Continuously Variable Transmissions
09-02-2009, 09:27 AM
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Continuously Variable Transmissions Not sure if this is the right place for this, but I was wondering if anyone had ever experimented with CVT transmissions in Fbodies. The reason I ask is because I recently had my first chance to drive a car with a CVT (step fathers 2008 altmia coupe). The whole time I was playing with it, it had amazing throttle response and constantly felt like it was right in the middle of the powerband. Really exceeded what I thought it could do. Anyway back to the question, has anyone tried this in fbodies and how has it performed?
09-02-2009, 05:16 PM
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i remember one of my buddies got one of those dodge caliber suv car thing and it had one in it.Was really neat setup...transmission that is. But anyways back to your question. I am curious about this also. Does gm have these trannies also?if so what are they in?
09-02-2009, 06:28 PM
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Not sure if this is the right place for this, but I was wondering if anyone had ever experimented with CVT transmissions in Fbodies. The reason I ask is because I recently had my first chance to drive a car with a CVT (step fathers 2008 altmia coupe). The whole time I was playing with it, it had amazing throttle response and constantly felt like it was right in the middle of the powerband. Really exceeded what I thought it could do. Anyway back to the question, has anyone tried this in fbodies and how has it performed?
09-02-2009, 10:44 PM
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I have heard that they arent that strong. Can they be built up, or are they pretty much you get what you get? I know a good converter would make it feel the same, but having pretty much one continuous gear was a really cool experience.
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09-02-2009, 11:40 PM
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the way a cvt works is by 2 pullies and a belt
it is the best design cuz of the infinite gear ratios, like a 4 speed auto. you have 1sr gear ratio and 2nd and 3rd and 4th but a cvt has every ratio in between
because of this, at wide open throttle you are always at redline, it never shifts down, its always in the powerband, yeah a car might make 400hp at 6000rpm but it only makes that power for a split second then has to shift, when it shifts it drops to 4000rpm and it only makes 200hp there, and it builds up to 6000rpm and 400hp then shifts again
so yeah a car might make 400hp but only for a split second then it shifts so under wide open throttle its average power would be around 300hp
but if this 400hp car had a cvt it would make 400 the whole time at wide open throttle cuz it would always be at 6000rpm, the gear ratios would consistently change not the rpm
your throttle position is always in the same place as the rpm, if you give a cvt car half throttle then the rpms would consistently be at half rpms and pull, and at full throttle the rpm would be at redline and stay there til you let off, like i said the engine rpm dosent change the infinite gear ratios do
alot of the atv's and 4 wheelers have this technology, some which are auto. have a cvt that has a kevlar belt like the kawasaki brute force 750
those bitches are bad, if you are at a stop and you floor it, the engine goes to redline and stays there the whole time til you let off, it consistently accelerates, i bet that 4 wheeler could hang with a mustang gt in the 1/8th mile
but about building a cvt tranny, well me and a tech at an old shop i used to work at had some drinks and talked over this and wanted to put this tranny in a corvette, but like the nissan altima's they have a steel belt, which is only so strong and to put something in there that is stronger then steel, it wouldnt be flexible enough to rotate circular around the 2 pullies
so basically the only thing people can do is make a steel belt, but it wont hold up to the power and torque of a v-8
it is the best design cuz of the infinite gear ratios, like a 4 speed auto. you have 1sr gear ratio and 2nd and 3rd and 4th but a cvt has every ratio in between
because of this, at wide open throttle you are always at redline, it never shifts down, its always in the powerband, yeah a car might make 400hp at 6000rpm but it only makes that power for a split second then has to shift, when it shifts it drops to 4000rpm and it only makes 200hp there, and it builds up to 6000rpm and 400hp then shifts again
so yeah a car might make 400hp but only for a split second then it shifts so under wide open throttle its average power would be around 300hp
but if this 400hp car had a cvt it would make 400 the whole time at wide open throttle cuz it would always be at 6000rpm, the gear ratios would consistently change not the rpm
your throttle position is always in the same place as the rpm, if you give a cvt car half throttle then the rpms would consistently be at half rpms and pull, and at full throttle the rpm would be at redline and stay there til you let off, like i said the engine rpm dosent change the infinite gear ratios do
alot of the atv's and 4 wheelers have this technology, some which are auto. have a cvt that has a kevlar belt like the kawasaki brute force 750
those bitches are bad, if you are at a stop and you floor it, the engine goes to redline and stays there the whole time til you let off, it consistently accelerates, i bet that 4 wheeler could hang with a mustang gt in the 1/8th mile
but about building a cvt tranny, well me and a tech at an old shop i used to work at had some drinks and talked over this and wanted to put this tranny in a corvette, but like the nissan altima's they have a steel belt, which is only so strong and to put something in there that is stronger then steel, it wouldnt be flexible enough to rotate circular around the 2 pullies
so basically the only thing people can do is make a steel belt, but it wont hold up to the power and torque of a v-8
09-03-2009, 02:10 PM
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Powerglide was just a sloppy converter that -felt-
like one gear. Dynaflow was a true variable torque
converter. I've never even seen hints of a CVT good
for more than a hundred lb-ft (bet the Nissan is no
more than 200 lb-ft motor and would not be at all
surprised if they torque-manage the hell out of it.
A properly selected, low-STR converter will give you
nearly the same feel and not -that- much less efficiency.
like one gear. Dynaflow was a true variable torque
converter. I've never even seen hints of a CVT good
for more than a hundred lb-ft (bet the Nissan is no
more than 200 lb-ft motor and would not be at all
surprised if they torque-manage the hell out of it.
A properly selected, low-STR converter will give you
nearly the same feel and not -that- much less efficiency.
09-05-2009, 12:07 PM
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Ford uses them in a few of their cars.... strange to drive... totally different world. They are weak.... seen a few failures at 75K plus mileage, and hell they are very expensive. Once the reliability gets ironed out, which Im sure it will, they will be a nice unit to have.
