[torsen] RE: RS2 turbocharger

Fri Jun 14 13:54:45 EDT 2002

Just curious...how do you know that it would spool at a lower rpm on the 20v
motor?  Just based on principle, 2 motors of the same displacement at the
same rpm would flow the same CFM assuming you are attempt to get the same
output.  If manifold/runner design is similar, I don't see how one motor can
differ from another.  Of course, I suppose the velocity of the exhaust gas
on the SOHC motor is faster at lower rpms than the twin-cam.
Am I on the right track?  Just tryin to help think of non-KKK options for us
20v-ers out there.  :)

Richard
1990 CQ 202K

>From: JShadzi at aol.com
>To: rpastore at animalfeeds.com (Robert Pastore), quattro at audifans.com
>CC: torsen at audifans.com
>Subject: RE: [torsen] RE: RS2 turbocharger
>Date: Fri, 14 Jun 2002 15:27:50 -0400
>
>Bob, my turbo is a T3 .63 stage 3 hot side, T3 water cooled center section
>with heavy duty shaft, and a full T04E cold side with 3" inlet and 50 trim.
>
>So, sounds like I have basically the same turbo.  Its not "too big" IMO,
>but in a 20v it won't give full boost until about 3800rpm or so.  In my
>10v, that is about 500rpm lower.
>
>If you want faster spool up, I'd recommend going with one of the big T3
>turbos with a 60 trim compressor, keep the stage 3 hotside.  I also have a
>K26/T03 with 45 trim that is a very flexible turbo, great low end and keep
>up well into the high range.
>
>Too big is very relative, it should be more what you're looking for
>driveability and max output-wise.
>
>Javad
>
> >Javid:
> >
> >Great post, I agree with you. =A0Do you know and would you share your t3=
/t4
> >hot side Specs? =A0I've got a t3 stage III, with a T4 Vi/V2 wheel that I
>have
> >never installed for fear it's just to damn big for 2.2L
> >http://www.turboneticsinc.com/
> >
> >Bob
> >
> >-----Original Message-----
> >From: JShadzi at aol.com [mailto:JShadzi at aol.com]
> >Sent: Thursday, June 13, 2002 11:56 PM
> >To: quattro at audifans.com
> >Cc: torsen at audifans.com
> >Subject: Re: [torsen] RE: RS2 turbocharger
> >
> >
> >Thing is, this conversation is nothing new, everyone knows that if you
>want
> >V8 torque response below 3krpm the K24 is the way to go, and if you want
> >great, strong midrange and good upper end the RS2 is the way to go.
> >
> >Now, if you don't want to spend the $1500 plus to get the RS2 (which I
> >wonder about the people who do), there are plenty of great options out
>there
> >for under $800. =A0Nothing that special about the RS2, its no K24, I like
>to
> >call it a K25.
> >
> >For example, my T3/T4E gets useable boost at about 2200 (I'd bet it
> >accelerates faster at 2500 than most 7A coupes at 5Krpm), full boost by
> >2800, and its moving by 3200, and the OMG factor is definitley in the
> >4000-6200 range.
> >
> >Also interesting to note, this is all very subject to ignition timing,
>with
> >8 degrees initial advance lag and response increase noticeably, with 20
>the
> >thing takes off straight from 1500rpm, esp. with the MC2 8.4:1. =A0This =
all
>in
> >a 10v, pretty good spread considering, the 20v is much more flexible in
>the
> >upper ranges.
> >
> >Though I think for the most part this conversation has remained civil and
> >interesting, I think its way too much thought into the obvious - a K24 is
>a
> >small, fast response turbo, use it for quick around town transitions, but
> >any multi-gear acceleration with any serious amount of boost will be
> >limited. =A0The RS2 is a step in the right direction, a mid-size turbo w=
ith
> >decent low speed response and excellent midrange power, still limited in
> >really high boost ranges, and definitely not a high hp turbo. =A0I'm hap=
py
> >with my turbo, I can accelerate from zero to 100mph in one shot, no heat
> >soak, the thing just breathes, granted its a little slow to respond under
>3k
> >rpm, but that's not the way I drive, and with the close gearing of the
>01A,
> >realistically, I'm never under 3k rpm anyway. =A0
> >
> >Javad
> >80tq.com
> >
> >In a message dated Thu, 13 Jun 2002 =A08:48:17 PM Eastern Daylight Time,
> >bernardl at acumenassociates.com writes:
> >
> >>
> >> Boy this torsen list is full of tough cookies. =A0Into the Dragon's Den
>we
> >> go...
> >>
> >> > just to remind everyone - these numbers come from official autocar
>road
> >> > tests, and so are as close to kosher as you could find -
> >> > electronic timing,
> >> > electronic speedo, and known conditions (both at the millbrook
>proving
> >> > ground). =A0also, once again, the cars share gear ratios, transmissi=
ons
> >and
> >> > other running gear. =A0it is about as close as you could get without
> >> > physically putting a k24 in an rs2, or an rs2 in an s2.
> >>
> >> OK everyone, I'll point out that what kind of stopwatch and speedo they
> >used
> >> and the identical running gear, etc., while essential things to have be
> >the
> >> same, do not in any way make the potential gap between an RS2 and an S2
> >> depend solely on turbocharger model.
> >>
> >> While I do not know these newer cars, I am prone to believing that
>there
> >are
> >> more differences between them than just the turbo. =A0My guess is the =
S2
>was
> >> optimized to be driven around town, and the RS2 was optimized to spank
> >other
> >> cars on the Autobahn.
> >>
> >> Most of us, I think, want to know, all other things in our cars being
> >equal,
> >> which is better for our purpose, the K24 or the RS2.
> >>
> >> Until someone takes a single car and runs K24 and RS2 turbos back to
>back;
> >> or two identical cars, but one with K24 and one with RS2, we really
> >> shouldn't conclude anything.
> >>
> >> My point here is that no one has presented data that
> >> warrants definitive
> >> conclusions being drawn.
> >>
> >> Best,
> >>
> >> Bernard Littau
> >> Woodinville, WA
> >> '88 5ktq
> >
> >
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