One more comment on intake manifolds & race results.   Do not ignore the benefits of a really clean air inlet with ram air recovery BEFORE the manifold.   At 1125 ft  msl, 220 IAS, I saw manifold pressures around 31.8" Hg.  Ignore this factor and you throw away about 6% "free" horsepower.

 

Al,  I forgot to comment on your last note about your MAP tap in manifold.  I think it is highly possible you were seeing errors induced by air stream eddies or some other unpredictable factors caused by that location.   It is a challenge to get MAP measurements when you have no real plenum, only runners with high velocity air.

Tracy

 

I use the stock ports in the TWM throttle body.  I assumed they would know where to place the port to get a good measurement.

Where do you measure MAP on your system?  I can’t believe that you could see that kind of pressure at the engine end of a long intake tube.  But I remember once before when I was wrongJ.

Al

I measure it at the dynamic/plenum chamber, just under the throttle body.

Tracy

Hum-m-m.   That’s about equivalent to me measuring it in the air plenum before the TB.  It would be very interesting to know what it is on yours about 4” from the intake port.  Then there is the whole question of ‘which’ MAP pressure the EC-2 should be interpreting – or maybe it doesn’t matter. . .

Al