The other night my friend and I were talking about why is double clutching necessary, when rev matching seems like the exact same thing but easier? After some research and test driving, we got a solid answer and I wanted to share it with you guys in case anybody else had the same question
Rev Matching
What is it?
Rev matching, or revolution matching, is when you bring up the RPM's of your car to "match" the next gear you are downshifting to. There are many reasons and benefits to doing this; mainly, it will allow you to shift into gear without any hesitation or jolting. It also reduce the strain on your transmission if done correctly.
The reasoning behind rev matching is that the current gear the engine is on will not be spinning fast enough to seamlessly switch to a lower gear. By increasing the RPM's beforehand, you will allow the engine to switch to the lower faster moving gear easily. If done correctly you will feel no jolt or hesitation and can accelerate much more easily.
When do I use it?
Typically, rev matching is used for two occasions. The first application is when you need to downshift without slowing down for a quick acceleration. The second is when coasting, and you need to get back in gear to add speed again. Simply match the RPM's to whatever gear you need to be in, and re-engage said gear.
Of course, there are other uses to rev matching. These were just two situations that I thought of that are the most practical.
How do I do it?
It's simple once you get the hang of it. When driving, hold in the clutch, apply gas to raise RPM's to desired level, downshift to lower gear, release clutch, enjoy. The tricky part is getting the RPM's to the correct level, but it really is quite easy.
Double Clutching
What is it?
Double clutching has the same principles and reasoning as rev matching. However, it is different in few ways. Double clutching is used only for huge accelerations, and in this aspect should only be applied for racing.
A double clutch is when you want skip one or two gears to downshift quickly, and increase your engine RPM's drastically to allow a seamless shift between 5th and 3rd, for example.
When do I use it?
Let's say you're on the highway, and some asshole decides he wants to race you with his rice machine. You're cruising in 5th (or 6th for you speeds out there), and decide to double clutch back to 3rd so you can have a massive acceleration as you will be into the 6k powerband area.
How do I do it?
Double clutching is just a tiny bit more difficult than rev matching. When driving, you engage clutch, shift to neutral, release clutch, apply gas, engage clutch, shift into desired gear, release clutch. This is where the name "double clutch" is derived from, as you end up engaging the clutch pedal twice quickly.
Double Clutching vs. Rev Matching
After realizing the difference between the two methods, I wondered why it was necessary to shift to neutral for double clutching. Why is that extra step needed, when you can just hold down the clutch?
There are two reasons for this. First, when in neutral, the engine can accelerate at a more rapid pace. If this confuses you, think of it this way. When backing up in reverse and you hold the clutch in, you can still hear the gear winding up. This is because the gear is still set in place, but holding the clutch down makes the engine act as if it is in neutral because it is not connected. When you shift to neutral, no gear is engaged which allows it to increase RPM's at a much faster rate.
The second reason is to save the synchros and clutch from being worn out more rapidly. When rev matching, no damage is made from changing the RPM's up by 400-1,000 while holding the clutch in, assuming you're driving at regular speeds. But when double clutching, you are increasing RPM's by more than 2,500 rapidly, which can cause a strain on your clutch and transmission if you are still in gear.
Conclusion
There is the main difference between the two shifting styles. In short: use rev matching when downshifting only one gear, use double clutching if downshifting more than one gear. If anyone has anymore knowledge to add, feel free. Hope this cleared up the difference for those of you who didn't know.
Rev Matching
What is it?
Rev matching, or revolution matching, is when you bring up the RPM's of your car to "match" the next gear you are downshifting to. There are many reasons and benefits to doing this; mainly, it will allow you to shift into gear without any hesitation or jolting. It also reduce the strain on your transmission if done correctly.
The reasoning behind rev matching is that the current gear the engine is on will not be spinning fast enough to seamlessly switch to a lower gear. By increasing the RPM's beforehand, you will allow the engine to switch to the lower faster moving gear easily. If done correctly you will feel no jolt or hesitation and can accelerate much more easily.
When do I use it?
Typically, rev matching is used for two occasions. The first application is when you need to downshift without slowing down for a quick acceleration. The second is when coasting, and you need to get back in gear to add speed again. Simply match the RPM's to whatever gear you need to be in, and re-engage said gear.
Of course, there are other uses to rev matching. These were just two situations that I thought of that are the most practical.
How do I do it?
It's simple once you get the hang of it. When driving, hold in the clutch, apply gas to raise RPM's to desired level, downshift to lower gear, release clutch, enjoy. The tricky part is getting the RPM's to the correct level, but it really is quite easy.
Double Clutching
What is it?
Double clutching has the same principles and reasoning as rev matching. However, it is different in few ways. Double clutching is used only for huge accelerations, and in this aspect should only be applied for racing.
A double clutch is when you want skip one or two gears to downshift quickly, and increase your engine RPM's drastically to allow a seamless shift between 5th and 3rd, for example.
When do I use it?
Let's say you're on the highway, and some asshole decides he wants to race you with his rice machine. You're cruising in 5th (or 6th for you speeds out there), and decide to double clutch back to 3rd so you can have a massive acceleration as you will be into the 6k powerband area.
How do I do it?
Double clutching is just a tiny bit more difficult than rev matching. When driving, you engage clutch, shift to neutral, release clutch, apply gas, engage clutch, shift into desired gear, release clutch. This is where the name "double clutch" is derived from, as you end up engaging the clutch pedal twice quickly.
Double Clutching vs. Rev Matching
After realizing the difference between the two methods, I wondered why it was necessary to shift to neutral for double clutching. Why is that extra step needed, when you can just hold down the clutch?
There are two reasons for this. First, when in neutral, the engine can accelerate at a more rapid pace. If this confuses you, think of it this way. When backing up in reverse and you hold the clutch in, you can still hear the gear winding up. This is because the gear is still set in place, but holding the clutch down makes the engine act as if it is in neutral because it is not connected. When you shift to neutral, no gear is engaged which allows it to increase RPM's at a much faster rate.
The second reason is to save the synchros and clutch from being worn out more rapidly. When rev matching, no damage is made from changing the RPM's up by 400-1,000 while holding the clutch in, assuming you're driving at regular speeds. But when double clutching, you are increasing RPM's by more than 2,500 rapidly, which can cause a strain on your clutch and transmission if you are still in gear.
Conclusion
There is the main difference between the two shifting styles. In short: use rev matching when downshifting only one gear, use double clutching if downshifting more than one gear. If anyone has anymore knowledge to add, feel free. Hope this cleared up the difference for those of you who didn't know.