Double clutching is better for downshifting, It brings the input shaft up to engine speed if you are about to power out of a corner. For stopping, whatever. I downshift while breaking so the engine assists in stopping, also, it keeps me in the right gear if I decide not to stop. Something I got into the habit of on my motorcycle.

 

there is no stress on the syncros. this word is getting thrown around in this thread and i dont think anyone knows what they are. syncro stands for syncronizer. all they do is line up the gears. you will not stress out your syncros by downshifting no matter what method you use. also, you put more stress on a clutch through acceleration than deceleration. it is fine to downshift w/out matching the revs...its just smoother if you do.

 

Here's one of the many bookmarks I have regarding rev-matching and downshifting:

http://forums.nasioc.com/forums/arch.../t-373228.html

Read Kha0S's post, 5th from the last one at the bottom. It makes sense!

End of discussion.

 

khoas makes sense in theory...and he does know what he is talking about...but can anyone really disagree w/ the fact that starting off facing up hill is more stressful on the clutch than downshifting. does that mean that i am going to avoid all hills just so i dont ruin my clutch? unless you are downshifting at like 4000rpm i highly doubt that you are wearing the clutch at all. and as far as the syncros go, they are made to line the gears up. that is the only reason they are in your tranny. your syncros are the last things that are going to wear down. if they do, your tranny is just old and worn and should be replaced anyway. my $.02

 

I've got ~128k on my Maxima... original clutch as far as I know (bought it with 92k but the transmission doesn't look like its ever been unbolted before). I downshift & rev match almost every time I slow down... or even when I go to speed up (when say cruising in 5th, my Maxima doesn't accel very well with the new 19s, so I drop it to 4th or even 3rd to get around trucks etc). I rarely like to use the brakes unless necessary (to come to a complete stop for instance). I've had no complaints from the engine, transmission, or clutch from doing it... I drive about 30 miles a day round trip to get to work and take a few good on/off ramps on my trip downshifting as I go... I get about 350 miles to a tank as well, mostly highway, but a good amount of city driving (probably 66/33 highway/city) which is normally about a 15-16 gallon fill up (last stop was a $36 fill).

As far the rev ranges... I routinely downshift from 3rd at ~4000 rpm into second with a blip of the throttle that normally engages into 2nd around 5500 rpm and then use the engine to slow down as I take the offramps... feels much more smooth and planted than when I try and brake to take the corner... but that's just how I personally like to drive...

 

Well, i've been driving stick since i was about 12.. I grew up in Puerto Rico where you have to take your road test in a stick shift car!!! My grandfather has a 1979 corolla with the stock clutch. Prob over 250k miles on it. Stock tranny and motor as well.. At highway speeds (60-70mph) there is no problem w/ downshifting to fourth after applying the brake slightly to slow the car down to about 40.. after that, 3 gear along with the brake will slow the car down enough to just use your brakes only..Downshifting is as essential as upshifting.. Automatic cars downshift as well.. if anyone has driven a car with a tiptronic tranny you will see how the car automatically downshifts.. if anyone needs me to go teach you how to drive your car let me know.. lol.. just kidding.. Have a nice day !!!

 

Amen brutha!!!

 

85k on mine, still has the original clutch, will still bark the tires on a 1-2 upshift if i try. I downshift to slow down all the time (just tap the gas between the shift and dont skip gears). I have in every car I have had since I was 16. Never any problems.

now obviously it is more wear on your clutch and snycros, you are engaging it more than if you just hit the breaks. obviously it costs more to replace a clutch than it does to get a break job. So you are better off to just hit the breaks in the long run as far as your pocket book goes. spirited driving on the other hand, well, cant put a cost on that..

 

I took this video not too long ago. I was trying to video tape and steer with my left hand and then shift with the right hand. Sorry for the wind noise, I forgot to roll the window down. I was exiting the fwy slowing down from about 50mph on 4th gear, downshifted to 3rd and 2nd while rev-matching and double-clutching.

 

I found this website pretty helpful: http://www.bmwm5.com/greg/school/.

 

I'm still new to downshifting and only do it when I'm going like 20-30mph in 4th and want to go to 3rd. I take it out of gear, rev the engine to raise the rpm maybe by 1k or so and put the car in 3rd, it's becoming pretty smooth. Is that a correct way to do it?

 

No. You are supposed to down shift at 100mph from 4th to 2nd so no braking is needed.

 

Also is it bad to slowly engage the clutch? In the mornings my clutch engagement is a bit harsh, first 10 minutes or so, so it takes me maybe 2-3 seconds to fully engage the clutch into 1st gear. Is it bad? Would it be better to just disengage the clutch quickly and feel the jerk?

Jeff, I'm not that new to it. Thanks for sarcastic reply though.

 

Slipping the clutch makes smooth. But that also wears the disc more. Technically it will wear the clutch more. But in reality, only the tards the beat on their clutches wear it down fast.

My reply wasn't directed towards you. Towards the tards that think downshifting as a means of slowing the car is a good idea. I knew that you know better and I thought you would get the joke.

 

I knew it was a joke but I wasn't sure if it was directed towards me. Since I drive like an old woman and visit the track not so often I guess my clutch will be fine for a while. Given the fact that I learned and still am learning to drive a manual on this car and the clutch and tranny still feel great I guess I'm pretty lucky.

 

I always double clutch when downshifting, if only becuase it feels so much better on tranny. Normally when downshifting you get quite a bit of resistance on the stick from the poor synchros fighting to match rpms. If you double clutch right the stick will go in butter smooth, almost feels strange its so easy. Double clutching also does wonders for the life of your clutch, because when the gears engage they are already traveling at roughly the same speed. I've done some spirited drives in my days...and I will tell you that downshifting to 2nd at 50 mph is NOT good for the transmission unless you double clutch. In the few times I havent double clutched I've even gotten grinds this way. However, if you double clutch right the stick still goes in butter smooth.

for those of you who don't know, a lot of the reason why racecar drivers downshift is to take some of the load off the brakes. I've done some 90-0 tests in my max with and without downshifting. The brakes smelled like burnt ribs when I didn't downshift, but when I used engine braking to help out the brakes were just fine.
your engine has a cooling system built in, your brakes don't. So if you plan on driving like a psycho, use the engine to brake as much as possible

 

Jesus...there's a lot of crap flying around here

The input shaft and the mainshaft need spinning up when downshifting, and your syncros are more than capable of this. Double-clutching, therefore, is completely pointless with our (and most new) transmissions.

Having said that, you should always go by the old rule of thumb (it's been said here): Brakes are cheaper than a clutch. The only time you should downshift is when you need to accelerate faster. In those cases, you should rev-match accordingly.

Shifting without the clutch is just dumb, for reasons stated in the other thread on that subject.

[edit: corrections: paragraph 2, sentence 1 (it appears I've thrown crap too )]

 

well spoken and for the most part what i have been trying to say the whole time allthough i dont think downshifting in any form will wear the clutch down...at least not noticably. i mean you got to remember that there are a lot of things more stressful to the clutch than downshifting.

 

I only downshift to accelerate hard, and I always rev-match when doing so. As for braking, I always pop it in neutral and hit the breaks.

 

Edited my previous post...was tired before, am less tired now.

Once the lever is in gear, your syncros are out of the loop. I don't imagine an input-shaft or mainshaft is too much load for the syncros...they are designed to spin those shafts up.

Now, downshifting w/o rev matching will cause wear on your clutch. I'd imagine that, depending how violent your clutch-work is, it's bad for your engine too. Remember, you're externally forcing the engine to rotate at a higher speed.

As to how much damage it causes, I'll leave that up to the experts to decide.

 

hey i was wondering if ne body can post a picture of the 2k rims (the ones i have on my car) painted black. im curious becuase it would be cool to black out the car more.

 

why the hell would u post that question in this thread?

i have started downshifting while double clutching and it is a world of difference while stopping. There is no help in stopping power. but when i double clutch correctly, it goes into the lower gear very smoothly, it just pops in. i have almost mastered the heel-toe, so braking while doubleclutch downshift is becoming easier everytime. hopefully this will make my tranny last longer.

 

I was thinking of actually getting 5th gen wheels once. But I decided not to. I mean, why? Those suckers are so big and heavy....you will decrease your acceleration. So fine, they look OK, but that's about it.

 

I don't downshift for engine braking. It wastes gas, and it wears clutch components instead of brake pads. Clutch components cost more and are harder to replace. Why this thread went 60+ posts I'll never understand - this is very simple.

But I guess it helps keep your rims clean

Dave

 

This thread was quiet until I posted a video.

 

There is absolutly no point in double clutching our cars. You did that in older cars without synchros.....with our new transmissions they have syncros wich eliminate the need for double clutching.

Secondly.. My father has been a truck driver for 35 years. He is now retired. These guys shift thousands of times a day so he knows what he is talking about. And when I learned to drive a stick. Downshifting as long as you rev-match (which is very easy to do) does not do any more harm to your clutch as upshifting does. It actual helps you maintain control of your car by assisting your brakes in slowing you down...The ability to downshift is esential..it helps you match your gear to your speed. The one thing to NEVER do is downshift into first. Only use first to get your car going from a stop.....Downshifting from other gears is a basic part of driving a standard...lets say you are approaching a red light at 45 MPH..You are in fourth gear. If you just use your brake to slow down and then the light turns green b4 u arrive and you are at 20MPH you would need to be in 2nd gear anyways to contunue back up to cruiseing speed. There is a lot of misinformation on this thread I feel. Here is a great website http://www.standardshift.com/index.html. And trust me downshifting as long as you dont go from 5th Gear to 2nd when going 90mph is not doing any harm to todays modern transmissions....(OFf my soap box)

 

No argue that downshifting is GOOD to be used just one question: Can someone please explain the Toe and Heel technique...Thanks

 

No, we have a maxima so why would you even attmpt heel/toe? It's almost impossbile with the way our pedals are placed.

 

Heel-toe first is a misnomer. Most drivers don't specifically use their heel and toe - I for one use the ball of my foot on the brake and the tip of my toe on the throttle.

What is does is simple: on a racetrack, you're on the throttle except when braking. As soon as you cross the apex of the turn, the immediate application of throttle is essential to going fast, and the car must already be in that gear or else you'll lose time. If it's a 30mph turn at the end of a 100mph straightaway, you've got to fit the downshift in there somewhere, so racers do it during the braking phase.

In standard racing transmission (which have no synchros to make downshifting easy) you must manually rev the engine in neutral to rev match the transmission before going to the lower gear. This is double-clutching, and it takes some time. Fortunately, you have the entire braking period to do this, but the problem is you have only 2 feet and now three pedals to use. So while standing on the brake, race drivers blip the throttle with their braking foot to get ready for the next gear. That's referred to as heel-toe, since in some race cars the toe stays hard on the brake and the heel is rotated over to blip the throttle. For many drivers, a slightly different foot position works better. It takes skill to do this without ruining the steady force on the brake pedal.

In a Maxima, you have a synchromesh transmission, and that blip in neutral is unnecessary. However, on exiting a turn it still helps to be in the next gear, and without some rev matching the clutch will rub hard and that can be enough to shake the car from it's traction. So even in racing, (which the Maxima is not a racecar), it's of limited use.

Regardless, the way I do this is:
- approaching the turn, get on the brake.
- keeping the ball of my right foot firmly on the brake, rotate my toe over the throttle.
- clutch in with the left foot, use toe to blip the throttle to the right speed for the lower gear. It doesn't need to be a blip, in fact I find with my limited skills that hovering the engine speed for about a second or two works better.
- select lower gear (2nd for example), and let out the clutch. Time the blip and letting out the clutch so that it engages with revs matched. By this point the car should be slowed enough put your speed within the range of 2nd gear
- finish braking/pass the apex and put down the throttle.

I used to practice this on the street, but found it wastes gas. It's a 'cool' skill to have, but it's actually harder to do on the street since you're not hard on the brake pedal. In a race situation, you stand hard on the brake, and the brake pedal sits closer to the floor and makes it easier to reach the throttle. When standing partially on the brake it's hard to keep the right braking force while making the blip. Also, the reach is further since the brake pedal sits above the throttle - I can only manage it in street driving when wearing shoes that make my size 12 feet just that little bit longer. I can't use my heel since I have long legs and my knee stops against the steering column.

Dave

 

Dave is right...Our cars are pretty hard to heel-toe based on the placement of our pedals...however it still can be done with a lot of practice. I got good at it when I was 16 and driving around a 5 Speed Camaro...I was an idiot at the time and I used to love doing brake tourques and leaving 100 yard strips at my local walmart parking lot.

To answer your question...The heel-toe technique is basically used to down shift when coming in to a corner which you would like to slow down in it..and then accelerate out of it in a lower gear for maximum acceleration.
THE SETUP
Use your left foot for the clutch, while the right foot spans both the brake and gas pedal, the toe is usually on the brake and heel on the gas.
TECHNIQUE
Push the clutch in and shift to a lower gear with your left foot. Now your right foot...Apply the brake with your toe...Use your heel to Rev-Match to the proper RPMS for the lower gear. And then let out the clutch to complete the shift.
I found a good way to practice this is...accelerating up to a safe speed like 25-35mph on a nice straight away. Try to downshift to 3rd or 2nd gear while braking using the toe/heel technique..Just enough to slow you down maybe to 20mph or so..and then accelerate back up to 35. This way you do not worry about making the turn and you can practice getting the feel for your brake and gas pedals.
Hope this was clear and helpful

 

Thanks dgeesaman and Kinger402. That explanation is really good, I didn't ask about it to use it regular but just to learn how to do it for myself-always wanted to do so. And earlier in this thread someone have posted a link to BMW_M5 driving school( http://www.vidload.de/script/kategor...&sort=filename ), there are a couple videos about downshifting which explain really good everything whether its good or not(just thought to tell this to everybody)

 

I swear I've read this thread before...a few years ago. Deja vu.

Keeping your foot off of the clutch pedal is the best way to increase the life of your clutch. Downshifting causes one more clutch slip than is necessary. This is why I say it wears your clutch. I'd rather wear my brakes than my clutch, even if it's only a little bit.

If you need to double-clutch to get your car into second gear (even at 50MPH), your syncros are failing miserably.

I use "heal-toe" pretty much whenever I turn. I have pretty wide feet, though. I'd also argue that it's probably not safe to do, as only the left edge of my foot is on the brake pedal. If my foot were to slip off the brake, it would naturally fall onto the gas...not good in a corner

 

Pads are so cheap and easy to replace. What's the argument for not just throwing it in neutral and braking?

 

really nothing, unless you're stopping from like 80+ mph.

 

The pads slow the car faster than the engine ever could...I'd imagine during extremely hard braking, the engine is offering more resistance to braking than anything.

 

wrong...the engine helps braking alot more than you think. i can come to a complete stop at a stoplight w/ barely using the brakes by downshifting. those of you who put the car in neutral and apply the brakes to stop instead of downshifting will go through brakes alot faster. been driving a stick since i was sixteen and have yet to wear a clutch out.

 

Yeah you can nearly stop a car, if you push it high into a low gear. Then you're wasting gasoline, and your passengers get to enjoy the surges of braking force.

I don't understand why people make things so complicated: brakes for braking, clutch for shifting.

Dave

 

Very well said Dave!

So now what about the argument that automatics downshift as you brake? My answer to that is because the transmission always needs to be in a gear because the car doesn't know when you will suddenly change from braking to 'gasing'. Am I right?

 

why are you wasting gasoline? if the throttle body is closed then the fuel injectors are basically closed too. downshifting is smoother than braking if you know how to do it right. and you come to a stop faster by downshifting and braking so its better. like i said, i have yet to wear out a clutch in 6yrs.

 

Larry thanks for jumping on my band wagon. I have been driiving a stick since i was 16 as well. And if you actualy know how to drive a stick. you will not wear outyour clutch ...the downshifts will be smooth as an automatic...and the deceleration even smoother than braking.....many people do not even know that i have a standard because i shift so smoothly and indescritly......learn to shift correctly and u will save brakes..and your be under more control with downshifting....as far as the gas comment....RPMs does not mean how much gas your engine is using....Larry is right it is how much your throttle body is open