hammer098

hello,
Just wanted some advice on clutch/transmission wear. I was always taught that it was better on clutch/trany to place car in neutral and have foot only on brake, also when possible slow down to a stop only on brake. The logic being brakes are less expensive than clutch and transmission....
Does any of this make sense?

mg7726

learning to rev-match on your shifts is the key to saving your synchos, clutch, and tranny.

http://www.standardshift.com/faq.html

http://www.turnfast.com/tech_driving..._heeltoe.shtml

i was taught to drive like you by one of the 'regular' driving instructors; but going to some driving events made me realize everything else i was missing. make sure to practice this in an empty parking lot, so you don't hurt yourself...or possibly others.

biker

Yes, you can use engine braking most of the time, but don't row gears on the way down to a stop. Rev matching just nets you worse fuel milage (and bragging rights).

MaxOctane

Hammer 098,

Please don't try to rev-match your shifts. mg7726 gave two links on heel-toe downshifting, which is a racing technique and does not necessarily explain how to rev-match your shifts. Unless you plan to race, I do not recommend this technique.

Rev-matching is the act of matching your engine speed with the wheel speed in the gear you want to shift to. If you do it just right, you can shift without ever having to push the clutch pedal in. Since you aren't pushing the clutch in, your pressure plate, clutch plate and flywheel never seperate and thus you will experience less wear on your clutch plate (which is what is made to wear out and be replaced when your clutch goes bad). Doing this requires alot of practice though, and if you don't do it right, your synchros will have to make up for any error and they will pay the price. Your synchros use friction to match the your layshaft speed with the pilot shaft, and when you have the clutch pedal pushed in, your pilot shaft is freewheeling so it's not hard to speed up or slow down. When you rev-match a shift, the pilot shaft is not freewheeling and so your synchros are trying to speed up or slow down a shaft that is directly attached to the engine. If you don't do it properly, your synchros will overheat attempting to speed up or slow down a shaft that YOU determine how fast is going by changing how much gas you give it. This is how big rigs are made to work.

I do not recommend this technique unless you really know what you are doing. It's risky for your tranny to save your clutch which is something that is made to wear out and be replaced anyway. If you really want to help save your clutch, make sure you push the pedal all the way in when you shift and don't rest your foot on the clutch when driving when the clutch pedal is meant to be out. Also, don't pop the clutch, and don't over-rev your shifts. For instance, if your going form second to third, and inbetween the shift you bring your engine to 6K RPM's and then let out on the clutch really quickly in third gear. Doing this will wear out your clutch really fast.

As a side note, most of your clutch wear occurs when the clutch plate is "rubbing" inbetween the pressure plate and the flywheel. This "rubbing" occurs when you give it alot of gas and slowly let out on the clutch pedal - you can feel the car start to move forward with the clutch halfway out...the sensation of the engine only being halfway engaged with the wheels is the "rubbing" I am talking about which wears out your clutch more. As you can imagine, the only time you really do this is when you are stopped and you are trying to get going like at a stop sign or stop light. Obviously, you cannot rev-match going from stopped to first gear and thus you will still experience alot of wear on your clutch even if you do master rev-matching. Over-reving your shifts which I talked about earlier will also cause alot of this rubbing and will wear out your clutch fast too. Does this make sense?

MaxOctane

Also, to answer your questions. Engine braking is usually not a great idea unless you have a specific reason for it. Usually braking when the tranny is in neutral is better because it will save gas and save revs on your engine. If you are braking excessively, then you might want to consider it because you don't want your brakes to overheat. Overheated brakes will fail. I usually brake to a stop in neutral.

waterrockets

I don't race, nor do I plan to, but I heel-toe. I almost never do it at high speed or under hard acceleration. It's just how I drive. There's no reason not to recommend heel-toe for "normal" driving if someone is motivated to learn how to do it.

My passengers have said that it's a really smooth feeling, and I get enjoyment out of it. Plus, it's easier to get back up to speed after a corner.

waterrockets

It's safer to stay in gear when slowing/stopping in case you have to accelerate suddenly to avoid a collision. The clutch need not be engaged, but keeping it in gear keeps the car ready-to-go.

MaxOctane

If you want to learn how to heel-toe be my guest. The original post was asking how to preserve clutch and tranny life, not how to accelerate through a turn more smoothly. I also recommended not to rev-match, which is different than heel-toeing (did you read my post?).

waterrockets

Easy tiger. I agreed that they're different in my post too.

Think about how you come out of a turn without heel-toe shifing. Say you approach in 5th gear at 40 mph, and take a right corner, exiting at 15 or 20. If you don't downshift, you'll be in a horrible gear coming out of the turn.

So, given that you have to shift to accomodate this much slower speed, when do you, MaxOctane, do it?

If you do it after slowing for the turn w/out rev-matching, then it's going to be a big clutch slip. Even if you do rev-match, it will be awkward and likely to require some clutch slippage along with a large RPM gain. If you go into neutral and coast the corner, then you're compromising safety on top of requiring a clutch slip, or a big blip with a rev-match.

If instead, you heel-toe on the approach and entry, then you have well-managed revs, and can nearly eliminate clutch slippage. And I'm talking about casual residential, kids-playing-ball-in-the-street kinds of driving here, not racing or breaking traffic laws.

So what's better for the transmission and clutch?

MaxOctane

When you heel toe, you blip the gas to match the rev of the car so when you let out on the clutch the speeds are matched BEFORE the turn. Alternatively, if you coast through a turn, you blip the gas to match the rev of the car so when you let out on the clutch the speeds are matched AFTER the turn. (both considered downshifts) There is no difference and both have equally the same chance of clutch slipping depending on how good you are. The ONLY difference between the two is that if you heel toe you go into the turn already in gear and you can accelerate through the turn, thus the reason it is primarily used for racing. If you're coasting through a turn you can obviously not accelerate until you have shifted. Both require depressing the clutch and releasing the clutch pedal. Both require matching the revs of the engine with the speed of the wheels and thus both are susceptible to the same amount of wear and tear. HOWEVER, heel-toe downshifting will lead to smoother and faster turns.

Now, take into consideration how often you do this. Then take into consideration every stopsign, every red stoplight, every time your in traffic on the highway and you come to a complete stop each and every 5 feet, and every left or right turn from a complete stop you take. Most of your clutch wear happens from going from stopped to 5mph. If I had to guess, 80-90% of your clutch wear happens then.

What do I do? I usually coast through a turn, however I rarely ever need to because of regular traffic. It's not much of a saftey hazard if you shift while in the turn and coast by holding the clutch in.

hammer098

thanks guys for the remarks....
so i GUESS my original question was answered, that being to either keep clutch in at or coming to a stop. The answer is coast out of gear and don't use the clutch until time to take off....
man you guys have a way of not actually reading the question ;-) ....
never really used the heal and toe technique, might have to read on actually how to do it...thanks for the info!

gdcwatt

Read your Bondurant On High Performance Driving. And don't practise at 7,000rpm (in case you mess up); heel-and-toe/rev-matching can be used at any speed.

gdcwatt

The other thing is when you're heel-and-toeing/downshifting WHILE you're braking, the brakes are stronger than a slightly mis-rev-matched shift, and it will seem smoother.

Different things will work for different people. There is no way that my feet have enough room to heel-and-toe in a Mazda6, and in my old Civic, where the gap between the brake and the gas pedal was so big, I had to use the top/side of my foot for the gas, while the ball of my foot was on the brake. Practise in your driveway, with the engine off, first.

waterrockets

Well it sounds like we agree then. But you were recommending against rev-matching to save wear and tear, when it really is required, as you describe in your cornering technique (you gotta do it to get moving after the corner).

The only thing about costing through corners is that a powered wheel has more traction than a coasting one. So, in rain, snow, ice, or on gravel, coasting becomes a little more dangerous as traction lowers environmentally.

FWIW, I only heel-toe if I'm going to be very temporarily slowed and getting back up to speed (cornering, minor traffic clump, etc.) otherwise, I brake while clutch-coasting, and shifting down through the gears in case I need to re-engage, then rev-match as necessary to get going again.

TSX.Fury

I find that to be the most efficient and probably best all around for the clutch.

MaxOctane

AH HA! So you didn't read my post after all (I had my doubts). In my original post I referred to rev-matching for non-clutch shifting. THAT is what I recommend against.

gsrthomas

I never use engine braking. Brakes are cheap to replace why waste gas and suffer more engine ware??

I have 140,000 miles on my 1996 Acura Integra GSR with the ORIGINAL CLUTCH.

West6MT

I have a few questions for you guys.

So is it not a good idea to downshift coming up to a light by rev matching. I dont mean doing it without using the clutch, but with the clutch. For ex,.......coming off the hwy in 5th and the turn is a "3rd gear speed" turn as you exit. So, off the gas and you start to slow down, little brake application,........then put the clutch in, shift down and blip throttle, let clutch out, and you are in 4th now. Repeat into third before turn. Is that gonna wear out the clutch or be bad for my tranny? Should I not do that,........what would be better?

I have only used heel/toeing in a race car,.....and it was more like toe/toeing,......cant use your heel really. Top part of foot on brake (but kind of to the side), and roll foot to the side to blip the gas. I got the hang of it pretty quick and it was a ton of fun,.....especially at the speeds we were going. I have seen video of my instructor doing it,......crazy fast. But that way (which i would prefer to do) wont work in the TSX I dont think because the brake and gas are too far apart (and I dont need to do it ever) but I was wondering about it last week. I am guessing that you guys, when you do heel/toe, do it like in that article that was posted (toes on brake, rotate foot and hit gas with heel). Is the TSX an easier or harder car to heel/toe in? How long did it take you go get the hang of it,.........or are you like pros?

Thanks if anyone answers my questions.

waterrockets

I see: I misread it, which is somewhat different from not reading it.

But... but... shifting is fun...

waterrockets

Well, it's extra wear on the transmission and the engine, but I don't think it's excessive or abusive. Done reasonably well, it's not significant clutch-wear.

Still, if I'm going to be accelerating again, I'll heel/toe it so the brakes are still doing most of the work. If I'm actually stopping or slowing for long time (traffic), I just row the gears (just in case...) with the clutch disengaged, and just use the brakes to stop.

I haven't been able to literally heel-toe since high school in my dad's full-size truck, where I had a lot of foot room and the pedals are far apart. Strangely, that heel-toe action was for off-road rock crawling -- to get started on a STEEP incline. I had to get the revs up to start, but stay on the brake to keep from flying down the trail backwards through the boulders.

As far as the TSX goes, I wear a size 12 shoe, and when the ball of my foot is on the brake, my heel will hit the floor before the gas pedal. So I toe-toe it, as you say, but still call it heel-toe to keep the language familiar.

On top of that, the TSX gas pedal is hinged at the bottom, making heel work more difficult anyway.

Oh, and I ain't no pro. I've got it reasonably smooth, but I'm more of an enthusiast than someone with actual talent. Certainly better than the average driver with a stick, but probably just average compared with anyone who's learned to heel-toe.

MaxOctane

The main wear parts that we are talking about here are your clutch plate (meant to be changed out eventually) and your synchro's in your tranny (not meant to be changed and expensive to do so). Let's go over what DOES wear these out and you should be able to decide if what you are doing wears it out faster.

Lets start with the synchro's. Have you ever tried to downshift into second or first gear when going maybe 50 or 60 miles per hour? It will feel like it doesn't want to go into gear. What's happening is your synchro is trying to match the speed of the pilot shaft (what connects to your engine) with the layshaft (what goes to the wheels). But since your wheels are going so fast and such a low gear requires a very fast pilot shaft speed, your synchro is having to work very hard to speed up the pilot shaft. The synchro uses friction to speed up/slow down the pilot shaft and when you force it into gear you wear out your synchros. Essentially the friction can heat them up and they wear out faster. With all of this said, it is never good to have to force it into gear, especially a lower gear. When you downshift, if it is hard to shift than you are exposing your synchros to more wear. Now, keep in mind that you can manually speed up your pilot shaft. Let's say you are going 40 and you want to downshift into second gear. If you try to shift directly into second, then it might be hard to, and your synchro will have to work hard to speed up your pilot shaft (essentially your pilot shaft will have to match the speed of going 40 mph in second gear which is pretty fast). What you can do is put it in neutral, let off on the clutch and blip the gas. Doing this will speed up the pilot shaft. Then, push the clutch in and shift into second. You'll have to do this quickly by the way. When all is said and done, this is totally not worth it. You are better off just waiting until you slow down enough to downshift. SO, the point is, to save your synchros, don't force a shift, especially a downshift. Some notchyness is expected in the shift and that is only your synchro's working.

Now about the clutch plate. You can read what I wrote earlier to get a good idea of what wears out the clutch plate. Essentially the rubbing of the clutch plate and the flywheel when the clutch is halfway engaged causes wear. When shifting, this can be minimized by matching your revs with the speed of the car. Most of your clutch wear will happen going from stopped to 5mph.

As long as your downshift is not forced into gear, your synchros should be okay. Going from 5th, to 4th, and then to 3rd as you mentioned helps step up the speed of the layshaft and will distribute the work of the synchros over several gears rather than going from 5th directly to 3rd. And if you are matching your revs with the speed of the car when you let off on the clutch, you should be okay. I cannot say for sure if you are causing more wear by doing this or by coasting through the turn and letting up on the clutch at the end of the turn. As I mentioned, most of the wear is going from stopped to 5mph, so I would think any extra wear would be negligible. If anything it is probably better for your synchros to not be downshifting so much since that is what you want to be more careful with considering they are more expensive to replace.

Racing shoes are very thin and allow you to feel the brake and gas pedal on the bottom of your feet well. I used to heel-toe in my old integra, but now the TSX and my Maxima's pedals are too far apart and are hard to heel-toe in especially with the large shoes I normally wear. Also, the gas pedal on the TSX is hard to depress on the bottom since it hinges from the bottom. I might be able to in the TSX if I were barefoot, but I don't see enough benefit for it. Heel-toeing doesnt decrease wear, and is hard to do and if not done properly it can increase wear. The only benefit for being able to do it is better acceleration in a turn and most of all: Bragging rights.....It's up to you to decide if you want to or not....

I am definitely not a pro, and it didn't take me too long to get used to, although it really depends on how well the pedals are positioned.

gdcwatt

Nicely put MaxOctane, but I don't like the sound of that "coasting through a corner with your foot on the clutch..." either. How fast are we talking about going here.

If we're talking about higher speeds, and you're using the gas pedal to also steer the car, then you need to be in the right gear to give you the thrust at the road to get both ends of the car working, as you near the limits of adhesion - to balance the understeer/oversteer. And if you're going through some esses, you might need to be changing gears along the way, so not doing anything jerky to upset that balance is a really good idea.

Coming up to a stop, I throw it into neutral before I stop. And this talk about "lightly braking", well, if you only need to lightly brake, then you probably won't soon be needing a lower gear for weight transfer, or acceleration, so you might as well enjoy your Sunday drive, and just not bother shifting.

It is agreed that brakes are cheaper than transmissions, so some compression braking because it sounds nice is probably not something to be done all the time. Not having the ability to maximize grip or control the car around a corner could cost you the car!

MaxOctane

This is difficult to answer. Power at the wheels while turning might help with grip, but how often? Typically this is not a problem unless you are racing around a corner and/or if the road is wet. Most of my turns are done very slow in second gear and there is no chance of losing control (especially with VSA on). Also, here is something to think about. What about rear wheel drive cars? They don't have power in the front wheels at all. If you are running a risk of losing control of your turn while coasting through, then it is no more than risk that a rear wheel drive car has because they don't have power at the front wheels either. Regardless, if you are pushing the limits of adehesion as you mentioned before, then extra precautions should be made. Also keep in mind that if you are pushing the limits of adhesion you are exposing yourself to many more risks and this is not recommended unless you know what you are doing. (If you know what you are doing then you don't need this thread because you should know all this already and you should know how to drive while pushing limits). Otherwise, for the majority of everybody else, take turns slow and reasonable and you won't have a problem even if your crusing through a turn in neutral. If your THAT concerned about it, you can run a slightly lower tire pressure in your front tires to help increase traction.

biker

Like it has been said, the major wear factor is from a stop. Synchros nowdays just don't go bad unless you abuse them. So go ahead and downshift to whaever gear you want when you come off that highway ramp. Going from 6th directly down to 2nd is not a problem under normal circumstances. Just slow down using brakes until you have to accelarate again and then change to whatever gear is needed. When coming to a stop keep it in whatever gear you were in until the RPMs drop to about 1500 (engine braking effect is minimal at this point) and then coast the rest of the way in neutral.

West6MT

Thanks for the great responses guys.

In most situations I just use the brakes to slow down when coming to a light then put it in neutral a little bit before coming to a stop. I tend to downshift when slowing down when coming off the hwy (like in my example) sometimes, but not all the time. In my old nissan, I could match the revs really well while downshifting, but cant seem to get it right all the time in the TSX. Sometimes they are a little too high, or a little too low,.....I would say half the time I get it right. Maybe its because of the drive by wire???? In any event, perhaps it would be best to not downshift so much (ex example) and just use the brakes more. Maybe im just not used to the TSX yet.

My stupid room mate from this past year was not very nice to her clutch in her neon. She would ALWAYS start from a standstill in 2nd gear,.......so she was riding the clutch ALL the time. I dont know if I ever saw her use 1st gear to be honest. I told her she was causing a lot of wear on her clutch but she wouldnt listen. I hope she does not still do that with her new mazda 3.

In terms of coasting around a corner,........I do that sometimes and sometimes I have it in gear with the power available. Its always 2nd gear corners, not racing around so its not a big deal. While at the race school a very important thing was to be on the Gas in the corners. If you coasted with the clutch in or just not on the gas the car would spin out on you. All the weight was at the back of the car and of course its rear wheel drive. Some of the other drivers spun out because they were pressing in the clutch coming up to and going through the turns (this included my dad once hahahaha). At the very start of the day I went into a corner too fast, but was on the gas (so not to spin out) and ended up on the grass for a second or two because the turn was wide LOL, but I wasnt gonna spin out. After that I did really well,....I was one of the fastest around the track and got the hang of heel/toeing in the car. Im going back next year,...SO MUCH FUN. Here is a pic of the car I drove.

http://img269.imageshack.us/img269/2429/img19555yj.jpg

The problems you guys mentioned with heel/toeing in the TSX are what I noticed too. I was just curious pretty much,.........the odd time I do get this urge to do it though. Im pretty sure I am not gonna try it,........I want to baby my TSX and dont wanna risk making a mistake and causing undue wear on its parts.

waterrockets

I wonder that too. I drove nothing but automatics for about 6 years, so I've forgotten some of the minor feedback feelings I get from the car. I feel like the TSX drive by wire system lets the engine hang longer from a blip, which may cause you to rev too high if you were used to a different system. It's tough for me to tell if that's what the TSX is actually doing. Whatever it is, it's subtle, but I think helpful if you embrace it.

Nice racecar by the way I hope to try a race school one day...

West6MT

I think we are right waterrockets.

I would highly recommend going to a race school. It is so much fun and you learn how to drive a fast car FAST. I am going to go back next summer,..hopefully for a longer course so we get more time in the cars etc. Its expensive but SO worth in IMO. I still get a huge grin on my face when I think about how great it was.