smooth driving

[brucelee]

i think my topic kinda fits in this section...searched but couldn't find anything so here it goes.
so yesterday my friend and i went to dinner, me driving. we got on the topic of driving smoothly. long story short, he proposed that if you're a good, "smooth" driver, you could place a cup of water in your cup holder, and it'll stay still pretty much all the time, even with hard cornering.
i want some some input concerning the main point that he made for cornering. he stated that, as you approach a corner, slow down to a speed slower than you want to take it, then at the point the turn starts, accelerate gradually (i.e. don't mash the pedal but press slowly). supposedly by accelerating through the entire turn, you are creating a new vector at every point of the curve, which will be smoother than keeping a constant speed through the turn. it kind of makes sense, to a point.
he says that by doing this you'll be able to drive smoother and faster. but i'm not sure what to think exactly. i'd say it's a steering input thing more than anything. and if you were to drive at the limit, i don't think this concept can work. will someone enlighten me?
btw for reference, his definition of being smooth is not getting the water in the cup to move more than maybe 1/4" on all sides. anything over is considered too hard.
thanks.

 

[G-Papi]

Does he want to race, chaufer, or drive the kids to soccer?

 

[FunkyBuddha]

Uhmm yeah..tell him he's watching too much Initial D.

Just practice and put the theory into application and see for yourself instead of typing up a theory/guess and having multiple inputs with all varied answers.

 

[brucelee]

he says that it will apply to pretty much all situations.
i did try it and to him my driving was too harsh. i don't consider it too harsh personally. but that's beside the point. if his idea is true then there's something i'm not doing right.

 

[twistedMSP]

This buddy of yours has clearly never autocrossed. Tell him to take his cup of water test to a track and see if his "smooth driving" gets him a decent time or wet trousers. i bet if he's dry at the end his time is horrible, but if he's a bit wet he might have a decent time.

 

[chuyler1]

This is sort of like the golf-ball method that was used for the Miata ZZL last year. The idea is to learn how to brake, accelerate, and load up the suspension smoothly to preven the balls from coming out of the glass bowl that was placed on top of the hood.

However, it is merely a teaching tool and you cannot actually get race-winning times and keep the balls in the bowl. But if you are aware of how you brake, accelerate, and load up the suspension entering and leaving a turn, it will help you shave seconds off your auto-x times.

 

[122 Vega]

He's never heard of the "traction circle" has he?

Limits of adhesion...

 

[apexlater]

drink the water first.

 

[122 Vega]

Ok wait, for a purely scientific standpoint:

What size cup? 32 oz touch the dash in the Pro, therefore giving it an additional point of contact.

How full is the cup? If 1/4" is "the limit" then can I ony fut 2oz of water in the cup so it would have to travel the 12" to the top of the 32 oz cup?

What if I can get the water to come out of the cup, but then correct it to catch the water without spilling it?

What about viscocities? Clearly, my peppermint mochas have less of a G-Limit than my Taco Bell 32oz Mt Dew. Water may not be the optimum referrence fluid.

We also have to consider the type of cup. If it is slick plactic, coarse styrofoam. this would change the fluid's ability to climb the walls of the cup, therefore altering the "repeatability" of the test.

Maybe some physics engineers could chime in on this subject, before this guy goes off to be the director for the Fast and the Furious 4.

Britt

 

[ChopstickHero]

tell your buddy to stop dreaming about Initial D and start learning how to drive.

 

[brucelee]

thanks for your replies. the golf ball method does seem like a similar concept. i guess that's what he was trying to get across to me. it just made me wonder if i was missing something that every driver (or every "good" driver) knew about. i'm always trying to improve my driving so i had to ask.
oh and i used a ~12oz quiznos paper cup filled up with quiznos water to the middle.

 

[Tom03es]

My Saturn with Toyo RA1 tires can corner at 1.2 Gs at a road course. Unless there's a lid on that cup, the water isn't staying in- regardless of how smooth you are unless the cup is hung in a sling and is allowed to freely move.

 

[G-Papi]

To me "smooth" means (1) not crossed up, and (2) not in the grass.

 

[ZoomZoomH]

you do realize takumi in initial D only does the cup-in-water trick when he's delivering tofu, so the tofu doesn't get squished right? and he's driving A LOT slower than maximum speed that he's capable of

it's a training tool, makes you aware of the inputs that you apply to your car (throttle, brake, steering), which IS very useful once you throw out that cup of water and really try to book.

 

[jersey_emt]

you do realize takumi in initial D only does the cup-in-water trick when he's delivering tofu, so the tofu doesn't get squished right? and he's driving A LOT slower than maximum speed that he's capable of

it's a training tool, makes you aware of the inputs that you apply to your car (throttle, brake, steering), which IS very useful once you throw out that cup of water and really try to book.

Exactly! Well said.

 

[chuyler1]

Now if you were talking about every day driving with passengers...I'd say the cup method is probably a good way to make your passengers comfortable. If you are bucking like a bronco in rush hour traffic perhaps you need a lesson or two on driving stick or at least how to maintain adequate space between yourself and the car in front of you.

 

[brucelee]

lol definitely not bronco'ing. i've come to the conclusion that he drives in a manner too docile for my taste. i don't drive aggressively at all. at least no one else who's ridden with me thinks/thought so.

 

[aMaff]

Uhmm yeah..tell him he's watching too much Initial D.

+1

He's never heard of the "traction circle" has he?

+2

drink the water first.

+ 3


Ya, there's no way you'd be able to make a decent time driving like that. You'd definately be very smooth, but smooth driving on track does not necessarily mean it'll feel smooth to a passenger / cup of water. I've ridden with some very fast, smooth drivers (in my so far futile attempts to become one ) and I can tell you for a fact that had there been a cup of water in the cup holder at the start of the run, there would have been water all over the car at the end of the run.

That being said, I don't think my grandma would spill one drop.............

 

[xelderx]

I run into this problem a lot instructing autocross novices. We drill into thier minds to be smooth with no abrupt inputs that may upset the car. This works for novices with little to no car control and helps them maintain proper lines. Once they become comfortable with the dynamics involved you have to push them harder and harder to reach the limits. Brake later and harder...back on the gas sooner...use wieght transfer to turn the car as much as the steering.

There is a huge difference here though that needs to be addressed. Most of us have autocrossed in some fashion and that takes a completely different skill set and approach to driving dynamics from road racing. Think of it like this...road racing is like a rollercoaster, longer and steadier g forces. Autocross is like an earthquake...constant g force transition.

The water concept does hold some truth in road racing type situations where transition from 0 "G" to maximum "G" is much slower.

 

[G-Papi]

Spend a significant time driving in snow and ice.

Then you get smooth, or tear something up.