Downshifting techniques
Thread Starter
New Member
Joined: 08-09-10
Posts: 138
Likes: 0
From: Windsor, ON
Downshifting techniques
I wanted to get some input from some of the guys that are really experience in manual transmissions or that even race cars professionally about downshifting. I'm not a serious driver but just a spirited one and I'd say I drove manual quite well. But one thing I do often that I've wondered if its an issue or not is skip gears when I downshift. When I'm cruising around day to day and I'm in 4th gear for example just driving down the road and I'm a approaching a sharp turn I'll brake in 4th take the corner drop it into 2nd rev match and accelerate out. Should I be downshifting into 3rd and then in 2nd? The reason I dont is because it just seems like a complete waste of time, and it would appear difficult as it would have to be done so quickly. If I'm cruising at 60 or 70KMH in 4th at a comfortable 1800RPM and slow down to 30 or 40 for a corner, the deceleration is done with the brakes in a literally a second. I can understand when you're driving a race car and you're at much higher speeds, and need more time and distance to slow down, so you downshift one gear at a time and let the engine assist in slowing you down, but is this necessary on the street. Doesnt seem like there is really enough time to downshift from gear to gear when you're driving within city speed limits, its seems to not only just be a hassle but I'd think it would put more wear and tear on the transmission, clutch etc., isnt that what brakes are for?
Another time when I don't ever really find myself downshifting is when coming to a stop, if there is a red light, stop sign etc. and I'm cruising in 4th or 5th I just slow down in gear with the brakes and then pop it into neutral right before I come to a dead stop. Ill often downshift from 5th to 4th just because its such an easy smooth shift and I really only drive in 5th when I'm at high speed or atleast a consistent speed where I'm just tryin to be fuel efficient, but never in any other gear. Just curious what other's techniques are...?
On a side note: I'm not too concerned about this technique is its a little too advanced for me, especially just for daily driving, but is it just me or is it nearly impossible to heel toe in this car? (I have the SS TC) but the way the pedals are situated and maybe the lack of flexibility I have in my foot I can not even get close to being able to control the gas pedal with my heel while my toes are on the brake or vice versa. It is beyond awkward.
Another time when I don't ever really find myself downshifting is when coming to a stop, if there is a red light, stop sign etc. and I'm cruising in 4th or 5th I just slow down in gear with the brakes and then pop it into neutral right before I come to a dead stop. Ill often downshift from 5th to 4th just because its such an easy smooth shift and I really only drive in 5th when I'm at high speed or atleast a consistent speed where I'm just tryin to be fuel efficient, but never in any other gear. Just curious what other's techniques are...?
On a side note: I'm not too concerned about this technique is its a little too advanced for me, especially just for daily driving, but is it just me or is it nearly impossible to heel toe in this car? (I have the SS TC) but the way the pedals are situated and maybe the lack of flexibility I have in my foot I can not even get close to being able to control the gas pedal with my heel while my toes are on the brake or vice versa. It is beyond awkward.
https://www.cobaltss.net/forums/gene...l-tips-197545/
But also sub'd. Cause I've always wondered about down shifting 2 gears at once. Mainly from 5th to 3rd.
Section 3: Upshifting and Downshifting – Rev-Matching (a.k.a. doing it properly)
I’ll start with downshifting. Many people don’t downshift, claiming it’s too hard, it wears the clutch, you can’t do it smoothly, etc. Wrong on all counts. Downshifting is the way to go on all levels, including safety, wear-and-tear (clutch/brakes), and fuel costs. For those that don't know, Cobalts have a feature called deceleration fuel cutoff (DFCO). When you're coasting at over 1,500rpm in all Cobalts except the SS/TC (2,250rpm in 1rst-4th, or above 1,250rpm in 5th for the SS/TC), the engine uses NO fuel and shuts off the injectors (Credit to Stamina!). When you downshift, you'll keep the engine spinning above these speeds and thus use much less gas. If you ride the clutch or neutral coast you're killing your fuel economy, and in the case of riding the clutch, killing your throwout bearing. The engine braking effect also reduces the need to use your actual brakes. Running down through the gears also ensures you always have the engine ready to respond should you need to get out of trouble.
So how can you downshift smoothly and eliminate almost all wear on your clutch? You may have tried downshifting before and felt a moderate-to-violent lurch when you let the clutch out into the lower gear. That lurch you feel after downshifting is caused by a difference in speeds between the engine and the transmission.
For example, if you're at 2,000rpm in third gear and you wish to downshift to second, when you depress the clutch the engine's speed drops. The transmission, however, will continue spinning, accelerating to the new speed in second gear. This is called "road speed." For a smooth shift, you want the engine speed to match the road speed when you let the clutch out. This is where rev-matching comes in.
During your downshift, while the clutch is down and you're moving the shifter to the next gate (ex: 3rd to 2nd), you "blip" the throttle to get the engine speed up. In my TC, if I'm going from 2,000rpm in 3rd down to 2nd, I'll give it a blip to about 3,000rpm and drop it into second. This isn't a science, it's all about feel. You'll need to practice. Eventually you'll know just how hard to stab the throttle for perfect rev-matches at almost any speed in any gear.
You'll know you're really good at this when you take someone new and unobservant in your car and they blurt out "this is a manual?!" 20 minutes into the drive . Not only will this help make your downshifts seamless, it also reduces wear on the clutch, since with a properly rev-matched downshift you can instantly snap the clutch out with no jerk, no lurch, and crucially, no clutch slip.
You can rev-match during upshifts, too. Ever get a jerk when you let the clutch out going from say 2nd to 3rd? The same concept applies here, but in reverse. The engine will often be spinning too fast after the upshift to properly match road speed, causing a little jolt. Say going from 3,000rpm in second up to third, RPM in third gear should be about 2,000rpm or so. Hesitate a moment while you're shifting to let the engine speed drop far enough for a seamless match.
I’ll start with downshifting. Many people don’t downshift, claiming it’s too hard, it wears the clutch, you can’t do it smoothly, etc. Wrong on all counts. Downshifting is the way to go on all levels, including safety, wear-and-tear (clutch/brakes), and fuel costs. For those that don't know, Cobalts have a feature called deceleration fuel cutoff (DFCO). When you're coasting at over 1,500rpm in all Cobalts except the SS/TC (2,250rpm in 1rst-4th, or above 1,250rpm in 5th for the SS/TC), the engine uses NO fuel and shuts off the injectors (Credit to Stamina!). When you downshift, you'll keep the engine spinning above these speeds and thus use much less gas. If you ride the clutch or neutral coast you're killing your fuel economy, and in the case of riding the clutch, killing your throwout bearing. The engine braking effect also reduces the need to use your actual brakes. Running down through the gears also ensures you always have the engine ready to respond should you need to get out of trouble.
So how can you downshift smoothly and eliminate almost all wear on your clutch? You may have tried downshifting before and felt a moderate-to-violent lurch when you let the clutch out into the lower gear. That lurch you feel after downshifting is caused by a difference in speeds between the engine and the transmission.
For example, if you're at 2,000rpm in third gear and you wish to downshift to second, when you depress the clutch the engine's speed drops. The transmission, however, will continue spinning, accelerating to the new speed in second gear. This is called "road speed." For a smooth shift, you want the engine speed to match the road speed when you let the clutch out. This is where rev-matching comes in.
During your downshift, while the clutch is down and you're moving the shifter to the next gate (ex: 3rd to 2nd), you "blip" the throttle to get the engine speed up. In my TC, if I'm going from 2,000rpm in 3rd down to 2nd, I'll give it a blip to about 3,000rpm and drop it into second. This isn't a science, it's all about feel. You'll need to practice. Eventually you'll know just how hard to stab the throttle for perfect rev-matches at almost any speed in any gear.
You'll know you're really good at this when you take someone new and unobservant in your car and they blurt out "this is a manual?!" 20 minutes into the drive . Not only will this help make your downshifts seamless, it also reduces wear on the clutch, since with a properly rev-matched downshift you can instantly snap the clutch out with no jerk, no lurch, and crucially, no clutch slip.
You can rev-match during upshifts, too. Ever get a jerk when you let the clutch out going from say 2nd to 3rd? The same concept applies here, but in reverse. The engine will often be spinning too fast after the upshift to properly match road speed, causing a little jolt. Say going from 3,000rpm in second up to third, RPM in third gear should be about 2,000rpm or so. Hesitate a moment while you're shifting to let the engine speed drop far enough for a seamless match.
Everything quoted above is true.
And no it won't hurt if you skip a gear while downshifting.
I also have problems with heel-toe downshifting in this car. Big ass feet. I don't even bother because I'm not at the track. However when I'm downshifting I tap the brake pedal just enough to let the people behind me know that I'm slowing down.
And no it won't hurt if you skip a gear while downshifting.
I also have problems with heel-toe downshifting in this car. Big ass feet. I don't even bother because I'm not at the track. However when I'm downshifting I tap the brake pedal just enough to let the people behind me know that I'm slowing down.
We make and sell the best solution: a bottom hinged gas pedal set,
but its way cheaper to get the SRS replacement pedal set, gets you about 50% of the way there and its very nicely made and good looking as well.
but its way cheaper to get the SRS replacement pedal set, gets you about 50% of the way there and its very nicely made and good looking as well.
its a misnomer. used to be that way, nowadays you roll the side of your foot over to catch the gas pedal so u can simultaneously brake and downshift while matching revs at the same time. It will become a lost art soon, now that we have computer aided rev matching and paddle shifters....
Question bout wat was quoted earlier...
Wouldn't you use less if not as much has slowin down or 'cruisin' with your foot on the clutch or in neutral as you would with dfco? It jus seems that way.. Makes sense to me
Wouldn't you use less if not as much has slowin down or 'cruisin' with your foot on the clutch or in neutral as you would with dfco? It jus seems that way.. Makes sense to me
If you engine brake, the ecm cuts fuel above a certain RPM and the weight of the car keeps the engine turning.
hmm... I jus filled up.. Ima try this...D F C Oamajiger for a lil.. an see wat happens.. I know its not always accurate, but my inst mpg is always higher when the clutch is in an I'm just rollin.. that's why I'm always doin it
downshift first, then brake. Risk? you may overrev and /or mechanically over rev your car if you are going fast enough and select a lower gear. takes longer.
brake first, then downshift. Risk? None if you match revs, but you stop braking to downshift therefore either 1.arrive at the corner too fast as you stopped braking or 2. overslow the car in advance of the corner to get it all done.
brake then match revs and downshift, successfully combining both functions. produces faster lap times.
or buy a paddle shift Ferrari 458?
just an idea...
I learned manual, downshifting, heel toe downshifting, double clutch downshifting, and double clutch heel toe all on my LSJ ever since I got it one year ago.
At first they all seemed impossible for me to be good at but then I practiced it every day and very soon it became a very natural motion much like up shifting. It is definitely very useful even for normal driving because you will be in the right gear at all times, plus it sounds cool
. I started practicing from 4th to 3rd (I find it the easiest), and 2nd to 1st is the toughest.
At first they all seemed impossible for me to be good at but then I practiced it every day and very soon it became a very natural motion much like up shifting. It is definitely very useful even for normal driving because you will be in the right gear at all times, plus it sounds cool
. I started practicing from 4th to 3rd (I find it the easiest), and 2nd to 1st is the toughest.
I'm not a serious driver but just a spirited one and I'd say I drove manual quite well. But one thing I do often that I've wondered if its an issue or not is skip gears when I downshift. When I'm cruising around day to day and I'm in 4th gear for example just driving down the road and I'm a approaching a sharp turn I'll brake in 4th take the corner drop it into 2nd rev match and accelerate out. Should I be downshifting into 3rd and then in 2nd? The reason I dont is because it just seems like a complete waste of time, and it would appear difficult as it would have to be done so quickly.
If I'm cruising at 60 or 70KMH in 4th at a comfortable 1800RPM and slow down to 30 or 40 for a corner, the deceleration is done with the brakes in a literally a second. I can understand when you're driving a race car and you're at much higher speeds, and need more time and distance to slow down, so you downshift one gear at a time and let the engine assist in slowing you down, but is this necessary on the street. Doesnt seem like there is really enough time to downshift from gear to gear when you're driving within city speed limits, its seems to not only just be a hassle but I'd think it would put more wear and tear on the transmission, clutch etc., isnt that what brakes are for?
Another time when I don't ever really find myself downshifting is when coming to a stop, if there is a red light, stop sign etc. and I'm cruising in 4th or 5th I just slow down in gear with the brakes and then pop it into neutral right before I come to a dead stop. Ill often downshift from 5th to 4th just because its such an easy smooth shift and I really only drive in 5th when I'm at high speed or atleast a consistent speed where I'm just tryin to be fuel efficient, but never in any other gear. Just curious what other's techniques are...?
Senior Member
Joined: 05-09-11
Posts: 613
Likes: 0
From: Kentucky
when I'm downshifting and rev matching I've found it easier to sort of roll the side of my foot from the brake and rev match that way. Heel toe is pretty much impossible in these cars due to the console. Apply brake, then clutch and just roll your foot to the gas to blip it while still in the brake, it takes a minute to get used to but it works perfectly for me everytime.
btw, double clutching hasn't been necessary in a manual transmission in quite some time, it has absolutely no benefit in newer transmissions.
btw, double clutching hasn't been necessary in a manual transmission in quite some time, it has absolutely no benefit in newer transmissions.
Senior Member
Joined: 11-20-07
Posts: 2,961
Likes: 1
From: Pittsburgh, Pistolvania
A skip downshift isn't a problem as long as you're not going to over-rev your engine and can do the proper rev match so it isn't jolting the hell out of your car. I drop from 5th to 3rd all the time for passing (To second if the guy in front is going under 40mph or slower). You just have to know where the downshift will put your RPM's at.
New Member
Joined: 05-03-10
Posts: 134
Likes: 0
From: NoVa
Here's another question in pretty much the same regard.. Is it bad to downshift without rev-matching if say you go from 4th at 40mph to 3rd? The rpm's will only go up to around 2500 or so, so i dont really see it being bad for the clutch/trans but I've been curious..
any time you use the clutch to slip the motor up to match engine to gear speeds you dont do nice things for the clutch. So driving right all the time is hard, but will help make your car last longer
New Member
Joined: 05-03-10
Posts: 134
Likes: 0
From: NoVa
Makes sense but just doesnt seem like its puting the car under that much stress by not rev-matching.. When i downishift, the rpm's never shoot up above 2500. It would be a completely different story if i were going from like highway speeds to like 3rd to slow down or something like that.
Thread
Thread Starter
Forum
Replies
Last Post