Tire psi effects on over/understeer...(long)
#11
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I was going home after a round of golf, and when I saw the hairpin turn coming up, instead of slowing down, I accelerated! (had just installed the SP8000's 500 miles before)
Turn was left, was way too fast, I braked too suddenly, and fishtailed to the right.
After overcorrection, I was heading backwards to the right shoulder. Performing routine Nascar behaviour, I jammed the brake pedal instantly and avoided a tree and a stone wall.
Very scary.
Turn was left, was way too fast, I braked too suddenly, and fishtailed to the right.
After overcorrection, I was heading backwards to the right shoulder. Performing routine Nascar behaviour, I jammed the brake pedal instantly and avoided a tree and a stone wall.
Very scary.
#12
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That move broke rear traction, and swung your end around. It's a fine line. After your end started to break free, the move is to then steer into the spin, towards the direction you want to go, then lay off the gas, and even apply VERY LIGHTLY the brakes if necessary, to reaffirm rear traction. Then you'd get the sideways drift, and slowly return to proper relationship to the road. Hindsight I know...
#15
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It seems to me that there are as many people who think raising the rears produces oversteer as there are that think raising the fronts does the same. I personally discovered that raising the rear pressure on MY CAR produced more oversteer. There are many variables at work here, mind you...tires, bars, springs, shocks, conditions. And I'm by no means an expert. But raising my rear pressure and lowering my front pressure, 39F-43R with AVS Sports, worked well for me at Watkins Glen.<ul><li><a href="https://www.audiworld.com/forum/m/racing/msgs/2131.phtml">Tire Pressures</a></li></ul>
#16
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Every day I would say to myself "I will not drive fast".
But I would set speed records nevertheless around rotaries (Massachessetts thing) and exit ramps.
That car would BEG me to drive fast. Going around corners, the inside rear wheel would lift (I knew because the engine would rev suddenly).
I crashed it 2 times. Wow, am I lucky,
But I would set speed records nevertheless around rotaries (Massachessetts thing) and exit ramps.
That car would BEG me to drive fast. Going around corners, the inside rear wheel would lift (I knew because the engine would rev suddenly).
I crashed it 2 times. Wow, am I lucky,
#18
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Craig, the most likely reason you spun out on the ramp is that you were first accelerating coming into the turn, and when you saw the sharp turn, you attempted to slow down by lifting off the throttle. So what happens when you do this?
First, the car's weight transfer up to the front and the rear of the car unweights thus causing decreased traction in the rear. Second, your steering wheel is cranked a bit and the increase weight up front causes more traction for your front tires. The combination causes your front end to turn fast while your rear end has no traction....you spin out. This is a definite NO NO at a track. Too many times, people come into turns too hot, lift off the throttle and spin out.
Do you remember the video of the subaru? He made the same mistake.
As for quattro, you get UNDERSTEER when accelerating because when you are accelerating, the front end lifts, and the front tires are trying to turn and accelerate at the same time. In a rwd car, the front tires only need to steer. There's still PLENTY of grip on the front end for that. That's why you hear so many stories about mustangs spinning out in the rain.
First, the car's weight transfer up to the front and the rear of the car unweights thus causing decreased traction in the rear. Second, your steering wheel is cranked a bit and the increase weight up front causes more traction for your front tires. The combination causes your front end to turn fast while your rear end has no traction....you spin out. This is a definite NO NO at a track. Too many times, people come into turns too hot, lift off the throttle and spin out.
Do you remember the video of the subaru? He made the same mistake.
As for quattro, you get UNDERSTEER when accelerating because when you are accelerating, the front end lifts, and the front tires are trying to turn and accelerate at the same time. In a rwd car, the front tires only need to steer. There's still PLENTY of grip on the front end for that. That's why you hear so many stories about mustangs spinning out in the rain.
#19
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It's really a mute issue. Everyone has their own opinions and I'm not up for arguing. What works for me may not for someone else. Ed, btw, where in Hotlanta are you? I was down there a few weeks ago to stay w/ my sister. She lives in the Post apts over by the Gold Club. Didn't see too many Audis...and when I did(the demographic)>30-something young professional women. How have you washed your car all summer with that damn water ban in effect? Her brand new Jetta is a grimey mess! Women!
#20
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but the rear will still break. The quattro only shifts a portion of course...
Not debating your point, just adding some thoughts. I have not tracked a quattro yet, so I'm listening to your point.
Not debating your point, just adding some thoughts. I have not tracked a quattro yet, so I'm listening to your point.