[torsen] RE: RS2 turbocharger
Dave.Eaton at clear.net.nz
Thu Jun 13 13:33:17 EDT 2002
scott, do you seriously expect people to accept that the difference in speed
between the rs2 and the 20v ur_q (or the s2) at low revs is due to the use
of a dual mass flywheel in the rs2? i'm talking the over 5 seconds of
difference (in equivalent gearing) going from 20-40mph, and over 4 seconds
going from 30-50mph, (again in equivalent gearing)....
i'd like to know where you get your understanding of physics from...
if you are so certain that this is the "problem", i'd encourage you to look
at the late model s2, also with a dual mass flywheel. i'd be happy to quote
the relevant in-gear times, where, due to the overboost available with the
k24, it is noticeably better than the older s2, and so it just makes the
comparison against the rs2 worse. the s2 (w/aby k24) is a far far better
machine at low engine speeds than the rs2 (and the s2).
look, i'll even include the 6-speed s4 avant w/k24 (aan) for you with that
nasty old dual flywheel. as you'll appreciate this is a considerably
heavier car than the rs2, and yet in 4th gear, beats the rs2 by 1 second
from 20-40 and by 1 second from 30-50mph.
also, i hope i don't have to explain to anyone why the rs2 is significantly
faster than the other cars when it comes to wide-open throttle applications
at high engine speeds.
back to normal programming...
From: QSHIPQ at aol.com
Date: Mon, 10 Jun 2002 10:23:56 EDT
Subject: RE: RS2 turbocharger
In a message dated 6/8/02 11:09:47 AM Central Daylight Time,
quattro-request at audifans.com writes:
>well i'm running an rs2 turbo on my 20v, with higher boost, modified
>cam, modified airbox, inlet and exhaust manifolds, and exhaust system. it
>has a larger intercooler, uprated fuel pump, slightly lower compression and
>an uprated motonic, and uses only 98 ron gas. throttle response and lag
>still not good, and cannot compare to the 3b w/k24. great top-end though.
>no, not great, wonderful - far better than the k24. but around town, even
>many times on the motorway, i'd trade the top-end for the "stomp" of the
>k24 - in the rs2, "stomp" almost always means changing down at least once.
Dave, get rid of the dual mass flywheel. Life gets better. Way better, see
your own numbers below.
>5th gear in the ur-q is 4% higher than 6th gear in the rs2, yet despite
>this, the 20-40mph time is 9.4s vs 14.8 sec for the rs2. for the 30-50mph
>time, read 7.1 against 12.5! even at 50-70mph, the ur_q is faster with 6.5
>against 7.7sec. so despite a slightly higher gear, the rs2 is on average
>over 50% *slower* than the ur_q - at any legal speed in top gear.
A couple things to think about Dave. You'd really have to look at the "how"
of this test to "blame" the difference on the turbo. IF you take the
standard test, which is to go from coast mode to WOT, this is a
mass problem. How can you conclude this? Well, despite your conclusions
that the RS2 is "40% slower", in straight line acceleration in a variety of
gears, the RS2 is significantly faster 0-60 or 1/4mile. What's the
difference? Well, reciprocating mass and bypass valve now eliminate the
spoolup differential. Which means that anything you can do to reduce
spoolup, makes a huge difference. FROM your own math (and specific car
examples) presented here that would point directly at the flywheel.
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