How do you know the limits of a car?

[Insomniator]

I've never taken any lessons or done auto x etc... I wonder how you 'know' the car is about to lose control or not. Screeching tires? Violent shaking?

I have a Mini S and am either too scared to get to that point or its just further away than i think. I'll take an off/on ramp at 50 and it feels fine, but I see plenty of regular cars do that too. I dunno if I just hit 61 and the limit is 60 am I gonna go flying into the woods?

For example what is the difference between an average corolla and a Porsche at cornering? Could the porsche take a ramp at 80 and the corolla at 40? Or is it way closer like 50 and 55?

 

[Railgun]

Experience.

Take it to a track and find out.

 

[Imported]

Experience.

Take it to a track and find out.

This. Or autocross. One of the groups I have tracked with before offers a class for newer drivers to learn limits, etc. as well.

 

[_Rick_]

In my Suzuki Swift Sport, it's very progressive, as long as you have a chance to steadily increase loads.
For example, there'a a nice 270 deg off-ramp, that depending on tire, temperature, wetness I can take somewhere between 35 and 45.
In the Mini you should start the front end getting less direct, when under-steer sets in. Which is what you are going to experience first. Be careful when backing off, as lift-off over steer is what you will get, when you back off to abruptly, maintaining the same lateral load. Going back on the gas should fix it.

As long as you know that you're on a decent surface, have decently sporty setup, with regards to springs and shocks, under steer will set in very progressively. You can feel the front end not quite tracking true, squirming away. If it does that, you will have to be careful with going on the power, or the added stress on the tire, will lead to grip suddenly disappearing.

The difference between different cars is in the stiffness of the setup and height of the center of gravity, which determines how loads are spread to the four tires of the car, and tire-to-weight/power ratios. Down force also plays a role, once you hit a certain speed, and have sufficient aero devices.

Again, the best thing to figure out where the limits of your car are, is to take it there very progressively on known surfaces. You should notice with your butt and hands when grip is about to run out, as these slightly sporty chassis are quite good at communicating.
The best way to get there on public roads is to accelerate out of corners. The added acceleration stress on the tires can be something that you can manage, and switch off, to kill the under-steer, and then you can just drive on, without moving about a lot. On the other hand, going too hot into a corner (without run-off) is a good way to end in the woods, because you have very little room to correct that initial slide.

Screeching tires are also a good sign, but I've only heard mine screech very rarely, and not during the more hairy moments.

 

[Midwayman]

It varies. Some tires howl well before they let go. Others are pretty quiet up to right before they let go. Most street tires let go in a pretty gradual fashion however. You'll bring it up to the limit and feel the tires start to slip and be able to dial it back down with some experience. As for actual difference in cornering speed- its rarely as drastic as double. A typical sedan might pull around 0.8 G in corning. A sports car on good street tires .92 G or so. Some can pull a bit over 1g on street tires. Moving up to R compound DOT tires will get you to 1.2 G or IIRC. Most people run out of balls before their cars run out of cornering ability.

Go to one of the SCCA autocross schools in your area. Its a real eye opener to have someone not afraid of the limits drive your car and show you what it really can do. Whatever you do, don't learn on public roads. Its extremely irresponsible to drive more than 7/10th or so on a public road.

 

[Ryan]

Take it to the track - I have AutoX'ed my cars in the past - You're in a safe situation where you can afford to go over the limit without consequences.

 

[Blieb]

You never truly know the limit until you cross it.

 

[JCH13]

Take it to the track - I have AutoX'ed my cars in the past - You're in a safe situation where you can afford to go over the limit without consequences.

You never truly know the limit until you cross it.

These two things. Preferably an auto-x school. The instructors will have you intentionally upset your car in a few different situations so you'll know what it's like.

Basically: most street tires will get really loud/growl/howl, the steering wheel will get really light and be unresponsive to increased steering input, you'll feel the chassis slide/rotate/roll in new and interesting ways and respond differently to throttle inputs.

 

[JulesMaximus]

I rented a Lotus Elise once a number of years ago. You could practically slide that car through a corner and still feel confident that you were in control. Basically a street legal go-kart.

Most cars are a huge compromise between comfort, safety, and handling. I haven't driven a car that was anywhere near that planted and neutrally handling ever.

 

[wirednuts]

hmm... I don't think my tires have a point where they are fully gripped to the road. I love my rear end truck with no weight in the back

how did I originally find its limits? I bought it, and ON THE WAY HOME I came around a corner too hot and the back end fished around. I ended up in a ditch. didn't roll the truck though! Im still driving it, 7 years and 120k miles later

 

[Zenmervolt]

With FWD cars, usually the steering starts to go "light" as you approach the steady-state limit and you can feel the understeer as the front tires start to skate sideways slightly. Lifting off too quickly can cause snap oversteer though, especially on short wheelbase cars or on FWD cars that are set up with the intention of trying to be more "neutral."

My old '88 Accord used to sort of "dance" though a long sweeper if I was near the limit; the front would start to understeer a little and lifting off a little would tuck the nose back in but the back would start to step out so I'd bring the power back on which brought back the understeer, so I'd back off which got the back end light again... Basically I could just keep modulating the throttle and sort of slide through the on-ramp.

My S70 is similar except that the rear doesn't get nearly as light if I come off the throttle.

Most street cars will not simply lose it if you pass the limit, especially not FWD cars like the Mini. If you overcook things, you're just going to start drifting wide and lifting off the throttle will fix things.

Still, the safest way to figure things out is on a track with a proper runoff area. If you really want to find the limits, go to a track.

ZV

 

[kitatech]

I run tests...braking in wet conditions, sharp turns as well...but in deserted areas....and not to the car's limits, but MINE.

 

[cbrsurfr]

That's important to note, not only does the car have it's limits but the drivers skill as well. Your skills can only improve with experience.

This is a progressive process once you start to gain experience with pushing the car more you can start to explore its limits. You'll learn how close you can get to them, and how to correct when you've gone beyond them.

The MB AMG driving academy videos might be a good start: https://www.youtube.com/watch?v=gcZqaFJVBZ0

Check out clubs in your area. I'm hooked in with Audi Club North America and USAudi. There's usually deals/discounts for first timers. The Mid Ohio school was really good with classroom, skid car, auto-x, threshold braking, slalom, and then track time. The skid car was really fun, the instructor had a hell of a time trying to trip me up.

 

[Fenixgoon]

Experience.

Take it to a track and find out.

This. Or autocross. One of the groups I have tracked with before offers a class for newer drivers to learn limits, etc. as well.

these

 

[jlee]

I'd recommend an autocross school (look up your local SCCA chapter) and take an instructor with you. In my experience there are usually a few around that are more than happy to ride with you and give you pointers.

 

[power_hour]

*removed*