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2018 Q50 Luxe, RSR springs, Hotchkis Sway Bars
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Discussion Starter · #1 ·
2018 Luxe

Hey Folks,

I noticed the other day that when slowing down aggressively in Sport mode, the tranny will also aggressively downshift to help slow the car. I HATE this. I have the Powerstop BBK so I would much rather put that extra stress on the braking system than the transmission. Is there any way to defeat this "feature"?
 

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I don’t think there is, other than taking it out of sport mode. Mine does the same thing and it freaks my wife out because of my exhaust system lol.
 

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That's the entire point of sports mode. Throttle/transmission/gear shifts are more aggressive. Don't drive in Sport or see if the personal setting let's you adjust more to your taste.
 

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Mine does it most pronounced in Sport+, although it can do it in Sport. My solution if I don't want it to happen is to just put it in Standard mode.

Personally, wouldn't worry about any "damage" to the transmission, it'll be fine...used to put shift kits in my cars and it would do a similar thing and the upshifts were quite firm (in a good way) and definitely offered "tire chirping authority" (to borrow a sales slogan), haha.
 

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Ddnspider is exactly right, the transmission is aggressively downshifting to be in the power band when you hit the accelerator again. It is more likely to engage when you are harder on the brakes in my experience. So when I am out having fun (or at the track) preparing for a curve, I hit the brakes hard to force it to downshift and then I am in a lower gear once I am ready to accelerate again.
Keep the car out of Sport or Sport+ and I don't think you will see this behavior. It sounds great by the way :)
 

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As others have said there isn't really any extra stress placed on the engine, it may run a bit hotter initially due to the higher RPMs but the throttle is closed if your braking
so very little or no air is making it to the engine for combustion so its generating less heat overall.

Downshifting when braking has a few extra benefits as well.

  • It keeps the engine in the power-band so you are able to quickly accelerate out of a turn or if you need to maneuver around something quickly.
  • It reduces wear/heat build up on the rotors and pads which can mean longer sustained usage (especially when coasting down a mountain or hauling).
  • It works alongside the brakes to aid in slowing the car down in a shorter distance.
  • It creates drag on the driveline in situations where you may have very little traction at the wheels themselves like on black ice.

So yeah its generally a good thing when driving!
 

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2018 Q50 Luxe, RSR springs, Hotchkis Sway Bars
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Discussion Starter · #9 · (Edited)
As others have said there isn't really any extra stress placed on the engine, it may run a bit hotter initially due to the higher RPMs but the throttle is closed if your braking
so very little or no air is making it to the engine for combustion so its generating less heat overall.
I'm not worried about stress on the engine. I'm speaking about the transmission specifically. The time I noticed it, I wasn't racing or anything. I had just gone over a rise fairly quickly, (65pmh or so), and was coming down the other side to a stop light so I was hitting the brakes fairly hard and the car downshifted a couple of times. In standard mode the car is pretty slow. I like the way the car revs higher and upshifts in Sport, I just don't like the way it downshifts.

Like I said, I'd rather hit my brakes hard than put that kind of sudden up-rev on the tranny. A brake job is way cheaper than replacing a tranny. Ugh, I really miss having a stick. Automatic is nice in commute traffic but 80% of the time I'd rather have a manual. Manual shifting in this car is lame.
 

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Fully agree that manual shifting an automatic is nothing like the real thing.

Keep it mind it's rev-matching (IIRC these units do) just as you would with a clutch while downshifting to slow down. So, don't think there is any additional 'shock' or 'load' on the transmission when it does do the aggressive downshifts upon braking.
 

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I'm not worried about stress on the engine. I'm speaking about the transmission specifically. The time I noticed it, I wasn't racing or anything. I had just gone over a rise fairly quickly, (65pmh or so), and was coming down the other side to a stop light so I was hitting the brakes fairly hard and the car downshifted a couple of times. In standard mode the car is pretty slow. I like the way the car upshifts in Sport, I just don't like the way it downshifts.

Like I said, I'd rather hit my brakes hard than put that kind of sudden up-rev on the tranny. A brake job is way cheaper than replacing a tranny. Ugh, I really miss having a stick. Automatic is nice in commute traffic but 80% of the time I'd rather have a manual. Manual shifting in this car is lame.
Sorry miss-understood your concern, the transmission will be fine as the engine is adjusting its RPMs to create a relatively smooth and synchronized shift of gears with the transmission, there is very little shock or load placed on the transmission itself thanks to the various sensors working together and the torque converter acting in place of the Clutch.

At worst it would probably cause a bit more wear on the transmission fluid, but if your changing the fluid every 60-70K miles (which I'd recommend) then I wouldn't worry too much about it.
But for sure we can all agree better new brakes than transmission if you had to pick. lol
 
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Sorry miss-understood your concern, the transmission will be fine as the engine is adjusting its RPMs to create a relatively smooth and synchronized shift of gears with the transmission, there is very little shock or load placed on the transmission itself thanks to the various sensors working together and the torque converter acting in place of the Clutch.

At worst it would probably cause a bit more wear on the transmission fluid, but if your changing the fluid every 60-70K miles (which I'd recommend) then I wouldn't worry too much about it.
But for sure we can all agree better new brakes than transmission if you had to pick. lol
Plan on changing the fluid every 30-35k miles. Changed mine at 35k because I felt the shift quality deteriorating. The fluid looked very dark and worn. Now I'm at 66k miles and the shifts are starting to feel sloppy again so I plan to change it soon.
 

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I'm not worried about stress on the engine. I'm speaking about the transmission specifically. The time I noticed it, I wasn't racing or anything. I had just gone over a rise fairly quickly, (65pmh or so), and was coming down the other side to a stop light so I was hitting the brakes fairly hard and the car downshifted a couple of times. In standard mode the car is pretty slow. I like the way the car revs higher and upshifts in Sport, I just don't like the way it downshifts.

Like I said, I'd rather hit my brakes hard than put that kind of sudden up-rev on the tranny. A brake job is way cheaper than replacing a tranny. Ugh, I really miss having a stick. Automatic is nice in commute traffic but 80% of the time I'd rather have a manual. Manual shifting in this car is lame.
its been told to you several times now but ill say it yet again in case you missed it, downshifting does not hurt the transmission. there is no additional wear to speak of, it doesnt hurt anything.
 

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Ddnspider is exactly right, the transmission is aggressively downshifting to be in the power band when you hit the accelerator again. It is more likely to engage when you are harder on the brakes in my experience. So when I am out having fun (or at the track) preparing for a curve, I hit the brakes hard to force it to downshift and then I am in a lower gear once I am ready to accelerate again.
Keep the car out of Sport or Sport+ and I don't think you will see this behavior. It sounds great by the way :)
I wish the Q came with the downshift feature my RT had. Blip the throttle and it'll go down a gear. Seems a lot more driver friendly than press the brakes harder IMO.
 

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2018 Luxe

Hey Folks,

I noticed the other day that when slowing down aggressively in Sport mode, the tranny will also aggressively downshift to help slow the car. I HATE this. I have the Powerstop BBK so I would much rather put that extra stress on the braking system than the transmission. Is there any way to defeat this "feature"?
It isn't doing that to try to slow the car. It is doing that to ensure you are in a proper low gear in case you need to accelerate out of a turn. That is inline with a Sport mode in my opinion. You may want to consider driving in standard mode, or personal mode and set the transmission to standard for personal mode.
 
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its been told to you several times now but ill say it yet again in case you missed it, downshifting does not hurt the transmission. there is no additional wear to speak of, it doesnt hurt anything.
I agree.
 

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I love that it downshifts in sport mode. These transmissions are rock solid. Plenty of people have pushed them harder than you ever will. I agree with what's been said, if you don't like it, why are you in sport mode?

Now granted the rev matching sucks and it's slower than a dual clutch, but when it bites it grabs hard af. It's a gem.
 

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Would reealllllly love to have the ability to tune the transmission. Cough*HPT*Cough 👀 ⏳🐌😕

Yes yes I know the circumstances, but I'm gonna complain like a petulant child anyways. 😤😔
 

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Would reealllllly love to have the ability to tune the transmission. Cough*HPT*Cough 👀 ⏳🐌😕

Yes yes I know the circumstances, but I'm gonna complain like a petulant child anyways. 😤😔
@Jsbowling42 and I are making some great progress on the ECU side of things that impacts the TCU. Right now I don't even use Sport mode because in casual cruising the car is holding gears longer and shifting crisp. I'm not saying the TCU won't bring added benefit, just that I'm extremely pleased with the way the car is driving right now, INCLUDING the transmission, with just the ECU tune.
 

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@Jsbowling42 and I are making some great progress on the ECU side of things that impacts the TCU. Right now I don't even use Sport mode because in casual cruising the car is holding gears longer and shifting crisp. I'm not saying the TCU won't bring added benefit, just that I'm extremely pleased with the way the car is driving right now, INCLUDING the transmission, with just the ECU tune.
I'm going to pick up hpt myself when I get back to my home station. I have to decide on an exhaust and then decide between a larger HX or go interchiller or not. Either way, I'm pretty sure hpt is what I want to do, mainly because of the transmission capabilities down the road.
 
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