Rob,
There is no top for the bypass. This is a non-bypassed set up.
The part that I was calling a bypass is actually an extension of the inlet. It extends under the engine serving as a shield. It resembles the botton half of a bypass. If you look at the pictures on the FEJ website you will see what the parts look like.
Also with the modification with the metal at the end of the turbine cone does this cause any problems with loss of power from the exhaust gasses i read about the wren pipe giving extra thrust if installed properly but can also loose thrust if installed incorrectly as air is drawn into the duct from the gap that is left if you get my meaning.
Absolutely not. I have about an inch gap between the engine tailcone and pipe bellmouth. The aluminum is positioned well above and around the engine allowing plenty of airflow to the pipe. As mentioned in my last post FEJ provides a U shaped piece of fiberglass for this purpose (see installation manual). I merely replaced it with a slightly larger piece of aluminum, since aluminum makes a much better heat shield than fiberglass.
I haven't flown it yet (waiting for spring) but I have run the engine a couple of times in the driveway. It has plenty of power and keeps the fuse nice and cool.
Joe