4.6L Throttle Body and Fresh Air

Last Updated on Saturday, 17 July 2010 08:15 Written by Glen Johnson Thursday, 26 October 2006 15:08

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Engine

70MM Ford Throttle Body Install for the 4.6L SOHC with a easy do it yourself cold air intake.


The 70MM Ford Motorsport throttle body (TB) was one of the very first parts to be released for the new modular Mustang 4.6L SOHC. The install is very straight forward and this is how it goes:

  1. Loosen the hose clamp that holds on the inlet tube attached to the factory TB, then pull it loose and move it to the side out of the way.

  2. Disconnect the throttle linkage from the TB.

  3. Disconnect the wire connector to the throttle position sensor (TPS). This is why I recommend a Ford Motorsport unit. The Ford Motorsports unit comes with a new throttle position sensor already attached to the throttle body. I have heard of nightmares removing the TPS from the old TB to put it on New TB’s that do not come with it.

  4. Remove the four bolts that anchor the TB.

  5. Remove the old TB.

  6. Throw away the old gasket. It will not work on the New TB. Just a reminder, the New TB does not come with a gasket, you must order it separate!

  7. Put the new gasket on and bolt on the New TB. Be careful when tightening the bolts, you just want to snug them down and re-snug the bolts after you have driven the car a few hundred miles, this is aluminum and they can strip easily, also if you over tighten you can warp the seat of the TB and you will develop a leak. Do not use gasket sealer.

  8. Reattach the air inlet and the connector going to the TPS. You're set!

After installing the unit I was initially disappointed with gain in power, if at all I only realized it at the high RPM level. This is why people say it is a waste of money. BUT WAIT, THERE’S A HAPPY ENDING! It dawned on me that opening up an induction system in the middle was only as good as the amount of air that could get to it. So I ripped out the restrictive snorkel (with the stock filter), this helped a little but I still was not seeing any significant gains. So I constructed a fresh air intake from the inner fender to the factory air box. This how I did it:

  1. I went to my local hardware store and purchased a flexible thermal hose 5inch diameter and about a foot in length. I also purchased a Rubber flashing made to go around a 4inch roof ventilation pipe and some permatex silicone adhesive/sealer.

  2. Unlatch the filter box and pull the filter out.

  3. Then unbolt the factory box and removed it (only one bolt holding it in)

  4. I cut the rubber flashing outer edges to match the large opening of the factory box where the snorkel once resided with a ½ inch over hang. This rubber flashing piece if you can find it works great.

  5. I then glued the rubber flashing onto the outside of the box (holds very strongly).

  6. Since the rubber flashing was already preformed to seal around a 4” pipe, I trimmed the hole to 4.75”.

  7. Next trim the 5inch flexible thermal hose to six inches in length.

  8. Insert the 5inch flexible thermal hose into the 4.75” open of the rubber flashing of the factory box. You will have to stretch the rubber flashing, but it will make for a tight fit with no fastening needed.

  9. Install the filter box back into it original position with the thermal flex tubing (the 5” tubing fits the hole perfectly) through the original hole in the inner fender wall where the snorkel once went.

I installed a K&N replacement filter along with the setup. I could not believe the difference!! The car pulled harder and it seemed to extend the usable RPM range. This setup only cost me $15 (without the K&N filter) and really woke up the 70MM throttle bottle installed, plus the fresh air setup looks clean. This setup may not be as fancy as a $170 ram air setup, but I bet it produces almost as much power! There is a lot to be said with matching bolt on’s. Alone the 70MM throttle body was not much, combined with the fresh air setup it is a killer combination.

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