Is there a way to reduce understeer? I took the Fiero to a grassy area when it snowed an inch, to try and get a feel for what the car will act like this winter, and I noticed that the car has a problem with understeer, like bad. Same thing in the gravel. Is there a way to reduce this problem? The alignment guy told me that although the upper balljoints were slotted, they were in as far as they can go. He did tell me they were within spec, but barely.
From what I have been reading, the car likely has too much positive camber. I'm new at the alignment thing. What I gather, is that manufacturers intentionally put positive camber in the cars to make them less likely to oversteer, and for some crazy reason they think it's safer that way. I am of a different opinion. When you go into a corner and the back lets go, you can do more with the car to correct the problem than if the front lets go first. At least that has been my experience.
------------------ I have a 1987 Fiero, 4 cylinder 5 speed. With an 88 engine.
[This message has been edited by Stainless1911 (edited 12-02-2012).]
Originally posted by Stainless1911: What I gather, is that manufacturers intentionally put positive camber in the cars to make them less likely to oversteer, and for some crazy reason they think it's safer that way. I am of a different opinion. When you go into a corner and the back lets go, you can do more with the car to correct the problem than if the front lets go first.
This is correct. Manufacturers do put suspension and steering settings to induce understeer. However, I am going to have to disagree with you on that oversteer is better & safer. In the philosophy of professional driving 101, one will eventually learn that even professional race cars are ultimately setup with a degree of understeer in mind. The major reason is that an vehicle setup with understeer will be much more stable and easier to control, thus producing a faster lap time than a vehicle that has oversteer.
Think about the basic philosophy of driving a corner. A driver sets himself/herself up to the threshold breaking point, induces threshold breaking, after the breaking point maneuvers the car into the apex, once hitting the apex rolling back onto the throttle, then exiting the corner on the throttle. If the car is oversteering, the driver will have to make unnecessary throttle and steering corrections in order to keep the car on the optimum line - and in actuality it will likely be "sliding" along the line thus scrubbing time. With understeer, after a few laps a driver will be able to adjust themselves just to the limit of speed and steering input for the fastest time around the circuit. Then when they need to increase the pace, understeering condition will allow them better throttle and steering input predictability, thus a much useable window for pace input without scrubbing too much time off of their laps.
If you put Formula 1 champ Sebastian Vettel into two identical Red Bull F1 cars, that are both near exact in both build and setup with the only difference being that one car is setup with a little understeer, the car that Vettel is driving that has the understeering condition will not only be more predictable to control, but also ultimately produce consistent & faster lap times.
I would much rather have a car with some degree of understeer condition than a car with unpredictable oversteer. It comes down to how the driver understands the dynamics of the vehicle in motion.
Im not talking about racing. My problem is when I steer the car, I want more to turn than just the steering wheel. I don't like the feeling of going into a corner, and the car goes a third of the way around the turn, and then the front wheels just plow and the car goes into the tree line, ditch, rail, or whatever is bordering that particular corner.
[This message has been edited by Stainless1911 (edited 12-02-2012).]
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07:57 PM
TheRealShadowX Member
Posts: 1456 From: Milwaukee Wisconsin USA Registered: Mar 2010
Im not talking about racing. My problem is when I steer the car, I want more to turn than just the steering wheel. I don't like the feeling of going into a corner, and the car goes a third of the way around the turn, and then the front wheels just plow and the car goes into the tree line, ditch, rail, or whatever is bordering that particular corner.
If negative camber is what I need to reduce the cars tendency to do that, then that's what I want to do. Not so much to make the car oversteer, but to reduce the understeer. Could I open up the slots on the upper control arm so the ball joint can move a bit further?
[This message has been edited by Stainless1911 (edited 12-02-2012).]
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08:00 PM
fieroguru Member
Posts: 12512 From: Champaign, IL Registered: Aug 2003
Sounds like you need more throttle!!!! Seriously, if I need to take a tight turn in the winter or dirt I just nailed the gas and the tail came around very predictably... Not even joking
Last September a fella brought his pristine 5-spd '88 Fiero GT to the autocross track. This GT had 10,000 miles on it, and the original tires. The car looked fantastic!
I got to drive it.
It was scary dangerous.
The GT slid all over the place (on dry pavement). No, it wasn't due to my (lack of) driving skills.
I suspect the rubber dries out over the years and loses it's ability to grip the asphalt.
[EDIT] Just for fun, I thought someone might enjoy reading below what I posted in the local Fiero club's forum after I had driven this car on the track.
quote
Charles walked up to me and said, "Do you want to co-drive my car?" Excuse me, do I want to co-drive an '88 GT with 10,000 miles on it? Hell Yeah!
It occurred to me that the last time someone autocrossed an '88 GT with 10,000 miles on it was probably back in 1989!!!!
Anyway, as excited as I was, I was also terrified that I might possibly damage this pristine car. Putting it into the fence would not be the wisest thing to do!
It turned out that the '88 GT had lots of power, which was great, but it also had 23 year old tires on it with rubber as hard as porcelain, which was not so great. Combine that with shocks and struts which have deteriorated from sitting for two decades and all I can say is that the first slalom I went through was... challenging. I couldn't believe how squirly the car felt. It felt dangerous. Did that slow me down? A little... until the next run.
The next run I wanted to push it a bit more, just a teeny weeny bit. Bad move. I totally lost control of the car and nailed, not clipped, but nailed two cones. Worse than that, one cone wedged under the front of the car. It was with great shame and embarrassment that I returned to the starting grid with a bright orange cone wedged under this beautiful pristine '88 Fiero GT. Did I mention that this GT only has 10,000 miles on it?
Charles was very good about it. He didn't yell at me or strike me or anything. Charles is a fine man.
[This message has been edited by Patrick (edited 12-03-2012).]
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12:28 AM
SCCAFiero Member
Posts: 1144 From: Boca Raton, Fl USA Registered: Apr 2006
This is correct. Manufacturers do put suspension and steering settings to induce understeer. However, I am going to have to disagree with you on that oversteer is better & safer. In the philosophy of professional driving 101, one will eventually learn that even professional race cars are ultimately setup with a degree of understeer in mind. The major reason is that an vehicle setup with understeer will be much more stable and easier to control, thus producing a faster lap time than a vehicle that has oversteer.
Think about the basic philosophy of driving a corner. A driver sets himself/herself up to the threshold breaking point, induces threshold breaking, after the breaking point maneuvers the car into the apex, once hitting the apex rolling back onto the throttle, then exiting the corner on the throttle. If the car is oversteering, the driver will have to make unnecessary throttle and steering corrections in order to keep the car on the optimum line - and in actuality it will likely be "sliding" along the line thus scrubbing time. With understeer, after a few laps a driver will be able to adjust themselves just to the limit of speed and steering input for the fastest time around the circuit. Then when they need to increase the pace, understeering condition will allow them better throttle and steering input predictability, thus a much useable window for pace input without scrubbing too much time off of their laps.
If you put Formula 1 champ Sebastian Vettel into two identical Red Bull F1 cars, that are both near exact in both build and setup with the only difference being that one car is setup with a little understeer, the car that Vettel is driving that has the understeering condition will not only be more predictable to control, but also ultimately produce consistent & faster lap times.
I would much rather have a car with some degree of understeer condition than a car with unpredictable oversteer. It comes down to how the driver understands the dynamics of the vehicle in motion.
This entire line of thinking must be related to F1 racing, of which I admit I know less about than sedan racing or street driving. For street cars and sedan racing I have yet to meet a driver that agrees with you. I would love to see your reference for "Philosophy of Professional Driving 101"
Let me see if I understand your racing opinion. You would rather have a car that will slide straight off the track, at the limit you are supposed to find, and then accept that limit as the fastest the car will go, instead of a car that will oversteer and allow both steering and throttle inputs to correct and allow you to probably complete the turn and therefore the race. Is that accurate? Drifting or oversteer is not the fast way around a turn, but for every racer and professional driver I have met and raced with, it is far more preferable than sitting there watching the wall of tires quickly approaching.
Oversteer is not unpredictable if the car is set up right. It is essentially drifting, of which a lot of control is still available to seasoned drivers. Another reason why racers want oversteer built in to their cars.
Manufacturers set up cars for understeer because it is an easier situation to deal with than oversteer, for the average driver who has never lost control of a car.
Just remove the link on one side of the sway bar. See how you like it that way; if it's too much oversteer than re-connect it & add a rear sway bar. The Fiero has WAY too much understeer built in... ~ Paul aka "Tha Driver"
yes, low traction is a nightmare in a Fiero. no steering - no braking. tires. snow tires. the only thing you can do. rear sway bar wont do anything for low traction conditions. not a thing. nor does the front sway bar. the tires are losing traction WAY before any weight shift occurs.
but, the better answer is to just get a FWD winter ride.
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10:15 AM
Gall757 Member
Posts: 10938 From: Holland, MI Registered: Jun 2010
Fiero drivers tend to buy the stickiest front tires they can find, but that still does not help in snow conditions. When you do the math there are only 600 lbs. on each front tire (in stock trim)...so it's no wonder that when accelerating and turning the car, it wants to go straight. Braking is another matter, however, so you have to re-learn how to drive. This should be no surprise since the engine is not where it was when you learned to drive in the first place.
+1 on the winter beater......Fieros don't like salt and they are getting scarce.
[This message has been edited by Gall757 (edited 12-03-2012).]
whoever tells you to put more weight on the front to decrease oversteer is giving you bad advice it is counterintuitive, but you need to DECREASE the weight in front, or increase it in back tires are able to grip a given amount of weight for a given situation, when you exceed it, the tires will lose traction ergo, decrease weight to decrease understeer
BTW, I race, and that is one of the fundamental cures for oversteer
the others are: stiffer bar in rear, or lighter or remove bar in front soften springs in front, or stiffen in rear more negative camber in front, less negative camber in rear larger front tire section in front, smaller in rear lower front tire pressure, increase rear tire pressure more caster in front
which of these you do may affect other characteristics, so only do one at a time and drive it to see the affect
GM historically designs cars for understeer, the first thing to do to an 88 if you want less understeer, would be to run the same size tire all around
having said all that winter may be different if you are talking about snow covered road, the tires need to bite through the snow, so a narrower tire would do that, or more weight, however, once it is through the snow and onto the pavement, normal rules apply
but whoever said "slow down" that's the best cure!
[This message has been edited by ZaraSpOOk (edited 12-03-2012).]
Seems that if you lowered the tire pressure in front, the sidewalls would tend to fold earlier exasperating the problem. I plan on adding a rear sway bar, and I'd like to put new rear springs in it.
How to I add more negative camber? How do I change the caster, is that done with the washers on the long bolt for the upper control arm? If so, what is the procedure?
I talked my mom into confronting this guy about the alignment problem tonight. We will see if he wants to be respectable. If not, hopefully, we can get a case started.
the other thing I would like to add is that driving on snow is the best reason to have a manual transmission and use engine braking to help you slow down and steer
one thing to keep in mind is that making the camber more negative could cause another problem, more wear on the insides of your tires look at your tires, are you getting even wear? if so, changing the camber is not the correct thing to do the wear on your tires tells you if you have the proper alignment for your car, for YOUR driving (that last part is real important, everyone drives different)
look at the tires, are they wearing in the middle? lower pressure (note that is a cure for understeer) are they wearing at the outer edge? assuming it is not alignment, increase pressure (I doubt this is your problem, it will actually increase understeer)
caster, that would be the last thing I would change to correct the problem as long as it is in spec
toe, zero toe is best, however, a racer (not dragstrip!) might want a little toe out, whereas most drivers would want a little toe in because there is play in the front end parts which results in zero toe at speed, the toe out for the racer will cause premature tire wear on the street
when it is time to replace tires, go with a slightly larger section in front to decrease understeer (most people don't want to decrease rear for obvious reasons)
[This message has been edited by ZaraSpOOk (edited 12-03-2012).]
I can't comment on tire wear as of yet. Only a thousand miles or so on used tires, and in that time, I rotated front to rear in an effort to isolate my wobble problem.
I'll reduce the tire pressure in the front and see what happens. I suppose I could unbolt the front sway bar just to see, I would prefer adding one to the rear than removing the front on a permanent basis.
ETA. I have to admit,I sort of enjoy figuring out stuff like this. The rear subwoofer idea didnt work as well as I had hoped, so I'm back to having a trunk. I used the lower portion of the trunk to hold a jack, 2 stands, some plywood for the stands, a chain, jumpers, and a few other odds and ends just to make a self rescue a little easier. That added weight should help things a bit, there's probably 80-100 pounds back there.
[This message has been edited by Stainless1911 (edited 12-03-2012).]
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12:42 PM
Pyrthian Member
Posts: 29569 From: Detroit, MI Registered: Jul 2002
for low traction environments - the sway bar has NO impact - front or rear. there is not enough traction to make any weight shifts. are you looking for snow advice or for sunny/dry advice?
for low traction environments - the sway bar has NO impact - front or rear. there is not enough traction to make any weight shifts. are you looking for snow advice or for sunny/dry advice?
Snow advice. I really dont push this car hard enough for all that on dry pavement, it's just a Duke.
for low traction environments - the sway bar has NO impact - front or rear. there is not enough traction to make any weight shifts. are you looking for snow advice or for sunny/dry advice?
that is an excellent point, if the understeer is not a problem in the dry, the answer is simple,... slow down on snow!
I did get onto a dry paved parking lot and pushed it to see what happened. The car went into understeer almost immediately, and when I backed off on the steering a little, it snapped out of its plowing. I straigtened the car out immediately because I was out of room.
[This message has been edited by Stainless1911 (edited 12-03-2012).]
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12:52 PM
Gall757 Member
Posts: 10938 From: Holland, MI Registered: Jun 2010
I didn't go into detail above, but the Fiero without a rear sway bar has FAR too much understeer. My Formula WITH a rear swaybar would plow badly just doing a simple u-turn if I gave it any throttle at all. Personally I like a car to be loose - I have better control that way. Very unnerving to turn the wheel & still go straight... I do believe the front swaybar disconnected would help a lot in the snow (unlike others above). Maybe you can try it & give us the result? ~ Paul aka "Tha Driver"
go for the rear swaybar to reduce understeer, however I would recommend that you get your alignment set up first as I have seen/commented in your other thread
there is a alignment sheet on the forum somewhere which gives specs for all fiero's from camber to castor and toe specs I wil try and find the link if nobody puts it up before me and give this to the alignment shop to follow
The Fiero seems to be quite a different animal altogether. I lowered the front tire pressure today, 40 rear, 35 front. I was making a left turn at an intersection today, I took the corner a little fast to get a feel for any change. I was expecting understeer, but as soon as I added the power to induce this understeer, the car went into a 4 wheel powerslide. Not what I was expecting. I steered into the direction of the slide, naturally, and must have over corrected, because the car did an immediate 180, the other direction, came to a stop, and I stalled the motor. It was fun, and the folks at the intersection got quite a show, but I'm a little confused to say the least.
WTF just happened? Hahahahaha
[This message has been edited by Stainless1911 (edited 12-03-2012).]
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03:27 PM
Patrick Member
Posts: 38670 From: Vancouver, British Columbia, Canada Registered: Apr 99
I lowered the front tire pressure today, 40 rear, 35 front.
From what you've posted, you're driving on old, skinny tires that you originally had 40 lbs of pressure in all around.
And today you spun the car 180 while driving on a public road.
Seriously, you need to get on an autocross track so you can safely find out the limitations of your car and/or your driving... before you hurt somebody.
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03:43 PM
PFF
System Bot
fieroguru Member
Posts: 12512 From: Champaign, IL Registered: Aug 2003
I was making a left turn at an intersection today, I took the corner a little fast to get a feel for any change. I was expecting understeer, but as soon as I added the power to induce this understeer, the car went into a 4 wheel powerslide. Not what I was expecting. I steered into the direction of the slide, naturally, and must have over corrected, because the car did an immediate 180, the other direction, came to a stop, and I stalled the motor. It was fun, and the folks at the intersection got quite a show, but I'm a little confused to say the least.
WTF just happened?
You need to slow way down... Slow an steady will let your car survive a winter wreck... you should not be trying to push its limits on city streets in the snow/rain.
@ Patrick. No kidding. I've never had a car behave that way before, mist be a mid engined rear drive thing. Trouble is, tracks cost money, I have a hard enough time keeping up with parts. You can't practice in an empty parking lot, because Michigan has a ridiculous reckless driving law, so all that's left for most of us, is a public road, and a radar detector. If I could afford it, I'd LOVE to take a professional driving course, but that;s out of the question.
[This message has been edited by Stainless1911 (edited 12-03-2012).]
You need to slow way down... Slow an steady will let your car survive a winter wreck... you should not be trying to push its limits on city streets in the snow/rain.
I was only doing 35 or 40, a corner that I have taken at closer to 55 in the camaro without an issue. If I thought for even a second, that I would have gotten anything more than a little front wheel slip, I would not have done that.
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04:04 PM
TONY_C Member
Posts: 2747 From: North Bellmore, NY 11710 Registered: May 2001
If you lost control on a curve at 40mph that a Camaro can handle at 55mph, there is something seriously wrong with your car/setup. Those tires sound like they need to be replaced. They are too old and too narrow and you have too much air in them too. And if the car is pushing that bad, something is wrong with the alignment.
You're right. Thats the purpose of this, and the other thread. Im trying to make this little car safe and comfortable to drive. I know I need tires, but due to money, I realistically won't be able to do that until the spring. Meanwhile, it's my only car. The Camaro stays in storage over the winter.
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04:15 PM
TONY_C Member
Posts: 2747 From: North Bellmore, NY 11710 Registered: May 2001
A day of autocrossing costs $40 here. I'm sure there are organizations/car clubs in your area who put on autocrosses on a regular basis. Experienced drivers at these events are always available to ride along and offer advice.
This is me on the track last June, on a very wet day. With a bit of practice, you learn how to not spin the car when conditions are bad.
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05:02 PM
imabaddude Member
Posts: 94 From: Braidwood, IL, US Registered: Sep 2012
I was only doing 35 or 40, a corner that I have taken at closer to 55 in the camaro without an issue. If I thought for even a second, that I would have gotten anything more than a little front wheel slip, I would not have done that.
I need new tires and an alignment, but my car still takes curves and turns better than my old 89 Iroc with the 9 bolt (with proper alignment, suspension in good working order, and brand new tires). Double check your suspension work (make sure all the parts you changed are seated properly, new and proper sized tires and an alignment, and it should make a world of difference. The tires alone should make a huge difference. BTW, wider tires means more gripping surface, which means it shouldn't be so "squirrelly."
Check the production date on the tire to see when each one was made. Personally, I never buy used tires unless for very short term. I had a brother that used to buy them all the time, and he had the tread separate from the tire, and destroy the wheel well and his battery. He was also getting "new" used ones on a more than monthly basis. Also, with a lot of places that sell used tires, they do a half butt job making sure the tires are balanced (unbalanced tires=bad). Using used tires can end up costing you a lot more than new tires once said and done.
[This message has been edited by imabaddude (edited 12-03-2012).]
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05:12 PM
Austrian Import Member
Posts: 3919 From: Monterey, CA Registered: Feb 2007
