Sp00led Ya

What the hell is rev matching, and is it a must when driving stick? I consider myself a very good driver and alway thought that as long as when going through the gears even with agressive driving as long as you werent getting a jolt from the gear change and accelerator application that it was done right, could I have been wrong all along?

3240

No, rev matching is not required.

WestSideBilly

iTrader: (1)

Moved to appropriate forum.

Danno

iTrader: (4)

Rev matching is exactly what it sounds like, you blip the throtal when shifting down a gear so you match the RPM going into the gear that it will be at when you let the clutch out.

racerjon1

Danno is right, that is what it is, and no it isn't "required" in all cases. For racing/high performance driving, it is certainly recommended though. Here is why:

When you push the clutch in to downshift your engine slows down, but your wheels/gears/etc.. keep moving at whatever speed you are going. When you let the clutch out for the next selected gear the engine is at idle, and then in an instant you are trying to make it run high RPMs. The shock will lock up the wheels causing a nasty little corner-entry twitch, which may result in a spin. By "rev-matching" which is keeping the revs up while the clutch is in, you decrease the chance of that happening.

So.. it makes for smoother gearshifts that make the car more stable, and is easier on the equipment.

I am going to guess since this was moved from some other forum, that the person was asking about doing this during street driving.. You shouldn't be driving hard enough on the street to need it (obligatory public service announcement) but.. This is one of those racing things that can be practiced on the street, (along with heel-toe) without doing any more damage than drinking a little extra gas.

Jon K

j3ffw19

iTrader: (3)

revmatching will make downshifting easier, my car seems to be happy. just shift to a lower gear before you let the clutch out blip the throttle alittle bit and then release. since the rpms are up there the trans doesn't have the speed up the motor, just seems easier on the trans and clutch.

Sp00led Ya

Ok well it pretty much is tapping the throttle after you downshifted and then just let the clutch out? How much of a blip? Doesn't it make the shift time alot longer because it now went from, gear change/clutch release... to gear change/blip/clutch release... and what if you blip TOO much. I know if I saw someone driving and then heard a rev in between gears I'd think they didn't know how to drive.

siantjab

iTrader: (2)

You want to blip the throttle enough to bring the RPMs up to where they would be in the lower gear at the current speed. So, if you are going say 40 MPH, and you want to down shift to 3rd gear, you give the throttle a little stab with your foot bringing the RPMs up to about ~3K - 3.5K, so that when you let the clutch out the car won't jerk or lurch at all. You get used to what speeds are where in what gear from driving; this is just an example of what to do. Once you learn it you won't even need to look at the tach; you'll just "feel" where it needs to be.

Now, if you are doing the same thing, and you rev to say ~5K and let the clutch out, you will get a push back as the engine is slowed to match the speed of the car. Sort of like dumping the clutch on a launch; only while moving. It's not a desirable situation, but neither is having the RPMs at only 1K on that shift. You really have to get the feel for your car; it's about practice.

Oh, and you are not reving between gears, you are simply matching the speed of the engine to the speed of the tires. If the proper rev speed is attained the car will shift as smooth as an automatic. You won't look foolish unless you do it wrong. Now, in the same situation, if you didn't rev match into a corner, you'd look really silly when you spin out from the lurch of the car being dropped a gear and not rev matched.

Good luck and practice.

j3ffw19

iTrader: (3)

^ true. trust me your car will thank you

Assassin

iTrader: (4)

I rev match all the time. I hate the jerk of downshifting without rev matching. feels like it hurts the car and strains it more if I don't.

Ludikraut

iTrader: (17)

Rev matching wasn't much of an issue for me on the stock clutch, but with the much grabbier Exedy Twin Metallic, I rev match all the time now ... even when putzing around town. Once you get into the habit it becomes second nature.

l8r)

marksae

iTrader: (12)

Changing to a brake pad w/ more initial bite can throw heel/toe downshift timing off. Changing shoes can also throw my timing off.

spdrcr456

iTrader: (7)

i drive a simi truck and u have to rev mach in order to downshift at all.if u dont u will never get it down into the next lower gear. it will just grind like crazy. that is due to not having syncros in the tranny so u are actually meshing two gears or more spinning at diferent gears.
u dont have that problem in ur car because that is why syncros were invented but like everyone else has already said, U dont have to rev match but it makes it much smoother and eisier on components. just dont do it coming up on stopped traffic quickly if u are new and just learning how. u dont wanna rev to high and lurch foward and hit them or concentrate so much on reving that u forget about braking. sorry bout the book.

Tonz of fun

iTrader: (3)

Then when you get good at that you can use downshifting to slow your car down when going a 120 on freeway off ramps. Then your breaks will thank you.

Sp00led Ya

So when you downshift you just blip the throttle and hope its the right RPM , or just blipping to get it SOMEWHERE in the range is good enough to be rev matching? I have no clue what rpm to hit when down shifting, there are so many different mph and 5-6 gears, I know what MPH I should be in for what gear but I cant predict what RPM im going to be at when I shift it