I was on an off ramp, in the wet, driving a little beyond the limit of the tires.

I started a small degree of push / understeer and all was well and WHAM!, VSC decides I am in a skid and almost makes me spin out.

I almost soiled myself. It just jumped into the game and actually almost made me lose control.

I don't know what it did.

Since I was in an understeer condition I would assume it would start braking the inside tires, but whatever it did it made the rear end loose and almost come around.

It has always been real effective at bringing the car into line, but this time it overreacted and almost made me lose control.

 

That line is money... but seriously, I don't know why VSA would do that to your car? You must've been going pretty fast off that offramp. I usually never try driving fast when it's raining / snowing. Too many close calls for my own good.

Glad you didn't crash though.. especially after soiling yourself (if you did), how would you explain that to your friends

 

were you pushing the car at all? The thing I love about our car is it has the tendency of a typical FWD car, but when being pushed hard, the tail loves to whip out and cause some oversteer, calmed down via VSA of course. But for an FWD car to oversteer slightly, . Here's to a great handling FWD Sports Sedan some critics say reminds them of an ITR, the pinnacle of FWD cars.

 

pushing your car beyond its limits on an offramp and raining is not advised...

 

VSA is there to save your ass, but if you push too hard, you can still over step the boundary of the VSA's capabilities. Driving hard in the rain is foolish to start with. Hopefully this incident will make you a little more careful about pushing hard in the wet.

 

Damn son, you're 17! No need for so many cars

 

How fast were you going? Stock tires?

 

SOMEONE wanna expand how VSA works and in what conditions it is recommended to be ON?

 

Hmm... to me it doesn't sound like it was the VSA, as much as it was the rain. If you're understeering and suddenly gain traction it can upset the balance enough to break the back end out. I would definately not suggest doing that in the rain though, way too many unknowns to drive safely.

 

. what can i say, i roll in

 

VSA uses a variety of sensors, including the ABS sensors, speed sensors, and individual wheel sensors, to monitor the cars motion. As the vehicle is traveling around a corner, the sensors compare the direction of travel to the steering angle and determine whether the car is traveling on the intended path. If the two paths don't match, the VSA system applies individual brakes to bring the car back on the intended path.

 

Yeah, and if you know you're going to do something stupid in the water, you turn the freakin' VSA OFF! I live in Oregon - every time I go to push a limit, I hit the button if I want total control.

I think you're blaming the VSA for solving a problem you created. It knows what's happening better than we do a vast majority of the time. If something "almost" happened, doesn't that mean it didn't happen?

 

would disable VSA lead to a better outcome or worse in this case? don't know. but lucky you escape this time, maybe VSA is smiling and sending a message to you; don't play in the rain!

 

I think I've had a similar experience as yours in the snow last year.

I was trying to turn a long curve, (large enough that I knew I had plenty of space so I could try things), and I started doing crazy understeering to see how the VSA would correct. When the VSA kicked in, the car started oversteering like crazy, and I had to really start correcting wildly to keep the car under control.

That situation perplexed me, but when I started thinking about it, I believe that, especially in an understeer situation, when the VSA licks in, and you are trying to correct the understeer by steering even more, the VSA interprets the understeer as being a lot worst than it really is, so it will overdo itself because the driver is sending in bad input with wheel positionning, sending you into a merry oversteer, and even keep you oversteering for a while.

So I guess that if you are into a situation where you are slipping, if you leave the VSA on, let the VSA do the job, and DON'T TRY CORRECTING THE CAR yourself. If you want to do correct the car, just turn the VSA off.

 

As usual sauceman has the answer.

 

x 3048972304783294

 

I think that's a pretty accurate description, but I'll add my experience to it.

When the VSA comes on, and applies braking to one or more wheels, this decelerates the car. Deceleration transfers weight to the front, increasing front grip, and the fronts bite and turn the car more.

Even if you don't change the steering angle, the effect is to snap from understeer to oversteer.

On my TSX my experience has been that if I maintain the steering angle, the VSA will finish its intervention and the car will transition back to understeer, but with less understeer and on the intended path.

Now I haven't had my TSX through a winter, so when I get a snowfall the first thing I'll do is find a big parking lot and learn what the car will do before the fact.

My suspicion is that if I am just driving around I'll have VSA on because it can definitely help you in unexpected slides "crap, that's not water, that's iiiiiiiice!!!!" - but if I'm driving to go fast, I'll turn it off.

YMMV

 

The tires are also a contributing factor. The stock tires are downright dangerous in the wet. They have reasonable grip to a point but when they get to the traction limit, they let go very suddenly. It's not a progressive slip at all and when the road is wet you don't hear any squealing to let you know how close to the limit you are. Earlier this year, I ran the TSX with stock tires in an autox in really heavy rain. It was shockingly easy to get the back end to break loose. I had VSA off, but I can understand how VSA applying a little bit of braking to to the inside back wheel could cause the whole back end to break loose on a wet surface.

 

car without vsa :

car with vsa :

that's how it works.

 

As was already mentioned, the VSA ECU compares what it belives the driver intends the car to be doing to what the it knows the car is actually doing from what it is getting from the wheel speed sensors, yaw sensor, and steering angle sensor.

Keep in mind VSA is there to assist the driver, not take over driving when the vehicle enters a skid. If you get yourself into trouble, VSA will try to help you get out of it, but there's something to be said for accountability, and you can still overpower VSA if you really want to lose it.

In an understeer condition VSA will focus its efforts on slowing down the inside rear wheel. This creates a moment that pulls the front end back towards the inside of the turn. If the front wheels are slipping, VSA will try its best to let them roll so that they can re-gain traction (braking the front wheels will only make things worse).

In an oversteer condition VSA will slow down the front outside wheel.

The fact you got oversteer after your initial understeer probably has more to do with your efforts to correct the problem than VSA over compensating. The system is set up to help the average driver... and the average driver does some 'stange' things when they lose control. In the hands of a professional driver who is concentrating on what the vehicle is doing, VSA is a handicap. For the average joe, they system will mute your incorrect inputs and suplement them with the correct inputs.

VSA will also keep the car closer to understeer rather than completely neutral. Again, this falls back on being tuned for the average driver. Most people react to a loss of control by lifting off the gas, this is the right thing to do for understeer, but the wrong thing to do for oversteer. Adding more steering is also the wrong thing to do for understeer, but most people still do it.

Bottom line, if you know what you're doing behind the wheel and the conditions are predicatable turn VSA off. If you're not experienced (track time is the best way to learn your car) keep it on. It is much faster than any driver, and 90% of the time it will interpret the situation correctly and help you save your own ass.

-SWRT

 

Good post.

 

ON TOPIC

I agree that the system was simply trying to get the car back inline with the steering angle. Normally it has been pretty non-intrusive, but this time it overreacted.

I am sure I reacted with a quick counter steer, as it was sending the car into a spin.

YES IT WAS MY FAULT, however, it was comparable to anyone comming into a corner too hot.

OFF TOPIC

I can't believe how many of you had to tell my the obvious "don't drive like that".

Been driving for 19 years, many of which with cars far more powerful than the TSX, and far less "driver aids". 1 accident at 15MPH in all that time (not speed or "dangerous" driving related). Never a single speeding ticket, etc...

I always have pushed my cars to the limits, in safe and controllable locations like parking lots, WIDE OPEN OFF RAMPS, etc... This way I can "learn" how the car is going to react when some uncontrolled situation happens like someone pulling out in front of me, or a deer, etc...

I think it is ignorant to never test the limits of a car and have to learn on the fly when all hell breaks loose.

I know way too many people that would go at the slightest indication that ABS activated. It scares me to share the road with these people.

 

Most of it was because we have no idea how experienced you were...

 

Just post up your age and voila, it'll give us an indication of your experience.

 

That's all great, and I agree....


....but why would you want to test those limits in the RAIN?

 

the way that the VSA helps u when ur in a understeering situation is to apply brakes and make ur car oversteer to get u back into the line..

 

Testing limits in the rain can be done at about 1/2 the speed as the dry. I was going about 35MPH in the wet and and to get that same understeer in the dry I would probably have to be doing 60MPH.

I'd much rather "learn" at 35MPH than 60MPH.

I also test the limits of my cars in the snow. In the snow that push would have come at about 15MPH. Even better to learn.

I didn't mean to get all pissy, I just figured that most TSX drivers actually "drive"
their cars. When people reply "don't do that", it really didn't address thr topic.

I both wanted to get people's input on the system and how it reacts as well as warn everybody to watch out for it's intervention.

Back in my psycho younger years, I actually drove my '91 5.0 Stang with summer performance tires thru the winter. Talk about !!!!!!!!!!!!!! Saved up money for an extra set of wheels and all season tires for the next winter! Better but still worlds from the stability of the TSX.

Thanks All!