Hey guys,
I've been working on a Triumph motorcycle ITB (Individual Throttle Body) project with AEM Infinity EFI (Electronic Fuel Injection). I am far from the first to use motorcycle throttle bodies on a 911, but wanted to share my take on the project.
The Triumph ITB's are from a Triumph Speed Triple 955i motorcycle. They came on years are 1997-2001, but the early ones 1997-1999 are a little better as they came with aluminum fuel rails. They later ones came with plastic fuel rails. The throttle bodies themselves are all the same, so if you have to mix and match it's okay, but i prefer the aluminum fuel rails.
One can find the throttle bodies used on eBay or at motorcycle salvage yards. One setup with throttle bodies, fuel rail, injectors (27lb is stock), throttle position sensor, and vacuum lines can be found for around $100.
In order to mount the ITB's to the 911, you need a manifold. Most use a Weber or PMO carb style manifold with adapter brackets to mount the ITBs on the manifold. There is nothing wrong with doing it this way, however the Weber/PMO spacing is different than the Triumph ITB's and using those manifolds requires splitting up the Triumph ITB assembly. This means custom fuel rails and custom linkage between each throttle body.
I wanted to keep the Triumph assembly intact and utilize the aluminum Triumph fuel rails. This required casting a new manifold that both fit the 911 and Triumph assemblies.
It all started with a few chicken scratch sketches
And a preliminary 3D model
Once the model was made, we 3D printed a sample. My printer's print bed was too small for the full manifold so this test piece was done in two halves and epoxied together.
It wasn't too pretty, but it fit well.
