12-06-2001, 05:51:00 PM
What is this exactly always hear about it on the shows on speedvision?
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12-06-2001, 05:51:00 PM
What is this exactly always hear about it on the shows on speedvision?
12-06-2001, 07:18:00 PM
understeer is a term used to describe how a car handles near the limit. This means when you start pushing it around corners that the car will go wide - ie: the front end starts losing traction first (I'm not talking a headlong slide here, but the car doesn't turn as tightly as the angle of the wheels are telling it to)
99% of cars are designed to have understeer because it is safer with 99% of drivers. When you go into a corner, realise you are going too fast, and the car starts going wide, what's your first reaction? Let off the gas, or hit the brakes, right?
what happens when you let off, or brake is that weight transferrs foward in the car. This increases traction up front, and decreases it in the rear, curing the understeer, and saving your @$$
Now, the opposite is OVERsteer. this is what the old Porsche 911's are known for. If you get in too fast, the REAR of the car looses traction first, and the car starts to spiral in on the corner. Now, take 99% of drivers when this happens - they will still hit the brakes. Hitting the brakes still transferrs weight foward, leaving the rear tires with even LESS grip. Hence, the rear slides out more, and you are very likely to spin out completley.
Now, for an experienced driver, oversteer can be very useful - they know not to hit the brakes (and don't usually go into a corner too fast http://www.nastyz28.com/ubb/smile.gif ). with an oversteering car, when you go in too fast, you want to either steer out of the corner, or hit the gas (assuming your motor won't break the rear tires loose). Steering out of the corner gets you going sideways, like in the movies, and hitting the gas moves weight to the back of the car, increasing rear traction, and reducing front traction.
This is also what they mean when they say you can 'steer a car with the throttle' more gas loosens the turn, less tightens it.
Now, ideally, you have a car that handles completley neutrally - neither end slides first. It's not as dramatic, but it's faster, and does take a bit more work in tuning the suspension.
*whew* sorry for the long post, I could go on for volumes. This is the stuff that really excites me about cars, even moreso than smoking burnouts and blazing 1/4 trips.
12-06-2001, 07:23:00 PM
My biggest problem with my camaro will be spinning the tires around a corner lets say a right turn then the rear of the car pitchs to the left what do you do in that situation?
12-06-2001, 11:25:00 PM
sounds like oversteer, right? The car is tightening up on the corner, and would head off the road to the inside of the turn if left uncorrected?
Also, when you say spinning, you mean you're breaking them loose and basically doing a burnout? (I'm jealous)
If that's the case, suspension tuning isn't really going to help you that much, you're simply overwhelming the traction the rear tires can provide. A certain tire can only give so much grip - if you're going hard into a corner, and using ALL that grip to hold the car laterally in the corner, then getting on the gas will put more demands on the traction that tire has, and if the total force exceeds the grip the tire has to provide then you'll spin 'em.
Now, this is different than steering with the throttle like I mentioned above - once you've broken the rear tires loose, the rear has basically NO traction, and is just going to swing out (as opposed to steering with the throttle when the rears remain connected and more gas would loosen the turn), and you need to reduce throttle to bring the rear back in line, or steer out of the corner some into a nice powerslide.
To remedy this, you either need wider tires (or better tires for more grip - not drag slicks, but performance radials designed for cornering) or don't hit the gas so hard!
Personally, I'd find some empty back roads that you know well, and play around. Learn how much you can get on the gas around a corner WITHOUT breaking the rear tires lose. Then (if you feel comfortable) try giving it a little more gas and experiment with some power slides - just picture what you see in the movies (and remember that they are TRAINED drivers, so take it slow!)
What I've done in the past is whenever I go over a certain stretch of road, increase my speed by 5mph or so and see what happens. If it starts getting squirelly, back off, and consider that the 'limit' for now.
Legal Disclamer: Do this at your own risk - playing around testing the limits of your cars handling on the street increases your chances of ending up in a ditch (or worse), or red-blue lights flashing behind you!
12-07-2001, 10:17:00 AM
Another way to find out how far you can go without having the rear end pass the front end is to take the car autocrossing. Much safer than doing it on the street and you might win a trophy http://www.nastyz28.com/ubb/smile.gif
1980 Money Pit deeper and deeper it goes
12-11-2001, 04:46:00 PM
Don't camaros start to lose the rear end first into a tight corner?
12-11-2001, 07:29:00 PM
Originally, I think they were tuned for understeer, most every car for quite awhile has been.
Nowadays, with all that has been done to most camaros, who knows...
12-11-2001, 07:31:00 PM
how about 73 z28's
12-14-2001, 02:56:00 PM
How does sway bar size effect under and over steer?
12-14-2001, 07:24:00 PM
sway bar size can have all sorts of affects on handling...
I know it sounds odd, but you either add, or increase the swaybar on the end of the car you want to decrease traction on. I suppose I should say relative traction, because adding a swaybar isn't going to reduce your cars handline potential.
Lets take this more from a tuning aspect - if you have a car that understeers, you want a larger rear swaybar. This reduces the relative traction in the rear, evening things out and taming the understeer. Now, since this is making the car handle closer to neutral, you are going to increase the overall cornering potential of the car.
check out madmikes camaro tuning pages - they have lots of tips and info for tuning your car for handlng.
greg - I was born in '81... I'm assuming that all camaros were originally tuned for understeer since it is safer on a car you're selling to every tom, dick, harry, and jane that comes along with money. The Z28 might have been set up with less understeer, but very few cars come from the factory tuned for oversteer. The older Porsche 911's are a notable exception, and the early ones are supposed to be very tailhappy, but even the new 911's are tamed down alot and have nearly neutral handling...
Now, age, wear, different tire sizes, or - what sounds like your case above - lots more power can change things alot.
Also, all these principles are based on having the tires gripping the ground - when you describe spinning the rear tires through a turn you're really changing the rules. Once you break the rear tires loose and spin them, you're really going to kill their lateral grip. Also, if you have drag ratials, or drag slicks those tires are short on lateral traction to start with, so things only get worse... What is your current setup for the engine/suspension?
12-15-2001, 01:28:00 AM
Ah I see. Do you know where I could find any numbers(spring rates, sway bar, anything else) that are known to put a car right in the middle?
12-15-2001, 01:38:00 AM
Almost all cars are set up for understeer from the factory-keeps the average driver on the road and out of trouble, except maybe the 911 Porsche, which has oversteer-that is why several actors/famous people flew off the PCH in them. The larger the front bar the more the understeer. The larger the rear bar the more tendency to oversteer. Of course the stiffness of the springs does the same thing. You want neutral handling car, where at a steady speed in a turn the car will drift equally front and rear. A neutral car can be steered through a turn with the accellerator-give it gas and the rear will come around and turn tighter, off the gas the car will go wide.
Also the closer the percentage of weight on the front and rear tires affects the handling, you want 50/50 front to rear.
I had an 84 corvette with the Z 51 suspension, and it handled fantastic-I think it had close to 50/50 weight distribution.
To get the best spring rate for your car you should call a manufacturer and let them know what you want out of the car. You should also find out the weight on the front wheels and the weight on the rears, along with the total weight of the car with you in it.
I just read blueyes post completely and noticed his bit on the 911 also LOL.
My 74 LT 4 speed has a budget setup that works pretty well for the cost. It has the stock soft LT springs, 16" wheels, and 1 1/4 front and 1" rear swaybars along with gas shocks.
[This message has been edited by Daniel (edited December 15, 2001).]
12-15-2001, 11:44:00 AM
what tires are you running on those rims? I'm having a hard time finding tires larger than 245 for a 16" rim... There's one company that makes a 255 width, but I'd like at least 265...
Despite the incredible lure of horsepower, I really want to set my camaro up for incredible handling first (although it will probably get vortech heads and EFI as well, but what I really want is a blower...) so I'm looking towards 17" rims, maybe even 18". I've just got to measure the wheel wells and see what is the most that will fit in there...