27

Bear with me, I'm going to clear up a myth, then answer your question. You will see that they are related. Higher throttle doesn't mean higher RPM. Higher throttle just means more fuel entering the combustion chamber. This will tend to accelerate your engine, but if it's under an accelerating load (increasing incline) at a constant gear, the engine will ...


23

Is it ok to give gas while releasing the clutch? Yes, but your goal is to give exactly the right amount of gas. The thing to remember is that the clutch is a consumable part (it's really a whole system of parts that can be consumed but let's pretend that it's a single unique piece for the sake of discussion). As such, it has a finite supply of work that ...


22

You can do this if your engine RPM, the speed of the vehicle, and the gear you are shifting to/from is just right. The reason you can do this is because you have synchros in the transmission which allows the two gears to match rotational speeds as they come in contact (basically, there is more to it than this, but hopefully you get the drift). The synchros ...


17

When the car is in D and you start the engine the hydraulic pump in the automatic transmission is not providing fluid pressure until the engine starts. This fluid pressure is used to engage clutches in the transmission to engage first gear or reverse. An automatic transmission does not have gears like a manual transmission which are physically meshed into ...


15

Heel-Toe shifting and clutchless shifting are 2 different things. I guess they can be done together.... The one thing both of these techniques have in common is rev matching. There is the RPM you are at when you come out of a gear, and the RPM you will be at when you go into the next (or previous) gear. When you rev match, you try and have the engine RPM ...


15

Reverse is pretty equivalent to first gear, for a ratio of around 3.2ish. If it were any lower, it would be difficult to get started from a stop since the torque just won't be there. If you've ever driven a stick-shift, try starting from a stop in 2nd or 3rd gear and you'll see what I mean. For example - ratios for my manual 5-speed 2007 Mazda6: 1st: 3....


14

My Volvo V70 (model year 2006) has the digital dashboard fuel consumption meter. I also have a nice, fairly long uphill climb on my way to work, so I've had opportunities to try various methods. This is a manual transmission car. According to the car, the fuel consumption is nearly the same whether I downshift from fifth to fourth gear and let off the gas ...


14

You can put your car into neutral by moving the gear selector into the position marked "N".


12

If your car is slowing down, and you are at a "safe" speed for 2nd gear, then its perfectly normal to skip gears. If you're going the wrong speed and the engine RPMs aren't even close to what they need to be, the syncros might have a hard time lining everything up and you could hear a little grinding, and cause a little wear, but it still shouldn't cause ...


11

It sounds like they're trying to take you for a ride to me. I can't see how driving style could cause the slave cylinder to fail - they're separated by a mechanical linkage. I would also dispute that anyone could destroy a clutch with 32k of normal driving - I'd expect it to last at least twice that long. However, a leaking cylinder might cause ...


11

Did you ever wonder why an open ended wrench is angled at exactly 15° ? That's so you can turn a nut a little bit, flip the wrench over, turn it a little bit more, and get the job done! You mentioned that you can turn the wrench 1/8th of a turn. That's plenty! In fact, I wouldn't be surprised if the mount was designed to accommodate the 15° wrench flip ...


11

The transmission has a lock up torque converter. The torque converter sits between the engine and transmission. It is kind of like a clutch on a manual transmission car. When the engine is idle, it is barely engaged, so the engine will not stall. It will engage harder and until a certain RPM. Torque converters will always have some slip in them until ...


10

This is a bad idea for several reasons. First, you run the risk of a runaway car. Second, you risk damaging your transmission, which could cause the runaway car in the first place. Thirdly, in newer fuel injected cars, you can actually get worse gas mileage. Let me explain. As stated before, by not having it in gear, you run the risk of your car getting ...


10

Background The Ducati transmission type is a constant mesh sequential. There is a ride by wire system that controls the the throttle butterfly's. Ride by wire is necessary in order for the ECU to regulate power based upon various maps the rider can select. Process The clutchless downshift is similar to the clutchless upshift in that it is essentially doing ...


10

It causes more wear on the clutch as you have to ride it a little more, but overall its fine. The syncros will likely wear a little faster also as the output shaft will be spinning in the opposite direction. The bigger the speed difference, the more it wears parts.


10

There are physical limits to sychronizers. When you upshift the synchronizer slows the clutch down which is relatively easy. When you down shift the synchronizer has to speed the clutch up which is much harder. Going down just a single gear is not that bad. When you're on the highway, shifting into first is not possible because you're asking the clutch to ...


9

It depends on how you do the skipping If, when you do it, you hear loud clunks, that means you are not matching the RPM's to the road speed, to the transmission. Motorcycles have a synchronous transmission with with relatively fragile shift forks operated by a shift drum. The forks move the gears side to side to engage. if you are hearing a loud 'clack' ...


9

I'm going to expand on rpmerf's answer, where he has disambiguated between Heel and toe and clutchless shifting. I'l briefly explain the driving technique only to better illustrate what it hopes to mechanically achieve. And so, please excuse me if get the nuance of the technique wrong. Here's an image of a gearbox. I couldn't find a one with synchromesh, ...


9

I'm assuming you have a manual transmission. Stop doing that, you will damage your transmission. Your powertrain can be broke down into three sections. The engine, including the fly wheels. The clutch and input to the transmission. Finally the transmission output. When you push the clutch the engine is disconnected from the transmission input. When you ...


8

If the engine had a gear position sensor or you were considering installing one, i'd assume you wouldn't be asking this question. Anyhow, still , if you can install one, that'd be your easiest option, - the sensor is a rotary potentiometer. Or you can use any other rotary encoders you please. The method you mention can be made pretty accurate, though, i'd ...


7

Look at it this way, the sequence is indeed linear - 1-2-3-4 and so on, with the neutral sitting in-between 1st and 2nd gear. Which means, to shift to neutral from 1st gear (or down from second), one has to gently nudge the shifter into neutral, else it would directly jump to 2nd gear. This is desire-able as one generally doesn't need to shift to neutral ...


7

Chilljeet has a good answer, but it's also partially a safety thing. When you're slowing down to a stop, you're clicking down in the gears until you can't click down anymore. If the bottom gear was neutral, you're a sitting duck until you can get back in gear if someone is coming up behind you at a high speed. You need to be in gear and able to react ...


7

Is it OK to "half-shift" in order to inch forward in tight spots? This is usually called slipping the clutch and as long as you don't do it for prolonged periods of time will not damage the clutch. Doing it for prolong periods will cause heat buildup to occur, which is very bad for the clutch and for the flywheel (can form heat cracks). As far as the ...


7

There is a distinction that needs made between an automatic and a manual. The majority of automatics will lock out reverse above a particular speed usually several miles an hour. If the car is below that speed reverse will engage while still moving forward. In a manual transmission everything depends on if reverse is synchronized. If it's not then you ...


6

We have a 2011 Ford Focus TDCi 115 engine (same, I assume in your Mondeo econetic) and we are currently having our slave cylinder and clutch plates changed. The car is on 35,000 miles and has previously had the clutch master cylinder replaced. According to many Ford forums, it is very common on these new 1.6 TDCi 115 engines to have clutch related issues. ...


6

The specific answer to your question lies in the BSFC (Brake Specific Fuel Consumption) map for your engine, combined with the desired output. The BSFC map shows how efficiently the engine converts chemical energy to mechanical work at any given condition. Here is an example:


6

I agree with MT_Head's and Donovan's answers, but I'd like to add that the downshift itself can be quite heavy on your synchromeshes if you don't do it right. When you up-shift, the input shaft drops in speed by ordinary friction, and the synchromeshes don't need to work much in order to match it to the speed of the output gear. However, when you down-shift,...


6

I've rebuilt a few transmissions (actually a lot of transmissions LOL) and no, manually shifting is just fine. All your doing is replacing the TCU with your own shifts. So your just fine manually shifting the car. WOW just saw this was a four year old question... sorry folks.


6

I'd like to add to the discussion about the cause of your issue, as this page is indexed highly in google: If your problem is only when the engine and gearbox are cold, and the 'box performs fine in all other respects then it may be that the synchromesh's in the gearbox are starting to wear. The reason this causes poor cold gear changes is thus: when the ...


6

Yes it's okay. As long as you are letting go of the clutch by a little bit and at the same time, you give it a little bit of gas. If you just let go of the clutch without giving any gas in first gear, you can go forward/fast then the car will just stall. I'm only 14 and I just know about this because of my brother.


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