[93mustang2.3]

first thing is first im a rookie and i can do anything to my air intake i just got to have directions. i took out my air silencer and it runs great i just got a question to ask. what is a "TB" and how do i half shaft it??? can someone help me out? thanks alot.

(93mustang2.3)

[dakine858]

Originally Posted by 93mustang2.3

first thing is first im a rookie and i can do anything to my air intake i just got to have directions. i took out my air silencer and it runs great i just got a question to ask. what is a "TB" and how do i half shaft it??? can someone help me out? thanks alot.

(93mustang2.3)

A "TB" is referring to your 'throttle body'. When half-shafting your throttle body, what your doing is removing the front half of the throttle blade shaft. With the throttle wide open, carefully grind the threaded ends off the throttle plate screws (since they are "staked" to keep them in place), and remove the butterfly plate. Look CAREFULLY at the throttleshaft, as you are going to cut the drilled side off, leaving just the threaded half of the shaft (know as "half-shafting"). Once you are absolutely positive which side is to be removed, use a coping saw or cutoff wheel to remove that half of the throttle shaft. Carefully grind the remaining nubs flush. This simple mod will increase the air through your stock TB at least 5%. For even more airflow, thin the front (stamped) side of the throttle plate as much as possible, and taper it to the ends (from the shaft, straight out). Do not get too close to the edge or you will have idle speed problems! Countersink the bolt holes (again, not all the way through!) and use M4-.7x8mm oval head machine screws to secure it. To reassemble, center the shaft and tighten ONE screw. Treat the other screw with 3m Loctite 271 "Red" for a permanent mount. After it has set (5 minutes or more), remove the remaining screw and Loctite it as well. After they have completely cured (24 hours), grind any exposed threads flush with the throttleshaft. Cheap and easy! I attached pictures so you can see what I'm talking about.

[pootitang]

Well done!!!!
This ought to go into the stickies on Performance Mods.

[krk105]

What kind of numbers are we talking about for increased performance? I know you said about 5% increase in air flow but how did you come that conclusion.

I geuss I'm just a little skeptical with out any documented supporting evidence on increased perforamnce. Please inform me further I want to learn.

[93mustang2.3]

thank you very much that really help ill do that soon

[dakine858]

Originally Posted by krk105

What kind of numbers are we talking about for increased performance? I know you said about 5% increase in air flow but how did you come that conclusion.

I geuss I'm just a little skeptical with out any documented supporting evidence on increased perforamnce. Please inform me further I want to learn.

I used a vacuum gauge to test the stock vacuum before cutting the shaft then converted that to o2 parts per million. After I did the TB mod, I checked the vacuum again, converted to parts per million, divided the variance and came up with 5%. Some basic logic will bring us to a similar conclusion as well. Air flowing through the throttle body is slowed down by the surface area of the TB shaft and plate. This means that if you reduce the surface area that the air has to flow over, while the engine's vacuum pressure stays the same, you are increasing the o2 ppm(oxygen parts per million) entering the intake manifold, which increases efficiency and performance.

[krk105]

I am still not convinced. I work as a Quality Engineer and I think 5% change could have been obtianed through operator error and other uncontrolled factors i.e. air temp.




1)What rpm was each recording taken at?
2)What position was the TB valve in when you recored the vacuum?
3)How do you convert vacuum to ppm of oxygen
4)Could you provide me with the equation so I can try this?
6)What temperature did you take these readings at?

[mg man 75]

Not being skeptical. But if that helps 5% what does the big throttle body change do to a NA motor. I did notice some improvement on my turbo when I put it on. http://i177.photobucket.com/albums/w...5/100_5531.jpg
Also that old intake hose is already gone. It keep blowing off.

[dakine858]

Originally Posted by krk105

I am still not convinced. I work as a Quality Engineer and I think 5% change could have been obtianed through operator error and other uncontrolled factors i.e. air temp.




1)What rpm was each recording taken at?
2)What position was the TB valve in when you recored the vacuum?
3)How do you convert vacuum to ppm of oxygen
4)Could you provide me with the equation so I can try this?
6)What temperature did you take these readings at?

Shouldn't you know how to do the conversion if you're an engineer? They were all taken at 1000 rpm, and the temperature was 71 degrees outside. As long as the temperature remains constant for the duration of the tests, the slight variations cancel themselves out. Calculating oxygen content; p=P / RxT Where p is the air density, P is pressure, R is the specific gas content, and T is the temperature in Kelvins. I have a degree in mechanical engineering and my neighbor who helped me with this has a PhD in applied physics so rest assured that when I posted a 5% improvement regarding the TB shaft mod, it wasn't just a guess. Also, we calculated the variance to be +- 1.3287%

If you want to leave the molecular science aspect out of determining the benefits from half shafting your TB, you can take the diameter of the throttle body to calculate the area for air flow, subtract the total width of the tb shaft and plate. This will give you the total surface area that the air has available to pass through to the intake manifold. After half-shafting the TB, do the same calculation again and you'll see that you increased the total area inside the TB for the air to flow by +- 5%. From a scientific standpoint, over complicating yourself by factoring humidity etc, is a waste of time and its just splitting hairs. Why? The second you pull out of your garage, the air temp, density, humidity etc is always fluctuating, which is why I went back and provided you with the variance (1.3287%).

[krk105]

Your right I should if I remembered everything that was ever tought to me in school, but considering I got a C in physics I & II there still is chance I would not know. Anyway..............In your equation did you measure vacuum in (Hg) or a (-psi) and could you show your math work. I think that would help. How did you convert a % into parts per million?