Has anybody had experience with getting their throttle body on a 4lt machined out, cause i was talking to a mechanic at ford in geelong and he suggested getting my throttle body machined out to gain a bit more power, any help woud be great....
EF Fairmont 4lt Auto - Wade 1004@112 Cam, Chiptorque Custom Chip, Lukey Stainless Extractors, Lukey 2.5" Exhaust, K&N Filter, AU3 XR8 Snorkle, Shiftkit, King Ultra Low Suspension, 18" Advantek Rims, DBA Gold Rotors, EBC Greenstuff Pads, Tickford Bodykit, Cornering Lamps, Kenwood H/U, 4x Response Splits, 2 x 12" Kicker Comp VR Subs, 2 x Response Amps, Roof Mount LCD, DVD Player.
My mate actually machines out throttle bodies for the 3.8 Ecotec Common-whores and he believes it is a worthwhile modification. Apparently people are gaining 3-4 rwkw with them but the Commo TB possibly doesn't flow as well as the Falcon's in stock form.
As Rick pointed out, the stock TB flows well enough to produce 230KW so i wouldn't even bother.
I notice that your pic is of an EF, therefore if anything, i would get rid of the standard intake and install a 2.5" or 3" pipe. Apparently people realise an increase in power with this sort of mod..
Your better off not polishing the inside smooth as gas velocity will be higher over a rough surface than that of a smooth one, a golf ball is a perfect example of this
That's not correct, a rough surface creates turbulence which reduces flow. The reason for golf balls having a rough surface is to allow them to control the flight characteristics of the ball. Polishing the inside of the TB will allow greater flow, but as already mentioned, the 65mm throttle body flows plenty already. On the V8's they are capable of 240+rwkw and the I6 should be no different.
You should use a 70-80grit sand paper finish. The turbulence is extremely minor, and it actally causes the air molecules that are trapped in the (very small) pockets produced by the roughness to act as bearings(for lact of a better word for it). polishing ports will not increase airflow at all, the air will in contact with the walls will 'stick' to them, which will slow the air down.
I hope this helps some people understand what is going on.
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