[200q20v] RS2 & 3B - Fueling Around

[Bernie Benz]

> From: "TM" <t44tq at mindspring.com>
> Date: Sat, 19 Jan 2002 21:55:20 -0500
> To: "'Brett Dikeman'" <brett at cloud9.net>, "'Greg Johnson'"
> <gregsj2 at attbi.com>, "'Audi SCars'" <s-car-list at yahoogroups.com>, "'200 List'"
> <200q20v at audifans.com>
> Subject: RE: [200q20v] RS2 & 3B - Fueling Around
>
> Not totally correct, Brett.
>
> If you read GregG's message completely, you'll see that he already
> has IA Stage III+, so another chip won't make any difference for him.
>
> Switching turbos will not change the maximum boost levels, but a larger
> turbo running the same boost will flow more air and require fuel map
> mods to maintain correct a/f ratios.
Nonsense, Taka!  At a fixed max boost level (your stated condition) and at
the same RPM, a larger turbo will pass exactly the same mass volume of air,
further constrained by the engine displacement.  Further, the combination of
any compattable MAF input to the ECU will, under closed loop control,
maintain the programed exaust gas O2 content, thus the proper A/F.

Bernie
>
> The RS2 manifold is a good idea for any setup beyond stock in that
> you will reduce the problems w/ cylinders 1 and 5 running lean and get
> rid of the stupid stock 3B manifold design. Once you get into very high
> power outputs north of 380hp, you'll need to look at alternative
> manifolds
> to take that next step beyond the magic 400 number.
>
> I would not add the RS2 MAF, injectors or software unless you do all of
> it at once, as the engine will not be running in proper spec- the RS2
> injectors run at a different fuel pressure than the 3B, requiring the
> RS2
> FPR or an adjustable unit running at RS2 FPR level, the MAF will give a
> faulty reading to the ECU w/o software calibrated to the RS2 MAF and
> the converse will occur w/ RS2 software running stock 3B components.
> Custom software (I know Lehman has this) to run a mix of components is
> possible and would be necessary should you decide to run something other
> than a full RS2 setup with that RS2 turbo, unless you're running just
> the manifold, which I don't believe would cause any problems.
>
> That's why I haven't gone beyond the simple chip- going to a bigger
> turbo
> requires so much other ancillary equipment that it gets quite expensive-
> that will have to wait until I get a real job. :-)
>
> Taka
>
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