Things to think about for suspension

[Rusi]

So, I bought the MR2 supercharge from the online dealership and I swear to God PD was reading my mind because for a few weeks I've been waiting for this car. I digress.

I'm just wondering what I should be thinking about when setting up a suspension for tiny wheels 190/60 R14 , light car 900+ and 280HP. I know there are suspension spreadsheets but I'm looking for concepts not the actual numbers.

 

[budious]

Disregard everything you ever knew about physics and mechanics; throw away the self help books; ask yourself why does my fully customized suspension kit use only X dampers by default... and what factor Y should I multiply the springs by if I increased the dampers by two fold. The answer is not a linear equation. Put on your thinking hat.

 

[Rusi]

Okay my initial thought with small tires is there is more normal force on the springs so to get a tighter suspension the dampers would be higher than I think they should be.

Am I on the right track?

 

[budious]

I don't even think tire size factors into anything in this game, or there would be specs available and more adjustments on tire sizes and air pressure if there was.

 

[Rusi]

If there is no effect of the tires then how do you calculate an accurate gear ratio.... Man sometimes this game baffles me.

 

[oppositelock]

Tire size definitely has an effect on both handling and gearing, even though GT doesn't actually give us a tire size. In regards to handling, narrower tires means less grip. Less grip means less weight transfer and body roll, meaning you can get away with softer suspension versus a similar car with wider tires. That's my take.

 

[Ronald6]

I don't even think tire size factors into anything in this game, or there would be specs available and more adjustments on tire sizes and air pressure if there was.

Was it PD that put out the Nascar games? I remember playing Nascar 2 on my pc years ago. You could adjust individual tire pressure on that game. So PD could probably incorporate it fairly easily if they wanted.

 

[budious]

Was it PD that put out the Nascar games? I remember playing Nascar 2 on my pc years ago. You could adjust individual tire pressure on that game. So PD could probably incorporate it fairly easily if they wanted.

PD (Polyphony Digital) never did a Nascar game.

 

[oopssorryy]

I like the idea of upgrading tires by increasing their width. But I don't think GT5 really needs tire pressure settings. That's just another level of tuning that the casual player won't understand. Simple upgrades like tire width however are simple to understand for more people. It would be interesting to see how these wider tires would affect suspension set ups as well.

Thing is though there are many more things people are asking for, like more RMs, premium models, generic front aero kits for standard models (this might be just me lol), and the ability to change and paint rims on standard cars. These things will probably come before tire issues will.

 

[budious]

If there was any difference in wheel size and tire sizes then changing the rims should have measurable differences on the track if none of the other control conditions were changed. If all rim upgrades have the same size tire equipped, the same curb weight, the same rotation weight, then I'd say it's safe to assume no other factor is involved either over simple appearance. There is enough broken aspects to this game already to imagine anyone at PD even wanting to open this can of worms.

 

[Adrenaline]

I agree with Oppositelock about tire size being taken into account. But it's also based on his spreadsheet of transmission tuning. X gear with Y Tire (based on real life measurements) result in Z speed, which has been accurate in my tests thus far.

 

[oopssorryy]

If there was any difference in wheel size and tire sizes then changing the rims should have measurable differences on the track if none of the other control conditions were changed. If all rim upgrades have the same size tire equipped, the same curb weight, the same rotation weight, then I'd say it's safe to assume no other factor is involved either over simple appearance. There is enough broken aspects to this game already to imagine anyone at PD even wanting to open this can of worms.

You do make a great point here. Like I said, although I would like to see this changed, there are a lot of easier changes that can better the game.

 

[budious]

I agree with Oppositelock about tire size being taken into account. But it's also based on his spreadsheet of transmission tuning. X gear with Y Tire (based on real life measurements) result in Z speed, which has been accurate in my tests thus far.

Looking at his spreadsheet, tire diameter only appears to adjust the final gear, which is set uniquely for each transmission per car independently of any gear ratio. There is a placebo effect there that the two are related to each other, but using the final gear as the manipulator allows the suspension and car physics to process the wheel size as a constant variable.

Edit: To put that into plain English, there is probably a variable defined for each car related to default tire diameter in order for the real world transmission figures to work out correctly in the game, and also for the tread wear in endurance mode (car gets slower as tire diameter decreases). Back to on topic, the discussion is whether this same variable gets loaded into formula for suspension handling, that's more difficult to determine.

 

[oopssorryy]

If my mind is working right, tire width would effect acceleration more than top speed. The wider the tire, the heavier it is, and the more the power train has to work to move the tires. I don't know if PD has any formulas on tire width to acceleration/top speed. I think all their info on tire width has to do with stopping distance and grip threw the corners. That's just my opinion, I have no real proof to back this up....

 

[rubberscrubber2]

One thing the game would benefit from would be to see the tyre temps for the outer/middle/inner of each tyre. This would give a good guide for getting camber set right.
I saw this in an old Nascar game a few years ago

 

[Rusi]

On the topic of camber. Is camber at 10 the most camber you can have without having the outer part of the tyre come of the ground?

 

[budious]

On the topic of camber. Is camber at 10 the most camber you can have without having the outer part of the tyre come of the ground?

That would really be subjective to tire width and how much deformation occurs.

 

[killerjimbag]

Here is the Nascar Racing 2003 chassis setup guide link.The game was way more detailed for setups than GT5.

http://www.racelinecentral.com/RacingSetupGuide.html

 

[Rusi]

Thanks everyone for the input.

Here is another question. When starting to alter my suspension and keeping max speed (obviously) in mind. Should I stress all other options before touching camber and toe.

And if anyone has some thoughts on camber and toe creating more speed that would be great. My initial thought on this point is if you increase the rear camber the balance of weight will be in the rear and give you more traction during acceleration.

 

[risewithefallen]

i love when i buy a car and have absolutely no idea how to tune it. nothing, to me, anyways, is more fun than taking a brand new car to the Nurburgring and testing out all sorts of different suspension settings and power levels and tire compounds. it may be that i'm a very technically driven person, but i absolutely love that type of thing. go to the ring, or some other track which you want to tune the car for, and grab a bag of chips and a coke and prepare to spend a good deal of time testing setups.

 

[chuyler1]

Thanks everyone for the input.

Here is another question. When starting to alter my suspension and keeping max speed (obviously) in mind. Should I stress all other options before touching camber and toe.

And if anyone has some thoughts on camber and toe creating more speed that would be great. My initial thought on this point is if you increase the rear camber the balance of weight will be in the rear and give you more traction during acceleration.

Camber is probably the last thing you should adjust. Set it to 0.5 or 1.0 for starters and leave it while you tune the rest of the suspension. Come back to it later to maximize mid-corner speed. Take a long sweeping turn (Cape Ring has a few including the giant loop) and check your speed and listen to the tires. Increase camber and try it again. As you get closer to an optimum setting, you should be able to hold more speed in the turns. While you do this, you should increase camber uniformly. After you are satisfied with mid-corner speed, you can adjust front and rear camber by a few clicks to dial in understeer/oversteer on corner entry/exit.

 

[Ronald6]

Just remember: Camber and toe angle are interdependant. Change the Camber and chances are you'll have to change the toe.

And if you change the Camber in the front chances are you have to change the Camber in the back a little, which means you'll need to change the toe front and back.

The smaller the changes the less you need to touch the other settings.

That's my take. If anyone disagrees let me know. (Like that's a problem on this site, hah!)

 

[nomis3613]

When starting to alter my suspension and keeping max speed (obviously) in mind. Should I stress all other options before touching camber and toe.

The settings all do slightly different things, so you need the right tool for each job.

A very blunt view is that "X, Y, Z reduce oversteer". And "A, B, C reduce understeer". But if you can be more specific, like "high speed understeer", "braking understeer", "entry understeer", etc then you will learn whether it is best to use A, B or C for the problem at hand. Using the correct tool will mean you don't have to use extreme values and you'll minimise side effects.

To answer more simply though, if you are mainly worried about top speed (and I question how important this is at most tracks ), then yes changing toe/camber has greater potential to reduce top speed than the other suspension settings.

And if anyone has some thoughts on camber and toe creating more speed that would be great. My initial thought on this point is if you increase the rear camber the balance of weight will be in the rear and give you more traction during acceleration.

Camber has nothing to do with weight balance, it is about getting your tyres working efficiently. Higher camber (until you go too far) gives better cornering grip, especially at high speed. But apparently for best acceleration and braking, lower angles are required (I haven't tested this yet in GT5).

 

[chuyler1]

I really wish there was a skid pad so we could test g-forces and speeds. It would make finding the optimum camber much easier. It wouldn't be the end-all of setting it, since perfect camber for corner grip doesn't always give you enough grip on corner entry/exit but at least you could find out what value is required to lock the car down mid corner.

...instead of a skid pad, i'd settle for data logging of tire temp for outside/center/inside.

 

[r0llinlacs]

Camber only helps my cornering speed if the corner is banked. The more the bank angle, the higher the camber angle. If I take that same camber setting on a flat corner, the cornering speed decreases. There is no "best" camber setting. The "best" setting is different for every track and every corner.

Is there a such thing as dynamic camber?

 

[chuyler1]

Camber vs banking. There is a relationship but it depends on other factors.

If you run a stiff suspension dropped to the ground, high camber is not going to help on flat turns and will in fact make things worse. In order for camber to be affective, the body of the car must roll and put additional weight on the outside tires. Low ride height, stiff dampers, and stiff roll bars will not work with high camber on any track except maybe Daytona and possibly Cape Ring.

You can run high camber on flat corners if your suspension has some give to it...but I think that's why it is best to set camber last. Get the suspension stiffness to a desirable setting and use camber to increase mid corner speed on whatever track you are on. If you like city courses, use the sweeping turns of Tokyo R246 but if you like road courses with moderate banks try deep forest or trial mountain. If you like circuits with mixed banking, take your findings from the former and the later and find a good compromise between the two.

 

[grip~drift]

http://www.club4ag.com/technical_main.htm

 

[nomis3613]

In order for camber to be affective, the body of the car must roll and put additional weight on the outside tires.

I beg to differ. Body roll does not cause extra weight transfer compared with stiff springs. Weight transfer is purely caused by cornering Gs, vehicle mass and CG height. Spring rates only determine the proportion of this total weight transfer that goes to the front and rear.

I do agree in general, though, that setting camber for banked corners might be totally different to flat corners.

http://www.club4ag.com/technical_main.htm

What are you trying to point out on this page please?