Variable brake assist behavior

[Thomby]

I've noticed when approaching stopped traffic at an intersection that braking often ramps up without a change in pedal effort. It's not emergency braking, but there's a definite lurch forward as I'm gently braking down over a couple hundred yards, as if the car noticed traffic ahead and decided I needed to brake harder.

I don't think it's the forward collision assist because there's no visual or sound alert, or steering wheel vibration, but the braking force ramps up pretty noticeably (say from 10-15% to 25-30%) and I haven't seen any other setting/system it could be. Any ideas? Is there some algo linking brake boost to speed, like drive by wire throttle response?

 

[Snicklefritz]

between the two stingers that I have driving experience with (one with brembos the other being the smaller discs and utilitarian calipers), the 2.0l has much 'grabbier' brakes, I need a lighter foot or else it wants to lurch to a stop. this is at low speeds, at highway stopping speeds I don't feel the difference as much. but you could try modifying your foot (lighter pressure) and brake earlier. adapt to the brakes you have instead of expecting the brakes to be a particular feel.

 

[Thomby]

between the two stingers that I have driving experience with (one with brembos the other being the smaller discs and utilitarian calipers), the 2.0l has much 'grabbier' brakes, I need a lighter foot or else it wants to lurch to a stop. this is at low speeds, at highway stopping speeds I don't feel the difference as much. but you could try modifying your foot (lighter pressure) and brake earlier. adapt to the brakes you have instead of expecting the brakes to be a particular feel.

So this isn't the brakes grabbing at different rates based on applying at different speeds. This is me applying the brakes at say 45-55mph, to gently brake down over several hundred yards approaching an intersection, and as I'm gradually decelerating, the brake force will suddenly ramp up with no change in brake input.

It feels as if there's either a step change in brake assist at some speed (which doesn't make sense, even if it is variable it should taper up/down), or as if the car suddenly detected the upcoming traffic and decided I need to brake at a higher rate (but again, no panic stop or alert).

 

[Snicklefritz]

I see, now it sounds like you could be confusing a 'harsh' downshift with the brakes increasing pressure. have you ruled out the somewhat common complaint of the tranny developing that downshift issue? I have forward collision avoidance too on my premium but keep it turned off. you could try turning yours off and see if that makes it go away.

 

[JSolo]

^^This could easily be put to the test.

On an empty road way get up to speed (50-60 mph?). Place shifter into N then brake as you did in post #1. If braking is normal then it confirms Snicklefritz's theory.

I will say this, coming from other cars, the downshifts, even in comfort (on the 2.5T) are some what more abrupt. This becomes less so after break in, but still present.

 

[NS_Stinger]

What drive mode are you in? If you drive around in sport mode it could definitely be a downshift causing it.

 

[Thomby]

I see, now it sounds like you could be confusing a 'harsh' downshift with the brakes increasing pressure. have you ruled out the somewhat common complaint of the tranny developing that downshift issue? I have forward collision avoidance too on my premium but keep it turned off. you could try turning yours off and see if that makes it go away.

^^This could easily be put to the test.

On an empty road way get up to speed (50-60 mph?). Place shifter into N then brake as you did in post #1. If braking is normal then it confirms Snicklefritz's theory.

I will say this, coming from other cars, the downshifts, even in comfort (on the 2.5T) are some what more abrupt. This becomes less so after break in, but still present.

You know, this didn't even occur to me, mainly because I don't typically have it in Sport and haven't noticed the engine revs spike (visually or by ear), but then again the Stinger's gearing is very close. Will definitely give it a try, thanks!

 

[nhcowboy28]

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[coffeelovr]

I've noticed when approaching stopped traffic at an intersection that braking often ramps up without a change in pedal effort. It's not emergency braking, but there's a definite lurch forward as I'm gently braking down over a couple hundred yards, as if the car noticed traffic ahead and decided I needed to brake harder.

I don't think it's the forward collision assist because there's no visual or sound alert, or steering wheel vibration, but the braking force ramps up pretty noticeably (say from 10-15% to 25-30%) and I haven't seen any other setting/system it could be. Any ideas? Is there some algo linking brake boost to speed, like drive by wire throttle response?

Did you ever figure out what is causing it?
My wife has the '23 GT2 and reports the exact same behavior. I told her to watch the tach while coming to a stop.

 

[fairmont1998]

100% the transmission downshifting as you slow.

 

[DoctorStiches]

In my opinion the stinger brakes are great but they do 'gain' power as you slow.
Assuming that is just heat building up getting the pads or whatever into prime grabby temps.

I've always adjusted my brake foot off the pedal as i reach a stop

The talk about town is also how the downshifts are or can be a bit ruff when reaching a stop.
MANUAL (flappy padels) Downshifts around 2k rpm's and adjusting the brake pedal as you slow can negate almost all of this.

All this said i prefer the need for driver imputs.

 

[Thomby]

Did you ever figure out what is causing it?
My wife has the '23 GT2 and reports the exact same behavior. I told her to watch the tach while coming to a stop.

It's downshifting. I didn't realize this because the gearing is so close that revs don't jump much.

In my opinion the stinger brakes are great but they do 'gain' power as you slow.
Assuming that is just heat building up getting the pads or whatever into prime grabby temps.

I've always adjusted my brake foot off the pedal as i reach a stop

The talk about town is also how the downshifts are or can be a bit ruff when reaching a stop.
MANUAL (flappy padels) Downshifts around 2k rpm's and adjusting the brake pedal as you slow can negate almost all of this.

All this said i prefer the need for driver imputs.

I do find myself easing up on the brakes in anticipation of the downshifts, which isn't a huge deal but kind of silly to have to compensate for it. They're more aggressive than any other automatic I've driven, even when in Smart drive mode. You'd think they'd reserve it for Sport mode only, but maybe it's part of the adaptive settings and my driving has made it more aggressive.