Manual Transmission T56 | T5 | MN12 | Clutches | Hydraulics | Shifters
View Poll Results: Do you guys downshift when decelerating?
Yes, all the time.
232
22.92%
Yeah, most of the time
355
35.08%
Nope, once in awhile though
355
35.08%
Never
70
6.92%
Voters: 1012. You may not vote on this poll

Downshifting

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Old 02-14-2006, 08:17 PM
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Default Downshifting

Do you guys downshift when slowing down? If you do... how? and at what rpm? You cause more wear on the clutch the more you use it, right? When I downshift I tend to ease off the clutch slowly so i slow down more smoothly, but doesn't that cause more wear on the clutch than if you let off it quick? I read that dumping the clutch at a fairly high rpm isn't nearly as bad as "riding" the clutch or easing off it slowly.

Using this logic makes me question why we even downshift. Of course I'm talking about when you're decelerating, not accelerating . By not downshifting you're transferring more of the energy and wear it takes to slow down to the brakes, right? Wouldn't that make more sense?? Since brakes are cheap and easy to replace compared the clutch... Wouldn't this cause less wear and tear on the clutch... and the transmission for that matter?
Old 02-14-2006, 09:01 PM
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I voted most of the time, but I really meant was that, I only do it when I want my car to be heard, Like around other fast cars, girls, people I know. And their is going to be excessive wear but just think the last time you heard someone say "well I got to get the tranny r and r'ed because I down shift all the time" or "I have to replace my clutch because I downshift to stop" Usually its more like the ya since the 13 trips down the strip my stock clutch blew up" Or Launching on DR's or slicks. While I’m not arguing that it causes more unnecessary wear on parts I don’t think its going to do anything noticeable to your car unless your being "THAT GUY" all the time. Just my opinion as always.
Old 02-14-2006, 09:33 PM
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Ok, downshifting is NOT harmful to the transmission if done properly. You must match the rev's in a "heel-toe" manuver to avoid sliping the clutch. If you can do this, there is no negative side effect to downshifting.

IF the clutch is slipping or you notice any accel/decel effects of the shift, your not doing it properly.

The only reason to downshift while decelerating is to prepare yourself for acceleration out of a corner so you do not have to shift in the middle or exit of the corner.

If your downshifting and coming to a stoplight it has NO benefit.
Old 02-14-2006, 11:21 PM
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i do it all the time and a quick blip of the throttle and down a gear. if you get it to where you dont feel it your doing it right. dont see how its hard on anything but maybe the snycs a little
Old 02-15-2006, 02:48 AM
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I do it for slowing down, like when getting off the highway and going onto a spiral ramp... Using the brakes and downshifting, and smoothly letting the clutch out so you can feel it slowing you down but not too much...
Old 02-15-2006, 03:18 AM
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Usually when entering/exiting a freeway with heavy traffic..But other then that just to race and be heard..The usual...
Old 02-15-2006, 07:32 AM
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Originally Posted by H8 LUZN
Ok, downshifting is NOT harmful to the transmission if done properly. You must match the rev's in a "heel-toe" manuver to avoid sliping the clutch. If you can do this, there is no negative side effect to downshifting.

IF the clutch is slipping or you notice any accel/decel effects of the shift, your not doing it properly.

The only reason to downshift while decelerating is to prepare yourself for acceleration out of a corner so you do not have to shift in the middle or exit of the corner.

If your downshifting and coming to a stoplight it has NO benefit.
Exactly.

If you want to downshift this way (ie. "double clutch"):

1. Clutch in, Shift into neutral
3. Clutch out
4. Blip throttle to rev to RPM you will be in lower gear
5. Clutch in, Shift into lower gear
6. Clutch out

If you do this properly and quick enough, you will not get the "lurch" that you normally get when downshifting. Also, the shifter will offer no resistance going to the lower gear.
Old 02-15-2006, 09:29 AM
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Brakes are a lot easier to change than a clutch. But I still do it every now and again for fun.
Old 02-15-2006, 10:27 AM
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I never downshift when coming to a stop. That is what the brakes are for.
Old 02-15-2006, 10:48 AM
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I do it all the time now to slow down because my rotors are shot so it really helps me to slow down. But when i get my new rotors im probably just going to continue. its just habit i guess. you get used it to a point where you almost dont even feel resistance when you shift down. you know you dont get that lurch. you just gotta get it into that lower gear before your rpm's drop so you dont beat up your clutch so much.
Old 02-15-2006, 10:54 AM
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Originally Posted by transam0486
Do you guys downshift when slowing down? If you do... how? and at what rpm? You cause more wear on the clutch the more you use it, right? When I downshift I tend to ease off the clutch slowly so i slow down more smoothly, but doesn't that cause more wear on the clutch than if you let off it quick? I read that dumping the clutch at a fairly high rpm isn't nearly as bad as "riding" the clutch or easing off it slowly.

Using this logic makes me question why we even downshift. Of course I'm talking about when you're decelerating, not accelerating . By not downshifting you're transferring more of the energy and wear it takes to slow down to the brakes, right? Wouldn't that make more sense?? Since brakes are cheap and easy to replace compared the clutch... Wouldn't this cause less wear and tear on the clutch... and the transmission for that matter?
Geeze some of you Americans have no idea about driving manual cars, lol

No serioiusly riding the clutch is BAD as a rule because it's basically slipping it which will case wear. This is up or down shifting.

HOWEVER the key to good driving is smoothness so dumping the clutch is not the best manoeuvre , plus if you do this when slowing down it can cause a lot of stress on the drivetrain and unsettle the car.

But the biggest thing with a manual is you can do most/much of the braking with the engine. This gives you far more control than an automatic. Hence ALL circuit and rally cars are always manual and never auto

So yes you should use the engine to brake. If you are driving quick cross country the you should use the brakes as little as possible because the engine will do the rest.

Heel and toe is a good technique, but difficult to perfect and in some cars near impossible due to pedal locations. But if you can "blip" the throttle between down shifts to match the revs then it won't unsettle the car, this allows a smoother faster transition and cornering ability.

Doing this will not damage the gearbox at all, it is common every day practice. Lorry drivers use this to great affect also as the brakes on a big rig are easy to over heat (least in years gone by).

4th to 2nd gear block changes are common as you can go from high speed to lower speed with plenty of control and enter a corner in the correct gear to accelarate out.

another bonus is fuel efficency. When an engine is coasting and down revving it won't be using any fuel. So by maximising downshifting and engine braking you can increase your mpg.

In my TR7 doing that on a daily 50 mile round commute to work and back I could increase my over all average MPG by 3mpg (24 to 27) which is a pretty big percentage.
Old 02-15-2006, 04:37 PM
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also drivers of big trucks semi's, 18 wheelers only use the clutch to start from a stop. I do downshift when driving my car and I you the double clutch method, usually sometime I don't use the clutch to upshift but not usually. But I do when I drive one of our old truck(1/2 tons and 1 tons not big trucks). the as you roll off the gas pull it into neutral and for the rpm to come down to where it needs to be for the next gear and when you pull on the gear shift it will go right in, it does takes some practice. to downshift as you let off the gas take it out of gear and rev motor to wear it needs to be for the lower gear and once again it will slip right in. this method does take some practice and not the fastest way.

in my opinion as far as regular downshifting I think it would be harder on the synchro's then the clutch, and I would rather replace a clutch then synchro's.
Old 02-15-2006, 05:08 PM
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I think once more Europeans start popping into hear youll hear more use of downshifting to brake.
Old 02-15-2006, 06:05 PM
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I do it to help save my brakes in the long run. And cause I love to hear my car. But the real time I do it and its needed is when i have to come to a very quick stop. Downshifting and braking helps to slow down the car a lot faster than just braking. Its helped save me a couple times I believe
Old 02-15-2006, 06:28 PM
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Doesn't downshifting cause excessive wear over time on the back side of the gears on a transmission? I have always been told this and I've seen some examples where gears where very thin in situtions where people did this in their everyday driving.
Old 02-15-2006, 06:30 PM
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Ive never owned an automatic vehicle, and Ive always downshifted when entering off-ramps or I want to slow down.....

If done properly, it has no negative effect on your tranny....

Youll find that most clutch problems are from the idiots driving the car.
Old 02-15-2006, 07:56 PM
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I rev match, down shift, heel toe, double clutch and about everything else. It makes driving a 6 speed car fun.
Old 02-15-2006, 08:18 PM
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Originally Posted by 300bhp/ton
Geeze some of you Americans have no idea about driving manual cars, lol

No serioiusly riding the clutch is BAD as a rule because it's basically slipping it which will case wear. This is up or down shifting.

HOWEVER the key to good driving is smoothness so dumping the clutch is not the best manoeuvre , plus if you do this when slowing down it can cause a lot of stress on the drivetrain and unsettle the car.

But the biggest thing with a manual is you can do most/much of the braking with the engine. This gives you far more control than an automatic. Hence ALL circuit and rally cars are always manual and never auto

So yes you should use the engine to brake. If you are driving quick cross country the you should use the brakes as little as possible because the engine will do the rest.

Heel and toe is a good technique, but difficult to perfect and in some cars near impossible due to pedal locations. But if you can "blip" the throttle between down shifts to match the revs then it won't unsettle the car, this allows a smoother faster transition and cornering ability.

Doing this will not damage the gearbox at all, it is common every day practice. Lorry drivers use this to great affect also as the brakes on a big rig are easy to over heat (least in years gone by).

4th to 2nd gear block changes are common as you can go from high speed to lower speed with plenty of control and enter a corner in the correct gear to accelarate out.

another bonus is fuel efficency. When an engine is coasting and down revving it won't be using any fuel. So by maximising downshifting and engine braking you can increase your mpg.

In my TR7 doing that on a daily 50 mile round commute to work and back I could increase my over all average MPG by 3mpg (24 to 27) which is a pretty big percentage.

I love these downshifting threads and all of the theoretical talk about wearing everything out. Thanks for coming in and setting some things right.

Basically, downshifting allows you to slow the car with much more control. Think of driving on icy roads as an example--not a good time to rely on brakes all of the time. A manual transmission has advantages if you learn how to use them. If you drive it like an automatic, then you might as well have an automatic--to take advantages of what it has to offer.
Old 02-15-2006, 09:28 PM
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I downshift all the time. I'll downshift once or twice depending on what gear/speed I'm slowing from but I do it whether hitting the exit ramp or stopping at a light. Abuse on parts comes from shock loads, whence the "I broke my clutch launching" or "I broke my tranny powershifting with 600hp" and I always rev match when downshifting. When done properly the car feels as smooth decelerating as if you put it in neutral and just used the brakes. Parts are going to wear over time no matter what you do, that's friction for you so if you're worried about wear then don't drive your car. In terms of wear on parts though, by using the brakes and tranny you're actually distributing the load (rather than placing it all on 1 set of parts) created when slowing the car. FWIW I just pulled my stock ls1 clutch/flywheel and they both look great with just under 20k on them. Again, I downshift all the time, the car's been to the strip a couple times, and the previous owner auto crossed it once.
Old 02-15-2006, 10:05 PM
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Im with the last few posts, downshifting and engine braking is more effeicient on the whole car. Especially if you are in racing mode. I figure the more engine breaking you do the less banging of the gears, i.e., less wear on the gear box and whole tranny. Ive been driving with engine braking alot more since I discovered what autoxing requires, lots of engine breaking to better control the vehicle. Plus it makes the car a whole lotta fun to drive. I only wish heel toe was easier with the stock rubber pedals.!!!!!!!


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