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You can use galvanized 5/16 wire to reinforce the air duct to keep it from collapsing. However under inspection using a remote camera I found this to be ineffective.

The symptom is subtle. Under WOT you will experience loss of power. This is most notable on hot days when the engine compartment heat is high. What is happening is the heat softens the plastic and the vacuum created inside the bellows at WOT causes the bellows to partially collapse. This affects all stock MY ZR-1s.


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Tools Required:

1. 1/8 or 1/4 in sheet aluminum 9x20in.

2. Vise

3. Long pry bar

4. 1.5 in tubing

5. vise grips



The bellows has a know design defect. It collapses a bit under hard acceleration when the engine compartment is hot. This mod is also available by purchasing a new and improved bellows made of silicone compounds. Or by purchasing a similar insert from Mid America (I think). What you are going to see here is a way of bending up your own. The whole procedure took about 1.5 hrs. Not including the time I waited while heating up the plastic bellow in my oven at 175 deg for 20 min.
 Using a piece of chain link fence post I bent the initial form to match the wire form.
The metal form is shown here roughed in and ready for fine tuning.
This is going to be hard to explain. Note the vise grips. They are there to hold the sheet metal as I drive the base of the form with the big vise head. This puts a bend in the flat portion of the sheet metal.
By forcing the pipe in after clamping the metal form in the vise, I get closer to the shape I want. Thing to do now is pound down on the protruding metal to shape the top.
I ended up bending the center down too far so I used the "big pipe" to force it up.

Here you can see that the form is just the right size.
The plastic bellows was put in my oven at 175 deg for 20 min. then the form was slid into it. Fits like a glove. Like it was made for it. Oh, that's right, it was made for it.
Here I am tightening up the fit by opening up the form inside a bit. Nice tight fit

The strength of the form inside the bellows needs all the leverage shown her to get it to bend out a bit.

All done now just have to mount it in

The new bellows insert
Expected Result: Absolutely no collapse of the bellows in any heat condition.

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