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Detailing and Cleaning


SPI - Throttle Body Swap usng Modified Mustang TB

Installing a Mustang's TB on an SPI engine can increase airflow to the engine. For a kick in the pants, try this out!

Time Required:

Tools Needed:

  • Vise or a hammer
  • Drill with a 1/4 in drill bit
  • 7/16 wrench
  • 7/16 and 8mm sockets and an extension
  • Razorblade or a pair of diagonal cutters (dykes)
  • red loctite (highest strength)
  • 7/32nds Allen key
  • pliers
  • flat-head screwdriver
  • crimp connectors and a crimping tool


    Props: Gigaherz on the Focaljet Forums for pioneering this hack and writing up the instructions!

    You must use a Zetec intake tube or an aftermarket Zetec intake for this to work.

    1) Remove the stock intake tube from the throttle body and the MAF sensor housing.
    2) Disconnect the accelerator and cruise control (if applicable) cables from the throttle body. Then, using a flat blade screwdriver, remove the accelerator and cruise cables from the SPI throttle bracket.
    3) Disconnect the TPS sensor plug from the throttle, using an 8mm socket and extension, remove the four bolts that hold the SPI throttle on and remove it from the manifold. Remove the bracket from the throttle and put it to the side.
    4) Put a rag or towel in the top of the intake manifold opening. Then scrape or file off any gasket material that might be sticking to the surface of the manifold. Vacuum out any debris in the intake and pull out the rag.

    5) Take the adapter plate apart by taking out the four black cap screw with the 7/32nds Allen wrench. Now using the four bolts you removed in step two, put the bottom half of the adapter plate and it's gasket on the manifold.

    6) Place the gasket and top half of the adapter on the bottom half and tighten the Allen head bolts. Place the throttle body gasket on top of the installed adapter.
    7) Smear a small amount of silicon on the outside top edge of the brass tube that is pressed into the adapter. Be careful not to get any inside the tube. Place the throttle body on the adapter. Slide the dipstick tube bracket up the tube till it can be bolted to the throttle body. Put it in place and carefully start hand tightening the four bolts supplied with the kit. The bolts should be spinning fairly easily, if not you may be stripping the threads by not putting the bolts in straight. Once you've got them in a little by hand then proceed to tighten them with a 7/16 socket and ratchet with and extension. Do no over tighten!
    8) You must bend or hammer the little tab on the stock SPI throttle bracket so that it is now flat. You have a choice at this point. You can put the bracket on with one bolt or two. Both methods will work just fine but for safety reasons I recommend the two bolt approach.
    9) To put the bracket on with one bolt, use one the 1/4 bolts and nuts supplied and just bolt the bracket to the top hole in the black fuel pressure regulator bracket on the Passenger side of the engine. Make sure to use loctite. Just rotate the bracket upwards till the hole in the plate for the throttle cable is in line with the throttle linkage. Then tighten the bolt. Some slight bending or slight moving of the oil dipstick tube will most likely be necessary. You can also use a zip-tie to secure the oil dipstick tube to the throttle cable/bracket. It makes everything a bit more sturdy.
    To put the bracket on with two bolts, you must drill two 1/4 in holes in the fuel pressure regulator bracket. To do this, you must keep the bracket horizontal and position it till the throttle cable cut-out in the plate is centered with the throttle linkage. Then using the existing hole in the plate, draw or scribe a circle onto the fuel pressure regulator bracket. Drill out the hole with a 1/4 in drill bit. Bolt the two brackets together with one bolt. Line everything up good and while it's still bolted together, drill another hole somewhere else through both the brackets at once and bolt the second bolt in.
    10) Now put the throttle and cruise cables back in the linkage plate and connect them to the throttle body. With a pair of pliers, bend the bracket forward and down until you feel that the angle of the throttle and cruise cables are more inline with the linkage.

    11) There is a fuel line in the way of the linkage. Just zip tie it to the fuel line closest to it so the fuel lines are out of the way. You may have to move a small vacuum line out of the way as well.
    12) Now all that is left is to cut the three TPS wires and extend them enough so that you can plug the harness into the throttle body. 6 crimp connectors will do the trick. Just crimp three pieces of wire to the three wires coming out of the plug. Connect the plug to the throttle body and get measurements of how long the extension wires should be and then crimp the extensions to the harness. Tape everything up with electrical tape and you're done.
    13) Connect the intake tube to the throttle and air cleaner and plug the MAF back in. Start her up and enjoy!

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