Need Some Good Explanation About Shifting
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Joined: Nov 2001
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ML
Need Some Good Explanation About Shifting
What really is rev. matched downshifting/upshifting. I believe the idea is to match the engine rev with the tranny rev when shifting but I don't quite get how to do it and what the advantages are, besides extremely smooth shifts. Thanks.
Member
Joined: Dec 2001
Posts: 127
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From: Northern NY
2002 CLK 430 Coupe
Obviously you are speaking about manual transmissions here. Upon downshifting to the next lower gear, blip the throttle to bring the revs up just before you release the clutch. With practice this will become second nature and allow you have the smoothest/jerk free downshifts the car is capable of. What you are doing is bringing the engine rpm up to where the next lower drive ratio will take it to. Practice. practice, practice. When the revs don't match, releasing the clutch creates slip if you let it out slowly - this wears the clutch plate. If you let the clutch out fast, you get a jerk feeling. You can't do this when upshifting because the rpm's drop with the selection of the next higher gear. Something you might try to get an idea of what is happening is (going at slow speeds), put the shifter in neutral, then apply slight pressure on the stick towards the next lower gear while blipping the throttle slightly - all the time NOT using the clutch. You will feel the synchronizers mesh and the next lower gear will slip right in. Just be careful when and if you do this - but it does work.
MBWorld Fanatic!
Joined: Nov 2001
Posts: 1,377
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From: Vancouver Island, B.C. Canada
2005 smart cabrio; 2008 Mercedes-Benz B 200
Rev Matching
Even better than rev matching is double-clutching and double declutching. This means, when shifting up or down (some only do it on downshifts), the clutch pedal is very quickly released when the gear selector is in neutral, during the gearshift. It sounds difficult, but it is not. If done properly, it does not add to the length of the gear shifting operation. It is also better for your gearbox's synchro rings than simple rev matching.
