I was wondering how to learn rev-match your car so it can be smooth when down shift? Is this something that you have to learn on your own or there's book for it? Rev-Matching is using heel to toe technique but it's hard to match perfectly rpm. What happended when you over rev or just down shift normally? Is it bad for the car when over rev or down shift normally?

I'll only drove stick car for only about 4 months. Thank You for all your help

 

Rev-matching is dangerous to your health and the environment around. you are literally pressing on the gas for no reason and it reduce about 5 years life of pedestrians aruond

 

give me a break

rev matching is fine. if done correctly it places less stress on your car. there are some write-ups available online, but best way to learn is practice. maybe watch some best motoring videos and get a feel for it. good luck

 

You, sir, are in the wrong car.

Yes, rev-matching is a learned skill. Some people pick it up quickly and naturally. Others take awhile. Its all about training your muscle memory through repetition.

I've beein doing it so long I didn't recall how much practice it took me. Until I started doing heel/toe downshifts. Now its like learning rev-matching all over again.

 

When you are not braking a rev match is quiet easy. Blip the throttle up and let the clutch out in the next gear. When under heavy braking to rev match you need to simultaneously use your braking foot to blip the throttle while maintaining firm pressure on the brake pedal. This second version is called heal-toe and requires more practice than a simple rev match.

After a while of doing it, you'll never decelerate any other way

 

Rev matching doesn't require heel-toe. If you're driving around normally, there is very rarely an occasion where you need to use heel-toe to brake and rev match. And when you come across one, it probably means you're just driving too fast.

With that said, forget about heel-toe for now, and practice blipping the throttle. And that's what it takes -- practice. You need to know approximately how much gas to give at various RPMs. It will be basically the same for each gear, so RPMs is all that matters. You just have to experiment.

The whole idea is to make the engine and clutch spin at the same speed as the tranny so when the clutch is forced to grab onto the tranny, there is no added force on the exchange. If the tranny is spinning faster, or the clutch is spinning faster, you will see greater clutch wear, and added, unnecessary stress on all components in involved in the transaction.

Giving too much gas, not giving enough gas, or giving no gas are more stressful on the drive train than a proper rev-matched down shift. I wouldn't say any of them are "bad", just not as good.

When you down shift with no gas, the tranny will be spinning much faster than the engine and clutch. The clutch is forced to play catchup as it grabs the tranny. This puts unneeded stress on the clutch, and it will wear more rapidly. Not to mention added stress on the syncros, etc.

Shifting with not enough gas is similar to above, but the clutch will be spinning at a speed closer to that of the tranny, so the stress isn't as large.

Giving too much gas is the reverse. The engine and clutch will be spinning faster than the tranny. At the moment when the two touch, the clutch will be required to grab the tranny and make it rotate faster. The force required to do this is greater than if the two were traveling at the same speed, so the clutch can potentially slip a little and cause wear.

 

10 years ago I started by practicing without braking. Start in 4th gear at maybe 3-5K, clutch in and you'll see the revs start to fall so blip the throttle while keeping the clutch down to send the revs higher than when you pushed the clutch in, shift to 3rd and let the clutch out. Start in slow motion and get a feel for the timing involved to engage the lower gear smoothly. Once you get that down really well, try the heel toe method (probably in a big empty lot although I started on back roads) and go from there.

The above method uses the syncros due to the fact that the clutch is held in while engaging the next gear. In racing school, and in the FF2000's I raced you HAD to double clutch for a downshift, or match really well without even touching the clutch (the latter I did very few times as I saw no benefits). This is because there are no syncro rings in the gearbox - they are streight cut with dog rings. I double clutch from time to time in the S2000 on the track for certain turns, something to do with the rythm I'm in or the angle I'm at in the car, and my friend that tracks his S swears by double clutching everyshift...not a bad habbit if you do it right but I tend to think the syncros on modern sports cars are tough enough to take a non DC shift as long as the revs are matched niceley.

 

Thank You to TEKSTAR, TOF, DAKTRUCKIE99 AND VTEC9 for clarification. Sorry to ask one more question what's blipping the throttle to rev-match? Thanks Again.

- Learning Skill

 

You basically tap the gas pedal with you foot to bring your rpms up to where the lower gear would be if you downshifted. Start off in 3rd gear(or whatver gear) and then downshift normally. Take note at what rpm you were at in 3rd gear and then what rpm you are at in 2nd. Find the difference(x) and thats how much you need to rev up to downshift smoothly. Now blip the throttle in 3rd to bring the rpms by x amount and downshift. Practice makes perfect, and youtube doesn't hurt either.

 

blip = a slight tap. So.. you're cruising along and decide to down shift to pass some asshat.

1) disengage the clutch
2) blip the throttle, i.e. press it so the engine's RPMs will be slightly above the level where they will end up when you shift to the lower gear.
3) engage the clutch

For example, you're in 4th at 50mph. The RPMs will be approx 4000. If you were traveling in 3rd at that moment instead of 4th, the RPMs would be approx 5100. So, to rev match in this instance on a downshift from 4th to 3rd, you need to blip the throttle to above 5100 rpms, then engage the clutch. When this is done, the engine, clutch, and tranny will all be spinning at the same speed when they touch (5100 rpms). You need to go a tad over 5100 on the blip because time will pass between you letting off the throttle, and the clutch engaging, and the RPMs will drop back down again during that break. So, rev to 5500 RPMs, engage the clutch, and by the time it catches, the RPMs should be right around 5100 and you have completed a smooth rev-matched downshift.