03Muskrat

I was wondering if any of you had really looked inside the stock intake plenum... if you do you will find that the stock tb is prob 3mm smaller around than the plenum, and where the plenum turns down into the plastic manifold there is a step down, and i also found many casting flaws in this area, can i get the same improvement from porting and polishing the TB and plenum to match each other as buying an accufab or C&L? I polished the stock one a bit with a die grinder and a rubber polishing wheel, but i wanted to find out if im going to help or hurt by modifying the architecture of the plenum somewhat... as far as matching the tb and plenum and rounding off the inside turn of the plenum beacause its like a 90 degree bend, which id imagine is causing turbulence in the airflow, as is the step up to the stock butterfly, cant really figure why thats there, it should at least be smoothed in instead of stepping up, then down.... any commentary would be helpful

Chopper

Your'e on the right track.Smoothing the airflow through the intake tract is what it's all about.You can start at the mouth of the TB and shape it to a sharper edge,and blend it into the narrow part where the throttle blade lives.Now go behind the blade and blend all that into the plenum,being careful to remove nothing from the blade area.With the plenum itself,polish the inside and round off the bottom corners just before where it joins the intake manifold(the shiny places).The only trouble is going to be the small size of the throttle blade.The restriction is still there and will limit how much of a gain you can get.You would probably be better off getting a new TB and plenum.

vshayes

Read these two threads:

https://mustangforums.com/tm.asp?m=163723

https://mustangforums.com/m_164293/m.../tm.htm#164313

03Muskrat

thanks chopper thats what i was looking for, pretty much if im gunna lose anything by opening up the intake tract