How about no MAF or MAP?

[Mike Klopfer]

 Tony Bryant <bryantt at stimpy.fp.co.nz> writes:

>The solution I have used is to solve two simultaneous equations 
>to find the air flow:
>
>AirFlow = M.A.Pressure * VE(RPM) * RPM  { Just like in a MAP system }
>
>&
>
>AirFlow = CriticalFlow(Throttle Pos) * compressible gas 
>                                           function(M.A.Pressure)
>

Since I don't understand some of the terminology used I'm guessing that
these are the equations for airflow out of and into the manifold
respectively. The following is a piece of a posting a did in the distant
past. I'm not sure if its very clear or along the lines of what your
looking for but if so it would be easy for me to get a hold of the paper
and post the equations. My copy doesn't have the last digit of the SAE
article number but it should be locatable given the title and partial
number.

>constants. The following is my understanding of models given in the paper
>SAE 93085? "Transient A/F Ratio Errors in Conventional SI Engine Control".
>This is largely derived from the
>ideal gas law n= PV/(rT). Where V is the volume of the cylinder, P is the 
>pressure in the cylinder, n is the number of moles of air?, T is the air 
>temperature and

...

>In the paper SAE 93085? cited above the authors include a volumetric 
>efficiency term in this equation.
>This term is of the form
>
> ve(rpm, P)= c1 + c2 * rpm + c3 * rpm * rpm + c4 * P
>
>This leads to the following formula 
>
>  injSt= (k1 * P * ve(rpm, P) / T) + k2         eqn 1
>
>This article also suggests that the air pressure sensor is slow. So perhaps
>an injector width versus throttle angle 
>and rpm map might respond to transients faster than an injector width versus 
>manifold pressure and rpm map. This article also has some equations relating
>mass flow into the manifold to throttle angle and ambient pressure. By
>using these one should be able to derive injSt as a function of throttle angle,
>manifold temperature and ambient pressure. There equation is of the form:
>
> M'= C1 * b1(a) * b2(P, P_0) + C2               eqn 2
>
>Where b1 is the area of the throttle opening at angle a and b2 is some
>nonlinear function of P and P_0 the ambient air pressure. M' is the time
>derivative of the mass of air flowing into the manifold. Using equation 1 to 
>determine the mass flow into the cylinder, and the fact that at
>steady state the flow into the cylinder equals the flow into the manifold
>one should be able to obtain the constants C1 and C2 by measuring the
>manifold pressure for a couple of values of throttle angle.