1.09 update physics changes....

  • Thread starter feydrautha
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I applaud everyone's efforts on camber. It is a very good thing to have multiple tuners from different backgrounds and driving style working to understand the new physics. So please, no one take the question below personally. I am not trying to attack. I am not trying to prove my theory (well, because I am still trying to formulate one). I am not trying to say that there is only one answer here.

But, I do have a question for the tuning community. Why is it that in every post that supports that camber is now fixed, works like real world, that there is always a qualifying statement right after? Camber works, IF you get the other settings right. Why can't camber just work? Is it possible to take a car with default suspension settings and only change camber and see a result? Are we able to isolate camber and define an effect? This is what I want to test next.

Thoughts?
I have been doing a ton of research into Camber Theory in order to update my guide and its complicated to say the very least. The idea of camber improving traction is a difficult one to prove in reality because that is not how it works. It doesn't improve the grip of a tyre but instead improves the way the existing grip is utilised to deal with either lateral or linear forces.
Gains are always going to vary from track to track and car to car due to the way it uses active suspension geometry and many other constantly changing variables to determine the shape of the contact patch of a tyre at any given moment. Its tricky to determine any patterns to how you should be adjusting your tunes to fit as there are a lot of potential variables.
 
The problem I see with that is some tuners being so stubborn and false confident, that they'll put junk camber tunes out, making it look like people have tougher time handling or can't turn better laps on the provided setup. Just some tuners I chalk into said "convinced that camber doesn't work" stubborn category. I'm not generalizing or grouping all of them.

These challenges go by tuners providing a given setup and testers go out an run, then they collaborate, right? I've not look into FITT much.
Kind of, tuners are given guidelines/rules and build the best tune they can. FITT tuners would not "sandbag" the results. I would think they would pick one side, i.e.; camber o.o, and try to build a tune that is faster than one that uses camber. If you have time, check out the latest challenge - Evo vs STI!
 
I have been doing a ton of research into Camber Theory in order to update my guide and its complicated to say the very least. The idea of camber improving traction is a difficult one to prove in reality because that is not how it works. It doesn't improve the grip of a tyre but instead improves the way the existing grip is utilised to deal with either lateral or linear forces.
Gains are always going to vary from track to track and car to car due to the way it uses active suspension geometry and many other constantly changing variables to determine the shape of the contact patch of a tyre at any given moment. Its tricky to determine any patterns to how you should be adjusting your tunes to fit as there are a lot of potential variables.

Well that is where I am stuck. If the affects of camber cannot be proven and described, then how do we update our tuning guides to be anything meaningful?
 
Dude, you need to calm down. I did not say anything you lacking knowledge pertaining to real world tuning. I'm not in dangerous territory and that is a ridiculous thing to put on someone on a forum. Cool your jets. I've read your threads and many of your posts. I didn't point you out now did I criticize YOU. Or anyone specifically for that matter.

That is my opinion on some tuners approaches and thoughts at the moment. I wasn't nasty, mean, etc. Nothing wrong with an opinion on peoples' approaches to things we are trying to test.
 
Dude, you need to calm down. I did not say anything you lacking knowledge pertaining to real world tuning. I'm not in dangerous territory and that is a ridiculous thing to put on someone on a forum. Cool your jets. I've read your threads and many of your posts.

You are calling me out for my tone. I'm sorry, but I was getting a real sense of arrogance from your posts. You need to calm it down and not imply that half of the other tuners on GTP are going to post false results to throw people off the scent. The tuning community on GTP seem to collaborate really well and try to work together.

Maybe I took your posts wrong. It felt to me that you were positioning your results as the rule and that half of the community is just lost and useless.
 
Ok.

Telling me I'm in dangerous territory, because you think I haven't "read up on who you are", isn't arrogant at all, though. I forgot I'm just peon. I wasn't being arrogant. If you read it as that, I don't know what to tell you. Just an opinion and observation.
 
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Ok.

Telling me I'm in dangerous territory, because you think I haven't "read up on who you are", isn't arrogant at all, though. I forgot I'm just peon. I wasn't being arrogant. If you read it as that, I don't know what to tell you. Just an opinion and observation.

Not a peon. Just someone with less than 20 posts in the tuning forum. You may be a fantastic tuner, but I just haven't seen enough tunes posted that would make me think it is ok to call out half the tuners on the site.

So we each know what we think of each other. We can be friends now?
 
Well that is where I am stuck. If the affects of camber cannot be proven and described, then how do we update our tuning guides to be anything meaningful?
I am in a similar situation really, my guide is based on simplified principals (ie. do this = this happens) but camber doesn't work like that unfortunately so its going to be hard to describe without going into all the complicated physics.
I will send you a link once I'm done updating (tomorrow most likely) so you can take a look and see if a similar approach will work for your guide. I'm also writing up a more in depth version that will explain all the ins and outs which I'd love to hear your thoughts on once finished.

As far as updating tunes goes, there is no rule that says camber is better than 0.0 in all situations so I'm not going to go back through and retune all of them.
 
@DolHaus Is there a car that you are working with now? Maybe PM the specs to me or post them here. I would be happy to run some tests in the same arena that you are.
 
Why can't camber just work? Is it possible to take a car with default suspension settings and only change camber and see a result? Are we able to isolate camber and define an effect? This is what I want to test next.

Thoughts?
I think you are right, we should be able to make an adjustment and see if the camber is hurting or not. Of course it all can be dependent on other geometry to see massive gains, but we should see a small gain/loss here or there. Your tuning guide and description of camber for GT5 is and will be a permanent addition to my notes. It works, end of! My problem with GT6 is trusting any sort of numbers involved in lap/ghost times, not having proper testing methods, or tools, like tire temp, to aid us in these decisions. I strongly feel like it is going to be mostly on feel, and that is why I vote for this as the next FITT challenge. With those of us involved in the events offering non-bias detailed reviews of cars that are setup by tuners from all ends of the spectrum, and with all of the cooperation of everyone, I'm confident there would be some issues resolved.

And if anyone would care to prove their theories, why not ask to enter your car(s) in the next FITT challenge and settle it on the track? As long as you get permission, abide by all of the rules set by the FITT admin, and respect everyone involved, I'd say give it a go.
 
@DolHaus Is there a car that you are working with now? Maybe PM the specs to me or post them here. I would be happy to run some tests in the same arena that you are.
I've been quite busy lately so the only car I have been working on since the update is my BTCC-8 car, its hard to gauge whether the performance has improved due to the RWD nerfing but camber has definitely improved the stability and usability of it.
 
edit: GTP had it's crash as i posted earlier :(

I found the way i tuned my cars (much like i would if I was applying it to RL) i have had to do minimal tweaking of any of my setups which is a god send. Throwing on camber, i find i usually only adjust rear springs/sway bar settings to fix things.

Agreed because now the tires to be more on the track then before...I notice that too..
 
I still have not heard much in the way of advice for tuning in GT6. This is all fine for a discussion about how things work in real life.

Where should people start and what should they expect at different settings?

With 1.0 front camber how much toe out is needed?
With 1.5 front camber how much toe out is needed and how does corner speed differ from 1.0?
With 2.0... Etc.
 
500+PP on comfort soft would be great for camber tests, comfort tires were more sensitive to camber changes back in 1.08 when it was broken. Don't use cars that has better chassis grip/handling. I would suggest a car that has natural tendency to understeer due to its weight balance, and FR. Aston Martin V8 Vantage '99 is a great candidate, tunes for this car is very rare :) Leave weight and distribution stock, no ballast, stock power, just suspension, stock LSD ( to remove variables - camber could make better use of high preload and lock LSD )
 
500+PP on comfort soft would be great for camber tests, comfort tires were more sensitive to camber changes back in 1.08 when it was broken. Don't use cars that has better chassis grip/handling. I would suggest a car that has natural tendency to understeer due to its weight balance, and FR. Aston Martin V8 Vantage '99 is a great candidate, tunes for this car is very rare :) Leave weight and distribution stock, no ballast, stock power, just suspension, stock LSD ( to remove variables - camber could make better use of high preload and lock LSD )
I disagree with your view on the LSD
If I was to add camber to my rear wheels then I have effectively made the rear track wider. A wider rear track changes the rotation speed of the inside and outside wheels and therefore it would be like having the Initial a click higher which could induce understeer
 
I disagree with your view on the LSD
If I was to add camber to my rear wheels then I have effectively made the rear track wider. A wider rear track changes the rotation speed of the inside and outside wheels and therefore it would be like having the Initial a click higher which could induce understeer

You may be right, but I drive without ABS and tend to tune the brake balance to give neutral entry under braking, maybe I got used to high lock LSD which I prefer as it's closer to how real life aftermarket plate type LSD would be setup. Even stock F40 IRL has 60% lock diff, and most Japanese aftermarket LSD has high lock preset when bought, even more so when you have high number of clutch discs - especially Tomei, Kaaz, ATS and OS Giken.

If you want to know how aggressive LSD would drive with high camber, try my RJN 370Z GT4 replica, it's built specifically for SS tire, but @cbarbosa has driven it on SH and enjoyed it :)
 
You may be right, but I drive without ABS and tend to tune the brake balance to give neutral entry under braking, maybe I got used to high lock LSD which I prefer as it's closer to how real life aftermarket plate type LSD would be setup. Even stock F40 IRL has 60% lock diff, and most Japanese aftermarket LSD has high lock preset when bought, even more so when you have high number of clutch discs - especially Tomei, Kaaz, ATS and OS Giken.

If you want to know how aggressive LSD would drive with high camber, try my RJN 370Z GT4 replica, it's built specifically for SS tire, but @cbarbosa has driven it on SH and enjoyed it :)
Remember the aim of this test is to find out the potential differences in performance and observe different tuning techniques, the end result doesn't have to be balanced because we are intentionally looking for difference. If we limit the tuning to exclude transmission, power/weight upgrades and aero then any differences will be purely down to the suspension and LSD setup.
 
Remember the aim of this test is to find out the potential differences in performance and observe different tuning techniques, the end result doesn't have to be balanced because we are intentionally looking for difference. If we limit the tuning to exclude transmission, power/weight upgrades and aero then any differences will be purely down to the suspension and LSD setup.

Wouldn't it be better to leave the LSD stock then ? The stock LSD on the Aston Martin V8 Vantage for example is closer to open diff, much like most tunes here which have low initial, accel and brake value :)
 
I am still skeptical that any challenge will help to solve anything. It is really convenient to say that camber is tied to other settings. I am just not satisfied with the answers of well it depends. Camber does something or it does not. We should be able to test that.

Maybe the magic is in the tuning order? Should each tuner build the same car two times. First build one that starts from zero camber. Second build one that starts with default camber. Would the same tuner end up with different tunes. If not, then camber is reliant on other settings. If so, then camber simple does what camber does.
 
Wouldn't it be better to leave the LSD stock then ? The stock LSD on the Aston Martin V8 Vantage for example is closer to open diff, much like most tunes here which have low initial, accel and brake value :)
No, it could more influential on either one and we wouldn't be able to determine which.

I am still skeptical that any challenge will help to solve anything. It is really convenient to say that camber is tied to other settings. I am just not satisfied with the answers of well it depends. Camber does something or it does not. We should be able to test that.

Maybe the magic is in the tuning order? Should each tuner build the same car two times. First build one that starts from zero camber. Second build one that starts with default camber. Would the same tuner end up with different tunes. If not, then camber is reliant on other settings. If so, then camber simple does what camber does.
What do you think camber should be doing? This isn't a jab or anything, I'm sure we all have our thoughts on what it should do based on gaming and real life experience, I just want to hear what you think camber should be doing
 
What do you think camber should be doing?

This is what camber should do if programmed like real life. GT5 was closer than GT6.

8464261164_7d63e3a3ff_z.jpg



Here is the link and the results from a test that I did in GT5. Camber showed little gain, and was not all that important for lap time tuning. https://www.gtplanet.net/forum/threads/camber-testing-by-motor-city-hamilton.244798/

6910496999_059da1bd0e.jpg

So maybe they did fix camber in GT6. They made it just as weak and useless as in GT5.
 
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This is what camber should do if programmed like real life. GT5 was closer than GT6.

8464261164_7d63e3a3ff_z.jpg



Here is the link and the results from a test that I did in GT5. Camber showed little gain, and was not all that important for lap time tuning. https://www.gtplanet.net/forum/threads/camber-testing-by-motor-city-hamilton.244798/

6910496999_059da1bd0e.jpg
What does camber do to a tyre and what effect would this have on performance?

I can sort of see what the top graph is trying to show but I'm not seeing a data source so I don't know what I'm comparing it to?
I can't really take data from GT5 as comparison, there are too many differences in the physics modelling to be comparable. Its sort of like comparing an apple to an orange, they're both fruit and they both come from a tree but they're not the same thing.
 
What does camber do to a tyre and what effect would this have on performance?

I can sort of see what the top graph is trying to show but I'm not seeing a data source so I don't know what I'm comparing it to?
I can't really take data from GT5 as comparison, there are too many differences in the physics modelling to be comparable. Its sort of like comparing an apple to an orange, they're both fruit and they both come from a tree but they're not the same thing.

I plan to do the same test in GT6. Someone has to be able to simplify camber. Right?
 
Back before camber was fixed, I always set the LSD 1st then camber at 0.2 or 0.3 when tuning, I intentionally reduce the grip slightly and give the grip loss more progression so I can tune the rest of suspension more aggressively. If I was building a replica with real life alignment, then I set the toe and camber first, then build the rest to accommodate that. More often I set the springs initially using real life coilover kits recommended rates, also taken into consideration any unique traits like wheelbase, motion ratio/wheel rate and preferred setup for track use or Auto X. Hakosuka for example, most owner IRL would set the rear springs a lot stiffer than the front - usually close to double the value of the front rate, as the car has tendency to hit the bump stop easily at the rear due to low motion ratio + wheel rate and requires quite a lot of travel - high ride height + stiff springs. This approach also works in GT6 - I built a Hakosuka grip/drift replica with similar setup.

With camber working, I may set the springs first with soft dampers and ARB, neutral toes and zero camber. Then the lengthy process of testing and tweaking, usually I will also tune the LSD to complement the springs, find a balance that I like or I wanted to aim ( replica ) when camber and toe still zero. Once I got the springs and LSD spot on, then on to dampers for entry grip and traction on exit, I may still tweak the LSD, but usually only change the initial slightly. I almost never touch the springs and LSD again, unless the car is a bad boy :lol:

When dampers are done, I get nice entry and exit traction, then I fine tune the balance further with ARB, with camber working, lower ARB should work better than before ( more effective ) I usually set the ARB to maintain stability in mid corner while giving good steering response. By this time, one click of ARB change can ruin the car balance or improve it :D

Last are camber and toe, toe mainly used to stabilize the car under heavy trail braking ( rear toe in ) and better steering ( front toe - neutral, in or out, depend on the car drivetrain, weight balance and purpose - race with tire wear or not ) For camber, I used it to polish the car overall handling and not to improve lap time like it was in pre 1.09 when zero was the quickest/highest possible lateral grip and I can use high camber to make the car a lot slower around corners due to the lack of lateral grip :lol:. I increase front or rear or both to smooth things out depend on the tires used, how stiff the springs are set, weight and distribution, drivetrain layout, amount of roll and how the car behaved on the limit ( twitchy, sharp steering, or lazy to change direction/heavy cars ).

I used mainly real world track for testing, Bathurst, Silverstone GP, Brands Hatch GP, Tsukuba, Willow Springs, Fuji Speedway F, Nordschleife and Suzuka. About 300-400+km are usually spent for testing and fine tuning on each car. I have logged close to 50,000km distance, over 9000km at Tsukuba, over 5000km at Bathurst, and at least over a thousand at Silverstone GP and Brands Hatch GP.

:lol: I talked too much.
 
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What I have found

on the exact same set-up, 0 toe angle, adding camber helps lap times and grip with a bias towards the heavy end of the car.

As toe angle increases, either +/-, you can incrementally increase camber.

I haven't found a mathematical relationship yet.
 
I plan to do the same test in GT6. Someone has to be able to simplify camber. Right?

Each tyre has a fixed amount of traction at any moment, this is determined by the contact patch and tyre style/compound.
The area of the contact patch is defined by this sum - Load/Tyre PSI = Contact patch area
This contact patch at 0.0 forms an ellipse shape that is wider than it is long (handles lateral force better/handles linear force worse)
At 5.0 the tyre is leaning on its inside edge which forces the contact patch into an ellipse that is longer than it is wide. (handles linear force better/handles lateral force worse)
Both of the contact patches have the same surface area and therefore traction but are more focussed to handling particular stresses.
Ideally you want the long/thin one for straight lines and the short/wide one for cornering.
We set our static camber in the garage but we must also be aware of active camber induced by suspension compression/extension. We gain more negative camber under compression so if your suspension is not are not properly setup for camber then you may be gaining too much or too little camber during cornering and presenting the wrong kind of contact patch for the situation.

This is why it depends on many variables in my opinion
 
I did a brief unpublished test on camber the other day. Where I ran 5 laps with camber, 5 laps without camber 3 times(I think?) and only ever matched the ghost with the camber added. The car was Lancia Delta Integrale `91 and the track was Streets Of Willow.
I have done a more scientific test today..........

Track : Streets of Willow. Lots of changes of direction and mix of corners. Plus I`ve done a lot of laps there recently.

Car :
Lancia Delta Integrale Evoluzione `91. Front heavy and badly needs more front end grip.

Stats :
473pp 319bhp 1105kg Sports Hard Tyres

Stock parts except for :
-FC Suspension stock except for zero toe front and rear.
-5 speed fixed trans.
-Custom LSD at 5/15/5 front and rear to eliminate the inside front wheel spin of the stock LSD. And because it now spins the outside wheel, if camber gives more grip this wheel should spin less as camber reaches its optimum.
-Stage 3 engine tuning
-Sports computer
- Racing exhaust
-Isometric exhaust manifold
-Sports cat
These gave enough power to warrant sports tyres
-Stage 3 weight reduction, carbon bonnet and window weight reduction. Lightening the car made it a bit less prone to understeer and hopefully make any benifits of camber more obvious. Also makes the standard springs act stiffer, again to help warrant the sports tyres.

I did a 5 lap warm up before the start of the test session.
Each test was 10 laps with DFGT
Grip set to real
ABS 1 only

Test 1 - Zero Camber

Best Laptime - 1:21.552

Car understeers on entry, is stable through mid corner and understeers on exit. Rear feels like its pushing the front wide. Lots of wheelspin on the outside front on corner exit, loads of black lines on the track! Brakes feel a bit soft.I wish I`d beefed up the brakes a bit! Oh well, I`ve started now!

Test 2 - 0.5 Front Camber Only

Best Laptime - 1:21.125

Felt better in the corners, not much but better. Rear end still too planted. Found it harder to be consistant. I think the brakes are struggling with the camber. I Felt like outside front wheelspin was less, but still lots of rubber on the track.

Test 3 - 1.0 Front Camber Only

Best Laptime - 1:21.281

Much less understeer. Back end now feels a bit looser, its really helped the balance. I can carry more speed through the corners. Only thing is now the brakes feel very soft. Less outside front wheelspin, definitely less rubber on the track.

Test 4 - 1.0 Front Camber Only and 7/5 Brake Balance

Best Laptime : 1:20.920

Brakes feel as they did before camber. Now goes as fast as it feels.

Test 5 - 1.5 Front Camber Only 7/5 Brake Balance

Best Laptime : 1:21.082

Rear end now doesn`t feel so loose. Understeer not noticeably worse, but a definite change in balance. I get the feeling i`ve gone past optimum front camber for this setup.

CRUNCH TIME!

Test 6 - Zero Camber 5/5 Brake balance

Best Laptime - 1:21.430

Going back to Test 1 setup to make sure that any improvement in lap times wasn`t just me getting better at the track. Only a slight improvement. Probably to be expected.

In conclusion. It is as I experienced in my previous test. A small amount of camber on the front of this car gave enough front end grip to improve lap times.
 
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Maybe I'm looking at this too simply but it seems like we are over complicating this. We need to take a track with level turns that can be taken super consistently, like the twin motegi oval.

I would then take a mid weight to heavy cars for each drive train and adjust camber only and compare lap times. Start with zero and work up to 5 or so with 5 laps each setting.

The results could even be displayed like the graph posted earlier but it would be times instead of lateral grip.

Then perhaps do a version with 0/0 toe settings to check for more or less gains.

Then half the suspension and dampers, then double the suspension and dampers.

I'm sure we could come up with enough different single variables for everyone to try something and we could pool our results.

Then we would know the optimum camber range for soft and stiff setups, and neutral and aggressive toe settings, and hard and soft tires.

Am I thinking to simply ? It seems like this would eliminate the tuning variable and get all the data we are all looking for.
 
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