rec.autos.simulators

by **Jim Sokolo** » Sun, 09 Mar 1997 04:00:00

>> Don, I pushed for this change myself during Beta testing. Cold air is
>> more dense than warm air, and this allows the engine to make more
>> HP. ...

>Just curious, does the extra horsepower only come after the crew adjusts
>the carb for a richer mix? I'm assuming that because you have more
>oxygen to mix with fuel this means you can afford the richer mix, and
>hence more horsepower without fouling plugs, etc.

Even without changing the jets, you'll get a little more horsepower,
by the mere ability to get more air into the engine. This will
slightly lean the mixture out, but the jet adjustment is a relatively
coarse one. (My WAG is maybe one jet for fif*** or twenty degrees
F...) Changing the jets will bring the mixture back into the proper
range, helping to keep the motor together and make more power.

Yes, you'll always get the right fuel mixture in our sims...
(Seriously, our engine model isn't quite THAT complex yet...)

---Jim Sokoloff, Papyrus

by **Kyle Langst** » Mon, 10 Mar 1997 04:00:00

>>Forward a copy of the message (include all of the header information)

>>with your complaint. Most ISP's are very appreciative of this notice
>>and will gladly talk with those users inappropriately using their
>>accounts.

>Eric's point about the headers is particularly important in this case,
>given that these posts were forged. (and they've been gradually
>appearing in every damn newsgroup I read, so I've been dutifully
>forwarding them everytime I see them.) If enough people do this,
>spammers will recognize that any account that they spam from will be
>shut down fairly quickly...

>---Jim

Heard on c-Net VERY recently that some company is setting up an ISP
JUST FOR SPAMMERS! For $50 a month a subscriber will be able to send
as much bulk mail as they want, and I would imagine there account
would not get shut down if someone notified the ISP's admin, since
that's the whole point of the special service. Yikes!

Kyle Langston
_________________________________

http://www.traction.git.net/nrcentral/

by **Jim Sokolo** » Mon, 10 Mar 1997 04:00:00

>Heard on c-Net VERY recently that some company is setting up an ISP
>JUST FOR SPAMMERS! For $50 a month a subscriber will be able to send
>as much bulk mail as they want, and I would imagine there account
>would not get shut down if someone notified the ISP's admin, since
>that's the whole point of the special service. Yikes!

That's OK, it's easy enough (particularly if your ISP will cooperate)
to summarily block all e-mail or netnews from a particular domain. (Am
I the only one to spot the fatal flaw in this "all spam, all the time"
business plan?)

---Jim

by **Richard Walk** » Mon, 10 Mar 1997 04:00:00

>>Tyres stick better with WARMER track temperatures, not COLDER!!

>Up to a point yes, but very hot asphalt becomes oily and slick rather
>than continuing to offer increased grip.

You've got to remember that I come from the UK. Days hot enough for the
asphalt to become appreciably slick are few & far between here ;-)

Guess it's too long since I took physics - thanks for the correction!

Cheers,
Richard

by **Mike Marshal** » Tue, 11 Mar 1997 04:00:00

Actually, humidity is a bad thing, regardless of temperature. As the
humidity increases the amount of water vapor in the air increases.
Water vapor (is not water droplets) is less dense than air. The more
water vapor you have per unit volume of air, the thinner the total air
mixture. Thus the more humid, the less horsepower, less downforce, etc.

As far as the drag issue is concerned, I can only reference the
relationships involved with aviation. The more dense the air, the more
horsepower, the more lift, and the more drag you get. However, the
amount of increased drag is always offset by the gains realized by more
power and lift. As far as automobiles goes, they are using the lift
(downforce) aspect, but I don't know if they gain as much benefit as an
aircraft wing. I would tend to think that the increased drag would
still be overcome by the benefits of the downforce and horsepower; up to
a certain speed anyway, as drag increases as the square of the speed.
That's why it takes so much more power to get that extra mile per hour
at Talladega and Daytona.

Mike

> Gases expand as their temperature increases as a result of the
> increased kinetic energy of the molecules. As they cool and the
> kinetic energy decreases, the molecules slow and the gas is more easily
> compressed thus it is more dense. As far as water content goes, warmer
> air has a higher saturation point (it can hold more water vapor). Thus
> air with 50% relative humidity at 100 degrees contains more water vapor
> than does air with the same relative humidity at 50 degrees. Because
> of this, Papyrus could model absolute humidity (the mass of water vapor
> present per unit volume of air) instead of the popularly reported
> relative humidity (water vapor content/water vapor capacity).

> --

> The IWCCCARS Project: Q & A Representative
> http://www.theuspits.com/iwcccars/index.html-ssi
> http://userwww.service.emory.edu/~ebusch/

> > Would the denser air be because of the water content? Like the cooler
> > water gets it expands? thus the water content in the air at colder
> temps
> > makes the air more dense? If this is so, maybe Pappy should add
> humidity
> > to the weather settings :)

by **Mike Marshal** » Tue, 11 Mar 1997 04:00:00

> >Tyres stick better with WARMER track temperatures, not COLDER!!

> Up to a point yes, but very hot asphalt becomes oily and slick rather
> than continuing to offer increased grip.

> >But air pressure is higher at colder temperatures leading to increased
> >engine power which is why superspeedway records are set in the cooler
> >months.
> Air DENSITY is higher; you cannot generalize that to air (barometric)
> pressure being higher.

> ---Jim Sokoloff, Papyrus

Well, barometric pressure does provide the same benefit as dense air to
a normally aspirated (non-turbo or supercharged) engines. It's the
roughly 30 inches of barometric pressure that shoves all that air into
the engine. The pistons don't suck in the air, it is shoved into the
vacuum created by pistons by the ambient air pressure. In aviation we
take a severe takeoff penalty for low atmospheric pressue and also gain
benefits by high atmospheric pressure.

Air density is a function of the temperature of the air. It is as
stated above, not directly related to barometric pressure, but
barometric pressure can hurt and help the normally aspirated engines,
just like the density.

Mike

rec.autos.simulators

NASCAR 2 COLDER IS FASTER HUH!!!!!

NASCAR 2 COLDER IS FASTER HUH!!!!!

NASCAR 2 COLDER IS FASTER HUH!!!!!

NASCAR 2 COLDER IS FASTER HUH!!!!!

NASCAR 2 COLDER IS FASTER HUH!!!!!

NASCAR 2 COLDER IS FASTER HUH!!!!!

NASCAR 2 COLDER IS FASTER HUH!!!!!