RS2 turbochargers

mlp mlped at
Tue Jun 18 11:08:05 EDT 2002

> Message: 15
> From: QSHIPQ at
> Date: Mon, 17 Jun 2002 10:03:53 EDT

lot of snipping

> I can share that IME, it isn't LAG that spoils the RS2 equipped cars.
> Without question, many on these lists need to get a better understanding
> "how turbos and turbo sizing works".  Specifically, what *doesn't*.
> After playing with modified turbos for over 10 years,
> I just come away with a lot more respect for that RS2 hot side
> wheel and housing than most.  It would appear that includes you, Dave.
> I'm quite comfortable with that.

end of QshipQ's message

I don't have much grist for the mill to add to all this, & wouldn't but for
Dave's comments / point on the "Porsche" label on (I take it the intake
manifold) under the bonnet of his S2 (or is it a UrQ?) and Scott's respect
and admiration for the RS2 hot side, &/or Porsche &/or KKK's engineering
thereof and finally the benefits, real, imaginary or illusory, of additional
displacement I offer the following apocryphal information....

In the FWLIMBW category,

- I know the K24 exhaust exit port* is @ 45mm to 46mm in diameter;

- I believe an RS2's is @ 54mm or 55mm, depending on who is doing the
measuring, IIRC (some one needs to re-check this);

- A Porsche 944 Turbo "S"** hot side exit is slight more than 62mm, say
62.75!  This I know cause the 2.5" down pipe flange into the flare out to
the 3" down pipe system almost can't cover the turbo discharge port.

The 944S KKK hot side has been hookup to a Garrett TO4E 60 trim (at least I
think its an Ë" trim) cold side.  When (or if ever) the turbo gets hooked
up, it will have @ 2.5 liters (2.522 cc swept volume) of displacement behind
it to push the blades.

Lag?  Well, that's still a great unknown, but I welcome your speculation;
HP?  That's another big unknown.  Again, I'd welcome your thoughts.


* by "exit port" I'm referring to where the exhaust will dump into the
exhaust system down pipe.

** the 944 Turbo "S" K26 is apparently NOT to be confused with the plain old
vanilla 944 Turbo's K26.  The 944 is an under square 2.4 liter (2479cc)
engine vs. the stock Audi AAN (& ABY or is it ADU and 3B's) over, some would
say way over, square 2.2 liter design.

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