am i imagining....
Dec 31, 2005, 02:21 PM
#17
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Your not even suppose to be braking while in the corner, braking should be done before the approach of the corner. I ve seen people spin because they panic and hit the brakes while turning a corner.
Dec 31, 2005, 02:25 PM
#18
Dude, the main poster doesn't sound like he's experienced. It doesn't even seem like he's experiencing any of the things you guys are mentioning, like understeering out of the corner. In fact, he states the opposite, that he was surprised that gassing his car eliminated the understeer. I'm talking all in relation to what I'm assuming HE's doing, not just blabbering basic track skills.
Dec 31, 2005, 02:45 PM
#19
Again man your posting more incorrect information. I have a national competition liscence from the SCCA, have been road racing for 2 years, autocrossing for 3, karting for 4, done a skip barber 3 day school, and currently instruct and race, not saying I am any sort of professional, but I know more about race and vehicle dynamics than your average 19 yr old... It does not matter if it is a decreasing radius turn, an off camber turn, a chicane, or a damn loopdy-loop, autocross or road racing turn, no matter what corner you are going around, if your goal is to go as fast as possible you want the highest average cornering speeds possible (the only exception is that some corners it is more advantageous in terms of track postion to either go for corner entrance speed "throw-away" corners, vs. corners like those before long straight aways where corner exit speed is much more vital to a quicker track time.) Optimum tire contact is not always the fastest way for a car around a track, go to any sort of organized motorsport event on tarmac, and I guarantee you will see many cars with wheels in the air, sometimes having a tire in the air is faser than having it stuck to the tarmac..... When you let off of the gas your front tires gain more grip, as you stated before when you mash the gas the weight transfers to the rear, the same is true in opposite directions for when you go from mashing the gas to letting off, the front of the car gets heavier, and the front tires get more grip. Also, if you have ever had an instructor drilling it into your head to keep it floored while around turns, let me know where you got this instructing so I can make sure nobody I care about goes there..... "If you let off the gas, you wipe out."-again another stupid comment, if you let off the gas while going around a corner in our cars front grip increases, just like any other. If you were driving a high HP rear wheel drive beast, or something like a Porsche, that like lots of slip angle to go fast, and really need to rotate to get the most out of then yes, letting off the gas will make you understeer more relative to the oversteer you are seeing throught the corner.
Scorke
p.s. evo637-you are absolutely correct. Braking while entering a corner or in the middle of the corner takes your car which is already severely loaded with lateral g's and then shoves even more weight to your outside front wheel, taking even more grip away from your rear and specifically your inside rear wheel, which provokes the car to rotate more (oversteer). It is called trailbraking and is often a great way to extend your straightaway by scrubbing off speed while still entering a turn.
Scorke
p.s. evo637-you are absolutely correct. Braking while entering a corner or in the middle of the corner takes your car which is already severely loaded with lateral g's and then shoves even more weight to your outside front wheel, taking even more grip away from your rear and specifically your inside rear wheel, which provokes the car to rotate more (oversteer). It is called trailbraking and is often a great way to extend your straightaway by scrubbing off speed while still entering a turn.
Last edited by scorke; Dec 31, 2005 at 02:55 PM. Reason: spelling......
Dec 31, 2005, 02:57 PM
#20
As much as I appreciate your chit chat, how does this relate to the original poster? True, optimum tire contact may not be the fastest way sometimes, but in it sure seemed so in his case. I'm telling him how he picked up grip and lost his understeer when he accelerated--in HIS situation. He seemed to pick up more traction somehow, while he threw the weight to the back.
Last edited by Thoe99; Dec 31, 2005 at 02:59 PM.
Dec 31, 2005, 03:00 PM
#21
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I dunno about you but in my FWD car if I gas it I correct the understear....this is proven by me time and again I dont' care what a physics book says. Same goes for my Evo....
Now my old mustang would correct itself if I let off the gas.....
You can quote books all ya want...I know what my car does when I drive it.
Now my old mustang would correct itself if I let off the gas.....
You can quote books all ya want...I know what my car does when I drive it.
Dec 31, 2005, 03:03 PM
#22
Originally Posted by Thoe99
Letting off the gas will INCREASE understeer. Understeer is when the front tires get all mashed in while you're turning, cuz you have all the weight up front. So if you gas the car, you'll throw the weight to the back and now you'll have all 4 tires with more ground contact to pull you out.
Dec 31, 2005, 07:58 PM
#27
Originally Posted by atlvalet
If I understand things correctly, when you lifted off the gas the car started to plow through the turn. When you stayed on the gas, you pulled/pushed the car through the turn.
Dec 31, 2005, 08:21 PM
#28
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Scorke knows his chit... He's correct when he says that it depends on the car. Some cars steer just as much with the throttle as they do with the steering wheel. His knowledge of vehicle dynamics is right on.
My STi steers with the throttle brilliantly and if it ever starts to push in a corner you can smoothly lift off the gas and it will pull itself back into line very tidily. This is great for people that don't know how to drive and get themselves in over their heads, it's very forgiving. But lifting off the accelerator mid corner means you did something wrong on entry and now you're going to have to make up for that loss of acceleration/ speed on corner exit.
My Evo handles differently, if you get it pushing in a corner (your overcooking the entry or too hard and early on the application of throttle mid corner) and lift, it doesn't react like the Subaru, it doesn't tighten it's line all that quickly but, it does stop pushing.
You're probably unconsciously letting it drift wide when you lift off the accelerator and when you get on the accelerator you're probably unconsciously feeding in more steering which is getting the car in it's ideal slip angle and it feels like it's tracking the line you want it to take.
Next time you try that corner try something different, keep your foot in the gas but very smoothly with your left foot apply some brake at the same time. Smooth is the key, with everything. You want to be smooth getting on the gas and you want to be smooth coming off the gas and the same applies to braking, apply pressure to the brake pedal smoothly and be even more smooth when coming off the brake pedal, just don't lift off abruptly. If your car is nose diving and then regaining composer you are unbalancing the chassis. Driving is just like anything, practice makes perfect, but you want to be practicing the right things.
The fact that your asking questions about vehicle dynamics is awesome. It means your interested in improving and not just driving along in an idiot haze like 95% of the drivers on our roads. It's good to ask questions but just make sure the people your asking are credible sources.
My STi steers with the throttle brilliantly and if it ever starts to push in a corner you can smoothly lift off the gas and it will pull itself back into line very tidily. This is great for people that don't know how to drive and get themselves in over their heads, it's very forgiving. But lifting off the accelerator mid corner means you did something wrong on entry and now you're going to have to make up for that loss of acceleration/ speed on corner exit.
My Evo handles differently, if you get it pushing in a corner (your overcooking the entry or too hard and early on the application of throttle mid corner) and lift, it doesn't react like the Subaru, it doesn't tighten it's line all that quickly but, it does stop pushing.
You're probably unconsciously letting it drift wide when you lift off the accelerator and when you get on the accelerator you're probably unconsciously feeding in more steering which is getting the car in it's ideal slip angle and it feels like it's tracking the line you want it to take.
Next time you try that corner try something different, keep your foot in the gas but very smoothly with your left foot apply some brake at the same time. Smooth is the key, with everything. You want to be smooth getting on the gas and you want to be smooth coming off the gas and the same applies to braking, apply pressure to the brake pedal smoothly and be even more smooth when coming off the brake pedal, just don't lift off abruptly. If your car is nose diving and then regaining composer you are unbalancing the chassis. Driving is just like anything, practice makes perfect, but you want to be practicing the right things.
The fact that your asking questions about vehicle dynamics is awesome. It means your interested in improving and not just driving along in an idiot haze like 95% of the drivers on our roads. It's good to ask questions but just make sure the people your asking are credible sources.
