B8 S4 Ownership
Discussion
silentbrown said:
Is that right ? You're saying that S-tronic - without HHA - will hold the car via the brakes on a slope without you activating the parking brake...?
No,I'm saying that in the second between coming off your foot brake and pressing the throttle it will hold. Without HHA.
Or you can just use the handbrake and move forward without turning it off.
End result... The car does not suffer a roll back like a manual where you need to something extra before you lift to the clutch biting point.
Hol said:
No,
I'm saying that in the second between coming off your foot brake and pressing the throttle it will hold. Without HHA.
Understood. Do you know how it does that (clutch slip, or braking pressure?), and what happens if "second between" becomes 10 seconds, for example. Will it roll back then?I'm saying that in the second between coming off your foot brake and pressing the throttle it will hold. Without HHA.
Not nitpicking - honest! Just trying to understand how the system operates. Does your car have engine stop-start, BTW?
Found this a while back:
"The hold assist doesn't use the handbrake to hold the car when you are not moving, what it uses is the ABS pressure pump, keeping closed the return valves of the system while the ABS pump is working to keep the car stopped.
In fact, If you stay too much time stopped and the ABS pump get hot the car automatically disengage the Autohold but engaging at the same time the hand brake avoiding the car to move. Later, when the ABS pump is again cold it keeps on using that system instead of the handbrake.
The reason why the Autohold system is not compatiblewith start-stop system is because the ABS pump needs the car is started to make pressure into the brake system, and if the car is stopped it can't do that.
Maybe some of you will ask why the auto hold doesn't use only the hand brake to keep the car stopped and the answer is because the handbrake is too rude working when it tries to stop smoothly the car and when it lets the car move later...
The normal electrical handbrake will release when you drive off (assumming seat belts on, door shut etc.
This is NOT hill hold assist
Hill Hold Assist is a cheap option (in the UK at least). The difference is that it automatically puts the "hand brake" on for you when you come to a halt. It also auto releases. It displays in the DIS as a green (P) symbol. If you have it on for a period or if you turn the engine off it changes to a red (P) symbol.
The difference is :
green (P) - hill hold assist - simply holds the car by pushing my pressure in to the calipers.
red (P) - electronic parking brake - holds the car by winding on the pads with an electric motor - hence the whirring noise."
"The hold assist doesn't use the handbrake to hold the car when you are not moving, what it uses is the ABS pressure pump, keeping closed the return valves of the system while the ABS pump is working to keep the car stopped.
In fact, If you stay too much time stopped and the ABS pump get hot the car automatically disengage the Autohold but engaging at the same time the hand brake avoiding the car to move. Later, when the ABS pump is again cold it keeps on using that system instead of the handbrake.
The reason why the Autohold system is not compatiblewith start-stop system is because the ABS pump needs the car is started to make pressure into the brake system, and if the car is stopped it can't do that.
Maybe some of you will ask why the auto hold doesn't use only the hand brake to keep the car stopped and the answer is because the handbrake is too rude working when it tries to stop smoothly the car and when it lets the car move later...
The normal electrical handbrake will release when you drive off (assumming seat belts on, door shut etc.
This is NOT hill hold assist
Hill Hold Assist is a cheap option (in the UK at least). The difference is that it automatically puts the "hand brake" on for you when you come to a halt. It also auto releases. It displays in the DIS as a green (P) symbol. If you have it on for a period or if you turn the engine off it changes to a red (P) symbol.
The difference is :
green (P) - hill hold assist - simply holds the car by pushing my pressure in to the calipers.
red (P) - electronic parking brake - holds the car by winding on the pads with an electric motor - hence the whirring noise."
jimmyjimjim said:
Found this a while back:
"The hold assist doesn't use the handbrake to hold the car when you are not moving, what it uses is the ABS pressure pump, keeping closed the return valves of the system while the ABS pump is working to keep the car stopped.
In fact, If you stay too much time stopped and the ABS pump get hot the car automatically disengage the Autohold but engaging at the same time the hand brake avoiding the car to move. Later, when the ABS pump is again cold it keeps on using that system instead of the handbrake.
The reason why the Autohold system is not compatiblewith start-stop system is because the ABS pump needs the car is started to make pressure into the brake system, and if the car is stopped it can't do that.
??"The hold assist doesn't use the handbrake to hold the car when you are not moving, what it uses is the ABS pressure pump, keeping closed the return valves of the system while the ABS pump is working to keep the car stopped.
In fact, If you stay too much time stopped and the ABS pump get hot the car automatically disengage the Autohold but engaging at the same time the hand brake avoiding the car to move. Later, when the ABS pump is again cold it keeps on using that system instead of the handbrake.
The reason why the Autohold system is not compatiblewith start-stop system is because the ABS pump needs the car is started to make pressure into the brake system, and if the car is stopped it can't do that.
some notes:
1) ABS works without the engine running, it's powered electrically, the pump can run without the engine.
2) autohold (or whatever you want to call it) does not have the pump running full time, it only runs enough to create the line pressure in the first place, once that is done, it stops, pressure is maintained by the valve-gear/accumulator.
3) if you stop the engine (as in YOU pull the key) and you're on auto-hold, it will engage the park-brake and drop auto-hold, it will not do this on stop-start activation.
Edited by Scuffers on Monday 17th November 13:50
Hill hold can be retrofitted fairly easily - 2 wires to the ABS controller if you have the right one from the factory, plus a new parking brake switch and some coding.
I had an A6 loan car with hill hold and stop/start a while ago - maybe it uses an accumulator for the brake pressure? I really liked it....
I had an A6 loan car with hill hold and stop/start a while ago - maybe it uses an accumulator for the brake pressure? I really liked it....
jimmyjimjim said:
Found this a while back:
The reason why the Autohold system is not compatiblewith start-stop system is because the ABS pump needs the car is started to make pressure into the brake system, and if the car is stopped it can't do that.
HHA shows as an option on the S4 configurator, and those all have stop-star system...?The reason why the Autohold system is not compatiblewith start-stop system is because the ABS pump needs the car is started to make pressure into the brake system, and if the car is stopped it can't do that.
Scuffers said:
it is, ours has both.
Yup, mine too. I find stop start quite annoying as it seems there is no rhyme or reason to it restarting. So much so I phoned my local service manager to ask. He said the car works on all the variables including voltage/battery condition etc. The stop start on my dad's Merc is much better. Switches off when you come to a standstill and doesn't restart until you hit the accelerator. Simple.
Adrian E said:
jimmyjimjim said:
Found it on one of the US forums some time ago...HHA isn't an option here, so I don't know how much of it is correct.
From memory a lot of USA market models have the 'wrong' ABS controller to support HHA, but I've probably read it from the same source you have!
).silentbrown said:
jimmyjimjim said:
Found this a while back:
The reason why the Autohold system is not compatible with start-stop system is because the ABS pump needs the car is started to make pressure into the brake system, and if the car is stopped it can't do that.
HHA shows as an option on the S4 configurator, and those all have stop-star system...?The reason why the Autohold system is not compatible with start-stop system is because the ABS pump needs the car is started to make pressure into the brake system, and if the car is stopped it can't do that.
Don't know. It seemed a reasonable explanation of the operation, though it appears not 100% correct (so average for the internet
).Wrt the 1AS/1AT ABS controller, one of the interesting things about the US spec is how it differs from the euro spec models; you lose out on a few odd things, apparently for cost reasons:
No cubbys under the front seats.
No emergency triangle in the boot.
Door mirrors aren't electrically folding (about $1k in parts to retrofit!!!!!).
I'm sure there's more, those are the ones I've picked up on through reading various forums.
No cubbys under the front seats.
No emergency triangle in the boot.
Door mirrors aren't electrically folding (about $1k in parts to retrofit!!!!!).
I'm sure there's more, those are the ones I've picked up on through reading various forums.
Found this nice guide all about the 3.0 S4 engine over on one of the american forums.
Thought I'd share it
http://www.s4-mtm.com/images/925803_3.0V6TFSIengin...
Thought I'd share it
http://www.s4-mtm.com/images/925803_3.0V6TFSIengin...
Thats actually very timely...
I'm planning to travel down to London from Scotland over the holidays and I'm considering taking the S4 Avant for the first time or the wife's Golf Tdi.
If I can squeeze 360+miles out of the tank I'd definitely take the S4!
Having picked up the car a couple of months ago I have a few minor points I'd like to share - nothing major, just me being me!
1.
I have Supersport Seats which do look lovely but I'm not overly impressed with the lateral support.
I'm of medium build and I could have done with some extra adjustment to hold me in tighter - I thought they would have had some sort of adjustment as I had on the E89 Z4 which really hold you in well with the push of a button.
2.
The chrome interior vent surrounds reflect really badly in the side view mirrors! Getting used to it now but a bit annoying.
3.
When I have the seat set low the way I like it you can't see the bottom-most segments of the cluster display because of the surround.
I have my backrest fairly upright yet I still can't see it. Wouldn't normally bother me but this is where the current gear message is displayed.
4.
I expected a little more room in the back for the toddler in her seat but she doesn't have much in the way of legroom so constantly kicks the back of the passenger seat so I've had to adjust it a lot more forward than I'd have expected but I guess the supersport seats are larger.
5.
The heated seat has 6 settings - why? lol
6.
Audi quotes 29mpg combined but it seems pretty difficult to get near that.
The Z4 I had quoted 33mpg and could always get 30mpg+ driving "quick-ish"
I've had four BMW's before this first Audi and have always got fairly close to the quoted values in the past.
7.
The paddles on the steering wheel are a bit small - something more of the B8 RS4 size would have been ideal.
However, I must say the car feels absolutely solid on the road and drives superbly!
Having came from an M Sport Z4 with sports suspension, 19" wheels, 30 section tyres and run flats - this S4 feels like I'm in an S Class!
And the power delivery - superb! Would love to open it up more but I fear of losing my license! It's just so effortless even without an remap.
And there is much to be said of Quattro grip - again, coming from rear wheel drive, just being able to get on the power early makes such a difference from having to tip toe around corners - remember I live in not-so-sunny Scotland!
Actually, truth be known - my brother has a TT-S and once I had a shot I was convinced that Quattro was the way to go. He left me for dead going around roundabouts in the wet when I was chasing in the Z4.
All in all pretty pleased so far - hopefully I'll be able to take it easy once the honeymoon period is over and nurse some more mpg's for the daily commute and conserve them for when they're really needed :-)
I'm planning to travel down to London from Scotland over the holidays and I'm considering taking the S4 Avant for the first time or the wife's Golf Tdi.
If I can squeeze 360+miles out of the tank I'd definitely take the S4!
Having picked up the car a couple of months ago I have a few minor points I'd like to share - nothing major, just me being me!
1.
I have Supersport Seats which do look lovely but I'm not overly impressed with the lateral support.
I'm of medium build and I could have done with some extra adjustment to hold me in tighter - I thought they would have had some sort of adjustment as I had on the E89 Z4 which really hold you in well with the push of a button.
2.
The chrome interior vent surrounds reflect really badly in the side view mirrors! Getting used to it now but a bit annoying.
3.
When I have the seat set low the way I like it you can't see the bottom-most segments of the cluster display because of the surround.
I have my backrest fairly upright yet I still can't see it. Wouldn't normally bother me but this is where the current gear message is displayed.
4.
I expected a little more room in the back for the toddler in her seat but she doesn't have much in the way of legroom so constantly kicks the back of the passenger seat so I've had to adjust it a lot more forward than I'd have expected but I guess the supersport seats are larger.
5.
The heated seat has 6 settings - why? lol
6.
Audi quotes 29mpg combined but it seems pretty difficult to get near that.
The Z4 I had quoted 33mpg and could always get 30mpg+ driving "quick-ish"
I've had four BMW's before this first Audi and have always got fairly close to the quoted values in the past.
7.
The paddles on the steering wheel are a bit small - something more of the B8 RS4 size would have been ideal.
However, I must say the car feels absolutely solid on the road and drives superbly!
Having came from an M Sport Z4 with sports suspension, 19" wheels, 30 section tyres and run flats - this S4 feels like I'm in an S Class!
And the power delivery - superb! Would love to open it up more but I fear of losing my license! It's just so effortless even without an remap.
And there is much to be said of Quattro grip - again, coming from rear wheel drive, just being able to get on the power early makes such a difference from having to tip toe around corners - remember I live in not-so-sunny Scotland!
Actually, truth be known - my brother has a TT-S and once I had a shot I was convinced that Quattro was the way to go. He left me for dead going around roundabouts in the wet when I was chasing in the Z4.
All in all pretty pleased so far - hopefully I'll be able to take it easy once the honeymoon period is over and nurse some more mpg's for the daily commute and conserve them for when they're really needed :-)
Edited by M7NDP on Thursday 27th November 23:32
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