ChristiaanJ,
Its going to be very difficult when the engine test bay is U shaped with the lower right hand corner of the U not being walled. To have the tail of the aircraft facing the blast deflectors you have to point the nose to the opposite wall, either 90 degrees or a smaller angle but it will face a wall. Have a look on Google Earth Toulouse airport and follow the Airbus facility. You will find the engine test bay and probably will understand why it was facing a wall.
http://maps.google.nl/maps?hl=nl&t=h...1457&z=16&om=0