So as you know I have converted to a normally aspirated state.  I went flying to vegas this weekend, and actually won $300 net even after my wife lost $100.

 

The engine ran as well as coulld be expected considering my sea level WOT MAP is only 28".  Max n.a. static is 46-4700 RPM.  Plenty enough to take off well over Van's recomended gross and fly at 130 KTAS (using only 8 gal/hr).  Better than a typical cessna - but less tan I had with the turbo.  Anyway,

 

The point of this e-mail is to discuss injector backflow...  I have always had a problem with a faint fuel smell in the cocktpit.  As part of the n.a. conversion I removed the plenum over the intake (see pic.).  Every flight since removing that plenum has included a rather strong smell of fuel coming in theough the passenger air vent.  This smell is only evident after take off.  It turns out that my TWM secondaries, mounted on a downhill part of the intakes, freely leak fuel down and out of the bellmouths even during WOT operations.  This leaked fuel then seeps out the cracks in my cowl and goes into the passenger air vent.  It also loostly covers everything on that side of the engine, and the side of the fues around the pax air intake with 2-stroke oil.  This was enouth to make me uncomfortable.  The wife, who is still reeling from the emergency landing after the turbo broke, now states that she will only fly cessnas from now on - due to the very disconcerting smell of fuel the whole trip - and I can't blamer her.

 

While in vegas I tried to program the 'B' computer to use the secondarys only above 27" MAP but I guess the adjustment did not take because we still had the same condition on return.  I have checked and re-checked the fuel system far any evidence of a leak.  It is coming out the back end of the intake for sure.

 

Something to think about if you are installing the TWM injectors near the air inlet end.