I think I experienced the snap oversteer phenomena last night and am still analyzing trying to figure out what I did wrong. I was exiting a tight but increasing radius curve and had was starting to accelerate (about 30-40 mph) when I got some wheel spin (tcs did not engage). I corrected for the resulting oversteer (and may have lifted off the throttle a little) which seemed to make things worse, snapping the car back the other way, corrected for that, when back the other way and off road. Luckily over a low curb into a flat grassy area, and miraculously no damage to the wheels. Other than slow down, any advice as to what I did wrong, how to handle the situation. I though I saw something in the faq's previously but couldn't find it again, so a visit from the faq or forum nazi's is not unexpected (and would actually be appreciated) but is there anyone out there who has experienced this and or can describe some proper driving techniques.
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Snap Oversteer
- Thread starter PaulC
- Start date
Classic mistake. You start to spin and head off the road/track to one side, but end up overcorrecting and go off the road/track on the OTHER side.
Couple of things can "help" this to happen. First, if you did lift off the throttle, you're tranfserring weight forward and the rear tires have less grip and are going to come around even faster. When you correct the oversteer situation, stay on the throttle. You can reduce throttle a bit if it was throttle induced oversteer, but you want to prevent trailing throttle oversteer induced by weight transfer to the fronts.
Now that you've started your spin and you're correcting, you need to return your steering input to neutral before the rear end starts coming around the OTHER way. It's hard to explain when to do this... many people have described it as a "pause" in the behavior of the car. The best way to learn is to get out on a wet skidpad and practice, practice, practice.
EDR
91 Black/Ivory #3012
Couple of things can "help" this to happen. First, if you did lift off the throttle, you're tranfserring weight forward and the rear tires have less grip and are going to come around even faster. When you correct the oversteer situation, stay on the throttle. You can reduce throttle a bit if it was throttle induced oversteer, but you want to prevent trailing throttle oversteer induced by weight transfer to the fronts.
Now that you've started your spin and you're correcting, you need to return your steering input to neutral before the rear end starts coming around the OTHER way. It's hard to explain when to do this... many people have described it as a "pause" in the behavior of the car. The best way to learn is to get out on a wet skidpad and practice, practice, practice.
EDR
91 Black/Ivory #3012
Paul it seem as though you've found your answer which was lifting off the throttle.Though the NSX TCS is very advanced I always turn it off when driving aggressive.
"If the direction of the car's body will exceed the driver's expected line-the TCS control unit signals the throttle actuator, which closes the throttle valve, thus reducing power." I have experienced this closing throttle valve which is like lifting off the throttle(scary)Maybe that's what you experienced. There are so many TCS variables that it makes it very hard to predict what it's going to do.The TCS at times will also allow wheel spin and sometimes not.This is dependent upon the 7 input sensors to the TCS control unit.There is a detailed explanation on the TCS in the NSX service manual. Try it again with your TCS off and see if that helps.
"If the direction of the car's body will exceed the driver's expected line-the TCS control unit signals the throttle actuator, which closes the throttle valve, thus reducing power." I have experienced this closing throttle valve which is like lifting off the throttle(scary)Maybe that's what you experienced. There are so many TCS variables that it makes it very hard to predict what it's going to do.The TCS at times will also allow wheel spin and sometimes not.This is dependent upon the 7 input sensors to the TCS control unit.There is a detailed explanation on the TCS in the NSX service manual. Try it again with your TCS off and see if that helps.
- Joined
- 10 April 2001
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- 662
I though I saw something in the faq's previously but couldn't find it again, so a visit from the faq or forum nazi's is not unexpected (and would actually be appreciated)
The previous discussion here was mostly about the effects of various mods.
http://www.nsxprime.com/ubb/Forum1/HTML/000091.html
The previous discussion here was mostly about the effects of various mods.
http://www.nsxprime.com/ubb/Forum1/HTML/000091.html
Thanks for the advice. The main reason for the throttle induced oversteer was not wanting to lift in the middle of the corner. It is quite possible that while the traction control didn't activate during the throttle induced oversteer, it may have cut power and aggravated the situation as the car came back around when I corrected for the oversteer. I'll take this incident as a free warning to explore the limits and characteristics of the car in more controlled locations before I start pushing the limits with aggressive driving on the street.
I second that the first mistake was lifting. You learn this very quickly on a motorcycle. My instructor always said "Keep the chain tight mid-corner". If you roll on the throttle and you start to oversteer, just stop inputing and keep the throttle constant. The bike (or car) will usually come back with some minor steering correction.
The second mistake is the use of TCS. Mine is a '92 and has never saved me and everytime its come on, it's only pissed me off.
My .02.
Vic
The second mistake is the use of TCS. Mine is a '92 and has never saved me and everytime its come on, it's only pissed me off.
My .02.
Vic
I've always been told and I agree, that you'll have the firmest control of any car when it's under slight throttle. If TCS is reducing throttle, then the only thing it's good for is maybe preventing wheelspin in rain or snow when taking off in a straight line. Next time, instead of lifting the throttle, try just putting the clutch in and coasting through the turn. While it's better to have a bit of throttle, no throttle is far better than engine braking. Just the fact that you are in a turn and sliding will slow you down so stay off the brakes.
I would agree wholeheartedly with the earlier post. Try this on a skidpad first. You'll see how throttle steering works and you might be able to see if TCS is acting in your best interest.
Marc
I would agree wholeheartedly with the earlier post. Try this on a skidpad first. You'll see how throttle steering works and you might be able to see if TCS is acting in your best interest.
Marc
The only part of any of the above to which I'd take significant exception is the part about disengaging the clutch. It's certainly better than stabbing the brakes and I can't state emphatically that it is always the wrong approach, but I've been "pressing my luck" around corners for decades and would not consider it an option. I steer with the throttle a lot and learning to feather it in such situations gives you much more potential for control.
[This message has been edited by sjs (edited 11 May 2001).]
[This message has been edited by sjs (edited 11 May 2001).]
All good advice, but the part about engaging the clutch doesn't make sense to me - wouldn't that result in transferring weight from the rear to the front?!?
Only options are throttle and steering, and after a certain point resorting to the old adage "in a spin both feet in, when in doubt both feet out".
Unfortunately I've had many spins, both in controlled and not so controlled environments.
Only options are throttle and steering, and after a certain point resorting to the old adage "in a spin both feet in, when in doubt both feet out".
Unfortunately I've had many spins, both in controlled and not so controlled environments.
I've autocrossed the car and not experienced this kind of instability, but then I did deactivate TCS and ABS when running it. Maybe TCS contributed to my problems, Although I give the driver 99.9% of the blame. SJS: I was feathering the throttle to control direction, but as the car was straightening out exiting the corner is when things went bad, maybe TCS started to take over and disturbed the balance of the car. Anyway, lesson learned - keep the TCS off for spirited dry driving.
Yeah, I thought I'd get some flack for suggesting to put the clutch in. What I was trying to get at is when the rear breaks loose, too much throttle or too much engine braking will cause the spin to continue. With no power or drag on the rear wheels, they can be brought back into line by just steering into the spin. Now I'm not suggesting that this be a standard way of driving. It's better to control the power to the rear and use that to control the front/rear traction.
To recover from:
Power-on oversteer - reduce throttle
oversteer - light throttle
understeer - reduce throttle
To recover from:
Power-on oversteer - reduce throttle
oversteer - light throttle
understeer - reduce throttle
I got the "snap oversteer" in the rain with the TCS on. It never activated to my knowledge. Not sure if it would have helped. I am definitely going to get my car on a skidpad if I can or at least a closed circuit so I can push the car to its limits. I still have trouble understanding why you have to stay on the throttle to keep the rear tires from loosing grip. I would think the suspension is so tight on the NSX that weight transfer is neglegible.
I still have trouble understanding why you have to stay on the throttle to keep the rear tires from loosing grip. I would think the suspension is so tight on the NSX that weight transfer is neglegible.
The stiffness of the suspension only affects how much the "attitude" of the car changes - the amount of nose dive during braking, and the amount of body roll during turns.
Weight transfer, OTOH, is unaffected by the stiffness of the suspension. It's a function of physics - the fact that the force of the car's forward momentum is at its center of gravity which is some distance above the ground, and the stopping force (the contact patch of the tires) is applied at ground level. The contact patch acts as a fulcrum (pivot point) for the momentum, which transfers weight from the rear wheels to the front wheels. This happens regardless of how stiff the suspension is.
The stiffness of the suspension only affects how much the "attitude" of the car changes - the amount of nose dive during braking, and the amount of body roll during turns.
Weight transfer, OTOH, is unaffected by the stiffness of the suspension. It's a function of physics - the fact that the force of the car's forward momentum is at its center of gravity which is some distance above the ground, and the stopping force (the contact patch of the tires) is applied at ground level. The contact patch acts as a fulcrum (pivot point) for the momentum, which transfers weight from the rear wheels to the front wheels. This happens regardless of how stiff the suspension is.
