Modifying Ford Plenum Cover for use

With Throttle body Spacer and Strut bar

The Ford Plenum cover is a beautiful and long awaited enhancement to the Mustang engine bay. Originally shown on the Mustang Concept vehicle in 2004, this piece was not available when the car was officially released as a 2005 model. In 2007, the plenum cover became available as part of the GT appearance package.

Unfortunately, once it was released, the ’07 Plenum cover was designed to wrap around the front of the throttle body and secures to two stud that hold down the fuel rail on each side of the engine. For those of us that use the throttle body spacer, the stock plenum cover can not be used. Also, if you are using a strut bar, the plenum cover may rub against the plenum cover.

Not wishing to sacrifice either the throttle body spacer or the strut bar brace, I decided to make some modifications to the plenum cover. The first step and the scariest was to cut the front of the plenum cover. I used a marker to draw a line just inside the rim of the plenum cover. I then used a roto-zip tool to cut along the line. Then, is used sand paper to smooth the edge of the cut. The problem with this is that I just removed the front anchor points for the plenum cover. Now I needed to come up with a method to hold down the front of the plenum cover.

To hold down the front of the plenum cover, I decided to use a large black ty-warp. The ty-wrap would not be affected by the engine temperatures because the plenum is made of plastic and does not get that hot. To attach the ty-wrap to the plenum cover I used two plastic cable clips. I used PC7 epoxy and allowed it to cure for about 24 hours. Once the epoxy cured, I used flat black paint to paint the staples. This will make them more difficult to see once installed. I then used two 21” ty-wraps, feeding the first through the staple clips, and attaching the second to the first.

To make sure that the plenum cover does not rub against the strut tower brace, it is necessary to remove the two rear grommets. The next step is to pull the wire looms on each side of the engine off the two studs in the rear of the engine. Next, remove the two studs using an 8 MM wrench. I then installed the plenum cover and tightened the ty-wraps around the plenum. When tight, I used a pair of cutters to trim the pig tails off. Then I re-installed the 8 mm studs on the rear of the plenum.

Finally, the strut bar was re-installed, followed byt the C&L cold air intake. There is a little over half an inch of clearance between the strut bar and the top of the plenum cover. This is plenty of room for the engine to move during hard acceleration without the plenum cover hitting the strut bar.