[s-cars] Euro Mass flow sensor

[mlp]

Well, if you want to take a look at this weeks www.autospeed.com , there's
an article devoted, in part to your Q.  The most visible difference between
the two pieces is the nature of the , ah let's just call them semi "porous
filtering devices" located both before & after the @ 1" measuring bulls
eye/orifice.  Careful use of a set of vernier calipers and some creative
math will net you some "figures" you can play with ` @ 20% of the "open"
area in your US maf is actually occupied by wire at each end of your MAF
intake/output path; vs. something more like only 9 - 10% of the same opening
in the "Euro" maf.

On a somewhat related note, while playing about with geometry (& please feel
free to check & or correct what could be errors of both logic &/or simple
addition and subtraction) the other day, FWIW:

Stages of                            Est. Air Velocity in MAF
MAF of Life        HP        CFM*       @72mm**     @86mm***
----------------------------------------------------------
Stock 		227 hp     330        @85 mph     @60 mph

+1 "chipped"       287 hp     420        @109        @76

+2 Chipped & RS2
     Turbo etc.   @320hp     480        @124 mph    @87 mph

+3 RS2 Turbo, 3
bar ECU, cam etc. @380 hp    560 cfm    @145 mph    @102

HaperSized~~     @440hp+/-   650+ cfm   @180 mph    @118 mph
-----------------------------------------------------------
  * using a rough ROT (Rule of Thumb) assumption that assigns
 @ 1.47 cfm per bhp, you, of course can use any other # you like.
  ** The 'unobstructed' area is actually slightly small as the
 base of the MAF includes a fair number of "cooling fins" that
 intrude into, and I assume slightly obstruct air flow.
  *** The 86mm hapersized MAF using the Bosch part DO NOT
  suffer from any cooling fin obstructions under the hot wire.
  ~~~ Just dream'n, but, .... FWIW, some "what if" numbers.
	& BTW, on the what if side, if you guess that the cold
      side nozzle exiting the turbo is, say @ 1.75" inside
      diameter (I don't think it is), at 650 cfm your input
      velocity into the "U" shaped Michelin Man hose is
      @ 450 mph.

If you want to do a search(try RS2 MAF &/or "egg crate"), there's some old
stuff in the archives about the differences, real &/or imagine and
theorizing over the effects, if any, of removal of that 'semi porous
material' located before and after you air measurement meter.

HTH,

mlp


~-----Original Message-----
~From: s-car-list-admin at audifans.com
~[mailto:s-car-list-admin at audifans.com]On Behalf Of Mark Hahn
~Sent: Monday, May 06, 2002 9:38 AM
~To: s-car-list at audifans.com
~Subject: [s-cars] Euro Mass flow sensor
~
~
~  Is there any benefit to bolting on a European Mass flow sensor for a
~'95 S6 or do I need other changes. The car only has IA chips currently
~but I have a new Stromung exhaust to install this summer. Do I need
~different injectors? I was interested to see the Euro Mass flow comes
~with a Porsche part # stamped on it next to the Bosch part number.
~Thanks again, MGH
~
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