Re: bmw-digest V9 #187

[Osh Minelian <racemarq@xxxxxxxxxxxxx>]

>Date: Sun, 20 Sep 1998 14:52:21 +0200
>From: "James R. McMillan" <jmcmillan@domain.elided>
>Subject: SCHRICK AND BMP INTAKE MAINIFOLDS

>Just wondering if anyone has installed either the Schrick Intake
>Manifold or the BMP designed Intake Manifold with individual throttle
>bodies.  What are the real advantages and do they perform as
advertized?

>Private responses also welcomed.

>Thanks,

>James R. McMillan
>US Army, Europe

>97 M3

In response to the above , we were hired to do an evaluation on the
Schrick manifold. We flow tested both the stock and the Schrick
manifolds. We tested at 25 inches (H20 )test pressure. The test was
performed with throttle body in place
The stock runners flowed 186 cfm
The Schrick runners flowed 230 cfm
The velocity dropped almost proportionately
Now the question, about how well does it work, is open to more than one
answer.
We dyno tested one 97 M3 and the results were less than favorable
overall. The larger runners effected the resonant wave dynamics tuned
into the motor by the factory rendering a loss of power in the lower rpm
range. In the higher rpm range, the engine management system did not
adapt well, resulting in air/fuel ratios nearing 11.5:1. We didn't have
the ability to calibrate the fuel mixture at the time as we do now, but
I would estimate by previous experience, if the fuel and ignition were
corrected the Schrick manifold would produce respectable power increase
in the higher rpm range. It would also lose some bottom end torque. For
those of you that belong to the 5000 (rpm) plus club, this manifold
would work well if properly fueled, but there will be a trade off with
bottom end performance. As far as the BMP set-up ,we haven't seen or
tested one.  It is pieced together with already available throttle
bodies bolted to castings specially made for BMP. The air plenum is also
for made for there application , The plenum seems small, not sure how
well its going to resonate. In any event the jury is still out for those
of you who must know absolutes on these new items.  These mods always
require additional tuning and with the Siemans box, it's tough to do.
When we hear the words , adaptive system, referring to BMW DMEs,
unfortunately it's adapting to what they need, not what we want :-)
This is a much involved topic ( resonant wave tuning), For those of you
who have to know about this stuff, there's lots of great info at
Superflow's web-site and others like it,. Don't have the link handy but
there pretty easy to find. They make flowbeches and dynos. Real ones,
not toys.

Sorry for carrying on.

Osh Minelian

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