Power Oversteer with FWD cars

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Dan Watkins

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Ok, something is really bugging me now with GT4, whats the deal with the power oversteer in powerfull FWD cars?, take the Focus RS or Alfa 147 on to Tsukuba and nail the throttle out of a tight corner and low and behold the back end starts coming round a la RWD oversteer.

Now, in I have driven many powerful-ish FWD cars IRL, Escort RS Turbo, Renault 5 Turbo etc etc, and have NEVER encounter any power on oversteer, lift off induced oversteer of course, but never power on oversteer.

Anyone have any thoughts on this?.

Dan.
 
Dan Watkins
Ok, something is really bugging me now with GT4, whats the deal with the power oversteer in powerfull FWD cars?, take the Focus RS or Alfa 147 on to Tsukuba and nail the throttle out of a tight corner and low and behold the back end starts coming round a la RWD oversteer.

Now, in I have driven many powerful-ish FWD cars IRL, Escort RS Turbo, Renault 5 Turbo etc etc, and have NEVER encounter any power on oversteer, lift off induced oversteer of course, but never power on oversteer.

Anyone have any thoughts on this?.

Dan.
Click to expand...

Well I would say that it's all a matter of grip, the rear end will swing whenever it hasn't got enough grip to counteract the forces generated by cornering. According to what you say I don't think that you are breaking the rear end grip using some left foot braking, so my guess is that the front end (despite the load transfert) still has more grip than the rear and does not induce any understeer that would make the rear end swing less noticeable.

BTW the R5 turbo is a mid-rear engine rear wheels drive, the R5 GT was a FWD as the R5 Alpine and Alpine turbo were.
 
I was about to say, the R5 Turbo is a mid-engine RWD car built on a FWD platform; a precursor to the Clio Sport V6.

I also have not noticed the effect you're talking about, as I have met very few cars in GT4 of any driveline that don't understeer on most occasions.

One question I will ask, are these arcade or relatively stock cars? Because a lot of unpredictable behaviour has been attributed to bottoming out on cars that have been lowered all the way.
 
Look, think about it...
A Front-Engine Front Wheel Drive car has pretty much everything...well, in the front...
You notice that when high powerd cars take off your front lifts and your back goes down from the G-forces...This is from the sudden power in acceleration!!
Now if you havea (powerful) Front-Engine Front Wheel Drive...you're going to be using your FRONT more...!
Now if your front is being lifted what do you think is going to happen?? You won't be able to get as much traction
This is what I think, as for me I have never encountered this problem out of all the 692 cars I have but good luck anyways!!

L28eT:tup:
 
"Well I would say that it's all a matter of grip, the rear end will swing whenever it hasn't got enough grip to counteract the forces generated"

Of course it will, and this is shown as lift-off oversteer, which is VERY easy to do in real life, what I am talking about is the apllied power oversteer that many powerfull FWD cars have in GT4.

Take the Ford Focus RS, put it on the Tsukuba curcuit, and drive round it reasonable slowly, you will see that you can indeed perform lift off oversteer, which is IMO the ONLY for of oversteer an FWD car should show.

Now go into a tight corner slowly but nail the throttle on the way out and see what happens, the back end starts coming round under power, this is VERY wrong, not only is there nothing other than the sideways force of the corner acting on the backend as it is being "dragged" round the corner, but ALL the weight is now being transfered to the back wheels as on acceleration the weight is shifting to the back of the car, which will give the backend more grip.

As for the R5 bit, what I was getting at is that I have driven a FWD R5 Turbo in real life, as well as a few other reasonable powerfull FWD cars, and none of these have ever shown this caractaristic.

This leads me to believe that the driving model for powerfull FWD cars is fudged.

Dan.
 
lol this is great. only a few days ago this force caught me real unexpected speeding round costa di amalfi reverse in a modified renault clio 2ltr. the first 2/3 corners are hairpins. i sped to the corner, braked, made the turn in as usual and thought id produce a bit of wheel spin on the turnout, however when i put my foot down, the front gripped and the rear didnt, sending the rear end swinging out and i had to counter quick before i lost it. i was shocked i can say! is this even possible in real life?
 
I have a lightly modded Grand Prix GTP (obviously IRL and not in-game). If I were to try to floor it in the middle of a turn, I'd end up understeering straight into a ditch. :crazy:


I've run into this issue before as well, though I do not remember which car it was. I hit the throttle too hard and the rear started coming around just like a powerful RWD car. That's definitely not correct. :indiff:

But I forgot about it, finished the race, and kept on playing the game anyway. :dopey:
 
flame me if you want but to rid all F.F. cars of over and under steering problems in gt4 try this...

1. set up your suspension as you like it.
2. fit hard slicks on the front and qualifying's on the rear.
3. set asm to 0,15,1 (1 on the traction control) will make it turn even tighter
4. hump everything that a family cup can throw at you.

it'll be so stable you can drive around with the e-brake on all the time and it still won't over/under steer.
 
I drove Focus RS in real life two weeks ago and must say this is true! This mad FWD car has QUAIFE limited slip differential and under full throttle you must very carefully hold your steering wheel, you can really feel power redistribution shaking with your wheel and very obvious thrust right INTO the corner, no understeer at all! This car is just mad and if any ends of car cannot withstand chosen speed through the corner, it's its rear end!!!
 
"I drove Focus RS in real life two weeks ago and must say this is true! This mad FWD car has QUAIFE limited slip differential and under full throttle you must very carefully hold your steering wheel, you can really feel power redistribution shaking with your wheel and very obvious thrust right INTO the corner, no understeer at all! This car is just mad and if any ends of car cannot withstand chosen speed through the corner, it's its rear end!!!"

Yes, they are a very wild ride, BUT, even in real life the Focus RS WILL NOT exhibit POWER ON oversteer, the type of oversteer that is initiated purely by applying power, unlike its GT4 counterpart, the same is true of the Alfa 147GTA, and EXTREMELY overpowered FWD car, this again shows this power on oversteer trait in GT4.

Dan.
 
There is no such thing as power on oversteer in a FWD car, it is an impossibility. So the game is wrong, live with it.
 
its possible i'd say, but the contrast in grip between the front and rear would have to be BIG
 
Wait, wait, wait, wait!

Dan: do you have your driving aids turned off? Because with the driving aids turned on (the over- and understeer stability controls, not the traction control), the cars will do very oddball things as the system kicks in. They default to the ON position.

I always turn all my driving aids for every car off, and I've never encountered what you're talking about. Maybe that's the difference?

[edit]

Also, if you use the reply button at the bottom of the post, it will automatically highlight the post to which you're replying, so you don't need to copy and paste it.
 
Like my GT3 Integra drift car :D

My friend's brother claims his Prelude SH is capable of powersliding (I forget why though). I don't think he's the type to make that sort of thing up or believe it if it wasn't true.
 
Emohawk
...My friend's brother claims his Prelude SH is capable of powersliding...
Click to expand...

Well, maybe, but it isn't "powersliding", because the power is being applied at the other end. In this case, its just "coming around", or "getting crossed up", or "getting loose", or "getting all squirrelly", or "starting to spin out".
 
bubba blackmeat
flame me if you want but to rid all F.F. cars of over and under steering problems in gt4 try this...

1. set up your suspension as you like it.
2. fit hard slicks on the front and qualifying's on the rear.
3. set asm to 0,15,1 (1 on the traction control) will make it turn even tighter
4. hump everything that a family cup can throw at you.

it'll be so stable you can drive around with the e-brake on all the time and it still won't over/under steer.
Click to expand...

I don't know about that. Have you driven the 1991 Honda Prelude VTEC in the game? If you go into a corner at anything over 40 mph, you keep going straight into the wall. Although i'm sure that would work on most cars, but in this case, it did nothing to help with the understeer of the ride. Good idea though, I suppose.
 
Dan Watkins
Ok, something is really bugging me now with GT4, whats the deal with the power oversteer in powerfull FWD cars?, take the Focus RS or Alfa 147 on to Tsukuba and nail the throttle out of a tight corner and low and behold the back end starts coming round a la RWD oversteer.

Now, in I have driven many powerful-ish FWD cars IRL, Escort RS Turbo, Renault 5 Turbo etc etc, and have NEVER encounter any power on oversteer, lift off induced oversteer of course, but never power on oversteer.

Anyone have any thoughts on this?.

Dan.
Click to expand...


i've encountered the same thing you have with a stock dodge srt-4 on tsukuba. i knew it was not exactly accurate compared to real life, but i just started using it to my advantage. if i remember correctly, i had an accord type r with semi-pro suspension installed in the game as well that had power oversteer. i don't know... if it's there, might as well just use it to ur advantage.
 
I believe the phenomenon you are experiencing is "torque steer." From Wikipedia:

Torque steer can be a problem on front wheel drive cars with higher torque motors. This is the name given to the tendency for some front wheel drive cars to pull to the left or right under hard acceleration. It is a result of the offset between the point about which the wheel steers (which falls at a point which is aligned with the points at which the wheel is connected to the steering mechanisms) and the centroid of its contact patch. The tractive force acts through the centroid of the contact patch, and the offset of the steering point means that a turning moment about the axis of steering is generated. In an ideal situation, the left and right wheels would generate equal and opposite moments, cancelling each other out, however in reality this is less likely to happen. Torque Steer is often incorrectly attributed to differing rates of twist along the lengths of unequal front drive shafts. An example of a car with strong torque steer would be the 257 hp (191 kW) Volvo S60 T5 FWD.
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of course its posible... I've done it in my RL astra and its not even powerful.
brake hard, hit corner... weight is now forward. power out of corner back slips even though weight is being transfered to the rear... I an not a physicist so I cant explain it but it happens. :)
 
i have experienced this fwd power oversteer, its definately not possible in real life, but i think in gt4, it may be caused by the front diff not being tight enough. when you nail the throttle out of a tight corner, the inside front spins up and you lose drive from it, now what i think happens is that you still get some acceleration from the outside front, and the car pivots around the spinning inside front and hence the back comes around.

the only reason for this phenomonen is that in gt4, the workings of a front diff doesnt reflect that of real life.
 
scraps
i have experienced this fwd power oversteer, its definately not possible in real life, but i think in gt4, it may be caused by the front diff not being tight enough. when you nail the throttle out of a tight corner, the inside front spins up and you lose drive from it, now what i think happens is that you still get some acceleration from the outside front, and the car pivots around the spinning inside front and hence the back comes around.

the only reason for this phenomonen is that in gt4, the workings of a front diff doesnt reflect that of real life.
Click to expand...


Yes I have noticed this. Its like the outside front has terrific grip (there is still a heavy engine right on top of it, so there's still a lot of wieght even when accelerating, it can't ALL go to the back...), the inside front is effectively doing nothing but spinning, so the overall effect is that the car 'pivots' around the outside front, which pulls the rear around. This phenomenon should only happen when the car is going reasonably slowly, on a tight corner so that the inside front loses a lot of grip. This effect should occur much less apparent (or non-existent) when cornering faster on a larger radius turn... well thats what I logically think anyway. Logically, it would only happen at the moment you hammer the throttle right on the apex of a turn, the car would 'settle' into its normal behaviour of understeer when continuously accelerating out of the corner as it builds speed. I don't think PD would screw up the whole idea of what FWD does, but they may have exaggerated a certain 'fun' aspect of it, to create more interest so the game is more enjoyable. It certainly makes the FWD cars more fun. I didn't touch them in GT3, but in GT4 this increased 'play' between (most of the time) understeer and oversteer is more interesting to drive...

Note that if PD screwed the FWD physics completely, the car would ALWAYS oversteer, and this certainly isn't the case, you need certain conditions for it to happen. :sly:

Lets face it, most FWD cars in the game don't behave in this manner.
 
Duke
Wait, wait, wait, wait!

Dan: do you have your driving aids turned off? Because with the driving aids turned on (the over- and understeer stability controls, not the traction control), the cars will do very oddball things as the system kicks in. They default to the ON position.

I always turn all my driving aids for every car off, and I've never encountered what you're talking about. Maybe that's the difference?

[edit]

Also, if you use the reply button at the bottom of the post, it will automatically highlight the post to which you're replying, so you don't need to copy and paste it.
Click to expand...

Yes, I have all the aids switched off, is there any other way to drive? 👍

Ok, so last night I did a bit more testing, it is certainly more noticable in the Focus RS and the Alfa 147GTA, but a lot of the other less powerfull cars do not show it at all, or at least its much less.

As for torque steer, its not that, I drive an '03 Ford Mondeo Zetec S TDCi, which is a pretty powerfull diesel car, 130BHP and 330NM of torque, and this thing torque steers its head of under hard acceleration, but this would not cause any sort oversteer.

I still maintain that some of the cars in GT4 are fudged, but like some guy said, so what, I think I will just use it to me advantage 👍

GT4 is still the best bit of CarPorn ever :)

Dan.
 
I usually see torque UNDERsteer when it comes to front-wheel drive machines. Ask anyone who's probably raced the Alfa Romeo in that IA license test with Suzuka's Esses all the way into Degner. Some front-drive cars are nimble, some are the complete opposite. And that GTV or Spider (not one of my favorites) is a shining example of a hard-to-drive front-drive car. Now in the license tests, you're mostly racing without ASM and TCS. When you disable these, you get to see the real character of the car, versus the car with driving aids equipped.

When you get to own the car in the game, you can modify it any way you please. My only problem tuning most street cars is that I find it hard to keep the car at a steady speed in the corners. In a race car, you're able to take a sweeping turn and not lose speed in the process. In some of my tuning, I have some trouble with some machines. That's why I've retired the 2006 Mitsubishi Eclipse GT that I once had. Even though the 2006 Eclipse GT kind of went through corners like a four-wheel driver, it just doesn't feel right in sweeping corners and kinks in the road. The first thing I normally do is check the Driving Aids and tone them down. Next with a racing suspension setup, I usually modify the camber, the toe, and if needed, the stabilizers. Sometimes they work, sometimes they don't. Even I can use a little more tuning help, but trying to get front-drive machines to function well can be pretty tough. What I should do is sample many front-drive vehicles and tune them to see if each car FWD requires a different level of tuning to try to get the cars to perform wonderfully. One of the better FWD cars is the Alfa Romeo GT. Mod it up well enough, you have a nice machine. The Italian car company surely is a great FIA Touring Car race team, so I guess it can do well for you in GT.
 
i have two pretty powerful VW Lupos a 1.4 and a GTI, and they used to understeer a lot under power, but i did a bit of suspension tuning by making the spring rates and the rear considerably lower than the front, it started being a lot more well balanced with no more understeer but a fair bit of oversteer.

so try this:

for understeer: have your front spring rates very soft, rears a bit harder
for oversteer: exact oppostie, fronts stiff, rear soft
i dont think theres anything wrong with the game
 
I noticed this, under certain conditions, with the 147 GTA. The conditions are: slow corner (second gear), wait for the front end to find grip, keep steering wheel turned hard over, floor throttle. One of two things happen: 1) the front wheels do not spin but the car understeers all the way back to the garage or 2) you hear lots of screeching noises, the nose dives towards the inside of the track, the tail swings out in oversteer that increases with more throttle, decreases with less throttle, and you have to apply opposite lock to stay on the track. It doesn't really feel like it's spinning out as such, it feels more like a sort of handbrake turn. Replays reveal the screeching noise is the inside front wheel spinning all by itself.

This totally unlike the behaviour I would expect from a front wheel drive car, and is certainly nothing I have ever experienced IRL, where power either helps kill lift off oversteer, or induces enough understeer to make me miss the entrance to the scrap yard where I would be driving the horrible FWD pile of junk. It's worth noting though that a Ford Focus engineer was once quoted as saying that Ford's handling philosophy was that under all conditions, if the steering wheel is turned more , the car should turn tighter.... i.e. no understeer, ever. Which I thought was a nice idea... It feels like the game is trying to replicate that philosophy.

In third gear corners or faster, the GTA seemed to experience the power understeer I would expect of a front wheel drive car with a dirty great V6 dangling way out in front of the front axle. :yuck:
 
Hey folks. FWD _are_ capable of experiencing power on oversteer. It's just not in its basic nature and the suspension has to be tuned to make it really possible.

It is correct that application of power will transfer weight from the front to the rear... reducing weight and therefore traction on the front tires and moving the dynamic balance of the car in the understeer direction.

However, there are other factors that affect the dynamic balance of the car besides weight transfer. There is also the size of the tire contact patches. And these are affected by factors like camber, caster, and roll centers. It is possible to tune these elements such that the oversteer effect they create under power is actually greater than the understeer effect produced by the weight transfer. Therefore producing an oversteer condition under power.

In short... GT4 is correct.

Some FWD are setup to do this. Most are not. So unless you've driven one, you'll have never encountered it in RL.

Cars really can exhibit all manner of handling properties you wouldn't normally expect. There are many more aspects of suspension geometry than GT allows you to twiddle. And yet it does seem to model them. It's just that they can't be altered. And frankly, for many of them, any changes would totally alter the car's personality... and in a bad way if you don't really know what you're doing.

Would you really want to adjust the length and anchor points of your car's A arms? You'd better know about bump steer and roll centers before you try that...

- Skant
 
exhorst
i have two pretty powerful VW Lupos a 1.4 and a GTI, and they used to understeer a lot under power, but i did a bit of suspension tuning by making the spring rates and the rear considerably lower than the front, it started being a lot more well balanced with no more understeer but a fair bit of oversteer.

so try this:

for understeer: have your front spring rates very soft, rears a bit harder
for oversteer: exact oppostie, fronts stiff, rear soft
i dont think theres anything wrong with the game
Click to expand...

I tuned my lupo GTI (maybe it was a polo my memory sucks) to race and was suprised to find it drifting most corners well. That was simply my settings but I also did experience power on oversteer.
 
I noticed in the AE111 Corolla Sprinter. But it only happened on EXTREMElY tight turns, such as the 180 turn on Hong Kong. And I think it does have to do with the differential and one tire spinning.

But I mostly noticed understeer in teh FF cars, aside from extremely tight low gear corners...
 
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