Re: GTI Hybrid Question
Dave has a good suggestion there. But to answer your Q, the Gti cam sprockets bolt straight on. (Vitara too I believe. )But are 25 mm. wide ( as is the Gti crank sprocket ) and your 19mm belt will walk forward and cut through your plastic cover. (ask me how I know.) If you can get a 25 mm. belt with 89 round teeth you should be right .
These belts were found on the very late model coilies. (Damn)
If you fit a lipped tensioner wheel with the 19 mm. belt it will work. Get an engineer type to press a lipped wheel onto your tensioner wheel.
I did this, it gives you a bit more adjustment if you get it a few mm. larger diameter.
Or do what Dave says.