[torsen] RE: RS2 turbocharger

[JShadzi at aol.com]

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.  Nothing 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.  This 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.  The RS2 is a step in the right direction, a mid-size turbo with decent low speed response and excellent midrange power, still limited in really high boost ranges, and definitely not a high hp turbo.  I'm happy 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.

Javad
80tq.com

In a message dated Thu, 13 Jun 2002  8:48:17 PM Eastern Daylight Time, bernardl at acumenassociates.com writes:

>
> Boy this torsen list is full of tough cookies.  Into 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).  also, once again, the cars share gear ratios, transmissions and
> > other running gear.  it 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.  My 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