Traction Control with no throttle input. Clarification req.

[kalibre46]

mikey k said:

I'm confused - are you saying you are corning at high speed with no throttle on at all and that trigger the TC?

Yep. If I represented the limit of grip on a particular corner as say 10 then i feel that anything over a 6 or 7 even in dry conditions will cause the TC to flicker on and off several times during the corner. This happens on left and right handers and is repeatable every time. Zero throttle input.

[peterr96]

It's got to be time to take this to the supplying dealer.

To me and to others it seems it's simply not right. No way should the TC flicker when the car simply gliding round the corner
Being such a dynamic fault it could be a right bd to find the issue though!

Suspect there will be some calls to and from the factory to get that resolved!

[mikey k]

kalibre46 said:

mikey k said:

I'm confused - are you saying you are corning at high speed with no throttle on at all and that trigger the TC?

Yep. If I represented the limit of grip on a particular corner as say 10 then i feel that anything over a 6 or 7 even in dry conditions will cause the TC to flicker on and off several times during the corner. This happens on left and right handers and is repeatable every time. Zero throttle input.

Zero throttle (as in foot off)
or
Flat input (as in on the power but holding flat)

It does seem like a back to back drive with a similar car at the dealers would be a good idea

[Cockernee]

mikey k said:

kalibre46 said:

mikey k said:

I'm confused - are you saying you are corning at high speed with no throttle on at all and that trigger the TC?

Yep. If I represented the limit of grip on a particular corner as say 10 then i feel that anything over a 6 or 7 even in dry conditions will cause the TC to flicker on and off several times during the corner. This happens on left and right handers and is repeatable every time. Zero throttle input.

Zero throttle (as in foot off)
or
Flat input (as in on the power but holding flat)

It does seem like a back to back drive with a similar car at the dealers would be a good idea

Mikey - Zero throttle. last 3 words of his previous post. Hence why I say this is a fault and never happened to me...

[mikey k]

I read it but it seems counter intuitive to be cornering at those speeds with no throttle on?
I was wondering if the TC was responding to a change in rear grip with no power on the rear
Sort of like the start of lift off over steer?
Mine does flash the TC in corners regularly but I've ALWAYS got power/throttle on

[Cockernee]

mikey k said:

I read it but it seems counter intuitive to be cornering at those speeds with no throttle on?
I was wondering if the TC was responding to a change in rear grip with no power on the rear
Sort of like the start of lift off over steer?
Mine does flash the TC in corners regularly but I've ALWAYS got power/throttle on

But if the system is DSC (Dynamic Stability Control) not just TC would this not make sense if the sensor thought the car was over the adhesion limit? If it is like my Audi snotter, then if the back end steps out off throttle the brakes apply automatically to bring it in-line again. If the Aston system is truly DSC then it measures slip on all wheels and will apply braking based on that to the relevant wheel. Are you saying that the AM system is only on the back wheels??? Where is Dr Mike when you need him

[mikey k]

You are right, though AFAIK these systems use the ABS sensors and G/yaw sensors to detect slip
I've seen something similar on a different car that was traced to a rear ABS sensor having been knocked out of alignment with the hub
I've also seen it with mild lift off over steer as the system applies the brakes to control it and flashes the DSC light
Both on RWD cars
Hence the question to clarify throttle position to try and eliminate one or the other.

[threesixty]

Slightly off topic but on the V12V is there anyway of getting the speed to display on the digital display when in track mode?

[Cockernee]

threesixty said:

Slightly off topic but on the V12V is there anyway of getting the speed to display on the digital display when in track mode?

Press the 'READ' Button

[kalibre46]

mikey k said:

You are right, though AFAIK these systems use the ABS sensors and G/yaw sensors to detect slip
I've seen something similar on a different car that was traced to a rear ABS sensor having been knocked out of alignment with the hub
I've also seen it with mild lift off over steer as the system applies the brakes to control it and flashes the DSC light
Both on RWD cars
Hence the question to clarify throttle position to try and eliminate one or the other.

So ordinarily yes I would drive through a corner with 'neutral' throttle so foot on. However since I noticed the lights I started experimenting:

1) Approach a corner from a straight section so the car is totally stable.
2) Take foot completely off of pedal prior to turn-in.
3) Initiate medium/hard turn-in and watch the light show.....

I'd try and grab a video of it, but I'd likely kill myself in a bad example of 'rub tummy pat head' limb confusion. Anyone use Dynolicious on their phone? I might do some runs and see what sort of lateral-g I'm pulling to activate the light. Otherwise I'll have to find some time for a dealer visit.

Stratstone have provided me with the 12-month warranty. I assume all aspects of this warranty are usable in any other dealer?

[mikey k]

Does it do the same with neutral throttle ie power on but no change through the corner?

[kalibre46]

mikey k said:

Does it do the same with neutral throttle ie power on but no change through the corner?

I'm pretty sure it does as that's how I found it, but I'll check when I have a little run in a bit. Any excuse...

[threesixty]

Cockernee said:

threesixty said:

Slightly off topic but on the V12V is there anyway of getting the speed to display on the digital display when in track mode?

Press the 'READ' Button

Nothings ever obvious in an Aston is it! I think the only time I've pressed 'read' so far was to switch it over to KM.

[kalibre46]

So went and had some fun....umm I mean a thorough scientific research session...

I could corner at 50mph with a relatively weak 0.4G lateral load with both zero throttle and neutral throttle but still the DSC light was chiming in a few times mid-corner. I thought I detected an element of the car 'tucking' indicating perhaps some selective braking being applied to the front wheels. One thing that I noted when the car was on the ramp getting geo'd was the the front tyres are date stamped 2008 meaning the originals. Now despite their age they show no signs of cracking, uneven wear or deformation. Given my experiences a minute ago I'm thinking could it be the tyre age/condition? Obviously I don't want to replace them needlessly given that the tread is still at probably 7-8mm.

I couldn't help being a big kid and doing a couple of 0-60 runs whilst I had the software active. My conclusions from these jaunts are two-fold:

1) I apparently suck (sorry 'Suk') at standing starts with my best of 3 runs being 4.8s 0-60.
2) In auto (sport) mode the change from 1st to 2nd is just shy of 5k rpm, whereas the gear is naturally taller in manual but does provoke some DSC lighting and bogging down if the change up is above 5k rpm. This is presumedly because of the introduction of excessive torque. Interesting I thought.

[Cockernee]

kalibre46 said:

So went and had some fun....umm I mean a thorough scientific research session...

I could corner at 50mph with a relatively weak 0.4G lateral load with both zero throttle and neutral throttle but still the DSC light was chiming in a few times mid-corner. I thought I detected an element of the car 'tucking' indicating perhaps some selective braking being applied to the front wheels. One thing that I noted when the car was on the ramp getting geo'd was the the front tyres are date stamped 2008 meaning the originals. Now despite their age they show no signs of cracking, uneven wear or deformation. Given my experiences a minute ago I'm thinking could it be the tyre age/condition? Obviously I don't want to replace them needlessly given that the tread is still at probably 7-8mm.

I couldn't help being a big kid and doing a couple of 0-60 runs whilst I had the software active. My conclusions from these jaunts are two-fold:

1) I apparently suck (sorry 'Suk') at standing starts with my best of 3 runs being 4.8s 0-60.
2) In auto (sport) mode the change from 1st to 2nd is just shy of 5k rpm, whereas the gear is naturally taller in manual but does provoke some DSC lighting and bogging down if the change up is above 5k rpm. This is presumedly because of the introduction of excessive torque. Interesting I thought.

While I have never had 5 year old tyres that definitely sounds wrong to me. 50 MPH and TC light?? Unless it was a hairpin and the car was struggling, that sounds wrong. 50 MPH on a fairly easy open bend should see no slip IMHO. Do you feel like the front end is pushing on?

[kalibre46]

Cockernee said:

While I have never had 5 year old tyres that definitely sounds wrong to me. 50 MPH and TC light?? Unless it was a hairpin and the car was struggling, that sounds wrong. 50 MPH on a fairly easy open bend should see no slip IMHO. Do you feel like the front end is pushing on?

This is the strange thing, I feel like the turn-in is spot on, certainly no signs understeer at those speeds (or much higher tbh). The age of the tyres is niggling me a bit now (especially with VMAX approaching) so part of me says do them anyway from a safety point of view, but I know it may not fix the issue.

[mikey k]

Cockernee said:

While I have never had 5 year old tyres that definitely sounds wrong to me. 50 MPH and TC light?? Unless it was a hairpin and the car was struggling, that sounds wrong. 50 MPH on a fairly easy open bend should see no slip IMHO. Do you feel like the front end is pushing on?

What state is the inside edge of the front tyres?

[kalibre46]

Thought I'd resurrect this one to tell you the result. It was the 'aged' front tyres apparently causing the issues. They were replaced last night and now the issue has disappeared. Car feels a bit more solid mid-corner now too, even though it wasn't bad before.

[Cockernee]

kalibre46 said:

Thought I'd resurrect this one to tell you the result. It was the 'aged' front tyres apparently causing the issues. They were replaced last night and now the issue has disappeared. Car feels a bit more solid mid-corner now too, even though it wasn't bad before.

So it seems 5 year old tyres are a bit passed their 'sell by date' so to speak. very interesting Doug and useful. Taylor172 had cracking on older tyres that needed replacement, so a top tip for people to check the date on their tyres and if experiencing handling issues, look here first. I have never had a car with tyres older than 2 years strangely I think the roads in Essex are very abrasive

[kalibre46]

Cockernee said:

So it seems 5 year old tyres are a bit passed their 'sell by date' so to speak. very interesting Doug and useful. Taylor172 had cracking on older tyres that needed replacement, so a top tip for people to check the date on their tyres and if experiencing handling issues, look here first. I have never had a car with tyres older than 2 years strangely I think the roads in Essex are very abrasive

TBH if I was armed with this thread before purchasing the car then I may have pushed for the dealer to replace the fronts on safety ground before I took delivery. I'm glad it's sorted, now I can attack the figures at VMAX without a sneaking doubt that my tyres may fail!