Newb questions about ASM and TCS.

[Bulldozer]

I already understand that the ASM and TCS settings under 'options' only apply to arcade mode - in sim mode you have to set them separately for each car. At least I figured out that much on my own.

Question one: how do they work? Does a computer in the car sense that some wheel is turning more than it should (compared to the other three) and reduce power? Does it reduce to just the spinning wheel or to all the drive wheels?

Question two: Is it realistic to leave them on, since some real life cars use these? Do performance cars have ASM and TCS? If so, do people turn them off for racing?

Question three: How much do they affect performance? Does that depend on the car, the driver's skills, or both? Obviously if I turn off TCS and just smoke my tires at the starting line, I'm going to have a slower start than if I leave TCS on 1 or 2, and launch off of the redline. Can I turn faster with ASM on or off?

Is the best strategy to always turn them off, and just get used to driving without them from day one?

 

[Greycap]

Question one: You pretty much nailed it. It slows the spinning/slipping wheel down.

Question two: If you want to. Values of 1 or 2 simulate real life systems pretty well. High performance cars seldom have systems like this and they are generally turned off for racing.

Question three: Very much. TCS isn't too bad if not overly applied but ASM is certainly going to slow you down a lot.

The best strategy really is turning them off and getting used to it, it'll pay back hugely in the future. 👍

- R -

 

[Parnelli Bone]

I'll agree with Greycap. Turn them off (especially if you're just driving a slower car). In GT1 there were no aids at all. Drive or be driven. In GT2, you could buy aids (TCS and ASC cost $50,000 apiece!!!) but they barely made any difference unless you were driving the most insanely-powered cars in the game like a Speed 12.

...my point is many of us "veterans" got used to GT without the aids...that's why we're vets. Sure you'll be prone to spinning, sliding and wheelspin a bit more, but in the long run you'll become a skillful driver if you leave them off. 💡 A car without driving aids on has a tendency to be less predictable but also more flexible in those corners; hence you can get away with all sorts of corner trickery to pivot you in turns and stuff that the Ai sim cars can't express. You'll eventually see what I mean.

Occasionally I'll use driving aids, especially if I know the real-life version of the car is equipped with them and I wanna get a feel for how that car would do with aids on (GT4 really got the feel down between on and off). But most driving I don't use them.

 

[Bulldozer]

Thanks Greycap and Parnelli. I've seen a few tunings at GTvault that had a TCS setting of 1 or 2, but hardly any of them using ASM.

Now I'm curious and I'm going to have to try some practice laps with ASM on and then off. See if I can feel the difference or if my lap times change.

I'm also interested in that "corner trickery" Parnelli. I'm guessing you mean there are some corners where you want to deviate from normal grip lines. Or are you talking about taking a corner differently when other cars are blocking the usual line. Can you give me an example?

 

[breakpoint]

I would assume parnelli talking about a little speed drifting. Lets take the last turn in deep forest. The left before you go up a small hill to the pits. This turn can be taken much much faster by speed drifting through it. I can take it at well over 100mph by speed drifting through it. I also don't care for the asm and tcs's. But then again all i do in GT3 now is drift so that would be a no brainer for me.

 

[Parnelli Bone]

Thanks Greycap and Parnelli. I've seen a few tunings at GTvault that had a TCS setting of 1 or 2, but hardly any of them using ASM.

Now I'm curious and I'm going to have to try some practice laps with ASM on and then off. See if I can feel the difference or if my lap times change.

I'm also interested in that "corner trickery" Parnelli. I'm guessing you mean there are some corners where you want to deviate from normal grip lines. Or are you talking about taking a corner differently when other cars are blocking the usual line. Can you give me an example?

Sometimes (like in a front-drive car that qualified up against a group of 4WD or mid-engine cars) a TCS setting of 1 doesn't hurt because when you qualify you're already rolling, but when you get in the race you have to do a cold-start. The Ai cars will beat you to pieces in your front-drive if you don't know how to modulate throttle, so if you're a newb you can give a bit of TCS to keep those front tires from spinning.

And by "corner trickery"....yes I am talking of deviating a bit from the norm. Sometimes for instance, you'll want to take a nice, wide classic "out-in-out" line thru a turn, but a clueless, stubborn Ai car has been blocking your way and you can't seem to get round him. Well, how about a mini-slide that (once you kick the throttle in) will give you an alternative line and get you past that guy? I'm just trying to illuminate that there are sometimes other ways to out-smart the Ai....depending on the car you drive.

....more on this topic later.

I would assume parnelli talking about a little speed drifting.

Yup, that's one thing you can do. The Ai always makes those perfect corners, even tho sometimes they aren't so perfect. The Ai at some tracks will go for that wide turn even if it means SMACKING THE 🤬 OUT OF A WALL!! Say we have the Pro-level FF Challenge. This race I think is 5 or 10 laps (I forget). Anyways, the fastest machine here is definitely the Spoon Civic. Even tho it's the fastest car in the race, it NEVER WINS AT DEEP FOREST! Why not? Cuz it would rather smack the wall in between tunnels 2 and 3 than slow down a tad.

WE on the other hand have other options. Remember this: there is never just one way to tackle a corner especially during a race where there's traffic ahead of you. Sure in license tests or in a Time Trial you'll want to get that perfect line, but when Ai cars are mucking about you can always experiment and try new things....

 

[TuneRVisioN]

Yeah, I never understood that. The Spoon Civic's cornering and accelerating performance is amazing! Especially for a 800Kg hatchback with Front Wheel Drive. I love driving this car around, it can drift (or slide) almost as good as my Mini Cooper! It corners soooo well, but the A.I. knows how to make a great car look bad.

 

[Parnelli Bone]

Yeah, I never understood that. The Spoon Civic's cornering and accelerating performance is amazing! Especially for a 800Kg hatchback with Front Wheel Drive. I love driving this car around, it can drift (or slide) almost as good as my Mini Cooper! It corners soooo well, but the A.I. knows how to make a great car look bad.

In that particular race (and I could give other examples when I have more time) the Spoon Civic truly screws up. And then it has to take a pitstop! So instead of the Spoon, focus on the Beetle which drives slower yet with clean cornering. In that race, I would always let the Civic get a lead while me and the Beetle had some cool cornering action going.

 

[Parnelli Bone]

I'm going for the bubble-dost here because Iwanted to add brakes to the corner-trickery discussion. Brakes and knowing when to brake are vastly more important in my opinion than traction controls or stability or even horsepower when it comes to out-smarting computer cars or your buddy. In most GT3 races the Ai has a tendency to brake a bit early and sometimes lays on the brakes like a steamroller.

If you (especially) have the sports brake package you can ultimately learn to brake up to a car-length or more later than the Ai, and get a huge advantage. The brake-controller further allows you to customize the angle you'll wind up taking as you approach turns and (assuming you're not using so much brakes your wheels are trying to lock up) also allows you to brake even later. The advantage you get with from all this may seem small at first, but if you think about it, every time you out-brake someone you gain small time advantages: maybe a half-second here and .300 there. As you drive round a course, these time-advantages tend to add up assuming you're able to find a route that takes you round some stubborn drivers. 👍

 

[Bulldozer]

Sports Brake? Ever since I read Scaff's tuning guide I stopped buying the brake upgrade. Do you think the sports brake package really helps?

I still use the brake balance controller, but mostly I just use it to set the front brakes to be stronger than the rear. My logic is that weight transfers to the front during braking, so the front brakes have to work harder.

I'm always using max brakes. I guess I figured that the ABS would keep the brakes from locking up. Is that wrong? And if I should be using less than 100% braking, how the heck do you do that with the DS2 controller? I mean, I know about going into options and changing brake from the button to the right stick, but I just can't imagine pulling it back halfway. Or say, 85%.

 

[breakpoint]

If you set the brake bias on the front this will just transfer all the weight to the front very fast and cause your rear end to start drifting out. I set my drift cars up with 21 in the front and 7 in the rear to help feint\brake into my drifts. The way i use brakes to not lock up the tires is to tune the break strength. I will goto a track like lets say, midfield. The first corner after the straight is a good one to tune with, hard right. If you have your breaks maxed out then they are just going to lock up on you and your rear end is going to step out because of the complete loss of weight over the rear. For grip try lowering the brakes down to around 9-11ish in the front and about 13 in the rear and see how you like that. If its too harsh then lower it some if not enough bite then raise it some. Generally in GT3 you don't want to max out any setting. I don't control how much break i am applying with the analog stick, i control that with the settings menu. Would be really hard and annoying to have to brake 32% with the stick.

 

[KAMKA-Z]

Sports Brake? Ever since I read Scaff's tuning guide I stopped buying the brake upgrade. Do you think the sports brake package really helps?

I still use the brake balance controller, but mostly I just use it to set the front brakes to be stronger than the rear. My logic is that weight transfers to the front during braking, so the front brakes have to work harder.

I'm always using max brakes. I guess I figured that the ABS would keep the brakes from locking up. Is that wrong? And if I should be using less than 100% braking, how the heck do you do that with the DS2 controller? I mean, I know about going into options and changing brake from the button to the right stick, but I just can't imagine pulling it back halfway. Or say, 85%.

There are some cars that I only buy the 'Sports Brakes' for. I recently did the TVR races and didn't opt for the brake ballance controller. I think they make a big difference.

Most cars I race with the brake bias controller have a slightly forward bias. I'll put more rear bias when I want to slide into the corner or induce more oversteer. (am I wrong? cause it sounds like breakpoint does the opposite.)

I'm using a wheel and pedals and I pretty much always use full braking. I guess since there's little resistance and it's not like the pedal is providing any feedback feel like a real car would. Guess I'm trusting the ABS too. I've often thought I should find a way to add more resistance to the brake pedal, but it would need a good solid feel just before lockup. I'll have to try sticking a chunk of compressible foam under it. My brake pedal has cracked and several pieces have broken off from panic brake abuse.

 

[breakpoint]

I'll put more rear bias when I want to slide into the corner or induce more understeer. (am I wrong? cause it sounds like breakpoint does the opposite.)

All settings are personal preferance really. So if that works for you then go with it:tup: But if you think about it in physics form then setting the brake bias mainly in the front will help loosin the rear end up because all of the weight has shifted to the front of the car. When i drift lets say there is a right hand turn coming up. I will jerk left quick before the turn to start my feint, right before i jerk back to the right to start my drift i will hit the breaks hard to shift all the weight to the front to allow the rear to step out freely without having to lock up the rear tires or use the e-brake...ugly! I try to use real life know how in the game and see if it works. The last race i went to ( i race 125cc shifter karts) on the first practice lap when i hit turn one the rear starting dancing on me. Got back into the pits and noticed that my rear brakes weren't working at all So finaly found out that all it needed was to be bled...phew Got back on the track and all was fine again, no getting loose now. What casued it to step out was i only had front breaks so it threw all the weight to the front when i came in the turn. And when you are doing 110mph 1/2 inch off the ground the last thing you want to do is get loose. Thats why i set my brakes like i do for drifting

 

[Duke]

But if you think about it in physics form then setting the brake bias mainly in the front will help loosin the rear end up because all of the weight has shifted to the front of the car.

Well, I hate to contradict you, but this simply isn't the case except in a situation like you described with your kart, which was doing the 4-wheel equivalent of a nollie or stoppie. It only works this way in something extremely light with a huge amount of traction, such as a kart or bike.

In a car, even on r-compound tires, too much front brake bias is more likely to just overwhelm the available traction and cause understeer at corner entry. Do you know about the concept of the 'traction circle'?

Imagine a circle of a given radius. This represents the contact patch of the tire, and the available amount of traction. Now imagine an arrow from the center to the edge, that can spin freely around the center point. This represents the amount of force the available traction can provide in any given direction.

If you point the arrow straight backward, ALL the force is applied toward the rear of the car and the car accelerates as quickly as it can. If you point it straight to the side, ALL the force is applied sideways and the car turns as hard as it can. Pointing it straight forward applies ALL the force as braking and the car slows as sharply as it can.

But when it's pointing at an angle, because of two inputs such as when you're braking AND turning, the available traction (full length of the traction vector) must be split between the longitudinal and lateral forces. So the harder you're steering, the less traction is left over for braking, and vice versa.

Setting the brake bias too far toward the front increases the amount of braking force applied to the front wheels, and this will grab most of the available traction for itself, and leave little traction force available for lateral steering input. This causes entry understeer.

On the other hand, you can use this to your advantage by setting the brake bias more to the rear to deliberately reduce the amount of lateral grip available to the rear wheels, making the car more prone to oversteer at corner entry.

It should be noted that setting the bias too far either way will lengthen your braking distances considerably, because one end of the car or the other is wasting traction that could be used for additional slowing.

Again, you're right to some extent with your real world example, but that example doesn't apply entirely to a full size car which has much less grip for its weight than something like a shifter kart.

 

[breakpoint]

Oh yeah i do agree that if you are grip racing then you do not want to have the bias set up in the front because of the car wanting to understeer when you are hitting the breaks. In GT3 when i hit the breaks i am doing it right before i initiat my drift so the effect is oversteering on my car. I don't hold the brake down while entering the turn, if i did then it would understeer like a Civic with 4 people in it. I basically only have the break jammed for maybe 1 second if that, just long enough to shift the weight and then im off of it. That doesn't give it enough time to effect the steering entering the turn. All of the things i was saying about the brake bias was for drifting only, not grip. In grip racing i keep mine a tad more in the rear.

 

[Bulldozer]

Well, I wanted to verify a couple things so I went to the test track. Basically, I wanted to see how brake balance would affect straight-line breaking. My theory is that, since weight transfers to the front under heavy braking, you should get the shortest stopping distance with a front brake bias. Sound reasonable?

So I used a CLK (moderately heavy FR car) with sports brakes and T4 tires. I set the transmission so that the rev limiter would give me 100 mph in 3rd gear (more consistent than trying to fine tune the throttle by hand). I used the analyser to measure the 100mph - 0 stopping distance, and averaged over 4 tries. The results:

Bias Front / Rear    Avg stopping distance
     24     1                .038 mi
      7    18                .037 mi
     12    13                .038 mi
     18     7                .036 mi
      6     7                .036 mi

WTH? It makes hardly any difference whether the braking is biased to the front or the rear. OK, the 18/7 is better than the 7/18, but 6/7 is just as good. And 6/7 is better than 12/13 - why?

I thought I'd try a second car. I also switched to 140mph - 0, because I thought a longer braking distance would be better for seeing minor differences. Second test was a RUF 3400 with T5 tires. :

Bias Front / Rear    Avg stopping distance
      20     5                .065 mi
       5    20                .066 mi

Again, better stopping distance with front bias, but only by a tiny margin. Probably smaller than the test's margin of error.

As a side test, I checked the braking distance of normal brakes in the CLK. Long story short, they stopped just as well as the high-performance brakes. At least for 100-0. And the normal brakes didn't show any signs of brake fade, either. I ran the car up to 140, braked to 40, repeated that 5 times, and checked the braking distance again. It was the same as before.

Conclusion: In GT3, brake bias makes little or no difference in straight-line stopping power. You might as well use your brake balance controller to tune your understeer and oversteer.

So from now on, I'm going to bias my brakes towards the rear. Because if I understand what Duke is saying, then less braking action in the front means that the front wheels will have more traction for steering. I just won't overdo it, because if the rear wheels don't have any lateral traction then I assume I'd get crazy oversteer to the point of completely spinning out.

I feel like we should page Scaff to this thread, because my results seem to run counter to what he said in his tuning guide. In particular,

Scaff's tuning guide says
With a few exceptions, I would never recommend using the brake balance controller to trim understeer or oversteer (despite what the GT4 screens say). Use of the brake balance controller to do this can and does have a serious effect on braking distances.

Maybe it's a GT4 vs GT3 thing and the physics are greatly improved in GT4. I dunno.

 

[Bulldozer]

I wanted to add one more run in the RUF. This is a worst case situation - max bias to the rear (1/24). This should give the worst braking performance.

Bias Front / Rear    Avg stopping distance
      20     5                .065 mi
       5    20                .066 mi
       1    24                .070 mi

And it does. So bias does affect braking distance. It's just that you have to get into some extreme values before it makes a noticeable (noticably bad) difference.

 

[Scaff]

I feel like we should page Scaff to this thread, because my results seem to run counter to what he said in his tuning guide. In particular, Maybe it's a GT4 vs GT3 thing and the physics are greatly improved in GT4. I dunno.

It is primarily a GT3 vs GT4 thing here, the guide and testing associated with in in regard to braking were all carried out on GT4, and its one area that GT moved on significantly with GT4 (its still a long way from 'real' but its certainly better).

From memory (and its been a while since I tuned in GT3) the GT3 brake balance controller is mainly a tool for tuning the cars balance. One of the reasons behind this is that it does not significantly alter the brake force itself (the GT4 BBC does), but rather the ratio between the front and rear. As such it will have little effect on overall stopping distances, but can be an aid in balancing the car.

In both GT3 and GT4 true tyre lock-up is almost imposable to (particularly in a straight line) and as such braking is significantly easier that reality and Brake Balance has a much reduced effect (however its role is far more significant in this regard in GT4). What does remain true is GT3, GT4 and reality is that braking components will only allow you to make the most of the tyres potential grip (before lock-up in the real world and ABS cut-in in GT), and the only way to significantly reduce stopping distances is through stickier rubber.

Regards

Scaff


Edited to add a reply to Dozzer's new post

I wanted to add one more run in the RUF. This is a worst case situation - max bias to the rear (1/24). This should give the worst braking performance.

Bias Front / Rear    Avg stopping distance
      20     5                .065 mi
       5    20                .066 mi
       1    24                .070 mi

And it does. So bias does affect braking distance. It's just that you have to get into some extreme values before it makes a noticeable (noticably bad) difference.

Nice test and one that illustrates that the GT3 BBC controls the ratio rather than the power, a massive ratio shift to the rear increases straight line stopping distance, but as braking power is not significantly effected (and true lock-up is not possible) the difference is small.

 

[Parnelli Bone]

Sports Brake? Ever since I read Scaff's tuning guide I stopped buying the brake upgrade. Do you think the sports brake package really helps?

My experience is yes it does. Now I'm talking about the upgrade that changes your rotors, pads, hoses, calipers, and brake fluid (costs around 4,500 cr) not the brake-controller. Since the sports brake package itself is cheaper than the controller, I often buy this when credits are low and I'm starting in a slower car. The difference it makes in races is small, but those small differences add up. 💡 See?

Anyways, I've competed virtually enough to know when I'm trying to out-brake a sim car and fail, then come back to the race with the SBP and have more success going into corners. In GT4 the SBP by itself is even more effective than in GT2 or 3. I am CONSTANTLY out-braking in GT4. To illustrate: about a month ago I entered a SCION xB in the Sunday Cup. Since the xB has about 108 hp when stock, I figured I'd better come prepared with some power ups.

Well check this out! I enter the race at Autumn Ring Mini with upped power (I forget how much) and kept winding up far ahead of the Ai. It felt like such a cheap win! I mean at the start it seemed I had no more power than the sims! I kept coming back to the same race with less and less power till I was literally stock. The race itself was tighter, but the reason I kept winning with just 108 horses was I knew when to brake (typically much later than the sims). And I would constantly be taking corner paths that were anything but textbook (usually that means going on the outside of a sim car rather than the inside) just so I could avoid their stupidity.

Also wanted to add that yes you're right: ABS keeps brakes from truly locking in the GT games, but that doesn't mean the brakes are not trying to lock. As your tests confirm, the BBC in GT3 is nothing but a ratio, 👍 and you tested straight-line braking, but I'm talking of braking that isn't always so straight....I'm talking of maybe slowing down into a corner, and then getting to the point where you are both braking and turning for a moment or 2. The Ai cars cannot do this with as much success, especially in normal passenger-car (non downforce) racing. What the Ai often does is brakes (mostly straight-line) enters a corner and then brakes AGAIN. And then sometimes AGAIN!! So I'm just trying to illuminate this primitive behavior. And what we can do to avoid it and maybe not rely on power or driver-aids so much.

In GT4 when you dial brakes higher than 15 in passenger cars, you can actually hear the tires begin to chirp as they're trying to lock. GT3 it seems isn't so drastic in this regard.

 

[Bulldozer]

Thanks Scaff. I remember you saying that the BBC in GT3 does NOT affect total braking power, I just thought that changing the front /rear bias would have more impact. And I realize that GT4 went further in their physics than GT3. One of these days I'll have to repeat the test in GT4.

Parnelli, That's a good point about straight-line braking versus the kind of braking people do in a race. And I'm sure that's where the sports brakes have advantages over the normal ones. Also, trying to measure in thousandths of a mile off the analyser isn't that precise. 8 meters sounds a little more significant than .005 miles. Definitely enough to pass a car going around a curve.

Guess I'll have to make some runs around a test track, and see if better brakes make a difference in my lap times. Trouble is, I'm not that consistent of a driver - my sloppy driving would probably be a bigger factor than the brakes.

 

[breakpoint]

Geeze, i would just like to say thank you to Bulldozer for doing far more than any other new member has ever done...lol. Most people ask questions that can be answered very easily with a quick trip to the search bar. You asked a valid question that couldn't be answered so easily and then helped find the answer to the question.

 

[Parnelli Bone]

Yeah some newbs go: "oh please oh pleeze sppoon-feed me!" then when someone like me acually gives an intelligent answer it's like there's no response.

So I'm thinking: Hmmm, did they ever read what we wrote back? If they read it, do they agree? disagree? Think I'm from Pluto? WHAT?

 

[Bulldozer]

Thanks for the compliment, breakpoint. I don't want to be spoon-fed, but on the other hand I've gotten a lot of help from folks here - especially Parnelli. 👍

BTW, Parnelli, my wife has a Scion xB (real-world) and it seems to me that those things have perfect aerodynamics... for decelerating. They're about as streamlined as a drag chute. With that flat grill and straight windshield I'm suprised you have to touch the brake pedal at all.

Do any real-world cars have active airfoils? Well, I know the new Porsche 911 has a spoiler that deploys at higher speeds, but I was thinking more of high-end race cars. Seems to me that you could rig a computer in the car to sense when you hit the brakes, and especially if you also start turning the steering wheel, then an actuator would change the angle of the spoilers. So when you're taking a corner, you get a little extra drag to slow you down and a lot of downforce to help turn, but when you're going fast in the straights, downforce is reduced. You could even program it to give you more front downforce initially, to reduce understeer, then transition to rear downforce to keep oversteer under control.

Then, if you want to get really high-tech, use a GPS as another input for the computer. You could custom program the amount of downforce for each individual turn. OK, that might be over the top.

 

[Duke]

The old old Chapparal 2E had a driver-adjustable airfoil. It used a clutchless transmission, so they installed a pedal where the clutch would go the would trim out the wing to give neutral downforce for minimum drag on the straights. The car was meant to be left-foot braked, so when you took your foot off the trim pedal to brake, it automatically flipped up for maximum downforce.

 

[Parnelli Bone]

I just like an intelligent discussion. 👍 Rather than the typical: MY SKUYLINE GOES 302 MPH NO WEEHLIE DUDE!!!!!! that often shows up here at GT3!

Yup, and the SCION xB is the box that rox! It's got the aerodynamics of a toaster, but you're right...the box-shape can help slow you down from over 70-ish mph as well as brakes & tires because it has a higher drag coefficient than, say ....a Lotus or a Corvette.