[torsen] RE: RS2 turbocharger

[David Eaton]

sorry good catch, and my mistake, i transposed the numbers from my
spreadsheet to the email, so the differences are actually the 4th gear
times, not the 3rd gear times.  the conclusions stay the same.

the real 3rd gear increments are (triple checked):

mph     rs2    s2     rpm range        outcome
20-40  5.2    3.8  (1515 to 3030)  rs2 37% slower
30-50  3.7    2.9  (2273 to 3788)  rs2 28% slower
40-60  2.8    2.9  (3030 to 4545)  rs2  3% faster
50-70  2.8    3.1  (3788 to 5303)  rs2  10% faster

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.

hth,
dave
'95 rs2
'90 ur-q

		-----Original Message-----
		From:	Bernard Littau
[mailto:bernardl at acumenassociates.com]
		Sent:	Friday, 14 June 2002 11:23 a.m.
		To:	David Eaton; 'Quattro List'
		Cc:	torsen at audifans.com
		Subject:	RE: [torsen] RE: RS2 turbocharger

		Hi Dave,

		That does surprise me that the RS2 is slower in the 2700 to
3800 rpm range,
		but then, much surprises me.

		How are you calculating your % difference in the outcome
column?  Row 3 is
		clearly incorrect, as the RS2 is faster.  Row 2 looks
suspect, as does Row
		1.  I get 36.2% slower, 9.3% slower, 3.6% faster and 5.5%
faster.

		I still think you need to compare like with like.  I can
make the numbers
		vary 10% within those rpm ranges on my car (10V MC) by
adjusting the cam
		timing to favor low end or high end.  I suspect I could get
even more
		variation by comparing a hot cam set up for high end against
a stock cam set
		up (timed) for low end.  This would be with the same car
with the same
		turbo.

		While this is a good topic, and I for one would sure like to
know where the
		K24 and the RS2 turbos perform best and how they compare to
each other, I
		can't conclude too much from your numbers as the test has
too many unknown
		variables.

		You really need to swap the turbos between your RS2 and the
S2, run the
		tests again, and do a 4-way compare :-)

		Best,

		Bernard Littau
		Woodinville, WA
		'88 5ktq

		> -----Original Message-----
		> From: David Eaton [mailto:deaton at tranzrail.co.nz]
		> Sent: Thursday, June 13, 2002 3:23 PM
		> To: 'Bernard Littau'; 'Quattro List'
		> Cc: torsen at audifans.com
		> Subject: RE: [torsen] RE: RS2 turbocharger
		>
		>
		> i used the 6th gear times for illustration, as the engine
speeds
		> are slower
		> and more illustrative of the lethargy of the rs2, which
was the discussion
		> point.
		>
		> however, if you look at the 3rd gear times, where the
engine speeds are
		> inevitably faster, the effects are the same, i.e. k24
beats rs2, but the
		> deltas are different.  particularly interesting in these
data are the
		> performance of the 2 cars in the 2,700 to 3,800 rpm range,
where
		> most would
		> assume that the rs2 would have ascendancy.  not according
to
		> these figures -
		> the k24 is still comprehensively faster.  this, once
again, ime, is
		> indicative of the lethargy of the rs2 below about
3,200rpm.
		>
		> mph     rs2    s2     rpm range        outcome
		> 20-40  5.7    3.8  (1515 to 3030)  rs2 22% slower
		> 30-50  3.2    2.9  (2723 to 3788)  rs2 27% slower
		> 40-60  2.8    2.9  (3030 to 4545)  rs2 14% slower
		> 50-70  3.6    3.8  (3788 to 5303)  rs2  5% faster
		>
		> dave
		> '95 rs2
		> '90 ur-q
		>