How do people downshift for more power without rev-matching?
Discussion
The majority of drivers on the road do not know how to rev-match, driving instructors don't teach it.
So for example, getting into a lower gear to make an overtake, or needing more power on an uphill incline.
I nearly got a fault on my driving test due to not knowing how to rev-match. On a NSL limit road I was in 4th gear and on an uphill incline the car wouldn't go above 40Mph with full throttle, with a car behind this could easily be a driving fault for "not making due progress" or whatever the fault for driving unnecessarily slowly is called.
Obviously in the same situation with my current driving skill, I would just rev-match down into 3rd to get the car higher in the rev-range for more power. But without matching the revs, surely the engine would just lose even more momentum when lifting the clutch and slow to well below 30Mph? Surely rev-matching is a necessary driving skill in this scenario? With the inability to rev-match, downshifting to 3rd did not seem a viable option to me.
How does the average driver avoid this loss of momentum when downshifting?
So for example, getting into a lower gear to make an overtake, or needing more power on an uphill incline.
I nearly got a fault on my driving test due to not knowing how to rev-match. On a NSL limit road I was in 4th gear and on an uphill incline the car wouldn't go above 40Mph with full throttle, with a car behind this could easily be a driving fault for "not making due progress" or whatever the fault for driving unnecessarily slowly is called.
Obviously in the same situation with my current driving skill, I would just rev-match down into 3rd to get the car higher in the rev-range for more power. But without matching the revs, surely the engine would just lose even more momentum when lifting the clutch and slow to well below 30Mph? Surely rev-matching is a necessary driving skill in this scenario? With the inability to rev-match, downshifting to 3rd did not seem a viable option to me.
How does the average driver avoid this loss of momentum when downshifting?
I have no idea what you're going on about.
If your car is chugging along in 5th doing 30mph and won't accelerate - even with your foot flat on the throttle, it is because you are in the wrong gear.
Rev matching or not (I assume you're on about blipping the throttle) being in the correct gear for the speed is going to put the engine back into its power band which will aid acceleration.
Unless I've fundamentally misunderstood your point, this is one of the strangest topics I've seen for a while.
Edit - after reading it again, you seem to think that when you lift the clutch after shifting from 4th to 3rd, the revs will somehow be the same as when it was in 4th unless you rev match.
When you go into 3rd and lift the clutch, the revs will typically rise around 2 to 3k higher than the previous gear because you're now in a different gear ratio.
Yep, still an odd thread.
If your car is chugging along in 5th doing 30mph and won't accelerate - even with your foot flat on the throttle, it is because you are in the wrong gear.
Rev matching or not (I assume you're on about blipping the throttle) being in the correct gear for the speed is going to put the engine back into its power band which will aid acceleration.
Unless I've fundamentally misunderstood your point, this is one of the strangest topics I've seen for a while.
Edit - after reading it again, you seem to think that when you lift the clutch after shifting from 4th to 3rd, the revs will somehow be the same as when it was in 4th unless you rev match.
When you go into 3rd and lift the clutch, the revs will typically rise around 2 to 3k higher than the previous gear because you're now in a different gear ratio.
Yep, still an odd thread.
Edited by Discendo Discimus on Monday 1st July 15:21
Edited by Discendo Discimus on Monday 1st July 15:54
No it's not necessarily for rev matching all the time if you are using the accelerator and clutch smoothly and in time.
By not taking ages to change gear and planning ahead there is no need to be messing about running an engine at too low an rpm for the gear or risk grinding to a halt on a minor incline.
By not taking ages to change gear and planning ahead there is no need to be messing about running an engine at too low an rpm for the gear or risk grinding to a halt on a minor incline.
People dump it into the lower gear, bring up the clutch, and let the road speed drag the engine speed up to the appropriate point, same as they do when decelerating
If you're relaly lucky they'll come on the throttle as they lift the clutch to sort of match. Only real powerfully built directors actually blip in the small period where the car is in neutral during your downshift.
If you're relaly lucky they'll come on the throttle as they lift the clutch to sort of match. Only real powerfully built directors actually blip in the small period where the car is in neutral during your downshift.
I just rev match to avoid that jerk as you change down, just seems to be more sympathetic to the car, plus I enjoy it, if I am honest part of why autos tend to bore me is not having that part of the pleasure, but its not necessary and not for everyone, its so satisfying when you get it right.
When I was first driving it used to annoy me that I couldnt brake and change down effectively, partly as my shoes didnt allow it so got some Reebok high top trainers/boots with dainty soles which enabled me to perfect this technique of braking and blipping the throttle at the same time, I honestly thought I had invented that and didnt equate it with heel and toeing, had heard of that but didnt twig it was what I was doing, and had also bought footwear that looked like the nearest thing to a racing shoe that you could get in a sports shop.
Rev matching is usually enough on the road, and track to be honest as most cars dont really lend themselves to Heel and Toe due to weird pedal heights, have altered the relative heights on my current car but the distance is a bit too far to bridge .
Have tried left foot braking but never really nailed that.
When I was first driving it used to annoy me that I couldnt brake and change down effectively, partly as my shoes didnt allow it so got some Reebok high top trainers/boots with dainty soles which enabled me to perfect this technique of braking and blipping the throttle at the same time, I honestly thought I had invented that and didnt equate it with heel and toeing, had heard of that but didnt twig it was what I was doing, and had also bought footwear that looked like the nearest thing to a racing shoe that you could get in a sports shop.
Rev matching is usually enough on the road, and track to be honest as most cars dont really lend themselves to Heel and Toe due to weird pedal heights, have altered the relative heights on my current car but the distance is a bit too far to bridge .
Have tried left foot braking but never really nailed that.
Discendo Discimus said:
Edit - after reading it again, you seem to think that when you lift the clutch after shifting from 4th to 3rd, the revs will somehow be the same as when it was in 4th unless you rev match.
When you go into 3rd and lift the clutch, the revs will typically rise around 2 to 3k because you're now in a different gear ratio.
Yep, still an odd thread.
I don't think that, I think that when rev-matching is left to the clutch, the engine speed will rise but the wheel speed will also decrease somewhat due to engine-braking, and even more so on an uphill incline.When you go into 3rd and lift the clutch, the revs will typically rise around 2 to 3k because you're now in a different gear ratio.
Yep, still an odd thread.
Edited by Discendo Discimus on Monday 1st July 15:21
DarkVeil said:
Discendo Discimus said:
Edit - after reading it again, you seem to think that when you lift the clutch after shifting from 4th to 3rd, the revs will somehow be the same as when it was in 4th unless you rev match.
When you go into 3rd and lift the clutch, the revs will typically rise around 2 to 3k because you're now in a different gear ratio.
Yep, still an odd thread.
I don't think that, I think that when rev-matching is left to the clutch, the engine speed will rise but the wheel speed will also decrease somewhat due to engine-braking, and even more so on an uphill incline.When you go into 3rd and lift the clutch, the revs will typically rise around 2 to 3k because you're now in a different gear ratio.
Yep, still an odd thread.
Edited by Discendo Discimus on Monday 1st July 15:21
Obviously if you downshifted, lifted the clutch and coasted it would slow down, but that's not what anybody does.
Discendo Discimus said:
But that's why you would be back on the throttle as soon as the clutch is lifted, because you're trying to accelerate.
Obviously if you downshifted, lifted the clutch and coasted it would slow down, but that's not what anybody does.
So there isn't any significant engine-braking when lifting up the clutch?Obviously if you downshifted, lifted the clutch and coasted it would slow down, but that's not what anybody does.
DarkVeil said:
I don't think that, I think that when rev-matching is left to the clutch, the engine speed will rise but the wheel speed will also decrease somewhat due to engine-braking, and even more so on an uphill incline.
Compare the rotating masses in the engine (i.e. everything before the clutch), with the driven wheels and transmission (i.e. everything after the clutch). Report back with your findings.
boyse7en said:
DarkVeil said:
How does the average driver avoid this loss of momentum when downshifting?
You shift down a bit earlier before the engine starts to labour. Spending your formative driving years in a super-low powered car soon gets you used to the idea of conserving momentum.Gassing Station | Advanced Driving | Top of Page | What's New | My Stuff