RE familia turbo..

[ARTHUR OKUN]

You wrote: 
>
>>With any luck FLAP = MAP x RPM x Constant & build with a few op-amps.
>
>My work shows that FLAP = MAP x RPM x VolEff where VolEff is the
>engines Volumetric Efficiency which will vary as function of speed
>and load.
>
>>Debatable. Might only be worth 5-10hp (at a guess). FLAP AFMs have an
>>advantage in that they automatically compensate for bigger exhausts 
etc
>>that change volumetric efficiency, whereas MAP need to be 
recalibrated.
>>In a closed loop self learning computer this isn't a big drama 
usually.
>>(actually I wonder if this is why virtually all EFI before the Mid 
80s
>>was Flap AFM based)
>
>Flap AFM's or for that matter all AFM including the later MAF
>hotwire types have one great advantage over the MAP (speed-density)
>type system, AFM's give an indication of the actual mass of air
>being "consumed" by the engine, the MAP type system gives you the
>data to allow you to try and infer the amount of air being consumed.
>The direct value is almost always more accurate than the indirect. 
>Trying to meet serious emissions with a speed-density system is not
>to be considered by anyone with a life, not unless they're starting
>out with a very good base-engine design which exhibits excellent
>feed-gas before bolting any electronics on it ......... 
>
>
>By the way, the Jenvey Dynamics phone number for throttle bodies
>in the UK is 
>                01746-768810(phone) / 01746-768363(fax)
> 
>
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>Brian Warburton, "Still searching for the perfect curve....."
>email: bwarb at turbo.win-uk.net
>                                Advanced Automotive Electronics Ltd,
>                                Van-Nuys, Scotlands Drive,
>                                Farnham Common, England.  SL2-3ES
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
   the only reason NOT yo use an afm is to save money on the cost of 
 an efi system.  Mafs are quite expensive as a replacement part
   and they do go out of calibration