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[tech] 4K vs 9a question was: What tranny is this?



The 4K is the performance transmission because in any gear at any given
engine RPM the torque at the front wheels is 7% (3.94/3.67=1.07) greater
than a 9A meaning the acceleration is 7% greater.
If you follow your logic then an FN of ACN would be the best because these
would give higher MPH potential than a 4K or 9A in 3rd, 4th or 5th. It's the
multiplication of engine torque by the gear ratios and the ability of close
spaced gears to keep the engine near its power peak that are important for
acceleration. Most 8Vs can't reach their RPM limit in 5th even with a 4K so
the potential max speed is irrelevent.
Dan
----- Original Message -----
From: <pbureau@attbi.com>
To: <scirocco-l@scirocco.org>
Sent: Sunday, April 07, 2002 10:31 AM
Subject: [tech] 4K vs 9a question was: What tranny is this?


> To throw my 5 cents worth, I have an 85 (09/84
> production date) and it is a JH Engine with a 9A
> tranny. I beleive the 4K production line finished in 84
> and 9A started in 85 production lines. the only
> difference between a 4K tranny and a 9A tranny is the
> final drive btw.
>
> why state the 4K being a they are the performance
> tranny on a vw when the 9a produced more MPH ??
>
> 4Y, 9A, ACD, AEN (8v Close Ratio)
> 3.67 3.45 2.12 1.44 1.13 0.89
>
> 4K
> 3.94 3.45 2.12 1.44 1.13 0.89
>
> just to compare number in a more "realistic" way
> here is a run down on each tranny on 205.50.15 @5000rpm
> on each gear...the result was calculated by
> scirocco.org "gear" sheet. here are the recorded results
> @5000 RPM
> Tranny   4k     9A
> 1rst    25MPH  27MPH
> 2nd     41MPH  44MPH
> 3rd     60MPH  64MPH
> 4th     77MPH  82MPH
> 5th     97MPH  105MPH
>
>
> THe 9a tranny WOULD be the tranny to have over the 4k,
> unless I am NOT understading the physic of
> transmissions, can someone enlightent me without
> bashing my head into a cement wall and setting my arse
> in fire okay?
>
> Thanks for Technical information here...
>
> ATS - Patrick Bureau
>
>
>
> ATS - Patrick Bureau
> 'HWB2002 - HouSton TX'
> > AFAIK all 020 tranmissions (as in all the tranmission specific part
numbers
> > are of the format 020 XXX XXX) have the same drive flange seals, so this
> > shouldn't be a big issue. Have you been identifying them as drive flange
> > seals or output shaft seals? That may be the confusion. 84 is a good
year to
> > identify the 4K.
> > Also, AFAIK the 1.8 L MK II Scirocco only came with the 4K tranny until
they
> > switched over to the 9A. For sure that happened sometime in 86, but it
may
> > have happened earlier.
> > The 4K is THE performance transmission for the Scirocco. If cruising
down
> > the highway at high RPM bothers you, you can change out 5th (currently
.89)
> > to a .80 or .75 or .71 gear. It's as durable as any 020 gearbox. Mine
has
> > 225K miles of hard use.
> > Dan
> >
> > ----- Original Message -----
> > From: Robbie Cotner <robw_z@yahoo.com>
> > To: <scirocco-l@scirocco.org>
> > Sent: Saturday, April 06, 2002 2:38 PM
> > Subject: What tranny is this?
> >
> >
> > > For all I know this question is extremely stupid, but
> > > I haven't been able to find the right output shaft(or
> > > drive flange) seals for my scirocco.  The tranny is
> > > out of a Rocco with a production date of 3/84, and on
> > > the case is stamped -4K12034-  Inside the bellhousing
> > > it says -020 301 107 H-  It also says -11a WWO- but
> > > that looks unimportant.  Is this the car's original
> > > tranny?  Everyplace I've gone to and asked for an
> > > output shaft seal, I get the wrong size(can't recall
> > > if it was too big or too small).  So I either need to
> > > know what year this tranny is, or what year I should
> > > tell NAPA(or others) my tranny is(Manipulation
> > > sometimes required when going to places like that)
> > > last but not least, is this considered a "good" tranny
> > > model.  How durable are they, this one already has
> > > 170k on it.  Thanks in advance-
> > > Rob
> > >
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