in the picture below.

http://memimage.cardomain.net/member.../993398_86.jpg
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Now disassemble the entire thing. Remove all the connectors, unscrew and remove the blade, and remove the shaft. After you take off the tps, you can simply whack the shaft out with a hammer. Don't feel bad it won't hurt anything. ***Pay attention as there is a very small washer that will fall out on the tps side too, do not lose this!!***

http://memimage.cardomain.net/member.../993398_87.jpg
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Optional: Now you need to fill in the cut out area that goes into the idle air bypass. I used 2 pieces of stainless tubing inserted before I filled it with metal filler. You can simply drill the holes later if you need to. I also put a piece of aluminum can against the opening and cut out 2 holes for the stainless tubes to slide through. This way the metal filler will not completely fill the cut out area and choke it off.

http://memimage.cardomain.net/member.../993398_88.jpg
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Optional: While that's drying, go ahead and knife edge the throttle blade. I used a bench grinder, but you can use the dremel if you choose. Also, round the back edge of the blade off "airflow off the back is as important as the front".

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Optional: Now move over to the shaft and get ready to cut it. What you will be doing is cutting off the front portion that you see when looking at the throttle body head on. When the blade is opened up this makes a big bump and a big restriction. Reference the marks you made before you took it apart and cut there.

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The shaft will look like this now:

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If you used metal filler, make sure it is dry. It's now time to start porting. It will take a while, but be patient and be careful, making sure not to go too far into the throttle body (keep an eye on the mark where the blade will sit). Knife edge the leading edge of the body and grind back to your mark. Pay attention to the area near that mark, as there is a "lip" right there that is a major obstruction to air flow. You are able to feel it with your finger. Your rough cut should look something like this (if you didn't use the stainless tubes, that area will be solid filler):

http://memimage.cardomain.net/member.../993398_92.jpg
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Be sure not to go past your mark!!

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