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Old 11-23-2007, 06:49 PM
scotchnrocks scotchnrocks is offline
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Join Date: Mar 2006
Posts: 808
Default Re: getting fast cars in automatic....

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I could be wrong, but i believe he's talking about tiptronic transmission, which originated in formula 1, and is now featured in several sports cars.

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To clarify, there are two types of "hybrid" transmissions: those which are essentially automatic transmissions but whose gears can be changed manually (e.g., Porsche Tiptronic), and those which are essentially (clutchless) manual transmissions which can auto-change gears to mimic automatic mode (e.g., BMW SMG). I have owned both types, and they are quite different. The former offers a smooth, automatic-like ride in auto mode, whereas the latter offers all the performance (actually superior) of a clutch manual gearbox.



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Yes, most everything out there with paddle shifters is still a torque converter equipped automatic. The only cars with hydraulic gearboxes are Ferrari, Lamborghini, Maserati, and BMW M cars. These hydraulically assisted gearboxes are usually the same internally as other manual transmissions but the shifting and the clutch is operated with a hydraulic system.

These things are getting very advance. On the M3 with SMG II, it does many things based on input from the engine and it's computer along with the hydraulic systems own accelerometers. For instance on a steep incline you can pull the left paddle back for ~3 seconds and it will slightly disengage the clutch to hold the car on the hill so it doesn't roll backwards. It can do emergency starts where the system detects a sudden flooring of the throttle and quickly engages the clutch, pulsating it several times per second to minimize wheel spin. Also computer controlled rev-matched downshifts. Probably a few more things that I'm forgetting. Also the more accurate control of the clutch via a computer extends the clutch life about 15-20% in my observation.
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