What's with the understeer??

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RenesisEvo

RenesisEvo

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GTP_Renesis
The Lotus Carlton. The Mercedes-Benz 190E EvoII road car. The TVR T350C. The Honda NSX. The BMW M3 GTR.

All rear-wheel drive. All with about 300bhp or more. All with stock set-ups.
AND THEY ALL UNDERSTEER!!

What is going on?? I would think in real life these cars would be far more biased to oversteer than the annoyance of understeer. Some, like the BMW, are purely lift-off oversteer, but the Merc and Carlton barely do that at all. Am I driving these cars in the 'wrong' manner? (I managed an 8min 58 for IA-15 with the Merc in stock form after 2 whole laps, in case anyone thinks I'm a real slow driver).

The orignal Gran Turismo, and GT2, more often that not I had cars spinning out because they were oversteering. GT3 - noticeably a lot harder to make cars turn - effectively more understeer put in the game. GT3 was such that the only way I could spin a car was to either accelerate hard in something with 600bhp out of the Casino hairpin at Monaco, with the inside wheels on the kerb, thus creating a very strong moment to spin the car, or hitting the barriers at the Test Course at 200mph. Otherwise, spinning never happened.

GT4 - okay, easier to spin the car. But also a lot harder to turn the things. I feel like they just add more understeer and call it "more realistic". With some cars, playing about with the spring rates generally starts to yield good results, i.e a bit less understeer and some more oversteer. But i think for the "real driving simulator" to mess up like this is a crime. Arcade mode - you can't change the suspension settings. That means its 371bhp, RWD, and understeer. It confuses me everytime I drive a RWD car.
 
Most cars are made to understeer for safety's sake. The TVR T350C definately understeers. Just watch some of the videos of it on the track.
 
i only ever find substantial oversteer in cars i heavily tune. for example a '89 300ZX tuned to 800+bhp, understeers ALOT on sports tyres, yet to try it on racing but i feel it may react the same as the R32 i have, which madly understeers
 
Drive ANY car in the world INTO a corner too fast and it'll understeer.

Example. You're approaching a 90 degree right-hand corner. You're doing 400mph. Rather than slowing down, you just yank the wheel to the right. What happens?

Will the car start to turn the corner, then have the back-end snap round? No. The front tyres will turn to the right but the car will carry on going in a straight line - understeer.

If everything understeers, you aren't slowing down enough.
 
Well fair enough, but I'm suggesting that I'm not necessarily going tooo quickly, rather than there seems to be far too much understeer built into the cars as standard, even those that shouldn't be. Some of those RWD cars were behaving like FFs... I understand that anything can understeer on corner entry. But also, when you put your foot down, gentle or not, the RWD cars just understeer out the corner too. Somewhere I wouldn't expect it to understeer. I'm guessing you'll find a reason why that happens too (too early on the throttle, too early apex etc etc.) but I really don't see why these cars feel so hard to turn, off throttle/on throttle, entry and exit.
 
What I think it might be is that when you're braking, you're locking up the front wheels; when you lock them up, you lose steering and your car goes straight. I've noticed this happening when I brake too hard late into the turn. Try easing up on the brakes a bit...

*shrugs* Just my thought.
 
I noticed the same problem with the BMW M3 GTR Strasse. Its brakes don't seem to work near as well as the CSLs, which is really odd because the Strasse should be pretty much the best M3 you can get for the road. I have found one thing that makes the car much more driveable and that is adding a wing to the car. The downforce really helps aid the braking to the point that is should actually probably be at. In fact, it makes the car that much more driveable. It is now one of my favorite cars that I have driven in GT4 so far.

I would say the 190E on the license test might be a problem of not braking early enough. If anything on that test, I had more of a problem with the car getting way too loose. It seemed to like to skitter across the tarmac a little too much at times. Actually my first to completely finish the license test with the car, I was only 20 seconds off of a gold time and that was mainly because of not knowing the track very well. I actually thought the car was pretty well balanced and didn't have an overly big amount of over or understeer, but lacked some grip that it really needed. Better tires definitely would have helped it.

Have you tried the NSX-R or NSX-R Concept? Neither of them have the problem with understeeer. They are extremely neutral and easy to drive. Another one of my favorite cars to drive because they are so well balanced.

Now that I think about it, that may be your problem. Each of the cars you mentioned may be extremely neutral in its balance and handling and that may cause some problems driving them because they have to be driven slightly different.
 
Er... I have no problem with the IA-15 license test - I've got gold by nearly 2 secs.

The problem aint with locking brakes either - its just that generally there is very little oversteer on cars that you see people getting very sideways in real life.
 
RenesisEvo
Er... I have no problem with the IA-15 license test - I've got gold by nearly 2 secs.

The problem aint with locking brakes either - its just that generally there is very little oversteer on cars that you see people getting very sideways in real life.
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GT4 like every previouse GT has whats like a constant level of traction control that you can't turn off. The power delivery isn't there to spin the wheels as much as real life, when people get sideways in real life and you can't in GT4, thats why. The understeer is correct, road cars are set to understeer because it's safer than setting them to overster.
 
Chris Criswell
What kind of ASM settings are you using?
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There is not one car in my garage with ASM turned on, oversteer or understeer. TCS only; normally 1; 2 around 500bhp; 3 for 700bhp; 4/5 for 1000bhp cars; 0 for anything below 30bhp.
 
I keep my TCS settings at 7. It proved to be the best for my cars after a long series of various tests at the 400M Test Run. I like to get as much immediate grip as possible as soon as I come out of a turn. But yeah, I don't have ASM turned on in any of my cars as well, and I haven't experienced understeer. I do experience oversteer some, not very often.
 
My guess is the driving line you're taking?

Are you taking corners at high angles with Rear Wheel Drive cars? And taking wide turns with Front Wheel Drive Cars? That seems to be the cost most often, I'm not syaing it is, but it is best to take Wide Angles with Rear Wheel Drive cars, and sharper angles with Front Wheel Drive, as far ass All Wheel Drive and 4 Wheel Drive cars go, you can take any kind of angles you want on the turn..
 
My guess is the driving line you're taking?

Are you taking corners at high angles with Rear Wheel Drive cars? And taking wide turns with Front Wheel Drive Cars? That seems to be the cost most often, I'm not syaing it is, but it is best to take Wide Angles with Rear Wheel Drive cars, and sharper angles with Front Wheel Drive, as far as All Wheel Drive and 4 Wheel Drive cars go, you can take any kind of angles you want on the turn..
 
I disagree with that. There is usually more handling freedom with a rear-wheel-drive car. Thats why a lot of professional races use rear-wheel-drive cars. Any other way, you're talking about stability instead of efficiency.

I believe AWD and FWD cars were safety measures because manufacturers began to notice that RWD cars aren't the safest way to travel. Thats why there are so many FWD cars out there on the streets.
 
AWD came about more for off road use than safety, it got on normal road cars through rallying because it was nessisary for homolagtion to make 4wd road cars for many classes of rallying and then it became a fad. Since then it's been improved and can be better on some cars than RWD.
 
AWD cars usually take a line similar to FWD's though. It is the way they utilize their grip. FWD can have aggressive turn-in's but their exits suffer from weight going to the back. RWD better on their exits, since the weight goes to the back tires when accelerating. AWD can become both.

FWD's are just cheaper to make.
 
I don't find the understeer to be unrealistic in GT4. Most new cars are designed to understeer to compensate for idiots who can't drive. However, for something with around 300hp or less, if you want throttle-oversteer you need to put something less sticky than S2s on it, try N3s or even N2s if under 300. Granted you'll get a lot slower laptimes, but it will get rid of the exiting-corner understeer. Also, turn off the traction control for <300hp cars and don't turn it above 1 for anything unless tire life is an issue. Beyond that, I tune the understeer out of all my cars with suspension and LSD tuning. It's pretty simple, and I can get the cars very well balanced throughout a turn whether braking, coasting, or accelerating. Stock cars will understeer just because that's what cars do, and S2 tires have too much grip for most cars to break them loose on corner exit :)
 
the 97 mr-2 gt-s with n2 tires has alot more understeer in high speed turns and it plows in low speed turns in comperison to my mr2. the WRX also has more understeer than its real life version and will not kick out in dry turns.
 
FAOLIU05
I disagree with that. There is usually more handling freedom with a rear-wheel-drive car. Thats why a lot of professional races use rear-wheel-drive cars. Any other way, you're talking about stability instead of efficiency.

I believe AWD and FWD cars were safety measures because manufacturers began to notice that RWD cars aren't the safest way to travel. Thats why there are so many FWD cars out there on the streets.
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I'm pretty sure the main reason for FF is packaging, and comfort. Gives you more cabin space (no transmission tunnel), and the transverse layout w/ gearbox (pioneered by the Issigonis Mini) means you can make a smaller car, or have more passenger space. Road cars are about safety (hence the built-in understeer), comfort and space (hence FF drivetrains).
 
JTSnooks
I don't find the understeer to be unrealistic in GT4. Most new cars are designed to understeer to compensate for idiots who can't drive. However, for something with around 300hp or less, if you want throttle-oversteer you need to put something less sticky than S2s on it, try N3s or even N2s if under 300. Granted you'll get a lot slower laptimes, but it will get rid of the exiting-corner understeer. Also, turn off the traction control for <300hp cars and don't turn it above 1 for anything unless tire life is an issue. Beyond that, I tune the understeer out of all my cars with suspension and LSD tuning. It's pretty simple, and I can get the cars very well balanced throughout a turn whether braking, coasting, or accelerating. Stock cars will understeer just because that's what cars do, and S2 tires have too much grip for most cars to break them loose on corner exit :)
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What suspension setting can you use to comensate for understeer? lower it? spring rate??
 
I remember when I first got GT4 I thought that the game was set to understeer. Well, as I went along, that doesn't seem to be the case.
 
FF also makes for better bad-weather traction which translates to safety. It won't spin around on you in the rain or snow...unless you're a REALLY big idiot :D As for what settings you can use to eliminate understeer....all of them. It takes a lot of adjusting for each car, but once you understand what all the settings do and how they relate you can fix any problem with a car pretty easy :) For getting rid of understeer it helps to soften the front suspension settings and stiffen the rear. But of course it's a lot more complicated than that, and some cars are the exact opposite.
 
Hmmm. I just did a lap of the 'ring in a Lotus Carlton. Bone stock... I couldn't get it to do anything other than oversteer. Its suspension is actually quite soft and vague (I may have gained that impression because i'm used to driving cars with modified suspension) and it smokes its boots out of second gear very willingly. The only time it understeered was when I went into high speed sweepers at too high a speed but obviously that was all my fault.
I also did a few laps around Midfield and it was oversteer city up in here! I drove normally for the first lap and the car is very well balanced with not much under or oversteer. Then I did the next few laps while trying to get oversteer and it was very easy obtain! Every corner was a laugh riot!

I think it's either your driving style or your settings. Or both.
 
I found the Carlton oversteered more and gripped less than I was expecting from what I'd read about the real thing (I've never driven it).

Then again, I've never done a chassis refresh on it, which is supposed to reduce oversteer.

Some cars have oversteered more than I expect, some understeer more (Spider Duetto) but I would not say the game in general has too much understeer, except if I'm playing with a DS controller, which makes my inputs too fast and harsh. If you whip any road car's steering wheel from straight ahead to full lock as fast as you possibly can, you should expect huge understeer. Do not try that at home unless you are wearing a helmet... That's what I get with a dual shock because I'm rubbish with it :)

I found when trying to drift GT4 cars, the harder I tried the less it wanted to oversteer, and, again, that mimicks my real life experiences. Cars, when treated harshly, on the most part either lapse into understeer or spin. They will rarely settle into a nice, balanced powerslide.
 
300zxforever
What suspension setting can you use to comensate for understeer? lower it? spring rate??
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Suspension : Softer settings on the front, and / or, harder settings on the rear. If you change the spring rate don't forget that the dampers should be changed accordingly (Softer springs -> softer dampers, harder springs -> harder dampers).

Camber : Increased on the front, and / or, reduced on the rear.

Easiest thing to try is to soften / harden the stabilizers.

I would try to change the front settings first, if this does not work I would get the front settings back to where they were and change the rear settings. If this still does not work I would start changing them both at the same time. If all this still does not improve the handling enough I would change the way I drive to suit this car, and / or , this track.

Driving tip : Brake hard first and then gradually decrease your braking force as the car approaches the steering point. You should have some braking left when you start turning the wheel, this will keep the load shifted toward the front and help the car "getting" in the corner. Ideally you should have the back end to gently start oversteering, at this point you can release your braking and gently get back on the gas. A little bit more on the wheel will keep the oversteer going, a little less will stop it. All this requires smoothness, and very small adjusments on the controls, millimeters of travel on the gas pedal and a few degrees of rotation on the wheel.

As you get better at doing this you will brake much later and the transition phase, when you steer and brake at the same time, will get shorter. All this is, of course, is much easier to do when your have the car setup to suit you. You'll never the get best lap times if you have to fight the car.


Hope this helps,

PhM
 

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