The mathematics of the 8Vvs16V problem

[txrocco at sbcglobal.net (Patrick Bureau)]

thank you for this information...I really enjoyed reading it..

Now to get a TDI crank and pistons and add more torque bandwidth :)


ATS - Patrick Bureau


->-----Original Message-----
->From: Jason Cammisa [mailto:jcammisa@alwaysonline.net]
->Sent: Monday, October 20, 2003 11:26 AM
->To: ATS - Patrick Bureau; _Scirocco Mailing List
->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