Quote:
Originally Posted by Abraxix
i'm going to ask!
most have mentioned i like to be in control of the car in a manual... how does having a manual transmission give you more control over the car? is it not you have more control over power of the vechicle, you still need to steer the car just as an auto driver would.
can someone explain this sence of i have more control in a manual ?
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There's more control in a manual because the power/torque going out of a manual box (i.e to the diffs/wheels) is directly related to the power coming in (i.e. from the engine). The only thing that alters the power passing through is the gear ratios themselves, but they are all gear wheels and the teeth just lock into each other. In other words, the input shaft of a manual box is 'locked' with the output shaft of the box.
What that means for the driver is that every adjustment to the throttle has a direct affect on the what the wheels are doing (obviously within reason i.e. flooring it in 6th gear at 60kmh isn't really going to do much for road speed in most vehicles..). This works in accel and deccel (putting the throttle down, or lifting off). As a driver you can use the entire rev range of the engine in whatever way you like (to drive fast, launch from a stop, change lanes, compression braking, etc). As a driver you can anticipate a move (say a lane change) and you can select the appropriate gear which will put the engine at its optimum rpm (i.e. producing good torque) before pulling out and overtaking.
A auto box is much more complicated than a manual with a lot of slipping parts or friction parts inside like clutches etc. The only time the input shaft and the output shaft are directly related to each other is when the torque converter (TCV) locks up. This usually occurs in top gear at light load. On your WJ this happens in 5th at approx 76kmh when cruising (or 3rd when over drive is off at approx 50kmh when cruising). But if you jump on the throttle again to overtake for example or to hold speed up a big enough hill, the TCV will unlock to allow the engine revs to rise and give you the power reqd to get the job done (with possible downshift if necessary).
The TCV is basically there to do the job of a clutch in a manual vehicle when taking off and when stationary, and the clutches inside the box are there to do the job of a clutch in a manual vehicle when changing gears.
Most auto boxes from the factory are designed to shift smoothly and provide a luxurious ride, which requires the clutches to slip. The TCV has stages of engagement for example when stationary its maybe 10%-20% engaged where only a little amount of power is transmitted to the rest of the box, then when rpms reach the 'stall speed' of the TCV at usually 1,500-2,500 rpm (depending on vehicle and petrol or diesel, etc) the TCV will begin to engage at anywhere up to 75%-85% (not exact figures, every auto is different) and allow this amount of power to transfer to the auto box (and this usually happens smoothly, not suddenly), then there's the full lock up at 100% in top gear at light load. The TCV also goes back to its first level of engagement (approx 10-20%) when ever you lift off the throttle completely as well, therefore engine braking capabilities will never be as good as a manual. Offroad this means that a auto 4wd can try to 'run away (rpms increase and therefore vehicle speed increases as opposed to holding and maintaining vehicle speed)' as you are trying to descend at a controlled pace without applying the brakes (there is absolutely no match in this area for a proper manual and clutch).
For the driver this means that the auto box does everything 'automatically' (lol). The downside is that auto boxes aren't very good at reading minds and therefore sometimes they don't shift when we want it to, or they're not in the gear we want at that particular time, or they take too long to get into the right gear we want. If you are literally just going to potter around and cruise and not ever be in a hurry to get anywhere, then the auto will be perfect as they can just go through their motions and no one will have an issue. Obviously some stock auto's are better than others, I will admit that the 545RFE in our WJ's (I know they are in many other Jeeps as well) is pretty responsive, which for me is tolerable. Also auto boxes built in the aftermarket can be built with parts and programmed to make them do whatever you want it to (i.e. shift faster than lightning, adj rpm shift points, 100% manual shifting, whatever stall speed you want etc), but then they're usually only good for the purpose they've been built for.
Manual boxes allow the driver to drive however they want, aggressive, fast, etc (provided the clutch itself is up to the task) or just slip the clutch a little and drive slow and smooth, all the while providing a 100% direct connection between the throttle position and the wheels.
Autos can feel like there's an elastic band between the throttle and the wheels due to the slippage etc that occurs inside the auto box. Plus all the time that a auto box is doing its thing (i.e. changing gears, etc) and the clutches are slipping, they are producing heat and the friction surfaces are wearing down, meaning that fluid temps need to be watched (i.e. when offroading in sand, when towing, etc) and changed more regularly than a manual. Plus all this slippage is costing horsepower and torque and reducing fuel economy.
Wow that's a long winded answer...
Quote:
Originally Posted by Abraxix
i have both and my jeep i feel i have just as much control over my suzi as i do in the manual suzi... the suzi i can kick in the guts and it's instant power in lower gears, but put the jeep in second (2) with O/D off. and i have the exact same result, i think people may be thinking auto's are useless as you drove one once and left it in (d) drive and you didn't have the instant oomph you wanted???
i use the gears in the jeep constantly and i feel very safe and in control? maybe it's just me or maybe i have a magic jeep transmission?
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The higher torque output of v8's and diesels help overcome the laziness of auto's. I guarantee that if you drove a auto version of your Zook that you wouldn't be saying that you can "kick it in the guts and it has instant power" etc.
