the way i see it, ayc tries to correct an out of balance car in a bend but this is something the driver should do not only to make things more fun but also more rewarding. AYC is great for road driving where you just wanna cover ground fast and don't mind having a bit of help on teh limit 'cos being on the limit on a public road is very dangerous in terms of run-off and oncoming traffic/horses etc.. but on the circuit it just makes the driving too easy and less pure. Also, if you want to play around with the grip i.e. slide around, then you have to get beyond the capabilities of the ayc before you have complete control of oversteer etc... so its baically in the way .
The reason for disconnecting AYC is because it is very intrusive, except on the 7 which has a much improved AYC. If I had a 6, I would be changing it for an LSD, just like Claudius and others. On the 7, it is much better, I suspect because it works in conjunction with the ACD and because of improved programming which makes it more progressive. On the 7 it is possible, by fitting a different ECU for the ACD, to improve the handling still further.
If the system works in an unobtrusive way, then its great because all it does is raise the roadholding limits of the car. On the 7 I can still get oversteerwhen I want it, just at a higher speed than if I didn't have it and esentually you don't notice the AYC. This I have proven to myself by driving the a car with and without AYC on the same stretch of road. Sorry to Leon at Ralliart for sliding their Extreme S (based on RS - no AYC) with him in the car but when I went back with my Extreme (GSR based - with AYC) it needed higher speed to get the same slide.
It is possible to fool the AYC on the 7 to misbehave and become intrusive by promoting violent lift off oversteer. Then you can feel the AYC help you out, no bad thing. As I have said, on the 6 it is very different in as far as you really notice it and it does get in the way .
Having said all that, if I was building a car for the track I wouldn't have AYC but would have a very good LSD. For mixed road and track use, I am not so sure but I believe tha SuperL, who was planning to fit an LSD in his 7 has now decided taht the system is good enough not to warrant the change.
That is interesting. Currently, I have an issue with my car (Eagle Talon TSi AWD - LSD center and rear, Open diff in the front) regarding the stick in the rear. Basically, as soon as the rear end starts coming around, center diff send more power to the front and car starts to push and goes wider than it should go. As a mater of fact is that with new triple adjustable Penske shocks this is much less of an issue, but it is very present with the regular suspensions. The thing is that I have to run very high springs in the rear in order to have a balanced car (currently 650 lb in the rear and potential 700s might get in there). The front has 800s as of now.
Is this an issue with AYC the reason people go with upgraded electronic units (K1 and such) to avoid this?
Also, is this more of an issue on pre-7 EVOs that have only AYC or it goes for all of them?
Personally I would rather have AYC than an open rear diff, why pay all that extra for an GSR and then end up worse than an RS!
Have you tried playing about with the front/rear Anti roll bars to sort out the oversteer/understeer? (you call them 'sway bars' over there )
Try a slightly thicker rear bar or softer front bar to reduce understeer.
I don't think I will be making any changes from what I have at the moment, because car feels pretty damn good. And the problem that I mentioned is more like a general problem that we have to fix by reducing the traction in the rear in order to make it right.
The thing is, I want to maximize everything rather than decreasing the amount of the traction in the rear. That is why I believe that good working AYC is nice thing to have, so we could go a bit softer (for more grip) and more camber instead of -1* degree which I have right now.
And, stiffer anti roll bars in the rear would just decrease amount of traction on that end, which is something that I am trying to overcome.
For the front, DSMs don't have that much of the travel to start with, so going softer would make me to raise the car a bit and that would kill my static camber too. And, due to the rules, I can't do much more from what I have at the moment camber wise (around 2.2 of negative).
and amp;gt; wouldn't the traction out of a bend be better in a non-ayc car ? More power loss with AYC ?
Well, the problem is that ones your rear end starts rotating (loose the traction in the rear), center diff takes over and send a bit more power to the front. That overdrives the front tires and makes car to push. So as the final result, you get a four wheel drift, which is a good thing sometimes, but sometimes is not. I am autoXing over here, and it is very important to be very precise, due to smaller sizes for the courses, so too much of a drift can throw you off more likely that help.
With AYC, you would have your rear end rotation under control without making front end of the car to go wide. And if it is controlled by the angle of the steering wheel (among the other things) than it almost perfect!
Don't forget that Playing around with suspension parts can also in theory mess up the balance that the Ayc is their for.
I would say that if you are going for top suspension drop the Ayc altogether and let the car be balanced on its own merits.
With lowering springs that I have my car is more balanced around a corner than with the old springs and I cant really feel the Ayc doing its job,Its so easy to beat the system if not too carefull.but then again with weight being distributed to the front end the back is light anyway.Too ridig a chassis and suspention and crap tyres and you'll loose it .
Some company ought to make a even brake bias kit so all 4 wheels stop with the same amount of friction and not be front end biased.
as hh6 has pointed out disconnecting the ayc is a bad idea you end up with an open diff
replacing the ayc with a mechanical lsd is in my view a backward step - if your fuel injection is not mapped correctly you don't replace it with a carburator
the problem with the ayc in the 6 imho is that if anything works too well, ie it optimises grip between the two back wheels
unfortunately it can not overcome the laws of physics so that when the break away does occur it is very sudden
as simon pointed out, this seems to have been realised by mitsi and they have toned it down a bit (possibly helped by acd, etc) in the 7
it worth remembering that the wrc cars run active diffs and it is possible that a future evolution will get an active front diff also
so the problem is what to do about the 6? this was discussed previously and at some point i plan to hook up sensors, etc to it and try and figure out what is what and whether it is possible to interfer with some of the sensors to alter the characteristics
I would be interested to know what you find out. I have had a brief look at this myself but my idea was to alter the system so the AYC ECU thought it was going in a straight line all the time and therefore act like a normal LSD. I thought this may have been an easier way to go than 'tuning' the AYC but now I don't think so due to a few reasons.
I think it is just the case of varying the output of the lateral G sensor to the AYC ECU so it thinks it is not cornering as hard. I don't think the other input sensors need to be touched. Bear in mind that I think the ABS ECU does have some input from the G sensor although I am not sure.
and amp;gt; I think it is just the case of varying the output of the lateral G sensor to the
and amp;gt; AYC ECU so it thinks it is not cornering as hard. I don't think the other input
and amp;gt; sensors need to be touched.
One of the idea is to add additional steering angle sensor (like the one that 7 has) and try to add it to the mix of everything else. I believe that this sensor is the most important in order to have a natural feel from the car. Basically, you control your front of the car with the steering wheel and according to the same inputs AYC controls the turning of the rear wheels.
The thing is, if anyone has available/broken the code for the AYC, extra input could help in there.
and amp;gt; Bear in mind that I think the ABS ECU does have some input from the G sensor
and amp;gt; although I am not sure.
I believe that ABS has an input from the G sensors. The major difference between the 6 and 7 is that new ABS in 7 also uses the steering angle and throttle positioning sensors (although I am not really sure whether 6 also uses the TPS as well).