Brand new at this please help !

[dr j]

Given the same size tires dr.j how much more stable is a vehicle that is the
 same size and weight that has 4  wheels rather than 2 in theory would it be 50 percent

Taper-
Stability depends on many things and which direction the force is applied.  I know that my 2 wheeled bike blew over in a crosswind while parked in line at the recent Ohio Mile.  I did not see any cars lying on their side.  Also as mentioned here before one of your assumptions is totally false.  You are assuming that the 2 wheel tires and the 4 wheel tires are the same when they never are.  As an article in this month's Rider magazine discussed car tires and bike tires have very different lateral stresses applied when turning and therefore car tires have a flat contact zone and bike tires are rounded.  So a car tire has a much larger traction contact patch than a same diameter bike tire.  Thus the advantage to the car in traction is way more than double or even quadruple if 4WD.  That contact patch also helps the lateral stability of the car.  
As for the traction needed at speed think of it as when the vehicle is at top speed it just means that the power applied to the ground equals the drag resisting it so no more acceleration.  The faster you go the drag is cubed so the power must be too.  Eventually your power is more than the traction available.  Now with my small bike I have more traction than power so one less worry.  But even on the concrete for the fast bikes the power can exceed the traction.  I believe I heard that one of the top bikes at Maxton had data recorders that said his rear tire was spinning 11mph faster than the bikes ground speed at the timing lights.
As for your concern about traction vs rolling drag of 2 vs 4 tires the cost per tire for rolling drag is minimal compared to the benefit of improved traction getting power to the ground when we are talking about the really powerful vehicles.

[taper41]

i hope thats a good thing glen haha, hopefully my question asking puts everyones thinking cap on, what stump me are concepts such as what manta stated a few posts up.

4 wheels permitted that there the same wheels will have better traction than 2,
if traction is as important as aero when it comes to top speed.
4 tires hurt your top speed obviously by creating more drag, but manta has stated that you need more traction the faster you go because of the force pushing against your , which would mean 4 wheels would help your top speed.

to you see what im getting at here it?

[Stan Back]

No.  Theoretically no, I mean.

[Glen]

Regarding traction on the salt is the fact over the 5 mile distance it changes all along the entire course. The fast vehicles prefer running in the early AM or late after noon as the track surface is better. Mid day with the heat the water table rises on the salt and becomes damp to wet. Also the wind conditions are generally better at those times.

The tracks get a surface sweep with a drag almost every night. The days are long.

[taper41]

it seems to me if we were to break down the factors of top speed in to separate categories it would look a bit like this.

traction: 4 wheeler

Aerodynamics: 2 wheeler

Stability for power and downforce: 4 wheeler

so to me i would think these are the 3 most important factors , now according to dr. j a 5% increase in aero is equivalent to having a 16% increase in power, well what about traction , is having lets say twice as much traction does that have an equivalent to aero and power aswell, is it like having 50 % better traction is equivalent to a 75% aero development, obviously that is just a example but does anyone no the real numbers ?

[manta22]

Maybe it's just me, or the lingering memory of a certain propster, but I'm beginning to smell a rat.

[saltwheels262]

I don't think it's just you.
not wanting to digress......

[Stan Back]

You mean a theoretical rat, don't you?

[Glen]

The propster can't write with that much logic, but he does monitor the site.

[Stan Back]

I was just thinking.  I'm not building it, but if I had a '57 Corvette, not a 58 with the dual headlights, and I dropped it from a plane at 17,000 feet down to the starting line, would it go faster with a 2x4' wing on just one side or when I dropped it again (theoretically) with a 2x2' wing on both sides?

[Glen]

but what would it do with a big propeller???

[dr j]

Stan,
1. What color is the Corvette?  Hardtop or convertible?
2. Is the 2x4' wing have the 4' or 2' as the leading edge and is it made of Norwegian wood?

now according to dr. j a 5% increase in aero is equivalent to having a 16% increase in power, well what about traction , is having lets say twice as much traction does that have an equivalent to aero and power aswell, is it like having 50 % better traction is equivalent to a 75% aero development, obviously that is just a example but does anyone no the real numbers ?

Taper,
Actually what I said was that a 5% increase in speed due to an aero improvement was equal to a 16% increase in power.  But since I, like most mere mortals, don't utilize a wind tunnel I do not have any actual drag numbers.  As I also said traction is only needed to be able to utilize your power.  So if my current traction is fine, then doubling my traction will give no advantage but will increase the rolling drag and would thus be a negative not a positive.  So there is no comparing traction and aero directly.  It must be power applied successfully to the ground which involves traction as a factor to avoid power loss.

[Stan Back]

Dr J

No, but I like the song.

[Glen]

OK, let's get back on the subject.

[Stan Back]

Glen --

I personally don't think that was any more frivolous than the rest of the discussion on this "theoretical"  what-if (but I'm not doing it, nor will I) subject.  But what do I know, I've got a roadster.

Stan