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SVT Shelby GT500
Standing mile or 200mph people... What tires do you use or recommend?
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<blockquote data-quote="Bad Company" data-source="post: 15677964" data-attributes="member: 141815"><p>I'm not sure how to post this without the post seeming to be argumentative with you Van. Its not meant to be construed in this manner. I want it to be informative for members to understand the gearing differences. I've thought about how to post without coming off as combative or putting you down. This is the only way I can explain it</p><p></p><p>In the heavy truck world all trucks must pass a engineering review after the new owner specifies the option combination of the new truck he ordered. One of the things that must be reviewed is what is called in the industry is the start-ability or grade-ability factor in percent. What this comes down to is how the truck is being built for versus the driveline components specified(transmission & rear axle ratio) for the working being performed and whether the truck will be able to pull off from a stop in those specified conditions. Example would be a heavy dump truck(80K Lbs) that works off-road(soft soil conditions) versus a tractor trailer that never leaves the asphalt while never going over a gross weight of 50K lbs. What they do is look at what the first gear ratio of the transmission and multiply it by the rear axle ration, along with the torque output of the engine at idle versus the specified working conditions of the truck. They want the new owner to be able to start from a stop in whatever adverse conditions he plans on working the vehicle in without slipping the clutch or shock loading the drivelive by dumping the clutch above engine idle to start moving the truck.</p><p></p><p>Until 2013 all prior GT500 6 speed transmissions have a 2.96 gear ratio in first gear. The 13/14 MY cars have a 2.66 first gear ratio 6 speed transmission</p><p></p><p>Now lets do a little math to see the actual torque multiplication of the rear axle and transmission ratio combined in first gear</p><p></p><p>2.97 first gear x 2.73 rear axle ration = 8.1081 combined final gear ratio multiplication factor</p><p></p><p>2.66 first gear x 2.73 rear axle ration = 7.2618 combined final gear ratio multiplication factor</p><p></p><p>Since the 3.31 gear is a fast gear for these cars and is stock in the 13/14 MY cars we will use it next</p><p></p><p>2.97 first gear x 3.31 rear axle ratio = 9.8307 combined final gear ratio multiplication factor</p><p></p><p>2.66 first gear x 3.31 rear axle ratio = 8.8046 combined final gear ratio multiplication factor</p><p></p><p>now lets try a 3.15 rear axle ration</p><p></p><p>2.97 first gear ratio x 3.15 rear axle ratio = 9.3555 combined final gear ratio multiplication factor</p><p></p><p>2.66 first gear ratio x 3.15 rear axle ratio = 8.379 combined final gear ratio multiplication factor</p><p></p><p>how about a 3.08 rear axle ratio</p><p></p><p>2.97 first gear x 3.08 rear axle ratio = 9.1476 combined final gear ratio multiplication factor</p><p></p><p>2.66 first gear x 3.08 rear axle ration = 8.1928 combined final gear ratio multiplication factor</p><p></p><p>These comments are meant for everybody to read and comprehend......not for me to argue a point with Van. Everyone thinking of doing a dedicated mile or 1/2 mile car needs to understand what I'm writing if you plan on doing a gear change for top speed, plus driving the car on the street. You may also want to consider if you live in a hilly area where you need to pull off from a stop on a steep grade while tooling around in the car. The first gear of the transmission has as much factor when you look at the math calculations to starting from a stop as the rear axle ratio it is combined with.</p><p></p><p>As can be seen by doing a little math there are big differences in whether a car will pull off from a standing start more easily than another with different combinations of transmissions and rear axle ratios. Engine torque is always multiplied by each gear ratio it passes through before being applied to the road surface. You can also see that a car with a 13/14 MY transmission or a 2.66 first gear Magnum XL that these cars will be much harder to start from a static position compared to a car with an earlier transmission on the street with the exact same rear axle ratio. In fact the earlier 2.97 first gear transmission has a higher torque multiple combination with a 3.08 rear axle than the stock 13/14 MY car with a 3.31 gear ratio. The 2.73 gear ratio with a 2.96 first gear ratio will finally drop below the start-ability of a stock 13/14 MY car.</p><p></p><p>For drive-ability the combination of parts makes the sum of the whole and how a car responds to pulling off in first gear of the transmission. This is something nobody ever thinks about. The other thing is not only is first gear ratio different, but the other ratios are slightly different as you go up through the gear box. I believe there are 3 different 5th gear ratios depending on the MY of the transmission. So my point is for you the reader to consider the sum of the parts to make a decision about modifying the car for a dual purpose application.</p></blockquote><p></p>
[QUOTE="Bad Company, post: 15677964, member: 141815"] I'm not sure how to post this without the post seeming to be argumentative with you Van. Its not meant to be construed in this manner. I want it to be informative for members to understand the gearing differences. I've thought about how to post without coming off as combative or putting you down. This is the only way I can explain it In the heavy truck world all trucks must pass a engineering review after the new owner specifies the option combination of the new truck he ordered. One of the things that must be reviewed is what is called in the industry is the start-ability or grade-ability factor in percent. What this comes down to is how the truck is being built for versus the driveline components specified(transmission & rear axle ratio) for the working being performed and whether the truck will be able to pull off from a stop in those specified conditions. Example would be a heavy dump truck(80K Lbs) that works off-road(soft soil conditions) versus a tractor trailer that never leaves the asphalt while never going over a gross weight of 50K lbs. What they do is look at what the first gear ratio of the transmission and multiply it by the rear axle ration, along with the torque output of the engine at idle versus the specified working conditions of the truck. They want the new owner to be able to start from a stop in whatever adverse conditions he plans on working the vehicle in without slipping the clutch or shock loading the drivelive by dumping the clutch above engine idle to start moving the truck. Until 2013 all prior GT500 6 speed transmissions have a 2.96 gear ratio in first gear. The 13/14 MY cars have a 2.66 first gear ratio 6 speed transmission Now lets do a little math to see the actual torque multiplication of the rear axle and transmission ratio combined in first gear 2.97 first gear x 2.73 rear axle ration = 8.1081 combined final gear ratio multiplication factor 2.66 first gear x 2.73 rear axle ration = 7.2618 combined final gear ratio multiplication factor Since the 3.31 gear is a fast gear for these cars and is stock in the 13/14 MY cars we will use it next 2.97 first gear x 3.31 rear axle ratio = 9.8307 combined final gear ratio multiplication factor 2.66 first gear x 3.31 rear axle ratio = 8.8046 combined final gear ratio multiplication factor now lets try a 3.15 rear axle ration 2.97 first gear ratio x 3.15 rear axle ratio = 9.3555 combined final gear ratio multiplication factor 2.66 first gear ratio x 3.15 rear axle ratio = 8.379 combined final gear ratio multiplication factor how about a 3.08 rear axle ratio 2.97 first gear x 3.08 rear axle ratio = 9.1476 combined final gear ratio multiplication factor 2.66 first gear x 3.08 rear axle ration = 8.1928 combined final gear ratio multiplication factor These comments are meant for everybody to read and comprehend......not for me to argue a point with Van. Everyone thinking of doing a dedicated mile or 1/2 mile car needs to understand what I'm writing if you plan on doing a gear change for top speed, plus driving the car on the street. You may also want to consider if you live in a hilly area where you need to pull off from a stop on a steep grade while tooling around in the car. The first gear of the transmission has as much factor when you look at the math calculations to starting from a stop as the rear axle ratio it is combined with. As can be seen by doing a little math there are big differences in whether a car will pull off from a standing start more easily than another with different combinations of transmissions and rear axle ratios. Engine torque is always multiplied by each gear ratio it passes through before being applied to the road surface. You can also see that a car with a 13/14 MY transmission or a 2.66 first gear Magnum XL that these cars will be much harder to start from a static position compared to a car with an earlier transmission on the street with the exact same rear axle ratio. In fact the earlier 2.97 first gear transmission has a higher torque multiple combination with a 3.08 rear axle than the stock 13/14 MY car with a 3.31 gear ratio. The 2.73 gear ratio with a 2.96 first gear ratio will finally drop below the start-ability of a stock 13/14 MY car. For drive-ability the combination of parts makes the sum of the whole and how a car responds to pulling off in first gear of the transmission. This is something nobody ever thinks about. The other thing is not only is first gear ratio different, but the other ratios are slightly different as you go up through the gear box. I believe there are 3 different 5th gear ratios depending on the MY of the transmission. So my point is for you the reader to consider the sum of the parts to make a decision about modifying the car for a dual purpose application. [/QUOTE]
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Standing mile or 200mph people... What tires do you use or recommend?
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