Porath's Blower

[John Fulford-Brown <john@xxxxxxxxxxxxxxxx>]

>    Hello everybody,
>
>  I saw on the NET a lot of companies that offer superchargers
>  kits for BMW between 5K-7K USD.
>  I am asking why so much for a supercharger.
>  All the kits contain: a supercharger unit with bypass valve and ceramic
>  bearings that is under 2000 USD.
>  brackets, CNC alluminium cranck pulley , fuel presure regulator
>  KN cone filter.
>  Why 7K USD ?
>  Nobody tried to make a supercharger.
>  I want to try to made one , but I have few questions:
>  where can I find alluminium cranck pulley, and where can I find
>  some info about building a SC.
>
>  Any advice will be appreciated,
>  Thank you,
>  Jeff >>
>
> Jeff,
>
> Please take this in the spirit it's intended:  If you're asking these
> questions, building a supercharger from scratch prolly isn't for you.
>
> Christopher

Guys!

Forget building a supercharger!  Go check out Jonathan Porath's cheap, nasty and
easy-to-install turbo system using an ordinary Sears (or Toro) leaf blower. Go to:
http://people.ne.mediaone.net/jporath/bmw/index.html

Now, here's a couple of tips that are not posted on the site (I did this mod on my '95
325 on the weekend).  In my hurry to add valuable extra HP to my Bimmer I rushed the
installation. After first firing up the system, I noticed a lot of smoke coming from
the tailpipe along with a bad bonfire-type smell.  I e-mailed Jon on this and he told
me to make sure that I cleaned out all loose leaves and other clippings that might be
still in the intake side of the blower before firing it up. Ooops!

Another thing.  Mount the whole shebang on the passenger-side of the hood for better
driver visability.  You'll need a couple of extra feet of dryer hose to make all the
connections.

Now here's the big thing.  Use a gas powered blower.  It provides it's own source of
power without drawing on the alternator and engine power.  Sorry Jon, but the electric
leaf blower just saps too much power from the car battery.  What you gain in HP is
lost through the alternator.  I've done the calculations.  Check it out: Boost =
Psi/280bhp (E30 M3) * 600ft/pound pressure at manifold.  The leaf blower draws 120v/AC
@ 10amp via Tandy voltage coverter to 12v/DC @ 100amps.  Ergo, net gain of 35HP
through blower at Psi/boost factor negative to power 7.556302, LESS 100amps/280bhp @
40lb torque = 33.5HP.  Net gain: 1.5 HP!  Is a net gain of 1.5 HP worth drilling two
bloody great big holes in the hood of your Bimmer?  What were you thinking???

John
'95 325.  Chipped.  SS.  Blown.

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