DIY Throttle Body Porting

[Naaman]

I've been on youtube and stuff checking out how-to vids on TB porting. Very helpful stuff... but I'm kinda scared to do it to my only TB...

Here are my concerns:

1) How do I determine the best size (opening) ?

2) How do I know when I'm finished?

3) What precautions can I take to make sure I don't mess it up?

4) What are the common (and not so common) mistakes people make when they attempt this for themselves?

[sjsingle1]

it was worth it to pay 50$ to get it done

[tatertot91]

It's rather easy if you take a good look at your throttle body.
The opening actually gets smaller than the blade then opens back up, when you port it your basically making a smooth transition from the opening to the blade

I had a pic that gave a pretty good idea of it but i lost it
If you want i can draw one up real quick

[Smittro]

I've been on youtube and stuff checking out how-to vids on TB porting. Very helpful stuff... but I'm kinda scared to do it to my only TB...

Here are my concerns:

1) How do I determine the best size (opening) ?

2) How do I know when I'm finished?

3) What precautions can I take to make sure I don't mess it up?

4) What are the common (and not so common) mistakes people make when they attempt this for themselves?

1. the larger the front is opened up the better.. HOWEVER, be carefull to stay within reason as if you make the TB wall too thin it will crack or break..

2. Once you removed the desired material you can then move to polishing the bore. Avoiding the ventury area.. But you can polish right up to it.. Hand sanding works well moving in a circular motion from about 500-1000-1500-2000 git sand papers. But you can also use a moto tool (be carefull) to remove material and to polish..

3. Never change the ventury bore. It's the area where the butterfly is.. That area is milled specifically for the blade (butterfly) changing its dimensions will cause problems..

4. One thing that is easy to have happen is damaging the ventury bore.. Like said, this will cause troubles..

The other could easily be opening up the rear bore too much..

The rear bore behind the ventury should not exceed the size of your intake manifold inlet diameter..

Here is some pics of my in house custom built/ported TB from my TT project hope this helps.. Good luck.










All in all, it's very easy to port/polish these youself..
Take your time, have an eye for detail, and you can tackle this yourself no prob..imho..

[Lunatikgixxer]

it really doesnt make a huge difference unless u get it tuned for that, just like removing the screen.... atleast thats what my tuner told me

[tatertot91]

it really doesnt make a huge difference unless u get it tuned for that, just like removing the screen.... atleast thats what my tuner told me

increased throttle response

[sjsingle1]

if you do it yourself or not......i do like my PP TB....and i recommend it

[KMdef9]

1. the larger the front is opened up the better.. HOWEVER, be carefull to stay within reason as if you make the TB wall too thin it will crack or break..

2. Once you removed the desired material you can then move to polishing the bore. Avoiding the ventury area.. But you can polish right up to it.. Hand sanding works well moving in a circular motion from about 500-1000-1500-2000 git sand papers. But you can also use a moto tool (be carefull) to remove material and to polish..

3. Never change the ventury bore. It's the area where the butterfly is.. That area is milled specifically for the blade (butterfly) changing its dimensions will cause problems..

4. One thing that is easy to have happen is damaging the ventury bore.. Like said, this will cause troubles..

The other could easily be opening up the rear bore too much..

The rear bore behind the ventury should not exceed the size of your intake manifold inlet diameter..

Here is some pics of my in house custom built/ported TB from my TT project hope this helps.. Good luck.










All in all, it's very easy to port/polish these youself..
Take your time, have an eye for detail, and you can tackle this yourself no prob..imho..

I agree here. Alot of having the right tools for the job makes this project easier or harder. I'm not sure what tools you do/don't have, but things even like a drill press could make this job alot easier than a dewalt drill obviously. So if you already have all of the holesaws, sandpaper, and dremel tips, I'd say give it a swing! If not, I'm with sjsingle on this, $50 and call it done if you don't want to spend the ~$200 for new aftermarket one.

[Naaman]

It's rather easy if you take a good look at your throttle body.
The opening actually gets smaller than the blade then opens back up, when you port it your basically making a smooth transition from the opening to the blade

I had a pic that gave a pretty good idea of it but i lost it
If you want i can draw one up real quick

I've actually read a thread where you were explaining it... I think you gave me a good understanding of it.

1. the larger the front is opened up the better.. HOWEVER, be carefull to stay within reason as if you make the TB wall too thin it will crack or break..

2. Once you removed the desired material you can then move to polishing the bore. Avoiding the ventury area.. But you can polish right up to it.. Hand sanding works well moving in a circular motion from about 500-1000-1500-2000 git sand papers. But you can also use a moto tool (be carefull) to remove material and to polish..

3. Never change the ventury bore. It's the area where the butterfly is.. That area is milled specifically for the blade (butterfly) changing its dimensions will cause problems..

4. One thing that is easy to have happen is damaging the ventury bore.. Like said, this will cause troubles..

The other could easily be opening up the rear bore too much..

The rear bore behind the ventury should not exceed the size of your intake manifold inlet diameter..

Here is some pics of my in house custom built/ported TB from my TT project hope this helps.. Good luck.

All in all, it's very easy to port/polish these youself..
Take your time, have an eye for detail, and you can tackle this yourself no prob..imho..

Effin Awesome! Great feedback.

I take it the venturi bore is the part of the bore that is "in contact" with the blade/disc/throttle thingy. You're saying it needs to "seal" up properly when idling, right?

I agree here. Alot of having the right tools for the job makes this project easier or harder. I'm not sure what tools you do/don't have, but things even like a drill press could make this job alot easier than a dewalt drill obviously. So if you already have all of the holesaws, sandpaper, and dremel tips, I'd say give it a swing! If not, I'm with sjsingle on this, $50 and call it done if you don't want to spend the ~$200 for new aftermarket one.

I was under the impression that it could be done with just a dremel tool (or a dremel tip on a drill). I assumed that was the best way to do it... glad I asked. One thing about learning this kind of stuff is that you never know how ignorant you are until you talk to the right people.

[KMdef9]

I was under the impression that it could be done with just a dremel tool (or a dremel tip on a drill). I assumed that was the best way to do it... glad I asked. One thing about learning this kind of stuff is that you never know how ignorant you are until you talk to the right people.

I'm sure you could, I think it would take more time and be more difficult to achieve a perfectly flat surface. Not impossible, but harder.

I'm not trying to steer you away from trying, we all have to start somewhere, just pointing out all options.

[00z28bubba]

increased throttle response

not sure if the 3.8 tb was different but the ls tb in the f bodies you can take some meat off the stopper. that will get you higher than 84%(stock) throttle.

[Smittro]

[QUOTE=Naaman;2594439][QUOTE


Effin Awesome! Great feedback.

I take it the venturi bore is the part of the bore that is "in contact" with the blade/disc/throttle thingy. You're saying it needs to "seal" up properly when idling, right?

QUOTE]

No prob.. Yes that is the area.. If you make it misshapen it will effect idle, or it may not even idle @ all..

[Naaman]

I'm sure you could, I think it would take more time and be more difficult to achieve a perfectly flat surface. Not impossible, but harder.

I'm not trying to steer you away from trying, we all have to start somewhere, just pointing out all options.

Yeah. That's how I interpreted it. Thanks for the pointers.