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Re: The "Power Box"

Jeff> From: jeff.tatum@domain.elided (Jeff Tatum)
Jeff> Date: Tue, 10 Jan 1995 04:07:45 GMT
Jeff> Subject: The "Power Box"

Jeff> I just got the January issue of Roundel in the mail today, and an ad
Jeff> caught my eye.  It is on page 57 for CCA members...

      Just happened to have my copy sitting on my computer here....
      Ahhh, there it is.  Page 57.

Jeff> A company called Performance 911, Ltd. is marketing a device that
Jeff> modifies the fuel pressure in the injection system.  They claim that it
Jeff> will yield "lower 0-60 and 1/4 mile times".  I called them and asked
Jeff> some questions, and they faxed me some info, including a one-page blurb
Jeff> citing a test "on an M5 BMW and at least a full second was dropped on
Jeff> the 0-60 MPH, with no change in fuel economy".

Jeff> They want $690 for this gizmo, which they claim bolts on in 30 minutes.

      Well, not knowing the exact specifics,  I'd say that the box is
      an extremely OVER-priced variable pressure regulator.

      This is what I think it does....

      On the fuel injected Bimmers, the fuel is pumped from the tank
      to the engine compartment.  On my E30, there is a low pressure
      pump in the tank, and a high pressure booster underneath the
      car.  The booster pump is capable of over 100psi, but the normal
      pressure is something like 60-80 psi (if memory serves me
      right).  The gasoline is pumped into the fuel rail on one end,
      and on the other end is a pressure regulator that "bleeds" the
      excess pressure from the fuel rail and routes it back to the
      fuel tank.   

      Looks to me like this contraption replaces the fixed pressure
      regulator with a variable pressure regulator.  If you increase
      the fuel pressure in the fuel rail, the reasoning is that you'll
      get more fuel into the cylinder and thus you'll get more power.

      I can't say how well this would/would not work, but seems to me
      it would put more stress on the booster pump and fuel injectors.
      I would also think that you'd have to recalibrate the air flow
      meter? since you're getting more fuel for the same volume of
      air?

      What technical information does that FAX you have say?

Jeff> My question is can this thing possibly work?  It really sounds too good
Jeff> to be true, and it just doesn't make sense.

      You know the saying, "If it sounds too good to be true, it
      usually is".  You don't get something for nothing.  You have to
      lose mpg to get more power/faster times.  If the thing doesn't
      increase mpg very much, then I would think that it doesn't work
      very well (if at all).  The definitive test would be to see the
      results of dyno test.  The problem with a 0-60 second test is
      the results are too variable.  Who's to say the before time was
      because of a "bad" run and the after time was because of a
      "good" run, and had no bearing on the "Power Box".  

Jeff> I called Dinan, and they really didn't have a definitive answer.

Jeff> Any wisdom from the net gurus?

      Also... BMW cars        are called "Bimmers".
              BMW motorcycles are called "Beemers"

      Their ad says "Turn your Beemer into a screamer".

      Barring the fact that "bimmer" and "screamer" do not rhyme, if
      they don't know the difference, I'd be skeptical that the
      product works...   :-)


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