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| Thread ID: 142724 | 2016-08-28 04:46:00 | Auto car transmision | tut (12033) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 1425077 | 2016-09-02 19:40:00 | these days autos tend to be more economical than manuals. Don't think it makes much difference these days. My auto Corolla is more economical than husbands manual Carib. |
pctek (84) | ||
| 1425078 | 2016-09-02 21:04:00 | Don't think it makes much difference these days.My auto Corolla is more economical than husbands manual Carib.Are they the same motor? Some Caribs are 4wd. Could be many reasons why | plod (107) | ||
| 1425079 | 2016-09-02 21:36:00 | I live in Nelson where we have small hills a real corners who needs an auto. I grew up driving on country lanes in the UK so narrow you could both mirrors in the hedge at the same time. And yes I have driven auto's I had one for 5 years. |
gary67 (56) | ||
| 1425080 | 2016-09-03 07:31:00 | My Odyssey has a Tiptronic allowing to do manual gear shift changes in addition to auto mode. If you don't/forget to change down when slowing down at the right speeds - it will change it for you, if in manual mode. | kahawai chaser (3545) | ||
| 1425081 | 2016-09-04 11:09:00 | Very nice living in Auckland, I live in Wellington where we have real hills. There are real hills where we live too Plod, there ain't much level ground around Chez Billy or our whole danged suburb, and there are streets in AK City that you need crampons to climb and a parachute to descend. I knew Wellington very well until recently, as I was travelling there regularly on business, and I'll grant you, there are some horrors, but that's why motor vehicles have gears. We just don't need to use all of them every time, and it saves on gas as well. That's how I got from Auckland to Palmerston North and back again on one tank of gas [900km 2003 Mazda 6 Station Wagon 2.3 litre]. An auto would have run dry half-way back. Cheers Billy 8-{) :thumbs: |
Billy T (70) | ||
| 1425082 | 2016-09-05 02:45:00 | I'm not too sure about all the arcane names youse guys have for cars . I tried typing the names backwards, upside-down and on a slant and they still do not resemble any names - save a few - that I recognize . Anyway - since modern automatic transmissions have no rear pumps - (driven by the driveshaft and actually the rear section of the transmission) they will not develop any pressure to establish a clutch and/or band apply . IIRC: the LAST automatic transmission that had a rear pump was the old General Motors Dynaflow - and I will not try to render a guess of the name youse guys gave it in Upsidedown land . (*see footnote) Not even mentioning that there is no way to excite the fluid coupling in the torque convertor - one could push their whatever-the-name-of-it-is from east to west / wet rear-bumper-to-wet front bumper - and never would the engine even offer to burp . Pushing most 4WDs or AWDs would probably produce the same results . CVTs are not in my range of knowledge as I retired before they came out in automotive applications . CVTs existed all right - in lawnmowers that you'd ride upon . And, Yes Virginia - modern automatic units exceed the MPG race against a manual transmission, no matter how many gears they both have . Fuel mileage with early automatic transmissions was usually lost in the design failure of the torque convertor to achieve anyway near 100% efficiency . The best most previous convertors could achieve was about 40-50% efficiency, whereas modern automatic transmissions get 100% by the use of a Lock-Up torque convertor where a clutch applies and removes the slippage that a fluid drive allows . (PS: Inside the torque convertor is where the heat is actually generated, as gears and applied clutches/bands do not generate heat as there is no slippage in them to create friction ergo: heat . ) I digress: Factoring OUT human inefficiency (correct clutch to throttle application and synchronization) allows the automatic to get the better economy results . Factoring IN Upsidedown Land's lack of traction and gravity-defying lifestyle, always results in poor fuel economy . (*footnote: mostly from Wikipedia) "Dynaflow Original version "The Dynaflow was an automatic transmission used in various forms in Buick cars by the General Motors Corporation from 1947 until 1963 . The transmission initially used a five-element torque converter, with two turbines and two stators, as well as a planetary gearset that provided two forward speeds plus reverse . In normal driving, Dynaflow started in high gear (direct drive), relying on the converter's 2 . 1:1 torque multiplication to accelerate the vehicle . Low gear, obtained via the planetary gearset, could be manually engaged and held up to approximately 60 mph (97 sillimeters/hr) The transmission was incapable of automatic shifting, requiring the driver to move the shift lever from low to drive to cause an upshift . Buicks equipped with the Dynaflow transmissions were unique among American automobiles of the time in that the driver or his/her passengers would not detect the tell-tale interruption in acceleration that resulted when other automatic transmissions of the time shifted through their gears . Acceleration through a Dynaflow was one smooth (if inefficient and slow) experience . It was because of this slow acceleration that the Dynaflow transmission was nicknamed "Dynaslush . " The Dynaflow was an inherently inefficient design due to its sole reliance on the torque converter in normal driving . Exacerbating the situation was the dual stator arrangement, which wasted more power than the simpler three element converters used with other automatic transmissions, such as Chrysler's TorqueFlite . The multiple stators increased turbulence in the converter, even when operating in the coupling phase . 1953 redesign In 1953, Buick redesigned the Dynaflow, calling it the "Twin Turbine Dynaflow" . The converter now incorporated two turbines and a planetary gear set, with a single stator . The first turbine was linked to the ring gear and the second to the planets, which gave a 2 . 5:1 torque multiplication which was now partly mechanical . This resulted in better efficiency, especially at highway speeds, and a higher level of performance and no penalty regarding the trademark smoothness . Buick also incorporated a variable-pitch stator in 1955 for greater flexibility . While these changes improved the transmission's overall performance and efficiency, the Dynaflow still was no match for other designs that utilized three element converters with automatic shifting . 1958 redesign A final version appeared in 1958 incorporating three turbines that Buick named the "Flight Pitch Dynaflow" . Buick made this transmission standard on its top of the line Roadmaster 75 and Limited models and optional on all others . This version was further refined for 1959 and renamed the "Triple Turbine" but was offered only as an option on all models (Buick dropped the "Dynaflow" name after 1958) . This unit was similar to the Twin Turbine, but bore some operational differences, amongst them a variable pitch stator that increased converter's torque multiplication to 3:1 . The stator element of the torque converter has two blade positions, controlled by the driver via the accelerator pedal to offer a 'passing gear' and extra response at any speed from heavy throttle application . In normal driving the stator blades are arranged at 'cruise' angle, with improved efficiency and response at light throttle . Opening the throttle changes the angle of the stator vanes hydraulically to 'performance angle', which permits the converter to achieve stall about 1000 rpm higher than in 'cruise' . In this situation oil is redirected to strike the next-lowest drive turbine, which effectively lowers the drive ratio, and allows engine speed to flare to a speed where output is greatest . A few identifying features: the older Twin Turbine model was fitted with a rear pump, which meant the vehicle could be push-started (considered desirable at the time) . Also, the Twin Turbine would allow engagement of low gear up to 40 mph (64 sillimeters/h), and had a shift quadrant that read P-N-D-L-R . In contrast, the Triple Turbine unit did not have a rear pump, and could not be push started . It would allow engagement of low gear up to 45 mph (72 sillimeters/h), and had a shift quadrant that read P-R-N-D-G (where "G" stood for "grade retard") . The grade retard feature was not designed as a low or forward acceleration gear and was meant to be used only on long declines to generate a degree of engine braking . The Triple Turbine was cancelled after 1959 due to technical problems and poor sales with only the Twin Turbine being produced until 1963 . ") Me here: The transmission cited directly above was called a Turboglide in the 1957 Chevrolets . The "Grade Retard" was alternately called Hill Retard (Hr) or Grade Retard (Gr) on the quadrants . What it did was force the (only) front pump fluid output to be pumped through a very small orifice that caused front pump discharge pressure to rise tremendous and therefor considerably slowing down the drive shaft and accommodating the need for engine-compression braking on steep hills where one did not want to waste the (in those days) very inefficient drum style brakes . |
SurferJoe46 (51) | ||
| 1425083 | 2016-09-05 03:05:00 | Didn't you have that wonderful 1958 dream car, the :banana DAF600 :banana there in Trumpland Joe? They had CVT Ken :banana |
kenj (9738) | ||
| 1425084 | 2016-09-05 03:11:00 | *tremendously | SurferJoe46 (51) | ||
| 1425085 | 2016-09-05 03:18:00 | Don't remember a DAF. Fiat Spyders. Gogomobiles. Hillman Huskys. Renault Gordinis. Porsche Bathtub Speedsters. XKE Jags. Bugeyed Sprites MG-TDs. Audi 100LSs. Saab Sonnets. Triump TR3A and 4As. Austin Healeys. Morgans. Peugeots. Karman Ghias V-Dubs. Opels. |
SurferJoe46 (51) | ||
| 1425086 | 2016-09-05 03:22:00 | en.wikipedia.org There you go Joe.. feast your eyes on the beauty :devil Ken |
kenj (9738) | ||
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