Alleged fastest numbers and poor comments...

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

David:
You are, of course, correct. My approach does suck!
In this particular case I don't know that I have to offer an explanation since the equations have
been presented (Drew's e-mail) and the calculations done (Mark's e-mail) for an example close enough
to Patricks to illustrate the situation.
Either Patrick's dyno runs are terribly inaccurate (and that may be possible since it seems his
engine should be good for at least 110 whp) or his instruments are terrribly inaccurate.
In either event 138 MPH isn't possible. I've done a spreadsheet that compares Patrick's engine power
every thousand RPM vs. power required to go the calculated speed for that RPM. It indicates 122MPH.
I'll post a link if I can find a place to put it.
Course the reason I'm such an asshole is that some people seem to think that the laws of physics are
negotiable or don't apply to them when it's far more likely their instruments are inaccurate.
What are the variables here? Cd, Area, Power, Velocity, instrument error.
Power has been documented by his dyno runs. Cd and Area can be off by 10% and cause only  a 3%
change in Velocity. Now what's left? The actual Velocity (not Patrick's claim) or Patrick's claimed
Velocity due to instument error??
Furthermore, do you know how Cd is determined? It's an empirical number that is derived from
applying the equations in Drew's e-mail to the measured drag of an actual car.
So, all the numbers presented have validity. It's not somebody's wild ass guess.
Why do I get frustrated? Cause I'm an engineer and I know the laws of physics are called laws for a
reason and I get tired of repeating and repeating and repeating when somebody is that far off the
mark.
Dan


----- Original Message ----- 
From: "David Utley" <mr.utility@highstream.net>
To: "Dan Bubb" <jdbubb@ix.netcom.com>
Cc: "Patrick Bureau" <ats@longcoeur.com>; <marc_scirocco@sympatico.ca>; "'scirocco'"
<scirocco-l@scirocco.org>
Sent: Tuesday, March 09, 2004 1:29 PM
Subject: Alleged fastest numbers and poor comments...


> Dan,
>    If one is appointing oneself as the 'truth police', then perhaps one ought
> to demonstrate why one should recieve the job?
>
>   You have unloaded on me a few times, and some of those times I have deserved
> it.  Howeverto be blunt, your approach sucks.  You may be bright, you might be
> certified (or certifiable, dunno  :-)), but I, nor the other folks on here
> deserve the tone that you often sling.  You told me in a private email that
> you don't have time to reply to every comment that I may throw out on your
> comments.  That is fine, however, if the comment is worth making, then it is
> worth explaining.  That is why we are all here, to learn or to educate.  The
> comment you offered below seems to indicate that you have less of a desire to
> educate, than to correct.  I apologize if my tone here is piss-poor as well,
> but I felt I had to say it...
>
> Rant mode disabled...
>
> David Utley
>
> Quoting Dan Bubb <jdbubb@ix.netcom.com>:
>
> > Nice dream!
> > Puuuuuleeasse stop!!!!!!!!
> > Get your instruments (tach and speedo) calibrated.
> > Guys with 16V's making 120-130 whp are getting 130MPH.
> > Did you read the part about power being proportional to V^3??
> > To go 10% faster you need 33% more power. You don't have 33% more power than
> > anything but a stock
> > 1.8 JH. That ought to get you ~120 if you're lucky.
> > One more thing. If you're actually attaining 6600 RPM at your top speed then
> > you're way past your
> > power peak and you don't have 102 cause your power is dropping off rapidly.
> > Just look at your dyno
> > runs.
> > Hate to be pissy, but wake up.
> > Dan
> > just tired of some of the ridiculous claims!
> >
>
>
> David Utley
> -----------
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