some food for thought about tires
09-06-06, 07:22 PM
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some food for thought about tires
hey everyone.. i was browsing an ariel atom board because im very fond of them.. and i came across some very technical information about tires.. i thought i would share with you guys because it's always nice to know..
Originally Posted by Jammer
For upgrade/part info:
A wider tire often does not yeild a larger contact patch. Food fot thought. Buy into it as you wish, or apply where you see fit. I jvae long held that Longitudinal (straight line) acceleration benifits from increasing the *length*, not the width, of the contact patch. Lateral (cornering) acceleration benefits from increasing the width of the contact patch.
Myth 1: Wider tires have a larger contact patch than narrow tires
Who knows...
What actually influences the size of the tires's contact patch? Is it the width of the tires, or the profile? The simple answer that it is neither of these; the size of the tires's contact patch is related to:
the weight on the wheel
the tires pressure.
For example, say that the weight on the tires was 900lb, and the tires pressure was 10 psi. That internal pressure means that each square inch of area can support 10lb, so, in this case, the contact patch will be 90 square inches. If the tires pressure was 30 psi, the contact area would be 30 square inches, and if the pressure was 90 psi, the contact area would be 10 square inches. This has been found to be almost exactly correct for most tires (the exceptions being so-called run-flat tires, or tires with extremely stiff sidewalls). For most other tires, carcass structure will have an effect, but by far the major factor is tires pressure.
So, as you can see, the size of the contact patch of a tires is not related to the width of the tires - it is, in fact, proportional to the tires pressure. What will change with the fitting of a wider tires is the shape of the contact patch - it will get wider, but shorter longways. (Think logically. If lay your pencil on the desk going east to west, slide it fowards. It should be easier to slide than if you rotated the pencil pointing north-south and sliding it foward. Same concept. The patch area stays the same, the dimenions change).
Myth 2: A larger contact patch = more grip
Okay, most people will come to the conclusion that if you have "more rubber on the road" you will have increased grip. Sorry to say this folks, but to very close to 100% accuracy, the size of the contact patch is irrelevant.
The actual grip that a tire can generate is dictated by the coefficient of friction of the rubber compound used in the tires. The higher the coefficient, the more grip which can be generated. The relation that is used is called Amonton's Law, and the equation is:
F=µN,
where F is the force generated, µ is the coefficient of friction, and N is the weight on the surface considered (in our case, the weight on the tires).
So, if you increase the weight on the tires, then the frictional force will increase as well, in proportion to the increase in weight on the tires - but the coefficient of friction will remain the same. The level of grip of the tires (forgetting about suspension niceties - we are only discussing tires here) is totally dictated by the coefficient of grip of the tires and the weight acting on it - not the area of the contact between the tires and the road. This can be aided by a LARGER DOWNFORCE wing (stock Supra wing puts down 62lbs of force at 90mph I believe)
So, I hear you argue, why bother with wide, low profile tires at all? Why not simply have narrow, high profile tires? The simple reply to that is heat (remember, we are simply talking grip here, not the niceties of handling finesse). The point is that, to get a contact patch of a certain size on the road, you need a certain portion of the tires to be flat. Taking the contact patch to be basically rectangular (though it is actually partially oval in shape), then the area of that patch will be its length times its width. Now, for a narrow tires, the contact patch will be quite long compared with a wide tires.
This introduces two problems for the tires.
First, to get that long flat section to give the required contact patch, the sidewall of the tires needs to deform quite a lot. This deformation actually causes the bending and unbending the rubber of the sidewall as it flattens and then the tread curves again. This bending and unbending process results in a lot of heat being generated. (Think about bending and unbending a piece of wire rapidly, and how hot it gets as you do so. If you bend it less, but at the same frequency, less heat will be generated). Obviously, the more it needs to bend, the greater the amount of heat generated.
The second relates to the length itself. There will be a greater percentage of the tires tread in contact with the road than if the contact patch length were shorter; this reduces the amount that the tread can cool. Also, there is a greater percentage of sidewall at any given time that is actually under bending stresses, again resulting in less opportunity to cool.
So, how much extra bending do you really get, and how much is potential tread cooling reduced? Let's take a theoretical example, and take a 155-width tires compared with a 225 tires of the same circumference. Agreed, this is an extreme example, but it will suit our point very well. Assume that the wheel/tires-unloaded circumference is 60cm. Assume the tires pressure is 30 psi, and that the weight on the wheel is 600lb, giving an area of 20 square inches (or 129 square cm). Assuming that the contact patch is rectangular, with the wider (225) tires, the patch will be 5.73cm long, and with the 155 tires, the patch will be 8.32cm long. Now, the circumference of the wheel-tires combination is 188cm, so the 225 is heating for 3% of its cycle, and cooling 97%, whereas the 155 is heating for 4.5% of the cycle and cooling for 95.5%. So, you can see that the narrower tires is generating heat 50% longer than the 225, and is not spending so much of its cycle cooling.
Now, as far as heating of the tires is concerned, simple geometry shows us that the 155 tires bends by 0.29cm, and the 225 bends by 0.14cm. Now, assuming that the heating of the tires is roughly proportional to the deformation, let's find out the results of all of this. We will multiply the deformation by the percentage of time the tires sidewall is under stress, and divide this number by the percentage of time that the tires is being cooled. Multiplying the resulting numbers by 100, we get a figure of 1.37 for the 155 tires, and 0.43 for the 225. Dividing the 155 tires's number by that of the 225, we find that the heat generation of the 155 is 3.2 times that of the 225! This is quite an amazing result, given that the 225 is only 45% wider than the 155.
As a result on this increased generation of heat, and the reduced capacity for self cooling, the tires need to be made of a harder rubber compound that is more able to resist heat. This harder compound will, of necessity, have a reduced coefficient of friction, particularly when cold. The tires that are wider can have a softer compound with better frictional properties. Due to the reduced bending stresses, and greater cooling opportunities, the tires will tend to stay within a narrow temperature range quite consistently, giving greater cold grip, while managing to have a reduced propensity for overheating. Obviously, this makes for a better performance tires.
On the issue of wheel size (the diameter, not the width), it is therefore clear that increasing the wheel/tires diameter combination is beneficial. The reason for this is that the tires will not have to deform so much to get the required contact patch length, and the percentage of the tires tread in contact with the road will be less than for a smaller diameter combination.
So, what about tires pressure? Obviously, tires pressure plays a very important part, but there are clearly limits on both sides of the tires pressure equation. At the higher end, there is the maximum tires pressure that can be sustained before there is damage to the carcass. At the low end, you don't want the sidewall almost collapsing, generating massive heat, and have the tires slipping on the rim. So, you can play around with tires pressures to optimise your set-up, but there are limitations.
A simple way to find out approximately what pressure is optimal for your combination is to draw a chalkline across the width of the tires, drive for a bit, and look at the wear pattern of the chalkmark. Wearing more quickly in the centre indicates pressure that is too high, and wear on the edges indicates too low a pressure.
One issue to consider is that, for wet weather driving, despite what you may have heard, it is better to increase your tires pressure, not reduce it. The reason is that there is a relationship between tires pressure and the speed at which there is the onset of aquaplaning. In the Imperial system, the equation is 9 times the square root of the tires pressure. So, if your tires are at 25 psi, if you drive into a puddle that is deeper than your tread depth, you will aquaplane at 45 mph (72 km/h), whereas if your tires pressure was 36psi, you would aquaplane at 54 mph (87 km/h). The advantages are obvious.
As far as tires profile is concerned, the main benefit is one of handling - the lower sidewalls give reduced sidewall deformation under lateral loading, which results in improved steering response and a more stable contact patch.
Conclusion
Summarizing, what factors are important in terms of tires grip? tires width has no direct relation to the amount of grip generated; it is a secondary factor, and the width basically relates to cooling potential and so the tires compound that can be used. The size of the contact patch has no bearing on the amount of grip generated at all, apart from the extreme of where the compound is getting so hot that it no longer acts as a solid (and therefore doesn't follow Amonton's Law). The tires pressure has no direct bearing on the level of grip (apart from aquaplaning), but it does have a bearing on the heating and cooling characteristics of the tires. Having a lower tires profile gives improved handling through reduced sidewall stress and improved contact patch shape stability.
A wider tire often does not yeild a larger contact patch. Food fot thought. Buy into it as you wish, or apply where you see fit. I jvae long held that Longitudinal (straight line) acceleration benifits from increasing the *length*, not the width, of the contact patch. Lateral (cornering) acceleration benefits from increasing the width of the contact patch.
Myth 1: Wider tires have a larger contact patch than narrow tires
Who knows...
What actually influences the size of the tires's contact patch? Is it the width of the tires, or the profile? The simple answer that it is neither of these; the size of the tires's contact patch is related to:
the weight on the wheel
the tires pressure.
For example, say that the weight on the tires was 900lb, and the tires pressure was 10 psi. That internal pressure means that each square inch of area can support 10lb, so, in this case, the contact patch will be 90 square inches. If the tires pressure was 30 psi, the contact area would be 30 square inches, and if the pressure was 90 psi, the contact area would be 10 square inches. This has been found to be almost exactly correct for most tires (the exceptions being so-called run-flat tires, or tires with extremely stiff sidewalls). For most other tires, carcass structure will have an effect, but by far the major factor is tires pressure.
So, as you can see, the size of the contact patch of a tires is not related to the width of the tires - it is, in fact, proportional to the tires pressure. What will change with the fitting of a wider tires is the shape of the contact patch - it will get wider, but shorter longways. (Think logically. If lay your pencil on the desk going east to west, slide it fowards. It should be easier to slide than if you rotated the pencil pointing north-south and sliding it foward. Same concept. The patch area stays the same, the dimenions change).
Myth 2: A larger contact patch = more grip
Okay, most people will come to the conclusion that if you have "more rubber on the road" you will have increased grip. Sorry to say this folks, but to very close to 100% accuracy, the size of the contact patch is irrelevant.
The actual grip that a tire can generate is dictated by the coefficient of friction of the rubber compound used in the tires. The higher the coefficient, the more grip which can be generated. The relation that is used is called Amonton's Law, and the equation is:
F=µN,
where F is the force generated, µ is the coefficient of friction, and N is the weight on the surface considered (in our case, the weight on the tires).
So, if you increase the weight on the tires, then the frictional force will increase as well, in proportion to the increase in weight on the tires - but the coefficient of friction will remain the same. The level of grip of the tires (forgetting about suspension niceties - we are only discussing tires here) is totally dictated by the coefficient of grip of the tires and the weight acting on it - not the area of the contact between the tires and the road. This can be aided by a LARGER DOWNFORCE wing (stock Supra wing puts down 62lbs of force at 90mph I believe)
So, I hear you argue, why bother with wide, low profile tires at all? Why not simply have narrow, high profile tires? The simple reply to that is heat (remember, we are simply talking grip here, not the niceties of handling finesse). The point is that, to get a contact patch of a certain size on the road, you need a certain portion of the tires to be flat. Taking the contact patch to be basically rectangular (though it is actually partially oval in shape), then the area of that patch will be its length times its width. Now, for a narrow tires, the contact patch will be quite long compared with a wide tires.
This introduces two problems for the tires.
First, to get that long flat section to give the required contact patch, the sidewall of the tires needs to deform quite a lot. This deformation actually causes the bending and unbending the rubber of the sidewall as it flattens and then the tread curves again. This bending and unbending process results in a lot of heat being generated. (Think about bending and unbending a piece of wire rapidly, and how hot it gets as you do so. If you bend it less, but at the same frequency, less heat will be generated). Obviously, the more it needs to bend, the greater the amount of heat generated.
The second relates to the length itself. There will be a greater percentage of the tires tread in contact with the road than if the contact patch length were shorter; this reduces the amount that the tread can cool. Also, there is a greater percentage of sidewall at any given time that is actually under bending stresses, again resulting in less opportunity to cool.
So, how much extra bending do you really get, and how much is potential tread cooling reduced? Let's take a theoretical example, and take a 155-width tires compared with a 225 tires of the same circumference. Agreed, this is an extreme example, but it will suit our point very well. Assume that the wheel/tires-unloaded circumference is 60cm. Assume the tires pressure is 30 psi, and that the weight on the wheel is 600lb, giving an area of 20 square inches (or 129 square cm). Assuming that the contact patch is rectangular, with the wider (225) tires, the patch will be 5.73cm long, and with the 155 tires, the patch will be 8.32cm long. Now, the circumference of the wheel-tires combination is 188cm, so the 225 is heating for 3% of its cycle, and cooling 97%, whereas the 155 is heating for 4.5% of the cycle and cooling for 95.5%. So, you can see that the narrower tires is generating heat 50% longer than the 225, and is not spending so much of its cycle cooling.
Now, as far as heating of the tires is concerned, simple geometry shows us that the 155 tires bends by 0.29cm, and the 225 bends by 0.14cm. Now, assuming that the heating of the tires is roughly proportional to the deformation, let's find out the results of all of this. We will multiply the deformation by the percentage of time the tires sidewall is under stress, and divide this number by the percentage of time that the tires is being cooled. Multiplying the resulting numbers by 100, we get a figure of 1.37 for the 155 tires, and 0.43 for the 225. Dividing the 155 tires's number by that of the 225, we find that the heat generation of the 155 is 3.2 times that of the 225! This is quite an amazing result, given that the 225 is only 45% wider than the 155.
As a result on this increased generation of heat, and the reduced capacity for self cooling, the tires need to be made of a harder rubber compound that is more able to resist heat. This harder compound will, of necessity, have a reduced coefficient of friction, particularly when cold. The tires that are wider can have a softer compound with better frictional properties. Due to the reduced bending stresses, and greater cooling opportunities, the tires will tend to stay within a narrow temperature range quite consistently, giving greater cold grip, while managing to have a reduced propensity for overheating. Obviously, this makes for a better performance tires.
On the issue of wheel size (the diameter, not the width), it is therefore clear that increasing the wheel/tires diameter combination is beneficial. The reason for this is that the tires will not have to deform so much to get the required contact patch length, and the percentage of the tires tread in contact with the road will be less than for a smaller diameter combination.
So, what about tires pressure? Obviously, tires pressure plays a very important part, but there are clearly limits on both sides of the tires pressure equation. At the higher end, there is the maximum tires pressure that can be sustained before there is damage to the carcass. At the low end, you don't want the sidewall almost collapsing, generating massive heat, and have the tires slipping on the rim. So, you can play around with tires pressures to optimise your set-up, but there are limitations.
A simple way to find out approximately what pressure is optimal for your combination is to draw a chalkline across the width of the tires, drive for a bit, and look at the wear pattern of the chalkmark. Wearing more quickly in the centre indicates pressure that is too high, and wear on the edges indicates too low a pressure.
One issue to consider is that, for wet weather driving, despite what you may have heard, it is better to increase your tires pressure, not reduce it. The reason is that there is a relationship between tires pressure and the speed at which there is the onset of aquaplaning. In the Imperial system, the equation is 9 times the square root of the tires pressure. So, if your tires are at 25 psi, if you drive into a puddle that is deeper than your tread depth, you will aquaplane at 45 mph (72 km/h), whereas if your tires pressure was 36psi, you would aquaplane at 54 mph (87 km/h). The advantages are obvious.
As far as tires profile is concerned, the main benefit is one of handling - the lower sidewalls give reduced sidewall deformation under lateral loading, which results in improved steering response and a more stable contact patch.
Conclusion
Summarizing, what factors are important in terms of tires grip? tires width has no direct relation to the amount of grip generated; it is a secondary factor, and the width basically relates to cooling potential and so the tires compound that can be used. The size of the contact patch has no bearing on the amount of grip generated at all, apart from the extreme of where the compound is getting so hot that it no longer acts as a solid (and therefore doesn't follow Amonton's Law). The tires pressure has no direct bearing on the level of grip (apart from aquaplaning), but it does have a bearing on the heating and cooling characteristics of the tires. Having a lower tires profile gives improved handling through reduced sidewall stress and improved contact patch shape stability.
09-06-06, 09:45 PM
#3
Eats, Sleeps, Dreams Rotary
pfff... wider tires = more grip (as a generalization).
The thing is that, for some cars, there's no reason to go so wide, because the tires won't have a chance to warm up to operating temp (ie, for a pure autocross car, which doesn't need the heavier steering that comes from more grip, either). Or because the car is so light it doesn't need more grip, and having uber-wide wheels would just increase weight (ie, go carts, Lotus Elises, AE86s...).
The thing is that, for some cars, there's no reason to go so wide, because the tires won't have a chance to warm up to operating temp (ie, for a pure autocross car, which doesn't need the heavier steering that comes from more grip, either). Or because the car is so light it doesn't need more grip, and having uber-wide wheels would just increase weight (ie, go carts, Lotus Elises, AE86s...).
09-06-06, 09:57 PM
#4
Lives on the Forum
F=µN
This ONLY applies to hard, dry surfaces.
A tire is not a hard surface.
Therefore this does not apply directly to tires.
There is a non-linear relationship with tires, as the load increases the grip does not increase directly proportionally to the load increase. If you double the load, you might only get 1.8x the grip, leading to less cornering force (unless the extra load is from downforce).
There is some truth to what was said in the wider tires don't = a bigger contact patch thing, the patch size will change from being more fore-aft to more side-side when wider tires are used, but the model they used to justify it totally neglects the support given by the sidewalls. If they weren't there then it'd be true, but it's not true. Wider tires will give a bigger contact patch and more grip, even longitudinally, not only laterally. And as stated above, the size of the contact patch does affect the grip, as with a larger contact patch, the pressure is less, so there's more grip. Just ask all the guys who went to wider tires and got less wheelspin with lots of power.
It's been shown time and time again that wider tires do give more grip, and that simple equations to do with coefficient of friction are useless, there are far too many factors that affect it to make it easily predictable.
This ONLY applies to hard, dry surfaces.
A tire is not a hard surface.
Therefore this does not apply directly to tires.
There is a non-linear relationship with tires, as the load increases the grip does not increase directly proportionally to the load increase. If you double the load, you might only get 1.8x the grip, leading to less cornering force (unless the extra load is from downforce).
There is some truth to what was said in the wider tires don't = a bigger contact patch thing, the patch size will change from being more fore-aft to more side-side when wider tires are used, but the model they used to justify it totally neglects the support given by the sidewalls. If they weren't there then it'd be true, but it's not true. Wider tires will give a bigger contact patch and more grip, even longitudinally, not only laterally. And as stated above, the size of the contact patch does affect the grip, as with a larger contact patch, the pressure is less, so there's more grip. Just ask all the guys who went to wider tires and got less wheelspin with lots of power.
It's been shown time and time again that wider tires do give more grip, and that simple equations to do with coefficient of friction are useless, there are far too many factors that affect it to make it easily predictable.
09-17-06, 12:35 AM
#6
I'll make it easier for everyone. The day a race team... any race team... uses a tire 1mm smaller than they're allowed to, and/or someboldy puts a MINIMUM size in the rules, you call me.
The only reason anyone would use a narrower tire would be to minimize aerodynamic drag..... or of course to sport the phat lip on wheels that don't fit so that they can bust the mad tyte drift skilz yo.
The only reason anyone would use a narrower tire would be to minimize aerodynamic drag..... or of course to sport the phat lip on wheels that don't fit so that they can bust the mad tyte drift skilz yo.
Last edited by ptrhahn; 09-17-06 at 12:38 AM.
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09-18-06, 09:15 AM
#8
Lives on the Forum
That post was full of **** 
I am however glad to see that people know better now
https://www.rx7club.com/suspension-wheels-tires-brakes-archive-112/17-vs-18-racing-mind-narrow-vs-wide-tires-292194/
Inside Racing Technology by Paul Haney; page 65.
Quoted from Sam Garrett; racecar designer and graduate mechanical engineer. Helped design the Kudzu Camel light cars as well as Dallaras.
"When I was a student at Georgia Tech, a physics professor asked our class why we were preoccupied with putting wider tires on our street cars. We told him we wanted to 'put more rubber on the road'. He tried to tell us that friction force is independent of contact area.
In most cases he's right. Friction force (Ff) depends on a coefficient of friction (Cf) which is characteristic of the materials involved and the vertical force (Fv) pressing the materials together: Ff=Cf x Fv. Area does not appear in the equation. In the real world, however, this only applies to materials with a 'hard' surface. To understand why that is, you have to look at what happnes on a microscopic level.
All materials no matter how smooth or flat they appear to our unaided eyes, have small surface imperfections as shown in the sketches. To simplify the sketch we show points on one side only, but really both blocks have irregular surfaces. When two solid objects touch they have an 'apparent' contact area which is the surface you can see and measure, but they also have a true, microscopic contact area which may be quite different. But for hard solids, the true contact area remains constant regardless of the apparent contact area. Here's why.
When two hard surfaces come in contact, they meet at many sharp points or peaks like you see in the sketch. If you apply a force the presses them together, the material actually yeilds and the peaks flatten out, increasing the actual area of contact. If we increase the size of the parts in order to increase the the apparent contact area, we lower the force at each peak because there are more peaks to take the same overall load. With less load on each peak the points flatten out less, and the actual area of contact is less per peak so, overall, the true contact area is about the same as before we made the parts bigger. That's why hard materials don't show an increase in friction forces with an increase in contact area.
Rubber is different. Rubber is an elastic solid which 'gives' at a very low stress level. There is no fixed yield point and the deformation is elastic-rubber deforms and recovers. It deforms at low stress levels, and conforms to the microscopic imperfections of a surface with which it comes in contact. You can see the sketch that more contact area means more imperfections to conform to. With rubber you get more friction force when you increase contact area"
___________End of article____________
This my friends explains why a lightweight and well handling but low horsepower car like a Formula Ford has no need for much wider tires at the rear compared to the front: it doesn't have enough horsepower to need the extra grip at the rear wheels. On the other hand, something like a Formula 1 car that is also lightweight and well handling but with very high horsepower needs much extra tire width at the rear in order to be able to actually use all the power it has. With narrower rear tires the car would automatically be handicapped as far as putting the power down. You'll find that unless rules limited, cars with big horsepower always have wider treads on the driven wheels compared to the undriven wheels. This allows the car to actually use the power because the wider wheels offers more grip! Shape of the contact patch be damned! It don't matter!
All you need to get more grip is to bring more rubber into contact with the road. It's that simple.
I am however glad to see that people know better now
https://www.rx7club.com/suspension-wheels-tires-brakes-archive-112/17-vs-18-racing-mind-narrow-vs-wide-tires-292194/
Inside Racing Technology by Paul Haney; page 65.
Quoted from Sam Garrett; racecar designer and graduate mechanical engineer. Helped design the Kudzu Camel light cars as well as Dallaras.
"When I was a student at Georgia Tech, a physics professor asked our class why we were preoccupied with putting wider tires on our street cars. We told him we wanted to 'put more rubber on the road'. He tried to tell us that friction force is independent of contact area.
In most cases he's right. Friction force (Ff) depends on a coefficient of friction (Cf) which is characteristic of the materials involved and the vertical force (Fv) pressing the materials together: Ff=Cf x Fv. Area does not appear in the equation. In the real world, however, this only applies to materials with a 'hard' surface. To understand why that is, you have to look at what happnes on a microscopic level.
All materials no matter how smooth or flat they appear to our unaided eyes, have small surface imperfections as shown in the sketches. To simplify the sketch we show points on one side only, but really both blocks have irregular surfaces. When two solid objects touch they have an 'apparent' contact area which is the surface you can see and measure, but they also have a true, microscopic contact area which may be quite different. But for hard solids, the true contact area remains constant regardless of the apparent contact area. Here's why.
When two hard surfaces come in contact, they meet at many sharp points or peaks like you see in the sketch. If you apply a force the presses them together, the material actually yeilds and the peaks flatten out, increasing the actual area of contact. If we increase the size of the parts in order to increase the the apparent contact area, we lower the force at each peak because there are more peaks to take the same overall load. With less load on each peak the points flatten out less, and the actual area of contact is less per peak so, overall, the true contact area is about the same as before we made the parts bigger. That's why hard materials don't show an increase in friction forces with an increase in contact area.
Rubber is different. Rubber is an elastic solid which 'gives' at a very low stress level. There is no fixed yield point and the deformation is elastic-rubber deforms and recovers. It deforms at low stress levels, and conforms to the microscopic imperfections of a surface with which it comes in contact. You can see the sketch that more contact area means more imperfections to conform to. With rubber you get more friction force when you increase contact area"
___________End of article____________
This my friends explains why a lightweight and well handling but low horsepower car like a Formula Ford has no need for much wider tires at the rear compared to the front: it doesn't have enough horsepower to need the extra grip at the rear wheels. On the other hand, something like a Formula 1 car that is also lightweight and well handling but with very high horsepower needs much extra tire width at the rear in order to be able to actually use all the power it has. With narrower rear tires the car would automatically be handicapped as far as putting the power down. You'll find that unless rules limited, cars with big horsepower always have wider treads on the driven wheels compared to the undriven wheels. This allows the car to actually use the power because the wider wheels offers more grip! Shape of the contact patch be damned! It don't matter!
All you need to get more grip is to bring more rubber into contact with the road. It's that simple.
Last edited by DamonB; 09-18-06 at 09:26 AM.
09-18-06, 09:22 AM
#9
Lives on the Forum
Originally Posted by raptor22
The big rpoblem here is that the friction coefficient goes down with load...
Last edited by DamonB; 09-18-06 at 09:26 AM.
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