DSG downshifting

[tonipepperoni77]

Was reading up on this and since I've been driving in manual mode a lot I obviously downshift when slowing down but also to lesson the amount of braking needed and letting the downshifts do some of the braking. I had read a few things about 5 years back some saying it can be bad for the DSG clutches but to me this is how a car should work. And I'm not downshifting from a high speed to a super low gear, max the RPMS jump to 3k when I downshift so I was just wondering about some of your thoughts on this


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[Golf R1]

Was reading up on this and since I've been driving in manual mode a lot I obviously downshift when slowing down but also to lesson the amount of braking needed and letting the downshifts do some of the braking. I had read a few things about 5 years back some saying it can be bad for the DSG clutches but to me this is how a car should work. And I'm not downshifting from a high speed to a super low gear, max the RPMS jump to 3k when I downshift so I was just wondering about some of your thoughts on this.

Good question, would like to know the same myself. I've also been using manual more myself. I'd rather replace the brake pads than clutch pads though engine braking is useful. I tend to follow the downshifting habits of my tcu; although it is hard to resist the urge to downshift with purpose while driving aggressively.

 

[kidbs]

Was reading up on this and since I've been driving in manual mode a lot I obviously downshift when slowing down but also to lesson the amount of braking needed and letting the downshifts do some of the braking. I had read a few things about 5 years back some saying it can be bad for the DSG clutches but to me this is how a car should work. And I'm not downshifting from a high speed to a super low gear, max the RPMS jump to 3k when I downshift so I was just wondering about some of your thoughts on this


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I've never understood why people want to use their clutch rather than their brakes to slow down. Brake pads are a lot cheaper than a new clutch. Also, you bought the DSG, let it do the work for you.

 

[NCM]

Was reading up on this and since I've been driving in manual mode a lot I obviously downshift when slowing down but also to lesson the amount of braking needed and letting the downshifts do some of the braking.

The engine is for going. The brakes are for stopping. The basic rule is that you downshift because you are going slowly, not because you want to go slowly.

Brakes are also absurdly cheap compared to engines, clutches and gearboxes — you do the math.

Neil

 

[tonipepperoni77]

The engine is for going. The brakes are for stopping. The basic rule is that you downshift because you are going slowly, not because you want to go slowly.

Brakes are also absurdly cheap compared to engines, clutches and gearboxes — you do the math.

Neil

I'm not saying I'm using it to slow down lol I'm using it and downshifting like a manual would that's all


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[The Fed]

I'm not saying I'm using it to slow down lol I'm using it and downshifting like a manual would that's all


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You're still stressing a lot of expensive components, and I believe the consensus will be use the brakes. You don't want to have a failure out of warranty. Also, letting the trans operate in D should use the least gas.

 

[tonipepperoni77]

See to me I'm not stressing anything that any other dual clutch system would do. Obviously I'm braking at the same time and when you brake you also downshift and it also helps the braking so to me there is no unusual wear and is how a dual clutch system works


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[biglilsteve]

See to me I'm not stressing anything that any other dual clutch system would do. Obviously I'm braking at the same time and when you brake you also downshift and it also helps the braking so to me there is no unusual wear and is how a dual clutch system works


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True, there is no unusual wear but there is still more wear than just using the brakes. You'll notice there is FAR less engine braking when just driving in D. Only downshift yourself when you want to have a little fun with the car. There's just no use of doing it during your regular commutes.

 

[The Fed]

Doesn't the DSG still have brass syncro rings that are used when shifting in either direction? That's reason enough to not use them any more than needed.

 

[CT GTI]

My co-worker has a 06 GTI with DSG. 190k miles on the orginal powertrain and DSG clutchs. He only uses manual mode. Just drive it like you want to.

 

[The Fed]

My co-worker has a 06 GTI with DSG. 190k miles on the orginal powertrain and DSG clutchs. He only uses manual mode. Just drive it like you want to.

All I can say is, I would need proof.

 

[tonipepperoni77]

My co-worker has a 06 GTI with DSG. 190k miles on the orginal powertrain and DSG clutchs. He only uses manual mode. Just drive it like you want to.

I believe it obvi downshifting hard into high RPMs I can see wear over time but if I downshift and it only goes to 3k I don't see any wear since that's how it's designed to downshift


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[cooljoe]

So here's the cool thing about the DSG. There are actually two input shafts, and each one is connected to a separate set of clutch packs. What this means is when you downshift, the computer pre-selects the new gear on the input shaft (let's call this input shaft 2) that is currently freely spinning (the clutch is disengaged). Next the computer quickly dis-engages the clutch packs for the other input shaft (input shaft 1). At this point, the car is, for a brief millisecond, coasting because both clutches are dis-engaged. The computer can then safely engage the clutch connected to input shaft 2 (which has the lower gear selected). At this point, the input shaft side of the clutch is actually moving quite a bit faster than the crank shaft side of the clutch. In other words, the transmission's input shaft is spinning faster than the engine's output shaft because the speed of the car is faster than the required rpm's for the current gearing ratio.

DSG transmissions typically use a set of "clutch packs", so there are a bunch of friction plates that get pressed together and the momentum of the car forces the engine to spin faster and match speed with the transmission. This is the main point where you would experience wear on your clutch packs as the rest of the time, they are either fully engaged or disengaged. That being said, your car is somewhat heavy and the engine requires quite a bit of force to turn, so the wear on the clutch packs is probably somewhat higher than if you were to make a less violent shift at lower speeds/rpms. Some of this force is also absorbed by the drive train and through the wheels, which you will feel as the car begins to slow down.

That being said, is this likely to damage your clutch? Given that these transmissions are supposed to last hundreds of thousands of miles, I don't think it will make a noticeable difference for the lifetime that you own the car. The amount of time that the clutch packs are actually being worn is very minimal and it's unlikely that the forces that are being applied are outside of the expected general wear and tear of the car.

I found an interesting diagram, but there are also plenty of really neat youtube videos of how a DSG actually works online.

 

[cooljoe]

Doesn't the DSG still have brass syncro rings that are used when shifting in either direction? That's reason enough to not use them any more than needed.

While the VW DSG apparently does have multiple synchronizer rings, there are actually two input shafts to the transmission, so when pre-selecting, the gears are already rotating at the correct speed for the corresponding input shaft. Unlike a traditional manual transmission where you have to wait for the input shaft to slow down or speed up and use the synchronizer gears to speed up that meshing process, in a DSG, the output shaft can be connected to the input shaft before the clutches are swapped. Many manufacturers like Ford don't actually use them in their dual clutch transmissions as they are less useful.

I guess I should also mention that engine breaking doesn't really do anything to hurt the car. Infact, you will likely find you have better gas mileage if you use engine breaking properly as most cars actually turn of the fuel injectors in the event of engine breaking. That being said, you are likely using manual mode so you can blast around town so the fuel savings are probably far offset by the extra usage from spirited driving.

 

[buyingconstant7]

I love engine braking, I do it all the time. Hell, before my R and a couple other cars, I had a 2006 Jetta TDI 5spd(now belongs to my sister). I bought it brand new in 2005 and put 320,000kms on it until early 2015. Original clutch, original brakes all around including pads as of this date, even with the now 355,000kms it has on it from my sisters takeover. I always downshifted and let the engine brake before I stopped at a set of lights, also, 9 times out of 10, you can anticipate the light and engine brake and before you go below 20mph, the light is green and you're off...saves wear on the clutch from taking off and saves fuel. So no, I'm not buying the fact that you shouldn't engine brake to save your clutch. I do it in my R too. I'll never stop doing it either.