Camber Theory

[DolHaus]

This is what I corrected. This does the opposite, because when you load the outside tire, more force it put on it, which wants to pull it backwards. Your pushing against the wheel from ahead of it as your travelling forward. What happens when you jack a car up and push the front of a wheel? It turns to the outside. Toe out. It is not a motorcycle. The mass above the wheel is not leaning inwards, allowing for the opposite effect. Camber thrust between something with two wheels and four is very, very different. The car is leaning outwards...loading the outer wheel. Essentially, making an example using a motorcycle simulates or illustrates loading the inside and unloading the outer wheel completely. The opposite of an example of a car. You have no opposing wheel. If you run 0 toe on an alignment rack and then drive down the road, you have slight negative toe out and it furthers between geometry and loads/forces. Adding camber does not create, simulate or give off a similar effect of any toe in. Caster plays into all of this as well. Pull the top of the strut backwards from upright in relation to the spindle and now you are somewhat fighting back forces that push the wheel backwards and out.

I don't have the energy for this today, sorry. Dk what else to say or how to describe it. Camber = toe out as the suspension compresses. Camber = toe and when you're driving forward, most notably through a turn under high load. The more drag and forces pushing it back, the more it wants to steer away from the chassis with zero or negative toe and negative camber. Even 0 camber will go negative under load, because of the manner a control arm moves upwards at the outer end under load. Could run 0 camber and 0 toe, the wheel will still want to push back and turn out from the chassis. I can't think of situation where toe in is forced by adding camber. As I said, just pushing back on a wheel from the front with the front of a car jacked up and tell us what it did. Toe in counters those forces that want to pull the wheel out...like moving forwards...which again, naturally wants to pull the wheels outwards.

DolHaus believes the opposite. That adding camber forces a "permanent" toe in effect. To boot, the more your turn the wheel, the more that outside, loaded wheel does't want to turn in and it wants to toe out more so, because the forces fighting back at it are increasing. It is no longer merely an oncoming force that is being received. Setting toe in with camber will set the wheel closer to zero as it loads and received that oncoming force of the road and bumps you drive over. If you drive over a bump on the right wheel, your wheel jerks to the right, correct? If you drove over a sticky patch of road on the right side, it would pull you to the right correct? Right, because the oncoming forces is forcing the wheel out. It just gets worse the more you load it. That was just an example of the force the wheel is having to fight to stay straight.

So, no. Camber does no create or have some sort of effect of permanent toe in or any toe in. It is the exact opposite.

That is rhetorical, because I have no idea how else to spell it out. Talk about thrust as you wish. That is not what I disputed. I will be baffled if someone comes back and says threat an incoming force creates toe in. That is ridiculous. Camber or no camber. Which ever produces more grip at x point in time.

Maybe this illustration will help clarify what I have been talking about.
As you can see, the resultant effect of leaning a wheel onto the inside edge using negative camber makes it want to follow an inward arc towards the centre line of the vehicle. This is the Toe In-like effect we are talking about, it is not actually changing toe but it is having a similar effect on the direction of travel of the wheel in that it is pointing in towards the centre line of the vehicle.

 

[Robbks]

I see your theory, and don;t discount anything.
but would like to see the physics of it.
It works on a bike because of the huge amount of mass that you're hanging off the top of it.
In the case of a non-driven axle, I'd think the toe out due to rolling resistance would cancel it out,
and on a driven axle under power, the effect of the drive torque would be more toe-in that the effect of camber.

Interesting point, but need to see the maths.

 

[DolHaus]

I see your theory, and don;t discount anything.
but would like to see the physics of it.
It works on a bike because of the huge amount of mass that you're hanging off the top of it.
In the case of a non-driven axle, I'd think the toe out due to rolling resistance would cancel it out,
and on a driven axle under power, the effect of the drive torque would be more toe-in that the effect of camber.

Interesting point, but need to see the maths.

The mass comes in the form of the cars weight and the resulting deformation on the tyres profile which shapes it sort of like a cone so it is marginaly thinner on the inside edge. I will have a look and see if I can find a decent link with the relevant maths involved 👍

Edit: I've found the maths and its... complicated... horribly... horribly complicated
(start at chapter 2 "Tire Mechanics")
http://books.google.co.uk/books?id=...v=onepage&q=camber thrust calculation&f=false

Good luck and bring a calculator

 

[332i]

Idk when you are going to lean an outside wheel on it's inside edge, but sure. I am too tired tonigjt for to keep going and I would be rhetorical, anyways. That picture was made by someone in Microsoft paint. Idk why you are talking about said arc. You've been reading the ice cream cone horse crap examples. Look at a car with negative camber. No picture the car sitting on said ice cream cones. Your example works for a vehicle with one turning wheel. You don't lean a car on inside edges of their tires. You do on a bike and that is why the ice cream cone example exist. When you go around a turn on a car, the car is leaning away from the turn. If you had a car with active suspension, sure, your example would work. The center axis of the wider end of the cone would be attached to the vehicle. Lean into a turn and onto the inside edge of the tire and your right. Idk why you are talking about inside edges on car when your leaning on the outside...which is why the outside of tires roll. Put a cone on a table and let it roll. It will spin in circles away from the center axis of the outside of the cone. The end that would be attached to the hub. On a motorcycle, that is what you want. That is why you will find the cone example on a lot of motorcycle forums and such. The cone rolls away from the vehicle when it is leaned on. Which would pull a motorcycle into a turn and pull a car out of it. You are picturing things in reverse. Camber provides a more stable patch of rubber for the ground when a suspension system compresses and the vehicle leans on said patch. X amount of camber with zero toe does not make the car want to do what x amount of toe and zero camber or whatever amount of camber and toe would. There is no shared effect or outcome. Camber on a car with zero toe makes the outside wheel toe out around a turn and when that happens, the car doesn't not want to follow the inside wheel...because there is little weight on it in comparison to the outside. Idk how you figure camber with zero toe and the arc in relation, when the outside tire is toeing out and the inner is toeing in. It toes in, because the tie rod angle is increasing. The outside wheel toes out, because the tie rod angle is decreasing. You can use whatever camber you want with zero toe. You're still going to get toe out. No amount of negative camber angle is going to remedy the toe out that occurs, because of it's presence. I am speechless.

/rhetoric that I said I wouldn't get into.

 

[DolHaus]

Idk when you are going to lean an outside wheel on it's inside edge, but sure. I am too tired tonigjt for to keep going and I would be rhetorical, anyways. That picture was made by someone in Microsoft paint. Idk why you are talking about said arc. You've been reading the ice cream cone horse crap examples. Look at a car with negative camber. No picture the car sitting on said ice cream cones. Your example works for a vehicle with one turning wheel. You don't lean a car on inside edges of their tires. You do on a bike and that is why the ice cream cone example exist. When you go around a turn on a car, the car is leaning away from the turn. If you had a car with active suspension, sure, your example would work. The center axis of the wider end of the cone would be attached to the vehicle. Lean into a turn and onto the inside edge of the tire and your right. Idk why you are talking about inside edges on car when your leaning on the outside...which is why the outside of tires roll. Put a cone on a table and let it roll. It will spin in circles away from the center axis of the outside of the cone. The end that would be attached to the hub. On a motorcycle, that is what you want. That is why you will find the cone example on a lot of motorcycle forums and such. The cone rolls away from the vehicle when it is leaned on. Which would pull a motorcycle into a turn and pull a car out of it. You are picturing things in reverse. Camber provides a more stable patch of rubber for the ground when a suspension system compresses and the vehicle leans on said patch. X amount of camber with zero toe does not make the car want to do what x amount of toe and zero camber or whatever amount of camber and toe would. There is no shared effect or outcome. Camber on a car with zero toe makes the outside wheel toe out around a turn and when that happens, the car doesn't not want to follow the inside wheel...because there is little weight on it in comparison to the outside. Idk how you figure camber with zero toe and the arc in relation, when the outside tire is toeing out and the inner is toeing in. It toes in, because the tie rod angle is increasing. The outside wheel toes out, because the tie rod angle is decreasing. You can use whatever camber you want with zero toe. You're still going to get toe out. No amount of negative camber angle is going to remedy the toe out that occurs, because of it's presence. I am speechless.

/rhetoric that I said I wouldn't get into.

Take it or leave it man, I'm done talking to you.

 

[332i]

Take it or leave it man, I'm done talking to you.

It's ok. I figured that would be your response. You don't agree with many of my posts anyways and I don't talk about something unless I actually know what I am talking about. I thought you would have learned that by now, after a few instances of me correcting you or you correcting me..only to be wrong. You went off and found something that doesn't really help your case lol. Your link is about how to achieve proper camber, thrust, etc., but it says nothing about toe or arcs and their relationship with camber. Last time I ever dispute one of your posts. Worry not. I legitimately explain things and how they are as such. You regurgitate concepts and tid bits of theory. Incorrectly sometimes, too. Start on chapter two? Ha, ok. Yes, link us to something that you should have read before you posted it.

 

[DolHaus]

It's ok. I figured that would be your response. You don't agree with many of my posts anyways and I don't talk about something unless I actually know what I am talking about. You we t off and found something that doesn't really help your case lol. Your link is about how to achieve proper camber, thrust, etc., but it says nothing about toe or arcs and their relationship with camber.

Its tricky to find a mathematical principal at short notice so I simply provided the most comprehensive reference I could find in the mean time.

Come and enter the latest FITT contest as a tuner, come and show me how good you really are.

 

[Robbks]

If this is the "cone" model (tyres shown are LH tyres)
http://goldwingdocs.com/forum/download/file.php?id=8506&mode=view
the cone works as @332i has said the tyre will try and toe out further the more -ve camber you use

the point is towards teh outdise edge

 

[DolHaus]

If this is the "cone" model (tyres shown are LH tyres)
http://goldwingdocs.com/forum/download/file.php?id=8506&mode=view
the cone works as @332i has said the tyre will try and toe out further the more -ve camber you use

the point is towards teh outdise edge

Please explain how those images show that?

All they show me is the change of shape in contact patch which is not the issue in question, my point concerns the effect of putting more weight on one side of the wheel and the resultant deformation to the shape of the tyre when viewed from the front/rear.
When one edge of the tyre is compressed the other side expands slightly to maintain constant tyre pressure, this results in the inside edge of the contact patch being vertically narrower than the outside edge. This in turn results in a wheel that does not want to travel in a straight line but more of an inward arc as illustrated previously.

 

[332i]

Dude. It is okay to be wrong sometimes. Obviously you want to stick to your britches, but it gets silly at a point.

Its tricky to find a mathematical principal at short notice so I simply provided the most comprehensive reference I could find in the mean time.

Come and enter the latest FITT contest as a tuner, come and show me how good you really are.

I'm all set with the FITT challenges and I couldn't give a damn as to what you think about my "skill" or to show you how "good" I am lololol. How old are you?? I get it. You're a "tuner" and you have something to prove. You want to show how great your tunes are, after all. Just because you do, does not mean other people want or feel like they need to.

I'll show anyone what I can do with my own, if they want to challenge me like you are, but I'm not down with the subjectiveness of other people using and reviewing it. Call it what you may, but that is how I feel about it. I have nothing against the FITT challenges, I just don't want to involve myself in them and I don't like being ridiculed. I don't do too shabby in the seasonals I have enough interest in to enter and I think that speaks fairly well for my tunes. Another reason I don't give them out is because I compete online with very good drivers. It is not to be a dick or out of avoidance. It is because there are drivers that are better and a better tune on my end may be the only chance I have. It is just a game, but I'm not interested in losing because I told people how I set all my cars up, essentially.

I take the same approach with all my tunes and do not want to give much away. I have no problem saying that x works the best in this or that window and many other things that I contribute with on here. My tunes are also sculpted around a 450 degree lock, trail braking, an inch and a half brake pedal travel, etc. I've run all sorts of great tunes, be them my own or someone else's on other wheels and the cars felt like trash on other locks. I've had buddies use my tunes and they were undriveable for them. Between the way I drive, my wheel and pedals. Differences of up to five seconds per lap. I had a friend use my tune for the lotus seasonal and he didn't like it too much. I was at his house last night, drive my setup on his wheel and pedals. I told him no kidding he struggles and that he should start learning to set the cars up and stop adopting my driving style, because you can't absorb or replicate someone else's driving style/patterns in entirety. Even small amounts. You can steal techniques and that is it. My tunes feel like garbage on his lock degree. Idk what the spec is.

I tune cars to compete and go for wins or to place well in seqsonals. I don't spend time setting cars up to show my "skill" as a tuner to other people. I have no interest in impressing or showing how good I am at something to other people. I take cars I race online competetively and break them down to a science as best I can. That is not how I do things. I just want to win for myself when it comes to racing. IDC if it is a sim or real life. Maybe that is good, maybe it is bad. I don't care.

If you want to go toe to toe against each other online, I'm all for that, though. By the way, I don't know these things from tuning gt games or reading internet articles or five pages of an internet book. I've been racing since I was eight years old and have taken a physics class or two. Cough.

 

[332i]

Please explain how those images show that?

All they show me is the change of shape in contact patch which is not the issue in question, my point concerns the effect of putting more weight on one side of the wheel and the resultant deformation to the shape of the tyre when viewed from the front/rear.
When one edge of the tyre is compressed the other side expands slightly to maintain constant tyre pressure, this results in the inside edge of the contact patch being vertically narrower than the outside edge. This in turn results in a wheel that does not want to travel in a straight line but more of an inward arc as illustrated previously.

The images don't, that is the problem. They don't make sense.

 

[Robbks]

The mass comes in the form of the cars weight and the resulting deformation on the tyres profile which shapes it sort of like a cone so it is marginaly thinner on the inside edge.

Ahh, ok i see what you're getting at.
add weight to the inside of the tyre, makes the VERTICAL profile smaller
I see your theory, but that would only hold try if the entire inner circumference of the tyre were smaller than the outside. The tyre still maintains it's original diameter, just in a differtent shape

The extra pressure increases the horizontal (fore-aft) contact area at that point also.
your tyre will not roll inwards towards it.

Regardless,
Any of these such effects are affected by much larger forces at play.
Thrust, from the driveshaft if it's a driven wheel
Rolling resistance from the road and braking forces
Aswell as weight transferr when turning which has a far more effect on tyre deformation

 

[Ridox2JZGTE]

Has anyone thought about the jacking effect ( ride height increase due to lean on one side ) when going around a corner ? Some of the wheels will gain positive camber and the toe might also change ( bump steer ) ? In static, some of the theories here might apply, but when a 4 wheel vehicle is moving, there's always changing load applied on all 4 wheesl, rear squat when accelerating, front dives when braking, side front and rear will lean and compress when in mid corner, while the inside will rise and going to positive camber direction as well toe changes ( depend on suspension geometry - swing axle is the worst )

 

[Robbks]

Pretty sure similar effects rated a mention earlier,
hence whey toe-in will cause a slower turn-in as the inside wheel is pointing the wrong direction.
But when the weight shifts to the outside wheel, it's pointing sharper into the corner.

At mid-corner your inside front may aswell not exist, it's un-laden. which is lucky as it's pointing in all the wrong directions
As you get on the power, the outside rear is doing all the heavy work until you straighten.

 

[Ridox2JZGTE]

@Ridox2JZGTE
Can you post a replica tune on The F430 Scud based on your info.
I have a decent tune on that now and is a very easy car to drive fast. I'd love to compare it to the RL Replica values.
EDIT: found it..
https://www.gtplanet.net/forum/thre...otabb-hondaaccord.294814/page-39#post-9746666

And the base for my current F430 (i tweaked the spring rates a little)
https://www.gtplanet.net/forum/tunes/ferrari-430-scuderia-07.499/

I do realise the effects of rolling resistance on toe (really only a factory due to compliance in suspension bushings, etc), but do we actually think PD have modelled dynamic toe..?
I doubt it, their toe angle is probably just +/- steering angle for each given wheel.
Also note that any driven axle will toe in under power

I don;t believe the permanent toe-in theory, it's all due to weight shift, dynamic camber and the effect that toe will have.
With camber set properly, as the car loads the outside tire mid-corner, the tyre is again flat on the road, giving maximum contact patch, having toe in at this point is essentially the same as turning the wheel harder,
but as you straighten up, you lose the contact patch that -ve camber camber has given you,
weight starts to transferr back to the inside wheel which also has -ve camber and still less contact patch size, but it's also got toe-in, but in the wrong direction, and you get understeer on exit as you've just lost a lot of grip.

this is where the rear comes into play,
A little "static" toe out down back will be overcome by driving forces, so now under acceleration your loaded outside rear wheel has toe-in, driving you in the direction you want to go, the inside wheel which isn't loaded as much (depending on LSD settings) may still have some toe-out from both the static alignment and the rolling forces. Either way, it's helping to get you through the corner exit.

As @332i has pointed out that little bit of toe out down back will help the car rotate when you're off the power on corner entry, but because the rear end kicking outwards on corner entry does "feel" like the rear end has let go, differentiating it from actual oversteer can be hard and lead to losing the rear end very quickly if it snaps

Looks like you found it Mmm, the race tune you linked has very close value in ride height and spring rate ratio to my AFCON springs F430 Scud replica
But it has altered the weight distribution, lower lock LSD and half the rear toe in to make it easier to handle

If you are interested, the NSX NA1 ( early years model ) also suffers the same issue in real life, HONDA factory alignment have 1.5 rear camber and 6mm toe in to make the rear more stable - early year models have higher stock rear spring rate than front. The rear spring rate was reduced on later year models ( from late '93 on NSX R - lower rear than front and '95 on basic NSX which has slightly higher rear spring at about 0.5-0.6kg/mm higher, except NSX Type S/Zanardi/ S Zero has lower rear spring than front similar to NSX R), thus less rear toe in was used from factory - 3mm toe in from '93 model year, the complaints from NSX owners about their rear tire wearing out quickly helps too.

Honda NSX Type R '92 ( Real World Setup version )
Ayrton Senna Tribute
Special Build with Real World Alignment Honda NSX Type R '92
Comfort Soft to Sports Medium​

View attachment 151525

​

CAR : Honda NSX Type R '92
Tire : Comfort Soft to Sports Medium

Specs
Horsepower:284 HP at 7000 RPM
Torque: 225.6 ft-lb at 5500 RPM
Power Limiter at : 100%
Weight: 1230 kg
Ballast : 136 kg
Ballast Position : 39
Weight Distribution : 42 / 58 as in real life
Performance Points: 463

GT AUTO
NO Oil change
Wheels : Stock
Car Paint : Milano Red


Tuning Parts Installed :
Suspension Fully Customizable Kit
Adjustable LSD
Weight Reduction Stage 2



Suspension - BC Racing Coilover Kit Lowered with Real World Alignment and Damper Setup
Front, Rear

Ride Height: 95 95
Spring Rate: 10.00 8.00
Dampers (Compression): 5 4
Dampers (Extension): 6 4
Anti-Roll Bars: 3 2
Camber Angle: 0.3 1.5 ( front camber range 0.3+-0.5, rear camber range 1.5+-0.5 )
Toe Angle: -0.30 0.49 ( front toe out 3.5mm+-1mm, rear toe in 6mm+-1mm )


LSD -Honda Torque Control Differential with factory preload
Initial Torque : 30
Acceleration Sensitivity: 30
Braking Sensitivity: 15

View attachment 151741​

Brake Balance:
6/5 ( personal BB) or for ABS 0 wheel : 6/5, for ABS 1 6/5 or feel free to use your preferred brake balance.

Recommended setting for DS3 user :
Steering sensitivity at +1 or +2, all aids off, except ABS 1 ( if not comfortable with ABS 0 ) with 6/5 brake balance as starting point.


Notes :
I made this special tune to commemorate Ayrton Senna
This time, the car is Honda NSX Type R '92, the 1st generation of Type R Honda

The car setup is not your typical GT6 tune, I used real world setup alignment, similar to some of my older replica like ADVOX Supra

Suspension has been changed with BC Racing Coilover, 10/8 springs and a well tuned damper for road and track complement the springs. The ARB, Toe and Camber are all based on real life setup of a stock Honda NSX Type R.

Most people do not know that later generation NSX has lower spring rate at the rear to give more grip and less oversteer. Most coilover kits uses the same arrangement, while KW V3 uses same spring rate. Obviously the real world spring rate works great in GT6.

Real life specs : front camber range 0.3+-0.5, rear camber range 1.5+-0.5; and front toe out 3.5mm+-1mm, rear toe in 6mm+-1mm.

The LSD has been updated using real world setup, Honda Torque Control Differential has high preload.

The weight distribution on the NSX is wrong in GT6, real life NSX has 42/58, so to achieve that, I used some ballast and weight reduction.

Don't expect this car to be quick, it's meant to be a what if the car has real world stock setup in GT6, something that never existed in GT6

To drive the NSX, you will need some real world driving approach, steer like you would in a real car, brake and gas like you would in your own car on the road

I tuned and tested the car at Ascari, Bathurst, Spa and Tsukuba.

It posted flat 1:06 at Tsukuba on a warm up lap using comfort soft

The car is a joy to drive, feels like what a real stock NSX would drive It made GT6 Honda NSX more sim like, well almost like on PC

UPDATE : New BC Racing Coilover kit and updated LSD to replicate real life setup.

ENJOY

View attachment 151749 ​

 

[Stotty]

This thread just keeps on giving

I think you're massively overcomplicating GT suspension... if the physics engine can't model something as basic as rake correctly, do you really believe it models the much more complex real life effects you're discussing?

Assuming GT is replicating real life will IMO, lead you down the garden path.

 

[Ridox2JZGTE]

I'm okay with what I have All of my cars are doing fine with the current state of physics and I don't tune like most tuners here. My next FITT HOT Version Drivetrain Challenge have a FF car with real life distribution ( more than 60% front ), real life rake ( lower front ), alignment ( big camber up front ), high lock LSD ( 20 plate disc with 45 cam angle 1.5 way and medium preload/initial torque - 8 to 15+kgf.m) and springs ( 10+kg/mm - stiff just like most FF cars for track racing ), and it drives quite well in terms of fun factor, won't be TT winner though. Most TT cars make the most of the options available and take advantage of physics engine ( lower rear or higher rear to easily cure under or over, ballast to change distribution for best handling, close to open diff LSD for easier throttle use, massive toe values on unstable cars, funky dampers ) At least I stick to something and aim for realistic driving

 

[Robbks]

I'm with you.
Realistic settings and rates.
Tight LSDs. I hate all the loose LSDs makes the car too snappy when it starts to slide.
Maybe a front lip as a aero upgrade.
Add a heap of power, give it hell and hang on...

 

[MrGrado]

Some testing of camber for anyone interested.



Start watching from about 14:00 if you like.

Also:



Car is Mazda Eunos roadster Race Car

498PP
Tyres: RH RH
Suspension:
90 90
11.15 11.15
6 6
6 6
4 4
3.9 3.1 (0 0)
0 0
5 5
Transmission:
2.900
2.054
1.682
1.369
1.170
3.430
Drive train:
5 25 15
Carbon shaft
Engine:
100%
Engine tune stage 3
supercharger
Body:
200 500
40kg@50

Note:
Running camber at Apricot hill, use 1.0 0.6.

Ideal camber values will vary with tyre, tune, surface grip, track layout, etc.

 

[CyKosis1973]

I have nothing against the FITT challenges, I just don't want to involve myself in them and I don't like being ridiculed.

That's not what these events are about. Nobody is ridiculed ... ever. These events are about sharing within the tuning community and the wider GTP community. You don't need to be involved with them, but please don't infer that people are ridiculed for or whilst taking part. Thank you...

{Cy}