Many people spend big $$$ on a Neuspeed or Audi 5000 throttlebody.  Sure, they are a direct bolt on, but why bother when you can have the same thing and save a lot of money by spending 30 minutes swapping the linkage from your original throttlebody to one from an A2 Golf/Jetta?

A1 and A2 Throttlebody Comparison

On the left is the original A1 throttle body (minus linkage) and  on the right is the newer A2 throttle body. The larger butterflies on the A2 allow for better airflow and throttle response. This modification is good for a few HP if done with other modifications.

A1 Intake Manifold - Ported for Throttle Body

Above is the intake manifold after being ported to match the larger A2 throttle body. Porting is necessary to realize any gains from the larger throttle body. This is easily done by using the new A2 throttle body gasket, marking the area to be removed, and grinding with a dremel or drill with appropriate grinding bits. Be careful not to remove too much since the back side could become too thin if additional material is not welded on.

Modified A1 Throttle Body

Above is the A2 throttle body after swapping the linkage from the original throttle body. (1) A "pin" was needed to attach one of the new linkage springs. (2) It was also necessary to mount the full throttle switch. Items (1) and (2) were accomplished using self-tapping screws**. (3) The unused port on the throttle body was plugged with a bolt and expanding rubber plug, then covered with a rubber cap that I had extra from an exhaust manifold.

** UPDATE 1/7/03:  Self-tapping screws worked... for a while.  For longevity, it is best to drill and tap.  While this method is more expensive, experience says that it is the best way to do it. The self-tapping screws were removed to replace the full-throttle switch bracket, after which, the screws continued to "self-loosen".

The A2 throttle body you use may vary from the one pictured. This is intended to show you the basics involved with swapping the linkage and the difference in butterflies.

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