Which is faster on the track. Z06 or GT-R

[Tremor14]

Unpossible, ruffdiddy is an engineer

[Ruffdaddy]

I sense a google war about to commence!

I'm actually educated and as I've said many times, I do this stuff for a living. So there is no need for google. However, feel free to continue mouth breathing and licking windows on the sidelines.

Ok genius; why don't you explain how a tires CF or anythings CF is calculated? I am talking about the entire object; not just the calculation of 1 square MM of it surface area.

I think you have a genuine interest here so I will try to explain it. I'm a shit teacher so bear with me.

Calculating Coefficient of Friction is simple, and is independent of surface area as long as you don't exceed the shear strength of either material under test. I have done some ASTM standard testing, but that is pretty complicated so I will leave that out.

But the basics are as follows:

Place the 2 materials you want to test in direct contact of one another. Lets say you place a 1" x 1" piece of steel on a 6" x 6" piece of PTFE. You then apply a known calibrated normal force to the 1" x 1" piece (lets say its 10 lbs) and pull in the direction parallel to the contact surfaces while measuring the force required to move the object. You will want to observe 2 things, First the force required to make it start moving (assume 4 lbs) and second the force required to make it continue moving (assume 2 lbs). THESE FORCES WILL BE DIFFERENT FOR STEEL ON STEEL.

The first coefficient of friction we will look at is the Coefficient of Static Friction (us...pronounced "mu sub s"). This will simple be the horizontal force divided by the normal force = 4/10=0.4. The coefficient of static friction is 0.4 and is unitless

The second coefficient of friction we will look at is the Coefficient of Kinetic Friction (uk...pronounced "mu sub k"). This is the same method but we use the force to continue motion=2/10. Therefore uk=0.2

Why do we need to know both? Say you want to know the absolute maximum torque you can apply to a drag wheel to launch WITHOUT wheel spin...you need to know the coefficient of static friction and not exceed it. OR you want to know maximum available braking force.

But what if you lock the wheels? Then you cannot use the static friction, you're now relying only on the coefficient of kinetic friction which is always lower. This is why ABS works...it prevents you from locking the wheels and keeps you in the static region instead of the dynamic friction region.


NOW...shear force...and why surface area matters.

Say I have a 5000lb car, and a coefficient of friction of 1.0 between my race tires and a race track.

dividing the 5000lb car by 4 wheels lets assume equal weight distribution so we have 1250lbs per wheel. In actuality there will be 1 or two wheels that require much higher weight distribution in cornering and lateral forces on some race cars can be in the 3-4 G range. our contact patch may change as well.

If the wheel contact area is 0.5" x 7" we get 3.5 square inches. That means we're applying 1250lbs/3.5in^2=357psi to the rubber while the car is simply sitting still...not cornering. But if the car is braking and cornering, that will be much higher.

So if the shear strength of the rubber is not greater than 357psi...it will SHEAR and not actually break loose due to friction. This would be an example of why you see solid streaks of rubber left on the ground during a lateral slide or locked brakes. Ever notice that hard tires rarely leave marks when spinning like soft tires? That's because they are breaking loose do to friction and not because they're exceeding the shear strength of the rubber.

The actual interaction is much more complicated...but this is the best I can do to SIMPLY explain why shear strength matters with respect to the coefficient of friction.

[SS Junk]

I'm actually educated and as I've said many times, I do this stuff for a living. So there is no need for google. However, feel free to continue mouth breathing and licking windows on the sidelines.

[ ] Originality

You haven't mentioned jack shit about tire profile being a factor, however you are the moron who said you have just as much stability deadlifting in sneakers than barefoot or DL slippers. SVO wins. Now get to googlins more of your fantabulous replies!

[Ruffdaddy]

[ ] Originality

You haven't mentioned jack shit about tire profile being a factor, however you are the moron who said you have just as much stability deadlifting in sneakers than barefoot or DL slippers. SVO wins. Now get to googlins more of your fantabulous replies!

Like i expected...licking windows lol. You sad out of shape old fuck.

1 - we are talking about the relationship between surface area and the ability to apply the tires coefficient of friction. Explain to me what you want to use profile for.

I know youre too senile to remember this...but im the one who said coefficient of friction is not the only thing that matters.

2 - Ive power lifted. Im in better shape than you. I win.

[SS Junk]

It doesn't matter what you claim you've done, you're an idiot for making those statements, and any one power lifter will tell you the same thing.

Wider tires can withstand higher shear forces.

Another dumb statement and now trying to save face. LOL
Imagine the possibilities if you had SVO's babies. I say you two should hook up and see what happens!

[Ruffdaddy]

It doesn't matter what you claim you've done, you're an idiot for making those statements, and any one power lifter will tell you the same thing.

Another dumb statement and now trying to save face. LOL
Imagine the possibilities if you had SVO's babies. I say you two should hook up and see what happens!

Tell me how that statement is wrong. Mathematically...i dont speak dumbass

[Ruffdaddy]

Also you never explained the relevance of your profile statement with respect to my discussion with svo...

[SS Junk]

Keep backpeddling. Make some bullshit generic statement and then lamely try and back it up with your frivolous google searches.

It wouldn't work. If you and SVO bumped uglies the universe would implode.

[Ruffdaddy]

Keep backpeddling. Make some bullshit generic statement and then lamely try and back it up with your frivolous google searches.

It wouldn't work. If you and SVO bumped uglies the universe would implode.

Youre literally narrating your own actions right now.

I just showed the math and science. Youve just shown your stupidity.

[AnthonyS]

Most Corvette fag boys just can't stand to loose any comparison, deal with it son!

I'm hardly a Corvette fanboy. And I'm definitely not the peter puffer that you are. I've raced enough cars to know that certain tracks favor certain types of cars. The Nurburgring is a tight narrow course even though it's lots of miles. That won't favor the 'Vette.

How about this list of cars at VIR with the Porsche 918 on top....

http://www.caranddriver.com/features/lightning-lap-2014-complete-ll-times-2006-to-2014-feature

Oh wait the 2015 ZR1 is faster than the 918 and the GT-R and by a lot.

http://www.roadandtrack.com/car-culture/videos/a24695/video-2015-corvette-z06-obliterates-virginia-international-raceway/

But what do I know?

[Ruffdaddy]

The fact that in f1 ferrari has beat mercedes twice this year is enough to show that certain tracks favor certain cars.

Is anyone really arguing otherwise?

[Mysticcobrakilla]

Unpossible, ruffdiddy is an engineer

Best post of the whole fucking thread.

[AnthonyS]

The fact that in f1 ferrari has beat mercedes twice this year is enough to show that certain tracks favor certain cars.

Is anyone really arguing otherwise?

Yes some asshats insinuated the GT-R is always faster than the ZR1 based on the Ring and the original post. Fact of the matter is with these two cars the driver will make the most difference and they are both driven very differently. A great driver will probably get more out of the 'Vette. AWD covers a lot of driving flaws and allows the driver to get away with more stupid shit. The 911 GT3 is going to need an even better driver due to the rear mounted engine but when driven right it's outrageously fast too.

[Craizie]

Yes some asshats insinuated the GT-R is always faster than the ZR1 based on the Ring and the original post. Fact of the matter is with these two cars the driver will make the most difference and they are both driven very differently. A great driver will probably get more out of the 'Vette. AWD covers a lot of driving flaws and allows the driver to get away with more stupid shit. The 911 GT3 is going to need an even better driver due to the rear mounted engine but when driven right it's outrageously fast too.

So is your mom.

[AnthonyS]

So is your mom.

If you can find her, tell her I said hello. I haven't seen her in over 30 years, and it's pretty much a non issue in deciding which car is faster.