Rev Matching?

[Silver8th]

On another fourm that im not registered at someone said you don't know how to drive manual until you know how to rev match. Can someone please define rev matching for me? I have been driving manual cars for over 10 years and never heard of rev matching. Even in racing school never heard of it.
One other thing I've seen on another forum is people complaining about the rpms staying up for a second when they shift the gears up. When I take my foot off of the gas and push in the cluch my rpms fall immediately. Is this what is suppose to happen? Thanks

[aznkukuboi]

Let's say you are cruising in 5th gear 70 mph at 3.5k rpms and want to pass the guy in the front.
You downshift to 4th gear...

You rev to uhh... 6k rpms and let go clutch.

There you just rev matched.

[Silver8th]

I know that is just an example, but I would never drop the car into 4th doing 70. I still don't get it. Can you explain any further? Thanks

[aznkukuboi]

Okay... when you downshift, don't you ever press on the gas pedal to get to higher rpms? If you don't your passengers will feel the nastiest knockback feeling. Or let's say you are cruising in neutral at 30 mph... and the green light just appears at the street. Don't you clutch, third gear, gas to 3k and let go clutch? Rev matching makes the shifting transaction much smoother. Racers do heel-toe down shifting... which is supposed to be even faster and better.


You've been driving stick for 10 years and don't know what rev matching is?

I've only driven a year and I know what the term means even before someone explaining in to me.


Man I wish I owned a new car. Even though I rev match, all my passengers get the knockback feeling since my car is SOOO OLD.

[webby]

a good example is going around a corner. Say you're in 4th gear and you're coming up on a curve. You basically put in the clutch, put it in 2nd, -blip the gas to raise up the RPMs - release the clutch. Basically you can even match up the exhaust note if you're good. Smooth transitions like aznkukuboi said as well.

Don't listen to someone saying you haven't driven stick till you rev match. Ask them how you've been able to get to work every day for the last 10 years without "rev matching" :rolleyes:

[Janizary]

So that's what I have been doing wrong for the last 25 years...and I wondered about the jerkiness when I was shifting gears...

j/k!!

[Silver8th]

I guess im rev matching and don't even realize it. I know how to drive the heck out of a manual transmission car without tearing the tranny out of it. I had a 95 MT civic for over 10 years and never had to replace the cluch. Thanks for the replys.

[Silver8th]

So rev matching is basicly being in the right rpm range for that gear. Does that make sense? Because I don't get jerky shifts anymore. At first I was until I figured out the DBW and what rpm to shift at so it would't be jerky. Now its cake and every shift to another gear is smooth.

[Fishytron]

most people rev match just they dont know the term. its just a matter of knowing the lingo, same with heel-toe, or double clutching.

[chickennoodles]

Originally Posted by webby

a good example is going around a corner. Say you're in 4th gear and you're coming up on a curve. You basically put in the clutch, put it in 2nd, -blip the gas to raise up the RPMs - release the clutch. Basically you can even match up the exhaust note if you're good. Smooth transitions like aznkukuboi said as well.

Don't listen to someone saying you haven't driven stick till you rev match. Ask them how you've been able to get to work every day for the last 10 years without "rev matching" :rolleyes:

I'm a new MT driver as well and learning on my 06 civic.
I've been driving for 1 week or so now and drive pretty smooth now all except when I slow down for a curve. So back to the scenario, if I'm in 4th and approaching a turn, I usually clutch, shift to 2nd, and brake. After making the turn, I slowly let the clutch out while apply some gas (similar to how I start) and everytime I do this the car jerks a bit. Does this have anythign to do with rev matching? I've tried letting the clutch out at different speeds but still feel some jerkiness.

[BantamSLK]

Originally Posted by chickennoodles

Does this have anythign to do with rev matching? I've tried letting the clutch out at different speeds but still feel some jerkiness.

I think you just haven't found quite the right spot to match yet, keep trying different RPM's and you will find the right one, you're on the right track.

[8thgenuser]

From cached text of Everything2.com via Google:

REV MATCHING is a driving technique for shifting a manual transmission smoothly. One simply memorizes approximately how many RPMs different the various gears are from one another at the same speed, and then matches the engine's revs with the gear they are shifting in to. When upshifting, you just let the revs drop and slip into gear. When downshifting, you tap the throttle (or stomp on it depending on how long it takes to rev up.) This is often referred to as 'blipping' it. This works easily primarily because of the syncromesh gears in your transmission; if your transmission does not have them, this is very, very difficult to do without grinding. Even so, it takes the right touch.

For example, in one car the gears might all be approximately 1,000 RPM apart at the same speed. When downshifting from third to second, for example, you would apply accelerator pressure to raise the engine RPMs by 1,000 (say, from 3,000 to 4,000) and make your shift. You can then use engine braking to reduce your speed.

This practice results in reduced brake wear, less of a lurch when shifting from a higher gear to a lower one, less clutch slippage when shifting from a lower gear to a higher one, and a smoother shift without having to slip the clutch so much.

In auto racing, one often uses the more advanced form of this activity, heel-toeing (Alternately heel-toe braking or heel-toe downshifting) in which one's heel is on the brake pedal, decelerating, while the toe is on the gas pedal, accelerating. This allows the use of both the brakes and the engine to perform braking.

*********
Not sure that that is the correct statement for the heel-toe technique, but whatever. I have included two more good links that show heel-toe downshifting.

Here is a good link for explanation of the heel-toe downshifting technique: http://www.turnfast.com/tech_driving..._heeltoe.shtml

Here is heel-toeing in action (5th Gear video). The heel-toe part comes when she drives the Ariel Atom...past 3/4 the way through the video:
http://www.youtube.com/watch?v=a1RvS9ulUTQ

[twistedframe]

good info, however has anyone else had difficult heel-toe shifting with this car? For some reason i can't seem to get it good, maybe its the pedal placement, b/c I had no problems doing it in any of my other cars.

[ZOE]

Originally Posted by twistedframe

good info, however has anyone else had difficult heel-toe shifting with this car? For some reason i can't seem to get it good, maybe its the pedal placement, b/c I had no problems doing it in any of my other cars.

I am! but its really into second thats pissing me off, like rev matching and heel-toe into second really suxs. i find you have to gas a lot to down gear to second and you just can't seem to get that kinda RPM with jsut a tap, which i do for rev matching/heel-toe. but when i got the car it was difficult to heel-toe for sure! seems the brakes are a lot higher than the gas, and the gas pedal is a little thin. but i've gotten the hang of it (ecpt for second) like the famous quote "practise makes perfect" (who said that anyways?)

[2RotorMotor]

Rev matching also allows you to shift into gear without using the clutch. Revmatching relieves stress on the clutch and syncro.

[2000civic]

while we are on the what is what subject can anybody explain to me what double clutching is? i have never got a good definition and i feel dumb when people talk about it. thanks.

[8thgenuser]

Google and wikis are your friends:
http://en.wikipedia.org/wiki/Double_declutch

[2RotorMotor]

Originally Posted by 2000civic

while we are on the what is what subject can anybody explain to me what double clutching is? i have never got a good definition and i feel dumb when people talk about it. thanks.

There are 2 definitions... There is the real definition and the F&F definition.

the real one is mainly for use when your syncros are bad or non existent. You press the clutch to take it out of gear, and then release the clutch to let the input shaft spin the same as the motor and then press the clutch again to put it in another gear... you press the clutch twice between shifts..

Then the F&F one, is when you are already in gear and press the clutch to raise the revs and release. Supposedly its supposed to help you out, but if you ever race someone, you'll notice that as soon as you press the clutch, the other person will gain on you... The only time I actually do this, is during a roll race. LEts say on a 20mph roll, halfway between the second and third honk, I slam the acc, pop the clutch and release the release the clutch. This should put you in vtec and as far as I can tell, its the si's rolling sweet spot.

[2000civic]

ah thanks for the info. so basically it is just rev matching while accelerating? does this help when if you drive a civic so to say and are drag racing? cause it just was talken about rally racing and big trucks.

[aznives3]

Originally Posted by ZOE

I am! but its really into second thats pissing me off, like rev matching and heel-toe into second really suxs. i find you have to gas a lot to down gear to second and you just can't seem to get that kinda RPM with jsut a tap, which i do for rev matching/heel-toe. but when i got the car it was difficult to heel-toe for sure! seems the brakes are a lot higher than the gas, and the gas pedal is a little thin. but i've gotten the hang of it (ecpt for second) like the famous quote "practise makes perfect" (who said that anyways?)

i noticed that too, the brakes seem alot closer to the driver than the gas so it does take some practise, but after experimenting with it for a while, i heel-toe all the time down into 2nd now, and i realized that "blipping" the throttle doesn't work at all, you have to hold the gas pedal down for a little longer than you would usually to get the revs up to rise...it should solve the trick...

p.s. If you wonder why a short blip of the throttle wont raise the revs much, next time your sitting in your car parked and in neutral, smash the gas pedal to the floor really quickly and let go and do this as fast as you can....the revs will barely get up there!