Snap oversteer
01-17-2010, 04:00 AM
#31
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Just to add to the general consensus. . . .
My autocross experience has been that given good surface, tires, and temperature the S2000 rotates a lot easier under lift than acceleration. No expert, but some cars like late braking and throttle while the AP1 prefers, even rewards, pushing the braking and throttle much further toward entry. Once you get turn-in, rolling smoothly into the throttle early pays big dividends. There is gobs of grip in relation to power. And if the back does step out under acceleration it is fairly easy to control by staying in it and counter-steering. If things get ugly under a lift it seems like the car becomes a chaotic mess of weight transfer, altering geometry, and rough input. The high-speed examples make all this look like a razors-edge dance. If the S does have it, I think it is limited to trailing-throttle snap oversteer.
My autocross experience has been that given good surface, tires, and temperature the S2000 rotates a lot easier under lift than acceleration. No expert, but some cars like late braking and throttle while the AP1 prefers, even rewards, pushing the braking and throttle much further toward entry. Once you get turn-in, rolling smoothly into the throttle early pays big dividends. There is gobs of grip in relation to power. And if the back does step out under acceleration it is fairly easy to control by staying in it and counter-steering. If things get ugly under a lift it seems like the car becomes a chaotic mess of weight transfer, altering geometry, and rough input. The high-speed examples make all this look like a razors-edge dance. If the S does have it, I think it is limited to trailing-throttle snap oversteer.
01-17-2010, 04:53 PM
#33
Originally Posted by Marrk,Jan 16 2010, 05:06 PM
ZDan: I wouldn't mind if you explained this: "rear toe change with bump." I don't know exactly what we are talking about. Does this mean toe alters when the suspension articulates?
Not the best idea...
01-18-2010, 12:41 AM
#34
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To the OP.
This is a question that is (rightfully) raised almost every week. And it always seems to recieve the same replies:
"You're either a driver, or your not" - "It's not the car, it's the driver"
The truth is:
The car snaps into oversteer, pure and simple.
Yes, you can learn it, tame it, adjust to its ways but the simple answer is that it is a snappy bugger that demands far more respect than almost any other contemporary rear drive sports car.
Miata's, Boxster's, Cayman's, Z4's, 370Z's, BMW 335's, Mustang's, Jaguars and Mercedes do not have this reputation, S2000's do and they do for good reason.
Be careful.
This is a question that is (rightfully) raised almost every week. And it always seems to recieve the same replies:
"You're either a driver, or your not" - "It's not the car, it's the driver"
The truth is:
The car snaps into oversteer, pure and simple.
Yes, you can learn it, tame it, adjust to its ways but the simple answer is that it is a snappy bugger that demands far more respect than almost any other contemporary rear drive sports car.
Miata's, Boxster's, Cayman's, Z4's, 370Z's, BMW 335's, Mustang's, Jaguars and Mercedes do not have this reputation, S2000's do and they do for good reason.
Be careful.
01-18-2010, 03:57 AM
#35
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I agree with this assessment. However, it's important to note WHY it's so. Basically (I'm no suspension expert), it's because the S was tuned as very neutral-handling. Design in some understeer, like 99% of the other vehicles out there, including the above list (most of which have LOTS of understeer), and the "snappiness" starts going away. I'm sure there's various suspension design decisions that can be blamed, too, but if you have a neutral-handling car, it's very easy to make it over- OR understeer. Som it's got more to do with driving the vehicle with that knowledge in mind. That doesn't mean anyone is necessarily a bad driver - it may simply be that this handling is outside of the experience base of any particular driver.
You can easily modify the car to make it more prone to understeer - make sure your tire sizes are appropriate, especially on the AP1s. The fronts are narrower than normal while the rears are wider. Take away a little negative camber from the front tires and/or add some to the rear. Replace the front swaybar with a stiffer one. All easy and cheap to do.
And learn the dynamics of a car with neutral handling. Some autocross or track time can pay huge dividends.
You can easily modify the car to make it more prone to understeer - make sure your tire sizes are appropriate, especially on the AP1s. The fronts are narrower than normal while the rears are wider. Take away a little negative camber from the front tires and/or add some to the rear. Replace the front swaybar with a stiffer one. All easy and cheap to do.
And learn the dynamics of a car with neutral handling. Some autocross or track time can pay huge dividends.
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lab_rat (06-10-2019)
01-18-2010, 05:34 AM
#36
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The S, being a mid engine vehicle, has low rotational inertia.
The lower rotational inertia causes it to spin much faster than a front or rear mounted engine vehicle.
Slow in, fast out.
My old '91 MR-2. That was snap oversteer... 
The lower rotational inertia causes it to spin much faster than a front or rear mounted engine vehicle.
Slow in, fast out.
My old '91 MR-2. That was snap oversteer...
01-18-2010, 07:27 AM
#37
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Ill add some advice here too.
Once you have determined that throttle and steering inputs are not going to change your situation, straighten out the steering wheel, if you dont, you will only spin again and again, as the front tires grab traction, then turn you over and over.
....and for the s2000 relating to oversteer...my experience with this car is to stay ON the throttle, even adding more gas when the rear end steps out. Point the wheels towards the straight and keep your foot on the gas, and you will likely come out clean. In the event that rear wheel-spin drastically increases with more throttle, SLOWLY SOFTLY GENTLY EASE off of the throttle, while at the same time SLOWLY SOFTLY GENTLY STRAIGHTENING out the wheel.
I dont know how many of you have ever used a bow before (Like bow and arrow bow) But your throttle lift should be the same as you would ease the string back in on a bow, should you have drawn for a shot and changed your mind. (weird analogy I know lol)
Once you have determined that throttle and steering inputs are not going to change your situation, straighten out the steering wheel, if you dont, you will only spin again and again, as the front tires grab traction, then turn you over and over.
....and for the s2000 relating to oversteer...my experience with this car is to stay ON the throttle, even adding more gas when the rear end steps out. Point the wheels towards the straight and keep your foot on the gas, and you will likely come out clean. In the event that rear wheel-spin drastically increases with more throttle, SLOWLY SOFTLY GENTLY EASE off of the throttle, while at the same time SLOWLY SOFTLY GENTLY STRAIGHTENING out the wheel.
I dont know how many of you have ever used a bow before (Like bow and arrow bow) But your throttle lift should be the same as you would ease the string back in on a bow, should you have drawn for a shot and changed your mind. (weird analogy I know lol)
01-18-2010, 07:37 AM
#38
For me, the S2000 is front-engine rear-drive, just like the Miata, Corvette, my 240Z, Viper, etc. etc.
Calling these cars "mid-engined" sort of destroys the usefulness of the term. Just about *any* performance-oriented front-engine rear-drive car is going to have the engine located predominantly aft of front wheel centerline. Some definitions of "midengined" even allow for front-engine cars where only the c.g. of the engine is aft of front wheel centerline (which would pretty much include *any* FR car), but either way it's sort of an arbitrary specification. What if some minor part of the S2000's engine like a thermostat housing were altered such that the front of it were barely in front of front-wheel centerline, would that transform it from "mid-engined" to "front-engined" even though weight distribution and polar moment were unaffected?
Call it what you will, to me it's classic front-engine/rear-drive.
I *FULLY APPRECIATE* that it is important for the engine in an FR car to be located well aft in the engine bay, for better weight distribution and reduced polar moment. But take a car like the 370Z, which ostensibly has its engine fully aft of front wheel centerline but only mangages a 55/45 front/rear weight distribution, while a BMW 335i, which has about the first cylinder and a half in front of front-wheel centerline but still manages a more-respectable 52/48 front/rear weight distribution, to say that these are fundamentally DIFFERENT vehicle layouts is to me absurd. They're both front-engine/rear-drive.
Call one or both of them and the S "front mid-engine" if you like, but to say that any of them is "mid-engined" with no qualifier at least, is to reduce the descriptiveness of the term.
What have normally historically been called "mid-engined" cars have had the engine behind the passenger compartment and predominantly in front of the rear wheels. This layout has inherent weight distribution and polar moment advantages over "front mid-engine" designs, including the S. The design which most enthusiasts continue to call "mid-engine" (aka "rear mid-engine") better centralizes major masses (including the driver).
To label front-engine/rear-drive cars (some with pretty poor f/r weight distribution, none having the centralized mass advantages of [rear] mid-engine design) as "mid-engined" is useful only for marketing.
Calling these cars "mid-engined" sort of destroys the usefulness of the term. Just about *any* performance-oriented front-engine rear-drive car is going to have the engine located predominantly aft of front wheel centerline. Some definitions of "midengined" even allow for front-engine cars where only the c.g. of the engine is aft of front wheel centerline (which would pretty much include *any* FR car), but either way it's sort of an arbitrary specification. What if some minor part of the S2000's engine like a thermostat housing were altered such that the front of it were barely in front of front-wheel centerline, would that transform it from "mid-engined" to "front-engined" even though weight distribution and polar moment were unaffected?
Call it what you will, to me it's classic front-engine/rear-drive.
I *FULLY APPRECIATE* that it is important for the engine in an FR car to be located well aft in the engine bay, for better weight distribution and reduced polar moment. But take a car like the 370Z, which ostensibly has its engine fully aft of front wheel centerline but only mangages a 55/45 front/rear weight distribution, while a BMW 335i, which has about the first cylinder and a half in front of front-wheel centerline but still manages a more-respectable 52/48 front/rear weight distribution, to say that these are fundamentally DIFFERENT vehicle layouts is to me absurd. They're both front-engine/rear-drive.
Call one or both of them and the S "front mid-engine" if you like, but to say that any of them is "mid-engined" with no qualifier at least, is to reduce the descriptiveness of the term.
What have normally historically been called "mid-engined" cars have had the engine behind the passenger compartment and predominantly in front of the rear wheels. This layout has inherent weight distribution and polar moment advantages over "front mid-engine" designs, including the S. The design which most enthusiasts continue to call "mid-engine" (aka "rear mid-engine") better centralizes major masses (including the driver).
To label front-engine/rear-drive cars (some with pretty poor f/r weight distribution, none having the centralized mass advantages of [rear] mid-engine design) as "mid-engined" is useful only for marketing.
01-18-2010, 07:38 AM
#39
Back on topic, the designed-in rear bumpsteer in the AP1's suspension geometry makes it more of a handful, while giving zero performance or overall balance benefit. This aspect of the AP1's suspension setup wasn't a good idea... If/when the car gets squirrelly, if the driver lifts, the outside rear toes OUT and the car often winds up in the weeds or worse. The AP1's rear roll stiffness bias was pretty extreme for a production car as well. Basically, the roll stiffness distribution gives initial oversteer, which the outside rear toeing out kind of "catches" *if* you don't do something stupid like LIFT, which 98% of the population absolutely WILL DO when the back end starts to feel loose!
The AP2 fixed the rear bumpsteer issue, while still maintaining enough rear roll stiffness bias to be fairly neutral at the limit, but even that is too much for many drivers who've been brought up driving cars designed to resolutely understeer at the limit.
The AP2 fixed the rear bumpsteer issue, while still maintaining enough rear roll stiffness bias to be fairly neutral at the limit, but even that is too much for many drivers who've been brought up driving cars designed to resolutely understeer at the limit.
01-18-2010, 10:06 AM
#40
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If you want to see something interesting do a youtube search for in-car video of s2000s spinning out. Pay close attention to how people deal with the steering wheel when the car starts to get loose (typically from a lift of the throttle once the car is on its way to the apex). You will see that a lot of spins are the result of drovers taking their hands off of 3 and 9 and letting the steering wheel slide through their hands, giving them zero ability to counter steer/corret. This "look ma, no hands" reaction is often a side effect of shuffle steering, and it's a particularly dangerous technique for an inexperienced drover in a tail-happy car like an s2000.
1:[media]http://www.youtube.com/watch?v=fZWSFTaHBzo [/media]
2: @ 1:04[media]http://www.youtube.com/watch?v=xbSGmD2MU04 [/media]
3:[media]http://www.youtube.com/watch?v=HUVfPmGb_NM [/media]&feature=related
4:[media]http://www.youtube.com/watch?v=gDzB1qF0_nY [/media]&feature=related
5: @ 7:35[media]http://www.youtube.com/watch?v=AGyq0AmFbhA [/media]&feature=related
6:[media]http://www.youtube.com/watch?v=9HUCXuNjCg8 [/media]&feature=related
"please dont hit me" funny ish
1:[media]http://www.youtube.com/watch?v=fZWSFTaHBzo [/media]
2: @ 1:04[media]http://www.youtube.com/watch?v=xbSGmD2MU04 [/media]
3:[media]http://www.youtube.com/watch?v=HUVfPmGb_NM [/media]&feature=related
4:[media]http://www.youtube.com/watch?v=gDzB1qF0_nY [/media]&feature=related
5: @ 7:35[media]http://www.youtube.com/watch?v=AGyq0AmFbhA [/media]&feature=related
6:[media]http://www.youtube.com/watch?v=9HUCXuNjCg8 [/media]&feature=related
"please dont hit me" funny ish