xTYBALTx

Is there a guide anywhere to setting up a vehicle?

I know understeer, oversteer and gearing, but have no idea what brake stiffness will do to the vehicle. Is it necessary to mess around with the actual components in the garage or is it sufficient to adjust the slider bars?

EDIT: Consolidated posted resources in this thread.
-- Mirfee

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Mirfee

An excellent question. And one I don't have an easy answer for.

We've been just experimenting, and in some cases trying out usermade setups that you can download in-game.

Honestly, I haven't got much more of a clue than you do. So I'm just learning as I go.

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Turbo

I have an idea for a future round. What about everyone using the same setup. That way the cars will be identical when we run all the same cars. Just a thought.

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Mirfee

Hmmm... someone else's setup might be uncontrollable in the hands of another driver (me, for instance ).

The only alternative is to use stock setups, making adjustments for fuel-load only.

However, the ability and temptation is still there to tweak and there's no way to police setups.

Hmmm... sorry Turbo. I didn't mean to come out 'n pee on your idea. Not over-ruling, just considering angles. We could try that if enough folks want to sometime.

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Turbo

It was just a thought, feel free to pee on it.

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xTYBALTx

I like Turbo's idea

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RocketPunch

http://www.wtrscca.org/tech.htm
http://www.nyracer.com/setup.htm

There is also a great book about driving and car physics in general I own called "Going Faster! Mastering the Art of Race Driving "
http://www.bentleypublishers.com/product.htm?code=gdba



The funny thing is I learn most of those stuff when I was a kid setting up RC car for racing, and don't let the scale fool you. All of the basic principles apply to real cars. I enjoy setting and testing the car for a specific race, for a specific track and for my driving style; and the knowledge one can gain from these session is both satisfying and invaluable.

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Slow is Smooth. Smooth is Fast!

Mirfee

The dvd that accompanies the book is quite helpful too. Granted, it was made about 20 yrs ago, but racing basics don't change. Check it out from Netflix... that's where I got it from.

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Wulfyn

The first and easiest thing to do is your gear ratios.

First you set your top end so that you just hit the rev limiter at the end of the longest straight. Setting it any higher is wasteful as your maximum revs are never going to be used, and you want your gearset as closely set as is possibly to increase acceleration.

Next set your second gear so that you can comfortably use it on the slowest corner. Allow for a mistake as you don't want to be thinking about gears at this point. Do not use first gear for this as you want that set extra low in case you have to restart and at the start of the race. The easiest place to overtake is at the start of a race, so setting your first gear lower could win you a position here, that will be hard to take back.

Finally for gears set the rest of them between. To start with you want them evenly spaced, and this is where you will base it from. Next you want to slightly adjust them so that they are slightly more concentrated at the bottom end (although I imagine with these cars that's not going to be a big factor). Finally test the gears on the track. If there is a corner that makes you overly work the gears (like upshifting 50m before your break point, or being on the edge of two gears as you feather the throttle round a corner) then I do suggest altering them as feels comfortable. You want driving to be simple, and the less you have to do on corners the more you can focus on everything else.


The next thing to consider is your suspension. The basic rule is the stiffer the suspension the better the car will griup a track, and thus the faster you will go. This however is only true whilst the car tyre is making good grip with the road (traction). Stiffer springs reduces this tendency, which is fine on a flat surface but hell on a bumpy one. So again it is about finding the worst corner and adjusting for that. Also pay attention to things like off camber downhill corners whihc will cause your inside tyres to lift and fall depending upon your line. With these tyres slightly off the road you are putting a lot of pressure on the outside wheels.

Again testing is the key here, if softening the springs saves you 0.5s in one corner, but loses you 0.1s in the other 6 then obviously you are not gaining anything. but do play around. Softening them again might save you another 0.5s in that corner but for no further loss in others (an overall gain of 0.4s). Just because a move looks backwards does not mean you should not continue exploring it.

The next important factor is your rollbars, and these are the main controlers of understeer / oversteer. Your dampeners / springs also have an effeect, which is why you have to do this part after your suspension in my opinion. The rollbars act against each other. The softer a rollbar is in comparison to the other the more that end of the car will move. So if you understeer (where the front of the car does not turn) then you need to soften the front. If you oversteer (where the front of the car moves too much, sending the back end to step out) then you need to stiffen the front. The softer both anti-roll bars are the less responsive the car will be, but the better grip you have.

The final important factor is brake balance. This is a simple one and is done last (in my opinion) as you need to know all of the other characteristics of your car to get it right. This is all about steering into corners. If you are understeering in move the brake balance back. If you are oversteering move it forward. The downside is that the further from centre you move the balance the sooner you have to brake (as your brakes are not working as efficiently). As all fast moving objects generally don't want to change direction all cars naturally understeer, which is why you find default brake balances tend to be 40:60 in favour of the back.

If that doesn't work then google one up

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Mirfee

Outstanding writeup Wulfyn! Thanks!

Your points about transmission gearing are equally good. Unfortunately, GT Legends only lets you change your final ratio (up or down from a middle default, despite having adjustment arrows).

I don't know how many other settings are restricted, but the ones I've dabbled with have been largely adjustable - unless a particular car didn't have adjustable camber or something... like the Alfa (fixed rear) and Cortina (fixed front and rear) - pretty much all solid rear axle cars. The design and construction of the car was intended for street production, so the vintage accuracy is priority in the real world racing circuit. This is true even within the SVRA (Sportscar Vintage Racing Assn.) here in the US.

EDIT: One point I have to contest is that my observations and experience shows that braking is biased to the front, as this is where the weight transfer goes. This means more grip in front. Overbiasing to the back means rear lockups as the back lifts and the front dives. Adjusting bias for track conditions, handling, etc is still necessary, but I believe the default is the reverse of what you say.

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Wulfyn

Maybe this is where my bias of experience towards setting up cars with a rear engine triggers a difference. You are right that as a car goes under braking the "weight" piles forward putting extra downforce on the front of the car. The difference is that in a GT type of car you also have the weight of the engine here, whereas in (say) a formula 1 car you have no weight at all. Thus the rear tyres in a rear-engined car will still have plenty of downforce on them to make them work.

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Mirfee

Yes, very important distinction. Looks like we're both coming at this from opposite ends (figuratively and literally).

The Porsches and another 1 or 2 cars in GTL are rear-engine. Their handling and braking bias will certainly need different attention than the predominantly front-engined cars that fill out the rest of the stable

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Wulfyn

One extra thing I have noticed for keyboard users is... my god these things understeer. It's definitely an AI thing as it is completely inconsistent. I think it may be based on where my car is at the turn in point. I'm playing in the championship A race in the cooper, and the turn is turn 3, the off camber downhill right hander. Let's just say I either nail it in third gear comfortably or crash pretty gruesomly! I think it is the AI doing this, so be careful.


Anyhow to illustrate the above point with the default setup I was getting a lap time of around 42.4 seconds on professional level (the computer cars run between 41.2 and 41.5). In the garage I:

a) dropped the Finish ratio down 1 point (as Mirfee said above you cannot change the ratio only the overall amount) as I was never hitting top end.

b) took the front roll bar down 0.2 deg and the rear roll up 0.2 to reduce the understeer I was getting

c) took the brake bias 3 points to the rear.


With this I acheived a lap time of 41.4 a whole second faster. I was still understeering horribly tho, and the track was also really bumpy in the crucial turns 3 and 4. In order to address this I:

a) took the front roll bar another point to the negative (-0.3) and the rear up to 0.3

b) took all dampeners to 2

c) reduced the tyre pressure down by 5kPa in front and rear

d) took the brake bias another point to the rear

And then immediately hit a 40.8s lap. Also now my lapping is consistently smoother, especially on turn 3 which seems to be the real time consumer of this circuit.

So that was 1.6s saved just by a few small changes - reason enough for everyone here to at least have a go.

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Mirfee

More great info! Thanks!

One thing to remember about the Mini Cooper in particular... it's the only front-drive car in the game. This provides a ton of advantages over its rear-drive brethren, but also comes with a price.

Due to front drive, you're placing enormous stress on the front tires to maintain traction. Where a rear-drive car only demands braking and turning from the front wheels, a front-drive car also expects power from the front wheels. This reduces the front tires' normal traction split of 1/2 and 1/2 to braking and turning respectively, to 1/3 and 1/3 and 1/3 for braking, turning, and accelerating. The front tires end up with only 33% of the braking and turning grip of a rear drive car. So... while Mini's are very difficult to fishtail or spin with oversteer, they are notorious for pushing straight through a turn if it's unique traction characteristics are placed under too much demand.

That said, the Mini is still the most maneuverable car in the game. While it'll lose every shootout with a Mustang down long straights, it'll carry the sort of speed through the turns that would launch a Mustang off the track. They didn't call it a giant killer for nothing! Just have to drive to its advantages and avoid its weaknesses.. like any other car.

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perry

http://www.miata.net/sport/Physics/ - that ought to keep some of you busy for a while, especially if you're any sort of math geek.

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