Blooze/Tonka WBT and 54.5%

[feuerdog]

I've been playing around with tuning theories again, and of course I took another look at what had been developed in the Kithchen Sink(s) and related spreadsheets.
The 54.5% Weight Bias Tuning value came up of course and has related meaning on how i'm working some of my possible new bias ideas.

I have a few questions for anyone that can help:

1. Do you guys still find that the success of the 54.5%  value holds true?
2. I remember mention of certain cars that did not work with this value, were there any trends in these rogue chassis?
3. ARB tuning; are you guys tending towards weight bias, a modified weight bias, or some other bias(rearward)?

I know it's been awhile(at least for me) since we worked with these calcs, but thanks for anything info you guys can provide.

[fndrbndr]

What were some of the trouble cars?

[Fit4aking]

If you mean as it relates to FM2 than yes they still hold true.  Most of my cars started out that way but after I found a value that worked more with my driving style I settled on 52.5% as my personal default.  Seeing as I haven't played the demo I can't speak intelligently about how or if it relates to the newest installment.  That is one of the things I am very curious to find out and can't wait to play with the second I have a car to tune.

There have been cars that are oddballs but I wasn't too fond of them anyway so I never spent time looking for trends. 

ARB tuning was always hit or miss with me.  I started with biasing them along with the rest of the suspension but they never seemed quite right.  Some minor tweeking was in order but always in relation to a specific ARB bias.  I seemed to like ARB's to be closer to 54 or 55% while the rest of the suspension stayed at 52%.  Perhaps it makes sense that a change in springs and dampers would effect the way a car reacts in all conditions while an ARB change tended to only effect the way a car reacts side to side.  Since they have different functions it should be no surprise that they need to be treated as a different entity but I still always started my cars at a generic 54.5% before fine tuning from there.

Hope it helps feuerdog, probably just jibberish at this point but I hope to make a larger contribution when the new version is accessible to my offline situation.

[feuerdog]

The established 54 ish% WBT works because it makes complete sense. It makes it possible to tune other parts like brake bias and diff settings in a way that the car is totally tuneable and easily driven to the limit.
I think the ARB effects fell within this balance, but may not have been in full agreement with the original chassis balance.
It was the "oddballs" I was particularly curious about, does anyone remember any specific ones?
I would assume the RR type cars (AWD Porsche 959, and 911s) did not fit the 54 ish% methods very well, and I suspect there may have been issues with cars light MR cars too.
These oddballs, whatever they are, are the key to proving my theory.


A part of my new tuning balance theory has alot to do with the purpose of ARBs and how they affect the suspension balances in relation to steering in particular and task/workload distribution.
I've been trying to come up with values to determine how much work each end of the car is doing and then cross referencing that with whhat the chassis is trying to accomplish. Once I can get a feel for how the work is distributed, I can tweak for ease of control, and then find a common calc.

ARBs have been central to my latest thoughts because they both fix and exaserbate problems related to camber and control.

I've come to a simple realization that ARB bias needs to be a somewhat fixed ratio, but variable based on CoG, to the rear of a chassis.
The counter balance of that rear biased ARB is found in caster settings.

For example, i've been able to tune every one of my FM2 test cars with a fixed ARB bias ratio of 1/3 f/r. FF, FR, MR, FA, and even RR chassis have all been not only tunable with this fixed ratio of 1/3, but in some cases have shown an improvement in response and handling.
This rear biased ARB follows the merits of the 0/40 settings found in some leaderboard cars, but also ties in with some new info i've gotten from IRL SCCA drivers on ARB tuning.

This idea isn't anything fundamentally new, better, or terribly exciting, but it has got me excited for tuning experimentation in FM3.

[Blooze]

The 54.5 thing came out relatively early in the development of the process.  I think alot of the drive behind it was that my personal driving style was bent toward cars with a forward weight bias.  Over time, and an extended stint spent with R# cars, and yet another with Porsches, I started moving the weight back, tending more toward a balanced car.

At this time I am tuning most production type cars to a 50% Wb and an SWR somewhere between 70%-78%.  If I should decide that more roll stability is required, I do it with the SWR setting in the Tonka Tuner, which keeps the ARB, Springs, and Dampers in sync.  Adjustments for drive type are usually handled with the Damper Senario settings (I am sure there is a discussion concerning these somewhere in my garage.  These settings are found at J43:R47 on my most current Car Sheet).

The original intent of the whole process was the idea that all cars, Drive Type to Engine Position, could be made to handle the same, and, for my part, I think this was accomplished.

My first order of business will be to verify that the game still uses the spring settings to dictate Wb and that the values in the Tonka SWR calculations are unchanged or at least similar.  My suspicion after driving the Mini in the Demo was that these aspects of the physics engine will be unchanged. My thinking was that the car was in serious need of a 50/76 tune, with the brake bias moved to the rear by 4%.


$

[feuerdog]

OK, cool. That makes sense.

Like I said this is nothing new i'm workin with, it's just a different kind of knife for skinning the same old cat.

I'm not anticipating any significant tuning practice changes for FM3, but the feel should/could make fine tuning a bit easier/deeper. I think your SWR ratio may see a slight rework(stretch) too.

[Spiny Anteater]

...
For example, i've been able to tune every one of my FM2 test cars with a fixed ARB bias ratio of 1/3 f/r. FF, FR, MR, FA, and even RR chassis have all been not only tunable with this fixed ratio of 1/3, but in some cases have shown an improvement in response and handling.
This rear biased ARB follows the merits of the 0/40 settings found in some leaderboard cars, but also ties in with some new info i've gotten from IRL SCCA drivers on ARB tuning.

This idea isn't anything fundamentally new, better, or terribly exciting, but it has got me excited for tuning experimentation in FM3.

First of all, I have to admit that I tend to start with the default tune now rather than follow the calculator, then make adjustments according to what I feel needs adjusting from the feel of the car on a test run at Mugello Short or the specific track it's required for if I am doing a track specific build. I'm pleased to say that this is something I've learnt over the last two years, mainly from the guys on here but also from Shiny Side Up's guide over at .net from about 2 years ago. Nice to see that my education is continuing at home as well as at work

The reason I've quoted the above comment from FD is that I usually end up with approximately a 1F:3R ration on my ARB's too (for FWD and 4WD only, RWD is still about 1:1). And that does interest me that FD has found similar results since my obtaining of those figures is purely from testing - I'm pleased to see that there may be some basis in reality for those values after all.

Generally I find that my builds are tending towards the rearward bias, especially for the FWDs and 4WDs which are easier to keep hold of in an oversteer situation.

I can't really comment on the weight bias theory though, as that's not really how I've been tuning the last year or so.

[One more question, but to Blooze this time - I'm just wondering why you think the brake bias needs moving towards the rear in the MINI - to me it felt like it needed moving a point or two forwards as, even though the front wheels were locking up first, the car still seems to want to rotate up until the braking threshold. I'm guessing it's preference, but am just interested whether you're basing your braking balance on the lock up point.]

[feuerdog]

The 1/3 ratio is VERY rough, but it seems to work as a decent starting point.

The 1/1 ratio makes more sense for a powerful FR chassis too. Again, this is a work in progress, i'm still in the number crunching phase.


EDIT: Like my very good handling BMW 92, which has 1/1 ARBs matched to everything else in the suspension at 50/50.

[bimmerlovere39]

I've been running 3:2 F:R on my FR cars for a while now, as that tends towards what the real bar diameters are (I treat 1 Forza Unit for ARBs as 1mm in diameter)

[Blooze]

[One more question, but to Blooze this time - I'm just wondering why you think the brake bias needs moving towards the rear in the MINI - to me it felt like it needed moving a point or two forwards as, even though the front wheels were locking up first, the car still seems to want to rotate up until the braking threshold. I'm guessing it's preference, but am just interested whether you're basing your braking balance on the lock up point.]

This may be more of a habit for me brought on by the first Race Pro game...  Mostly, I just wanted to insure that the fronts didn't lock up.  I will spend more time on the setting this time around...

$

[fndrbndr]

Honestly, I usually left it at 47% and just didn't worry about it.  Then again, a different setting might allow for more trail braking, so maybe some fiddling is in order.

[barumba]

The 1/3 ratio is VERY rough, but it seems to work as a decent starting point.

The 1/1 ratio makes more sense for a powerful FR chassis too. Again, this is a work in progress, i'm still in the number crunching phase.


EDIT: Like my very good handling BMW 92, which has 1/1 ARBs matched to everything else in the suspension at 50/50.

I sorted my saved calc tunes by drive type and by weight distribution, noting the ratio for each type. There were a few anomolies, so I extracted them from the average, will comment on them seperately. I split FR into 3 averages, since my cars ranged from 50% to 58% weight balance.
Here is the list...

Drive   Weight %   FRT Ratio   RR Ratio                Anomolies
FA      59.00          1.00       1.07           Porsche 911 GT2 997 2008    1.00/1.22         
FF      61.29          1.02       1.00           Acura VIS Type-R 2000         1.00/1.03
FR      50.00          1.04       1.00           
FR      53.73          1.33       1.00
FR      56.90          1.53       1.00
MA      43.00          1.00       1.63
MR      43.00          1.00       1.11
RR      38.67          1.00       1.30           Porsche GT2 1995                1.15/1.00


I don't know what to make of all that, but at least, it shows me a trend where I can choose a starting point if I don't like what the calc gives me, I'll plug in the average for the DR type and go from there.
One thing is for sure, with my current tendency to go with a stiffer suspension set up than most of the available calcs, I soften the ARB's, since the springs are doing a lot more work.

[feuerdog]

The 1/3 ratio for all cars idea has been scrapped. I was looking for a similarity/connection between FA and RR drive types and it didn't pan out.

I'm working on a new weight bias based ARB ratios now.


 

[feuerdog]

I've had some interesting thoughts in the past 72 hours while working on some new weight bias and damping relationships.

1. My calculators bias weight according to drivetype. I think now that this is fundamentally wrong. Blooze had it right where he was rebiasing springs based on weight distribution itself. I think I have found a way to blend the two methods, in addition to other work loads.

2. I have always based bump damping directly on modified spring strength. While this is realistic for the most part, it is somewhat biased to the weight redistribution spring rates. I think I might be able to tie damping to overall weight(or maybe factory weight distribution) in a way that will disregard any post calc biased settings. The advantage of this is better baseline values for fine tuning damper ratios. Another benefit may come from the chassis mass multipliers I use in the base spring calcs, a relationship that will improve the responses of extreme(heavy/light) weight chassis.

3. My new ARB relationship theories are falling in place now too, again, based on weight distribution in combination with drivetype, and not just drivetype, weight dist., or modified weight dist. as I have done before.

Some questions I need answered:
1. What are the heaviest and lightest vehicles in FM3, and what are thier allowable spring and damper tuning ranges.

2. Is damping value a fixed representation of speed(distance over time by inverse value), or is it a measure of resistant influenced by the velocity/force of suspension compression/extension?
The difference would be time based damping vs. force based damping.

[TheTechnobear]

Its certainly going to be interesting once we can see what the stock cars are tuned in at by T10.

a couple of things im going to be looking are :
- Fm3 values compared to Fm2, which cars values change alot, and which dont... (SR and arbs mainly) ?
- How is CoG being brought into play? esp. lateral roll.

given the tendency for cars to roll in the reviews/clips ive seen - im intrigued, they seem to have alot of roll...
(but perhaps this really is only going to be on certain cars).