Rev matching is a technique that is used by all racing and performance drivers when they drive manual cars at high speeds. There are many benefits to using the technique, but it can be tough to master rev matching.
The 5 steps to perfect rev matching are:
- Clutch use
- Throttle blipping
- Changing gear
Rev matching is the first step to learning how to heel and toe like a pro racing driver. There aren’t many steps involved in rev matching, so it’s easy to remember what you need to do, and we go through it all in detail below.
How A Gearbox Works
Let’s say that we have a manual gearbox with five gears. Each gear has an effective operating range of speeds. For example, first gear is used for 0 mph all the way through to 20 mph, second gear is 20 mph through to 40 mph, and so on. Let’s say each gear operates between 1000 rpm and 8000 rpm.
As you accelerate, the crankshaft rotates faster (as the cylinders in the engine move up and down) to the point where you need to change gears. Each gear has a range of optimum efficiency, which is known as the power band. The power band is where the fastest acceleration happens through your rev ranges.
The Power Band
Each gear has a different rpm range in its power band. For example, the power band in first gear might be 1500 rpm to 3000 rpm, then the second gear power band might be 2000 rpm to 3500 rpm, and so on.
Racing drivers try to stay within this power band when on track in order to keep their car running at its optimum speed. When it comes to rev matching, they use this power band within the gear ratios to find the perfect point at which they can get the fastest acceleration in a specific gear. But where does rev matching come into all of this?
Why Should You Use Rev Matching?
Rev matching is an effective way to shift down gears in a manual car (we’ll not discuss using the technique for upshifts here). This is especially useful on a race track, when you need optimum acceleration to set fast lap times. Rev matching can also take some stress off of your clutch, as it will be doing less work in matching your engine speed to the wheels.
Moreover, when rev matching, there will be a much smoother weight transfer when cornering. If you simply change gear and let your foot off your clutch, the car can lurch forward unexpectedly, and that sudden forward movement while braking or cornering can completely upset the balance of the car, making it easy to lose control at critical moments.
Note: You can use rev matching in your road car, but we'll largely be discussing this technique in terms of driving a car on the track
Locking Up Wheels
In some extreme cases, where there is a big discrepancy between your engine speed and the speed of the car, downshifting without rev matching can lead to your rear wheels locking up. This is because your clutch is working overtime trying to match up the speeds, and it is simply not designed to do that.
Finally, rev matching will also help to prevent engine braking. In some cases, engine braking can be useful, but it can put a lot of stress on the engine and other vital components. Rev matching can help to take that element away from downshifts and slowing down your car.
Rev matching is a technique that should become second nature if you want to drive a car fast on the track. It takes some practice to get right, but once you get the hang of it, it becomes somewhat of a habit, like learning how to drive a manual car at first.
How Does Rev Matching Work?
When you are on track and going into a corner, you want to be in the gear that will give you the fastest acceleration out of the exit of the corner. This gear needs to be engaged before you reach the corner, as changing gears during a corner will upset the balance of the car.
Rev matching works by matching the engine speed (rpm) to the speed that the wheels are turning when you release the clutch. This takes a step away from the work that the clutch needs to do.
Blipping The Throttle
You need to ‘blip’ the throttle in order to bring the revs up to match the engine speed to the gear you are selecting. Blipping the throttle is simply opening the throttle a little bit in order to bring the revs up higher. Essentially, you press down the throttle slightly and very quickly lift off again.
This means that the car will be much more stable and the engine will be within the optimum rpm range, allowing for a fast and smooth acceleration out of the corner. Rev matching is a part of the heel and toe technique, which has been used by racing drivers for many years and was made famous in Formula 1 by Ayrton Senna.
KEY POINTS• Rev matching is a useful technique for smoothly changing down the gears
• It’s only used in cars with manual gearboxes
• It can allow for smoother and faster acceleration out of corners
The 5 Steps To Perfect Rev Matching
Rev matching is mostly used to downshift for corners where you will need to accelerate out of them quickly. Imagine you are accelerating down the long main straight in fifth gear. You are approaching your braking point and preparing to enter the corner.
As you approach the corner, you need to brake until you have reached your cornering speed. During braking, your engine speed will drop.
2. Clutch Use
You know you will need to use second gear to get quick acceleration out of the corner. Your car’s speed has now dropped to the point where changing to second is possible, but not yet optimal.
3. Throttle Blipping
While braking in a straight line, press the clutch in to disengage the engine from the wheels. When you do this, the engine speed will drop quickly. Now select second gear.
You have almost reached your turn-in point, you have your foot pressed down on the clutch, and you have changed to second gear, but you’re still in a neutral state with the clutch depressed.
4. Changing Gear
Before lifting your foot off the clutch, you need to bring your engine revs up to where they would ideally be if you engaged second gear. You do this by ‘blipping’ the throttle in order to rev the engine. You don’t necessarily do this to a specific rpm number, but rather a rough range that you’ll learn with practice and getting a feel for the car.
This will allow you to ‘catch’ your revs and immediately start accelerating, rather than slowly releasing the clutch to try and match the revs to the road speed. So, you blip the throttle, to say 2500 rpm, but you still have the clutch pedal depressed.
When you have the revs where you want them, release the clutch very smoothly and progressively, turn into the corner, and accelerate out of it. If you execute this well, the car will accelerate very smoothly and there will be no forward jolt or instability from the car when you release the clutch.
It is important to practice these steps at low speeds first, especially if you are not able to heel and toe to use the brakes as well. When practicing, remember that you don’t need to be 100% accurate on matching your revs at first. As with any skill, it takes some practice to master. With time, you will start to recognise when your engine speed matches your road speed.
Rev matching can help you to downshift effectively and help to take stress off your engine, clutch and gearbox if you execute it well. It’s used in lots of racing series, with NASCAR drivers using rev matching without actually using the clutch. It’s an important skill to learn if you want to be fast on a track and smooth on the open road.