V12VSM AM Shift - hmmm
Discussion
Just before I tell Aston that my car is misbehaving I wanted to check with others about AMShift operation.
When it is on, it seems to rev match every gear change, up or down. When it is doing this the throttle pedal (on mine at least) is disabled. Mainly when the clutch is depressed as then the ECU I guess takes over.
This is fine when you are hammering along and also fine if you are wanting to drive smoothly as for example first-to-second is always nice without you accidentally putting too much power on.
However, if for example you slow for a roundabout, have nearly stopped but are still rolling so decide to start in 2nd instead of 1st and go to slip the clutch with a little bit of power on then what actually happens is an almost stall, as the computer decides that the RPM for 2nd at 5mph is 200 so when you press the throttle nothing happens. Even foot flat down.
If you do the same with AMShift off then it all happens normally, a little bit of power and clutch slip for a fraction of a second and you purr off nicely in 2nd rather than downshifting to 1st every time you approach a standstill.
I can rationalise the design behind this but obviously am not happy that it is turning off my throttle pedal.
AMShift does make me laugh as I blast down the gears coming to a slow corner but it deciding to not let me add power has me concerned.
Question to others:
a) My bad driving
b) That's how AMShift is
c) My car is misbehaving
When it is on, it seems to rev match every gear change, up or down. When it is doing this the throttle pedal (on mine at least) is disabled. Mainly when the clutch is depressed as then the ECU I guess takes over.
This is fine when you are hammering along and also fine if you are wanting to drive smoothly as for example first-to-second is always nice without you accidentally putting too much power on.
However, if for example you slow for a roundabout, have nearly stopped but are still rolling so decide to start in 2nd instead of 1st and go to slip the clutch with a little bit of power on then what actually happens is an almost stall, as the computer decides that the RPM for 2nd at 5mph is 200 so when you press the throttle nothing happens. Even foot flat down.
If you do the same with AMShift off then it all happens normally, a little bit of power and clutch slip for a fraction of a second and you purr off nicely in 2nd rather than downshifting to 1st every time you approach a standstill.
I can rationalise the design behind this but obviously am not happy that it is turning off my throttle pedal.
AMShift does make me laugh as I blast down the gears coming to a slow corner but it deciding to not let me add power has me concerned.
Question to others:
a) My bad driving
b) That's how AMShift is
c) My car is misbehaving
cayman-black said:
(d) manual v12v is better.
Err it is a manual (or do I misunderstand you)?AMShift explained:
https://www.google.com/url?sa=t&rct=j&q=&a...
madcal said:
Just before I tell Aston that my car is misbehaving I wanted to check with others about AMShift operation.
When it is on, it seems to rev match every gear change, up or down. When it is doing this the throttle pedal (on mine at least) is disabled. Mainly when the clutch is depressed as then the ECU I guess takes over.
This is fine when you are hammering along and also fine if you are wanting to drive smoothly as for example first-to-second is always nice without you accidentally putting too much power on.
However, if for example you slow for a roundabout, have nearly stopped but are still rolling so decide to start in 2nd instead of 1st and go to slip the clutch with a little bit of power on then what actually happens is an almost stall, as the computer decides that the RPM for 2nd at 5mph is 200 so when you press the throttle nothing happens. Even foot flat down.
If you do the same with AMShift off then it all happens normally, a little bit of power and clutch slip for a fraction of a second and you purr off nicely in 2nd rather than downshifting to 1st every time you approach a standstill.
I can rationalise the design behind this but obviously am not happy that it is turning off my throttle pedal.
AMShift does make me laugh as I blast down the gears coming to a slow corner but it deciding to not let me add power has me concerned.
Question to others:
a) My bad driving
b) That's how AMShift is
c) My car is misbehaving
If you are in second gear and rolling, why would you need to slip the clutch? Surely in this case you'd take your foot off the clutch then apply throttle?When it is on, it seems to rev match every gear change, up or down. When it is doing this the throttle pedal (on mine at least) is disabled. Mainly when the clutch is depressed as then the ECU I guess takes over.
This is fine when you are hammering along and also fine if you are wanting to drive smoothly as for example first-to-second is always nice without you accidentally putting too much power on.
However, if for example you slow for a roundabout, have nearly stopped but are still rolling so decide to start in 2nd instead of 1st and go to slip the clutch with a little bit of power on then what actually happens is an almost stall, as the computer decides that the RPM for 2nd at 5mph is 200 so when you press the throttle nothing happens. Even foot flat down.
If you do the same with AMShift off then it all happens normally, a little bit of power and clutch slip for a fraction of a second and you purr off nicely in 2nd rather than downshifting to 1st every time you approach a standstill.
I can rationalise the design behind this but obviously am not happy that it is turning off my throttle pedal.
AMShift does make me laugh as I blast down the gears coming to a slow corner but it deciding to not let me add power has me concerned.
Question to others:
a) My bad driving
b) That's how AMShift is
c) My car is misbehaving
JohnG1 said:
If you are in second gear and rolling, why would you need to slip the clutch? Surely in this case you'd take your foot off the clutch then apply throttle?
Indeed, that is what I do; but the throttle is not doing anything and as a result when you lift the clutch it starts to stall. When it starts to stall you instinctively slip the clutch a little and press the throttle. But then nothing happens....Only when you have AMShift on.
My does exactly the same, discussed with a staff member at AMBristol with experience of AMshift who described it in the same way.
AMshift seems to need to be in a gear to know what it’s doing. If you’re coasting up to a roundabout it then takes a second or two to play guess the gear! I was using it all the time, as it is great fun and makes me feel like a driving god, but in the exact circumstances you describe, it doesn’t inspire confidence!
I think I probably have a bad driving habit with it, but now I either remember to always have it in gear without coasting, or switches off and it feels like a normal manual.
Interested to hear if you get told any different, of course.
AMshift seems to need to be in a gear to know what it’s doing. If you’re coasting up to a roundabout it then takes a second or two to play guess the gear! I was using it all the time, as it is great fun and makes me feel like a driving god, but in the exact circumstances you describe, it doesn’t inspire confidence!
I think I probably have a bad driving habit with it, but now I either remember to always have it in gear without coasting, or switches off and it feels like a normal manual.
Interested to hear if you get told any different, of course.
If you think about it then in order to match the RPM nicely it would have to control the throttle.
It does flatter your driving, if you gently go from 1st to 2nd and have your foot lightly on the throttle leading to RPM being too high for the speed then without AMShift you would have a little jerk when driving, but with it it disregards your lead foot and keeps the RPM matched to make the change smooth as silk.
I guess the downside is not being able to drop into 2nd at 5mph at a roundabout, as it then seems to keep the RPM as low as possible, sadly just too low to avoid a stall or at minimum nasty drivetrain judder. When this happened the first time I thought I had lost all power as had my foot flat on the throttle but nothing happened. Was relieved when I put it back into neutral and the throttle started working again. Of course then you jam it into 1st and blast off.
Not very gentlemanly.
I guess the answer is to leave AMShift off unless you are "on-it". Then I have to improve my Miss Daisy driving style a little to ensure smoothness.
Having said all that when you are blasting along, either speeding up or slowing down AMShift is great.
I will have works check it out anyhow.
It does flatter your driving, if you gently go from 1st to 2nd and have your foot lightly on the throttle leading to RPM being too high for the speed then without AMShift you would have a little jerk when driving, but with it it disregards your lead foot and keeps the RPM matched to make the change smooth as silk.
I guess the downside is not being able to drop into 2nd at 5mph at a roundabout, as it then seems to keep the RPM as low as possible, sadly just too low to avoid a stall or at minimum nasty drivetrain judder. When this happened the first time I thought I had lost all power as had my foot flat on the throttle but nothing happened. Was relieved when I put it back into neutral and the throttle started working again. Of course then you jam it into 1st and blast off.
Not very gentlemanly.
I guess the answer is to leave AMShift off unless you are "on-it". Then I have to improve my Miss Daisy driving style a little to ensure smoothness.
Having said all that when you are blasting along, either speeding up or slowing down AMShift is great.
I will have works check it out anyhow.
You aren't going mad, I've noticed the same
with AMshift on, in 2nd gear, at low revs, near a junction, it can feel like the car is about to stall and/or there is no power. It takes a very specific set of circumstances. I find popping the car into neutral for a moment or into 1st, seems to sort it but it can be disconcerting
with AMshift on, in 2nd gear, at low revs, near a junction, it can feel like the car is about to stall and/or there is no power. It takes a very specific set of circumstances. I find popping the car into neutral for a moment or into 1st, seems to sort it but it can be disconcerting
madcal said:
a) My bad driving
b) That's how AMShift is
c) My car is misbehaving
I think its a combination of a) and b), but mostly b)...b) That's how AMShift is
c) My car is misbehaving
AMshift matches the engine revs precisely to the speed and gear that you have the gear knob pushed into, and in effect the throttle pedal is disabled whilst the clutch is pressed.
The idea being that you get perfect changes everytime, which of course is what happens when pressing on hard.
What it sounds like you are doing is pushing the car into too high a gear for the speed you are travelling at, so AMShift is matching the revs to a very low number of revs which of course results in no power / almost stalling.
Try finding an empty straight piece of road, cruise at 40mph and then press the clutch and zip between each of the gears from 2 to 7. The revs jump up and down as you push the level into each gear position.
I personally never use AMShift whilst driving in traffic as it does highlight anomalies such as this, which like you say you would normally compensate for by adding a little throttle. AMShift is however a lot of fun and seems to add additional cracks and pops from the exhaust I find when changing down during spirited driving, so I tend to switch it on for these times.
In summary, I don't think there is anything wrong with your car. Either turn it off for traffic or adapt your driving style and don't put it in too high a gear for the speed you are travelling at.
Had it checked by Works and against other cars.
Normal behaviour, it matches revs based on car speed, so if you are in 2nd at 5-10mph it will set throttle appropriately. Only rarely does this mean a stutter but it can happen (heavily damped throttle is the term).
So all good, just wanted to be sure something was not awry.
Normal behaviour, it matches revs based on car speed, so if you are in 2nd at 5-10mph it will set throttle appropriately. Only rarely does this mean a stutter but it can happen (heavily damped throttle is the term).
So all good, just wanted to be sure something was not awry.
Gassing Station | Aston Martin | Top of Page | What's New | My Stuff