The mathematics of the 8Vvs16V problem

[jdbubb at ix.netcom.com (Dan Bubb)]

Jason:
There is no doubt that a 16V in an equal state of tune will make more power
than an 8V and I stated that in my original semi-sarcastic post.
The point I was making was it would be erroneous to assume that because you
have a 16V you're going to trounce any 8V you come across. In my mind it
comes down to what have you done to your engine, 8V or 16V. I've done alot
to my 8V and am happy with the results. It's faster than most 16V's and will
get eaten up and spit out by some.  Considering I bought it new before 16V's
were even available I don't often revisit the issue of why I have an 8V.
Having said all that and knowing what a contentious guy I am, it does get a
little irritating hearing the 16V chant from somebody that has less HP than
I do.
This dyno reflects my current state of tune although the mixture has been
richened up some since then since it's alittle lean here.

http://home.netcom.com/~jdbubb/sitebuildercontent/sitebuilderpictures/Sciroc
co_dyno.jpg
Dan
Micropenis!! Ouch!


----- Original Message -----
From: "Jason" <jason@scirocco.org>
To: <scirocco-l@scirocco.org>
Sent: Monday, October 20, 2003 12:27 PM
Subject: RE: The mathematics of the 8Vvs16V problem


> Heya Patrick,
>          Thanks for posting that graph.  Your torque curve illustrates
> exactly what I pointed out in my last mail:
>
> Even though your engine pushes out a very, very healthy peak of around 118
> lb-ft of torque to the wheels, it manages only 98hp.  Exactly as I said,
> the 8V concentrates its torque output down low in the rpm range - yours
> peaks at around 2700rpm.  This is ideal for a daily driver -- around town
> at leisurely rpms, your car is at its happiest.  It'll squirt off the line
> like a beast...
>
> As you can see though, the torque curve peaks early and then falls off
> gradually as you approach redline.  Horsepower is nothing more than torque
> at high rpms.  Since your car is making relatively little torque at high
> rpms, its Horsepower number is so much smaller.  Horsepower isn't my
> favorite number when used to gauge the overall driveability and feel of an
> engine, but it's the only number you need when you're talking about
all-out
> acceleration.  At full-tilt, if geared correctly, a 240hp, 3000lb Honda
> with 180 lb-ft of torque will still be even with a 240hp, 3000lb V8 with
> double the torque.
>
> The reason why is simple:  Under full acceleration, you're between, say,
> 4000rpm and redline all the time... save for the initial launch, which
> admittedly, if done properly, will be in that range, too.  Ignore what
> happens at low revs on your chart, and you'll see why a stock 1.8 16V with
> the same gearing will outrun your car... it puts more torque down at those
> speeds and can rev 1000rpm more.
>
> Now, with that said:  Driving your car and driving that stock 1.8 16V will
> feel completely different.  Let's say you and the 16V are puttering along
> in 2nd gear at 2500rpm next to each other, and you both realize that your
> two lanes are about to turn into one, and you both gun it.  The 16V will
be
> eating your hard-earned 8-Valve dust.
>
> Now, if you both kept your foot in it, the 16V would eventually catch up
> and walk away from you.  But your subjective impression from the short
race
> will be of course, that your car is faster than a 16V.
>
> This is why I say quite clearly that the 8V is certainly not without its
> merits.  The 8V versus 16V war is certainly akin to the V8 and big
> displacement versus VTEC and revs debate, albeit on a lesser scale.  Flat
> out at the 1/4 mile, the VTEC Honda can keep up with the V8s.  The reason
> is because the high revving motor will let you take advantage of gearing,
> where the big V8 just pulls and pulls from low revs.  You have to work
> harder to keep up in the Honda, but if you do, you'll be rewarded with the
> same acceleration times as the big boys.
>
> So yes, your car will, without a shred of doubt in my mind, be a whole lot
> more fun around town than a 1.8 16V would.  Low-end torque is what the
> American public wants -- that's why we have Buicks with pushrod 3800
> V6s.  They give fantastic acceleration off idle and feel powerful, smooth,
> and fun -- until it's time to really get moving. When it comes to the
> stoplight race - or racetrack - or 1/4 mile track - or high speed race -
or
> Autobahn cruise, all of that advantage is lost, and indeed a stock 16V
> would be faster than your fun-to-drive, torquey and happy built 8V.  It's
> just a matter of physics... not me trying to diss ya!
>
> Jason
>
>
>
>
>
>
>
> At 10:40 AM 10/20/2003, ATS - Patrick Bureau wrote:
> >jason how about this 8v (mine) I think my torque curve is quite broad,
you
> >got 133ft'lbs, I got 118ft'lbs torque and in the same manner of the 16v
it
> >instersecs the HP curve. stock JH head and 2L bottom end with only a g
Grind
> >in it.
> >
> ><http://www.longcoeur.com/scirocco/various/dyno/dyno%5Fatsgtx01%2EJPG>
> >
> >is this what you where looking for ? or perhaps I did not understand the
> >question.
> >
> >
> >
> >ATS - Patrick Bureau - txrocco@sbcglobal.net
> >----------------------------------------------
> >MSN:ATSGTX@hotmail.com |YAHOO:ATSGTX@yahoo.com
> >ICQ:32918816           |AIM:Texasscirocco
> >----------------------------------------------
> >
> >
> >=>-----Original Message-----
> >=>Case in point, please see the following curve:
> >=>http://www.scirocco16v.org/dyno/16V.jpg
> >=>This is a dyno plot from one of our veteran list members.  It's a 2.0
16V
> >=>with a slightly P+P and shaved head; Schrick 260/276 cams, and an
> >=>exhaust.  That's a relatively stock motor in my book -- the entire
bottom
> >=>end is completely stock.
> >=>
> >=>You'll see that not only does it peak out at 144whp and almost 133
lb-ft
> >of torque, but the torque curve itself is tremendously broad and
> >=>beefy:  This engine puts more than 120 lb-ft of torque to the wheels
from
> >3000 until 6250rpm.  That is a simply awesome number from a 2-liter
> >engine... and
> >=>flies directly in the face of any complaints of the 16V being a dog
down
> >low.   And further, this particular motor puts down about the same torque
> >=>at 2000rpm that the 1.8 16V does at its peak -- just under 100 to the
> >wheels -- which is, as we know, more torque than any VW 8V motor
> >=>(including the ABA) did from the factory.  So there's monumental
high-rpm
> >power (VR6 territory) with low rev torque besting all other VW
4-cylinders.
> >=>You just can't do that in an 8V VW motor.
> >=>
> >=>http://neubayern.net/mailman/listinfo/scirocco-l
>
>
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