Insane speed in german cars... [Freightliner]

[jason@scirocco.org (Jason)]

At 12:59 PM 11/6/2002, Joe Doty wrote:
>Actually based on a quick search it looks like 450hp isn't too far off
>for a Detroit diesel.  One engine I saw had 450hp/1450ftlbs.

Wow!  Holy hell, can you imagine how much fun 1450ft-lb would be?  You 
could essentially have a 1:1 overall gear ratio with that thing in a 
Scirocco and still burn tire from idle to redline (which, at 3000rpm, would 
be, oh 500 mph?!)


>I think one reason that it's possible that it could hit a decently high
>top speed with such a heavy load is because it has so damn many gears,
>which can keep it at peak power all the time.  Wouldn't this reduce the
>time it takes it to get to its top speed?  Just theorizing.

Yeah, it would reduce the time needed to get to top speed, but it wouldn't 
necessarily increase the top speed.  If we had some numbers (namely frontal 
surface area and coefficient of drag) we could easily calculate how much 
power you'd need to get that thing to 100mph.

Jason





>Joe Doty
>IT/Development
>joe@lcnetwork.com
>
>-----Original Message-----
>From: Jason [mailto:jason@scirocco.org]
>Sent: Wednesday, November 06, 2002 7:51 AM
>To: John Van Vuren; Scirocco List
>Subject: Re: Insane speed in german cars... [Freightliner]
>
>At 05:37 PM 11/5/2002, John Van Vuren wrote:
> >Actually, a Freightliner will do 100mph with a 450hp engine...  just
>not a
> >VW 450hp engine.  They are geared to take advantage of torque, which a
>450hp
> >Cummins, Cat, Detroit, etc will provide in large numbers
>
>Those of you who know me know that I'm not a fan of HP numbers, since
>they
>are misleading.  There is exactly one time where HP becomes important,
>though, and that's in top speed.
>
>Gearing multiplies torque, but nothing effects horsepower:
>          (Gear something down 2:1 and you put out 2x the torque, but at
>exactly half the speed, which means HP is uneffected).
>
>All that torque is great for acceleration and pulling, but because it
>happens at such low RPMs, gearing will be very high and the result will
>be
>a reduction in torque.
>
>You can calculate, for example, using the Cd and stuff, the horsepower
>you
>need to go a certain speed.  That number is, however, independent of
>torque.  So, while you're completely right that the Freightliner making
>450hp at 3000rpm makes massive amounts of torque, it unfortunately isn't
>
>helping all that much in top speed.
>
>Jason
>
>PS:  I have no idea if 450hp is sufficient to get a Freightliner to
>100.  My guess is that it probably is close to being enough...
>
>
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