Yes.  As you may recall, I also run with the TWM TB, and I also see lower MAP than the local atmospheric pressure.  That is quite likely as it should be, or if not; it doesn’t matter.  The MAP reading depends on where you measure it.   

Hi Al,   Yes, I recall that we've had this conversation before :-)

I certainly agree that it matters where you measure the MAP, and it would be nice if we were all measuring it in the same place for comparison.  I'm thinking of trying to put a port at the intake flange, but I'm not sure if I have room to drill and tap a hole there yet.  I'm also not sure it will give an accurate reading.  Still, it won't give an apples to apples comparison to anyone else.     

On the dyno at WOT at 5300 rpm with a local barometric pressure of 29.5”, the MAP reading was 27.5”.  At 6000 rpm, WOT, MAP had dropped to about 26.5”, and it was putting out close to 85 hp/rotor (SAE corrected, which means actual measured of just over 80) with 9.0 rotors.  At 7000 rpm the MAP reading was 23.5” and the power was still climbing at 95 hp/rotor.   

Reading these numbers sounds like the definition of "restriction" to me.  If you've got 95 hp/rotor now, imagine what it could be with less restriction.  

Yes, I agree it does, and I have worried about it also.  But you don’t get velocity without restriction, or IOW, there is no such thing as “no restriction” before getting to the port.  Perhaps the question is – Is anyone getting more than 85 hp/rotor at 6000 rpm, MEASURED, with normally aspirated, untuned intake, stock side-port, with 9.0 compression, newly overhauled engine.  If so; I’ll start considering a lower restriction induction system.

Hoping this makes you feel better, 

I'm afraid not, just the opposite in fact, but thanks for trying :-)

Have you tried Zoloft? J

Al