Larger runflats ??
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I haven't heard of anyone making them in that size. Probably not much of a market since most go to non-runflats when getting them in the Z06 sizes.
Le Mans Master
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From: Shiloh Ohio
I think you will need to jump up to 19s and 18s to get more meat with a run flat. I would be curious if anyone has tried the OEM C6 Z06 rims and tires. I am sure they stick out a little in the rear, but it depends on the wheel offset of course.
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Melting Slicks
Joined: Mar 2001
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The 18 and 19 sizes is what I was thinking about doing with the new Z51 C6 tires and buying new wheels. The problem is matching wheels I want, with these tire sizes. I wish Good Year would just make the new style Supercar runflats in the correct C5 Z06 sizes. 
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Melting Slicks
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That is why I would like to see the new style Good Year Supercar runflats made in a wider variety of sizes. They are much lighter and also a better performing tire than the older style runflats. This new style is used on the new C6 ZO6. But, so far only 4 sizes....
Race Director
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Originally Posted by skip89
That is why I would like to see the new style Good Year Supercar runflats made in a wider variety of sizes. They are much lighter and also a better performing tire than the older style runflats. This new style is used on the new C6 ZO6. But, so far only 4 sizes....
Lighter tires give you less unsprung weight, which has other benefits, but one of them is not making you faster.
Safety Car
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From: Jackson Tn
St. Jude Donor '06-'07-'08-'09
Originally Posted by EHS
Skip -- I was being facetious.
Lighter tires give you less unsprung weight, which has other benefits, but one of them is not making you faster.
Lighter tires give you less unsprung weight, which has other benefits, but one of them is not making you faster.
Le Mans Master
Joined: Sep 2004
Posts: 7,027
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From: Shiloh Ohio
Originally Posted by vintage driver
Why would it not make the car faster?
My car went slower when I added un sprung weight. Close to a tenth in the qtr mile. I added about 6 lbs per wheel total. I would speculate it would also reduce top speed, do not have any proof on that though.
Race Director
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Originally Posted by C5Coup
Now I'm all confused? From what I hear, the lighter the wheel and tire package the better your acceleration and handling ,check out some of the topics on un sprung weight
http://www.musclecarclub.com/library/tech/weight.shtml
"An important concept is "unsprung weight." This is weight that is not supported by the suspension of the car. This usually includes the the weight of the wheels and tires as well as a percentage of the weight of the suspension itself, including control arms, anti-roll bars, shocks, and struts. Reducing unsprung weight is the key to improving handling. The lower the unsprung weight, the less work the shocks and springs have to do to keep the tires in contact with the road over bumpy surfaces. An easy way to reduce unsprung weight and improve traction is to replace stock wheels and tires with special lightweight wheels. Note that as the wheel diameter or width increases, the weight of the overall wheel and tire package increases, thereby increasing unsprung weight."
http://en.wikipedia.org/wiki/Unsprung_weight
Unsprung weight is the mass of a vehicle's suspension, wheels, and components directly connected to them rather than supported by the suspension. Unsprung weight includes the mass of components such as the wheel spindles, wheel bearings, tires, and a portion of the weight of driveshafts, springs, shock absorbers, and suspension links. If the vehicle's brakes are mounted outboard (i.e., within the wheel rather than inboard), their weight is also part of the unsprung weight.
The components that comprise a vehicle's unsprung weight are acted on by road shocks and bumps, and therefore the unsprung weight determines the reactive force that any motion of the wheels and suspension exert on the body of vehicle. The smoothness of the ride is closely related to the ratio of unsprung to sprung weight: the higher this ratio, the more severely bumps affect the vehicle.
Unsprung weight also governs the inertia of suspension components, affecting their ability to respond to bumps and changes in direction or road surface. High unsprung weight has a negative effect on overall handling ability, especially on imperfect surfaces.
High unsprung weight also exacerbates wheel control under hard acceleration or braking. If the vehicle does not have adequate wheel location in the vertical plane, such as on a rear-wheel drive car with Hotchkiss drive (a live axle supported by simple leaf springs), the torque exerted by acceleration or hard braking may cause severe wheel hop, compromising traction and steering control.
Unsprung weight is largely a function of the design of a vehicle's suspension and the materials used in the construction of suspension components. Beam axle suspensions, in which wheels on opposite sides are connected as a rigid unit, generally have greater unsprung weight than independent suspension systems, in which the wheels are suspended and allowed to move separately. Mounting heavy components such as the differential directly to the body rather than the suspension (as in a de Dion tube rear suspension) removes some or all of their mass from the unsprung weight, making it instead part of the sprung weight. Lightweight materials, such as aluminum, plastic, carbon fiber, and/or hollow components can provide further weight reductions at the expense of greater cost and/or fragility."
http://www.tirerack.com/wheels/tech/....jsp?techid=98
"Performance Benefits: While many people choose alloy wheels for their beauty, there are equally important performance benefits to be derived including...
Reduced Unsprung Weight Compared to Steel Wheels: This is one of the most critical factors affecting a vehicle's road holding ability. Unsprung weight is that portion of a vehicle that is not supported by the suspension (i.e. wheels, tires and brakes) and therefore most susceptible to road shock and cornering forces. By reducing unsprung weight, alloy wheels provide more precise steering input and improved "turning in" characteristics.
Improved Acceleration and Braking: By reducing the weight of the vehicle's rotational mass, alloy wheels provide more responsive acceleration and braking.
Added Rigidity: The added strength of a quality alloy wheel can significantly reduce wheel/tire deflection in cornering. This is particularly critical with an automobile equipped with high performance tires where lateral forces may approach 1.0g.
Increased Brake Cooling: The metals in alloy wheels are excellent conductors of heat - improving heat dissipation from the brakes - reducing risk of brake fade under demanding conditions. Additionally, alloy wheels can be designed to allow more cooling air to flow over the brakes.
The gentleman above was alluding to the fact that the car goes faster with lowwer unsprung weight. It doesn't, unless you want to factor in the couple of pounds difference per tire -- I don't think that 64 lbs. less total vehicle weight will increase your top speed significantly.
Yes, it may accelerate slightly faster, but don't confuse acceleration with speed (see www.newtonfordummies.com).
The best benefit of less unsprung weight is an imporvement in handling, not top speed.
Race Director
Joined: May 2000
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Originally Posted by C5Coup
Now I'm all confused? From what I hear, the lighter the wheel and tire package the better your acceleration and handling ,check out some of the topics on un sprung weight
http://www.musclecarclub.com/library/tech/weight.shtml
"An important concept is "unsprung weight." This is weight that is not supported by the suspension of the car. This usually includes the the weight of the wheels and tires as well as a percentage of the weight of the suspension itself, including control arms, anti-roll bars, shocks, and struts. Reducing unsprung weight is the key to improving handling. The lower the unsprung weight, the less work the shocks and springs have to do to keep the tires in contact with the road over bumpy surfaces. An easy way to reduce unsprung weight and improve traction is to replace stock wheels and tires with special lightweight wheels. Note that as the wheel diameter or width increases, the weight of the overall wheel and tire package increases, thereby increasing unsprung weight."
http://en.wikipedia.org/wiki/Unsprung_weight
Unsprung weight is the mass of a vehicle's suspension, wheels, and components directly connected to them rather than supported by the suspension. Unsprung weight includes the mass of components such as the wheel spindles, wheel bearings, tires, and a portion of the weight of driveshafts, springs, shock absorbers, and suspension links. If the vehicle's brakes are mounted outboard (i.e., within the wheel rather than inboard), their weight is also part of the unsprung weight.
The components that comprise a vehicle's unsprung weight are acted on by road shocks and bumps, and therefore the unsprung weight determines the reactive force that any motion of the wheels and suspension exert on the body of vehicle. The smoothness of the ride is closely related to the ratio of unsprung to sprung weight: the higher this ratio, the more severely bumps affect the vehicle.
Unsprung weight also governs the inertia of suspension components, affecting their ability to respond to bumps and changes in direction or road surface. High unsprung weight has a negative effect on overall handling ability, especially on imperfect surfaces.
High unsprung weight also exacerbates wheel control under hard acceleration or braking. If the vehicle does not have adequate wheel location in the vertical plane, such as on a rear-wheel drive car with Hotchkiss drive (a live axle supported by simple leaf springs), the torque exerted by acceleration or hard braking may cause severe wheel hop, compromising traction and steering control.
Unsprung weight is largely a function of the design of a vehicle's suspension and the materials used in the construction of suspension components. Beam axle suspensions, in which wheels on opposite sides are connected as a rigid unit, generally have greater unsprung weight than independent suspension systems, in which the wheels are suspended and allowed to move separately. Mounting heavy components such as the differential directly to the body rather than the suspension (as in a de Dion tube rear suspension) removes some or all of their mass from the unsprung weight, making it instead part of the sprung weight. Lightweight materials, such as aluminum, plastic, carbon fiber, and/or hollow components can provide further weight reductions at the expense of greater cost and/or fragility."
http://www.tirerack.com/wheels/tech/....jsp?techid=98
"Performance Benefits: While many people choose alloy wheels for their beauty, there are equally important performance benefits to be derived including...
Reduced Unsprung Weight Compared to Steel Wheels: This is one of the most critical factors affecting a vehicle's road holding ability. Unsprung weight is that portion of a vehicle that is not supported by the suspension (i.e. wheels, tires and brakes) and therefore most susceptible to road shock and cornering forces. By reducing unsprung weight, alloy wheels provide more precise steering input and improved "turning in" characteristics.
Improved Acceleration and Braking: By reducing the weight of the vehicle's rotational mass, alloy wheels provide more responsive acceleration and braking.
Added Rigidity: The added strength of a quality alloy wheel can significantly reduce wheel/tire deflection in cornering. This is particularly critical with an automobile equipped with high performance tires where lateral forces may approach 1.0g.
Increased Brake Cooling: The metals in alloy wheels are excellent conductors of heat - improving heat dissipation from the brakes - reducing risk of brake fade under demanding conditions. Additionally, alloy wheels can be designed to allow more cooling air to flow over the brakes.
The gentleman above was alluding to the fact that the car goes faster with lowwer unsprung weight. It doesn't, unless you want to factor in the couple of pounds difference per tire -- I don't think that 8 lbs. less total vehicle weight will increase your top speed significantly.
Yes, it may accelerate slightly faster, but don't confuse acceleration with speed (see www.newtonfordummies.com).
The best benefit of less unsprung weight is an imporvement in handling, not top speed.
Le Mans Master
Joined: Sep 2004
Posts: 7,027
Likes: 6
From: Shiloh Ohio
Now that is a lot of reading. I started to read it but my attention span is a little short. I can tell you something and save my time reading all that. If they say heavier un sprung weight does not slow a car they are wrong.
Race Director
Joined: May 2000
Posts: 14,542
Likes: 5
Originally Posted by shurite44
Now that is a lot of reading. I started to read it but my attention span is a little short. I can tell you something and save my time reading all that. If they say heavier un sprung weight does not slow a car they are wrong.
Cheerio!
Le Mans Master
Joined: Sep 2004
Posts: 7,027
Likes: 6
From: Shiloh Ohio
Originally Posted by skip89
So, does anyone know if Good Year will expand their sizes of the new lighter Supercar runflats? Right now, I think they only make 4 sizes. None are in the 17 & 18 inch standard 04 ZO6 sizes.
I am with you though, it would be great if they did. Not only Z06's could run them but C5 guy's who want to go wider could stick with runflats.
Safety Car
Joined: Jul 2005
Posts: 3,572
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From: Jackson Tn
St. Jude Donor '06-'07-'08-'09
EHS,
I never said the lighter spinning weight would add top speed but I said it would make the car faster..... if you are drag racing you will accelerate faster, if your on a road corse your will turn faster times around the track, yes because of better handeling and faster acceleration. So, are you not going faster if your times are lower?
I think we just have a misunderstanding here with the english language in the meaning of the word (faster)
Nice reading what you posted!
sorry skip89, didn't mean to hi-jack your thread.
I never said the lighter spinning weight would add top speed but I said it would make the car faster..... if you are drag racing you will accelerate faster, if your on a road corse your will turn faster times around the track, yes because of better handeling and faster acceleration. So, are you not going faster if your times are lower?
I think we just have a misunderstanding here with the english language in the meaning of the word (faster)
Nice reading what you posted!
sorry skip89, didn't mean to hi-jack your thread.
Last edited by vintage driver; Nov 26, 2005 at 07:39 PM.