Why PD, Why? (FR Cars which Understeer Horribly)

[Bounty Hunter]

the new GTO isnt an american car

but yeah, have found that the new GT4 is more difficult to setup cars for controlable oversteer than it was in GT3
have also found that playing with suspension settings does not give you the results that you would expect in real life

 

[omnispeed]

What she is saying, is that you can tune a vehicle to take advantage of the understeering problem in GT4... In theory, the understeering bug could be utilized (with the right settings) to give you increased countersteer control, via the extra grip to the front wheels...

I still don't understand... how is it possible to have oversteer and understeer at the same time. It can't be possible...

 

[Droptop_Chick]

I still don't understand... how is it possible to have oversteer and understeer at the same time. It can't be possible...

It's not understeering while oversteering. It's using understeer to gauge your tires ability to grip the road. An oversteer prone car doesn't always equate to strong front tire grip. Front tire grip is your ONLY control factor with a RWD. Countersteer all you like but with no grip you'll slide off the road.

Even though understeer does mean you break front traction before you break rear traction, it does determine your maximum level of lateral grip BEFORE any given weight transfer. When you move the load of weight to the front/sides of the car via braking/feinting/lift-off, you exponentially increase tire grip, depending on the amount of weight you move and where you move it. Essentially I see it as going from an instant of understeering during weight transfer, to flipping a 180 of strong front tire grip and weak rear tire grip. The same theory applies into running increased camber on the front wheels even though it promotes understeer, you increase lateral grip when the load of weight is moved to the front and to the side. It doesn't mean you should try and get yoru cars to understeer like crazy because obviously it won't drift. A moderate amount can give you more consistant countersteer, which increases your control ability. Using the understeer to gauge your level of grip before your shift in weight begins to take effect, you can judge if it's possible to enter at a higher speed or higher angle. If you watch peoples drift videos, sometimes you see smoke come off the a front tire before the rear start to smoke, that's basically the extreme limit of entry speed for that car with that tire/suspension setup. You have to know how to understeer if you want to oversteer...

 

[Delphic Reason]

It's not understeering while oversteering. It's using understeer to gauge your tires ability to grip the road. An oversteer prone car doesn't always equate to strong front tire grip. Front tire grip is your ONLY control factor with a RWD. Countersteer all you like but with no grip you'll slide off the road.

Even though understeer does mean you break front traction before you break rear traction, it does determine your maximum level of lateral grip. When you move the load of weight to the front/sides of the car via braking/feinting/lift-off, you exponentially increase tire grip, depending on the amount of weight you move and where you move it. Essentially I see it as going from an instant of understeering during weight transfer, to flipping a 180 of strong front tire grip and weak rear tire grip. The same theory applies into running increased camber on the front wheels even though it promotes understeer, you increase lateral grip when the load of weight is moved to the front and to the side. It doesn't mean you should try and get yoru cars to understeer like crazy because obviously it won't drift. A moderate amount can give you more consistant countersteer, which increases your control ability.

Well said...

 

[rickjames]

You can always set the rear camber to 10 and the toe to -4, but I guess at that point you're not really braking traction anymore, just controlling the absence of it. I personaly never set settings crazy like that, but with extreme understeer cars, it is part of the tuning process.

DR is back,

< Vin >

hey i did cuz i was bored take alook at my drift4ever vid :-P the red s13

 

[Onikaze]

A lot of cars have "useful" understeer.

The Z4, the M3 CSL, both on N1 front and rear will light up the inside front tire before the tail steps out, and it just lets you start ridiculously early and drift forever and ever.

But where those cars go from slight understeer and break away into smooth oversteer...

The Mustang starts with moderate understeer, and then breaks into severe understeer...

Terrible, and too much work having to get it sooo unstable with all the wheel sawing to actually get it at a decent enough slip angle to keep the rear tires smoking.


I've just accepted that it's either ridiculously extreme anti-understeer tuning, or N2/N1 tires, or just drive the GT-350R, which goes from understeer, to oversteer, like the new one should.

 

[omnispeed]

It's not understeering while oversteering. It's using understeer to gauge your tires ability to grip the road. An oversteer prone car doesn't always equate to strong front tire grip. Front tire grip is your ONLY control factor with a RWD. Countersteer all you like but with no grip you'll slide off the road.

Even though understeer does mean you break front traction before you break rear traction, it does determine your maximum level of lateral grip BEFORE any given weight transfer. When you move the load of weight to the front/sides of the car via braking/feinting/lift-off, you exponentially increase tire grip, depending on the amount of weight you move and where you move it. Essentially I see it as going from an instant of understeering during weight transfer, to flipping a 180 of strong front tire grip and weak rear tire grip. The same theory applies into running increased camber on the front wheels even though it promotes understeer, you increase lateral grip when the load of weight is moved to the front and to the side. It doesn't mean you should try and get yoru cars to understeer like crazy because obviously it won't drift. A moderate amount can give you more consistant countersteer, which increases your control ability. Using the understeer to gauge your level of grip before your shift in weight begins to take effect, you can judge if it's possible to enter at a higher speed or higher angle. If you watch peoples drift videos, sometimes you see smoke come off the a front tire before the rear start to smoke, that's basically the extreme limit of entry speed for that car with that tire/suspension setup. You have to know how to understeer if you want to oversteer...

It has never been explained to me that way. Interesting!! I would've never realized understeer was the reason the front tires grip before a drift.



Thanks for the explanation 👍

 

[rsmithdrift]

You, know for some strange reason I get the feeling that the problem is somewhere between the back of the seat and the steering wheel.
'Cause I can drift the Mustang just fine with n2 front and rear and no spoiler.

I tend to find that understeer thing kinda realistic but unrealistic at the same time. Most cars tend to understeer slightly from the factory, but in real life it is very easy to create oversteer in those same cars.

My 300zx (in real life) is perfectly balanced from the factory, but after installing my lsd it now understeers unless I make it oversteer.

I just remembered my secret to drifting these cars. REAR BALAST!!!!!!!! I cannot advertise this enough. Both of these cars ('05 Mustang GT, and Corvette Z06) have too much front wieght from the factory due to the LARGE V8 ENGINE and also have a LONG WHEELBASE. The understeer problem caused by this combination is both unrealistically huge, and hard to counter.

To counteract this problem the best solution is REAR BALAST. Use however much you need to make the car drift easily and comfortably. I run 100kg of balast all the way in to the rear in the '05 Mustang GT. That works very well for me.

Also, the best way to get a car to braking/let-off drift is to increase rear balast. Take the '00 Mustang Cobra R, for example, it would not braking drift. So I added 100kg of balast and moved it all the way to the rear, and viola!! Braking and let-off drifting was now easy.

Note on Balast: Changing balast position will have no affect if there is no balast to move. In other words, the higher the amount of balast weight, the more affect moving it will have on the car. Just for compairison, I moved it all to the front and could no longer get the car sideways. All the way to the rear and the once understeering car was now loose as a goose and harder to control. TRY TO MAKE THE CAR NEUTRAL. A loose car is hard to control and a tight car is hard to get sideways, A NEUTRAL CAR IS EASY TO GET SIDEWAYS AND EASY TO CONTROL.

Also, adding rear balast will increase forward bite in a rear wheel drive car, making it harder to get wheelspin. Likewise it is recommended to only do this with high powered cars. However, the increase in rear momentum will usually overcome the increase in rear tire grip.

Also, (this should be obvious) adding balast will slow the car down on the straightaways, so use it wisely.

 

[JTSnooks]

I think there is a fundamental flaw with the GT4 Physics Model, and although it does not entirely spoil the game, it's still a major drag with some cars. Ever tried this: Spin a donut with a powerful RWD or AWD car. Stay on the gas and let go of the steering (DS analog stick for this experiment).

• What happens in GT4? The Rear bites and the car takes off in a straight line.
• What happens in my real life car (has RWD + LSD)? The car continues to spin until the rotation gently slows down, stops, the car first disappears in a cloud of tire smoke, and then slowly takes off, but not necessarily in a straight line.

Conclusion: Something badly wrong with the dynamic friction / static friction parameters?!
What would the engineers on this board say to that?

What I'd like to say is that you're right! It seems that the static friction coefficient of the tires is set too high, while the kinetic friction coefficient is set WAY too low. What this means is that it is too hard to get the tires to slide, and once they start to slide they don't stop easily enough. If you've ever slid a car in real life, you know that it doesn't slide for long, and without a LOT of momentum, the tires will regain their grip very easily. The same thing happens when doing a burnout. They'll spin really easily when you get them going, but as soon as they start to hook up, they grab hard. There's no long slowing down until they finally grip, it's *spin, spin, spin, GRIP!*. Anyway, I'm done.

 

[Mr. Apex]

I agree to everything you said, except...

Note on Balast: Changing balast position will have no affect if there is no balast to move.

To me it is obvious that changing ballast position without adding weight HAS an effect in GT4. It is definitely measurable. The effect could be compared with moving the battery IRL.

Got any doubts? Try this experiment: Buy one of the old RUF Porsches. Have a short test drive to get a feel of the stock balance. Add full weight reduction and power upgrades and have another test drive. The Porsche is now VERY oversteery due to the heavy rear. Now move the ballast position (without adding weight) towards the front and have another test drive. Et voilà, neutral to mild oversteer handling, just how it should be.

 

[rsmithdrift]

I agree to everything you said, except...



To me it is obvious that changing ballast position without adding weight HAS an effect in GT4. It is definitely measurable. The effect could be compared with moving the battery IRL.

Got any doubts? Try this experiment: Buy one of the old RUF Porsches. Have a short test drive to get a feel of the stock balance. Add full weight reduction and power upgrades and have another test drive. The Porsche is now VERY oversteery due to the heavy rear. Now move the ballast position (without adding weight) towards the front and have another test drive. Et voilà, neutral to mild oversteer handling, just how it should be.

Really? I tried it with the Mustang and a few others but I never tried it with such an unstable car. I'll try it. Who knows, the cars I tried it on were prob. too stable to feel the difference.

I'll be back in a few to edit this and the earlier post if necessary, after I play with it some more to see if this is true.

Edit: Ok. I'm back. I got in my RUF "Yellow Bird" and fully modded it. (everything accept for NOS, Racing Tires, and Roll Cage(ie. Rigidity Increase)) I took it to two tracks (High Speed Ring and Autumn Ring) and ran the following tests:
1. Weight distribution all the way forward (-50), N2 tires.
2. Weight dist. all the way back (+50), N2 tires.
3. Weight dist. all the way forward, S3 tires.
4. Weight dist. all the way back, S3 tires.
Note: all tests performed with same car setup (accept for changes stated) and all aids turned off, balast weight set to 0.

Conclusion: The car drove the same regardless of wieght distribution on S3 tires. Changed to N2 tires so that changes would be more noticable. The car still behaved the same with Front/Rear Balance at -50 as it did with it at +50.
In my honest opinion, if balast weight is set to 0, there is no change if Front/Rear Balance is changed because there is no balast to be moved.
And I quote "This adjusts the front/rear weight distribution by changing the position the balast is to be mounted in the car."- this from the ticker in the tuning menu displayed for Front/Rear Balance.
Also "This adjusts the weight of the balast."- this from the ticker in the tuning menu displayed for Balast Weight.
I think you think GT4 is more realistic than it really is. They sacraficed many bits of realism to make the game more "user friendly"

Honestly I believe you suffer from the "Placebo Affect" Meaning that because you expect the car to handle differently, you think that it does, even though there is no change in reality.
An example of this happening to me: I thought that one of my cars handled like crap. So I changed the suspension set up, ALOT. However, I hit triangle instead of selecting "OK" and the changes were not made, but I didn't know that so I drove the car and thought that the changes made a huge difference and the car was so easy to drive now. I went back to setup and was shocked to find that the setup was the same and it was me that had changed.
Because you're driving style changes when you expect the car to be different, it can make it feel like it fixed it, but in reality it is you that was fixed, NOT THE CAR.

 

[niky]

hmmm.... interesting.

Maybe the problem with understeer is that GT doesn't model driver weight? Or does it? I would think that the 70kg or so of driver normally present nearer the rear axle of long-hooded cars like the Mustang and Z06 would have some effect... think we could try it?

I've gotten over the "understeer problem" already... although it urks me that some cars I feel should have no understeer (like the Tuscans) have them in spades, I don't really feel that the Z06 is too understeery for a fron-engined car with really huge gumballs in the back.

 

[Mr. Apex]

Honestly I believe you suffer from the "Placebo Affect" Meaning that because you expect the car to handle differently, you think that it does, even though there is no change in reality.

Thanks for the Input.

Hmmm... now you made me a bit unsure about this.
I was really certain because I had discussed this with tankspanker and onikaze in the ballast thread and had carried out a couple of experiments back then with a RUF BTR '86 and an NSX Type S.

I guess I'll head home to the good old drawing board then. Gotta think of something to really make this measurable. I'll post the results tomorrow.

Edit: Couldn't make it yesterday. I'll post the results after the weekend.

Final Edit: I can't prove anything. Maybe you're right. With some cars it even doesn't make much of a difference when you add 100 kg of ballast and move it all the way back to the bumper. Really weird. I still think there might be an effect (without adding ballast) with very light cars (kind of like shifting the center of mass for a little bit), but like I said I can't prove it.

I really wish PD would've made this different, so you could see the actual weight distribution of the car instead of having to guess. 👎

 

[tedaconda]

I drifted the 70 chevelle ss all throughout the american power-style races. first it was just tap the nos and itll get sideways, but the torque alone should do the trick. other than that i shun any american cars as drifters. theyre big and slow.

Gettin sideways is more like snowboarding or iceskating. keep the american football players out of this.

forward this to Rhys Millen and Sam Hubinette, theyll prolly agree.

 

[Onikaze]

Ford GT is a great American Drifter.

Lots of fun, and while it has understeer in certain situations, it is for the most part easily dealt with.

The Z06...I still haven't felt the urge to pick that back up.

I'll give the Mustang a try on my Midfield run that I use for my high speed drift setup testing.

Some of the problem I'm sure is from my earlier penchant for running Tsukuba with drift cars.

 

[Gabkicks]

Z06's are not as tame IRL as they are ingame. we have plenty around here and they arent exactly a challenge to get sideways.

the physics flaws were all debated months ago in hundreds of different threads.

 

[lllb0y]

Actually, to me, I LOVE the car to understeer under gas because that's how I sustain long drifts without spinning AND also minimum counter-steer.