True or False - Tuning Statements

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Hello Everyone,

So about a week ago I decided that the Tuning Lounge is full of great suggestions and Tuning advice. If only I could get it all together in one place so I ran through from page 9 to 1 picking out various bits and compiled a list of statements and helpful info. I’m now just wondering how accurate they all are and I’m sure these statements will get some good discussion going.

Here’s what I ended up with. Are they all True or are some False?

Softer Springs are faster in most cases and you can compensate with stiffer dampening.

You can use weight bias to begin with to work out initial settings. Reduce overall by 20%

Set Ride height to as low as possible and use uneven ride heights to shift more weight to front/or back.

Rear Bump should almost always be lower than Front Bump
-From 1-4 is the ideal range for Bump in the game generally
-From 8-13 is the ideal range for Rebound in the game generally

Springs and dampening setting on AWD vehicles should be more even as opposed to RWD

Bottoming out can be caused by and in my preferred order of adjusting to resolve
- TOO SOFT SPRING,
- TOO SOFT ARB,
- TOO SOFT BUMP SETTING,
- TOO LOW RIDE HEIGHT.

Tracks with more elevation change in them should benefit from stiffer springs and a slightly softer Overall Damping setting – aim to get as soft as possible still though.

Softer Bump might absorb curbs better, particularly front
Harder Bump will give more response, particularly front
Go as low in bump as it takes so that you have enough response and are clearing those curbs nicely.

Rebound offers grip to front and rear
-More Rear will improve Front Grip
-More Front will improve Rear Grip

Less Rear Rebound can reduce the effects of losing traction on exit of slow cornering.

Stiffer Front Springs helps with Braking – more resistance over that initial dive so to improve braking distance stiffen up front as well as front ARB’s.

Too much ARB’s may cause locking of Brakes.

Under braking Cornering (ENTRY) damping should be considered as the outside front wheel becomes compressed and your inside rear wheel will extend – use telemetry to see where friction/grip is being lost under braking and corner entry.
Under Acceleration out of a Corner(Exit and Particularly with RWD) your Outside Rear Compresses under squat and your inside rear extends. Use telemetry in these situations to find the balance.

Front of the car pulling = Positive Caster

CAUSES OF HIGH SPEED OVERSTEER
1. Springs - Front too soft in relation to the rear.
2. Aero - Rear downforce too low in relation to the front downforce.
3. Too much Toe out in Rear.
4. Rear Camber too low.
5. Rear Tyre Pressure too high
6. Rear ride height too high in relation to the front ride height
Damping is also a cause but doesn’t affect the car too much…

Spring calc
You will need to do this equation for front and rear it can give some ok settings and sometimes not.
take cars total weight add in total downforce (front and rear) next multiply by cars weight balance % (convert into a decimal) take this number and divide by cars ride height next multiply this by the cars lat G’s (found on tuning menu at the bottom left)

WHAT SEEMS TO WORK IN FORZA 5

In addition to the True or False statements we might as well consider the Forza world.

Here’s a few things I have picked up along the way…

Camber settings work if they’re really quite high in negative value

Low Bump Settings, High Rebound settings

I have no idea why but the following settings work…

ARB’S
Front - 0 or 40
Rear - 40 or 0
DAMPERS
FR - 13 or 0
RR - 0 or 13
FB - 0 or 13
RB - 13 or 0

High Caster works well

I don’t know why that works so would love to know.

Anymore anyone?

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very interesting read i would be intrested to try the last spring formula as i use the first method you spoke of and i found that - 25% is giving me better results and is very consistent at the moment for me

3

The thing a lot of people miss with weight bias is the weight bias is relevant in the garage. Out on the track weight transfer plays a big part. For example one time when springs are put under pressure is when braking - weight transfers to the front. So should the front to back spring ratio exactly match the weight bias?

I see plenty of great open source tunes where the spring bias is more to the front than the weight bias would suggest.

4

False. Spring settings that are balanced to weight ratio and have aero factored in, will maintain balance far far better through braking, entry, apex and exit. Though, feeling this balance is dependant on your other settings in FM4 at least. This doesn’t mean there are not creative alternatives.

5

Maybe I did not give the right explanation but your last sentence is really the point I am making and your last sentence really contradicts your previous statement that weight ratio is the way to go.

When talking true and false the reaility is there are leaderboard topping or top tenning at least tunes that do not apply the weight balance formula in its standard form and many open source tunes on these forums reflect that. Some I have used recently are for the E21 by BRYCE and umadbroyolo with a few more letters mixed in lol

The point I was trying to make was being boxed in by the pure maths does not always result in the quickest tunes and therefore it is not black and white, true or false that using the standard weight ratio formula is always best and if top tunes are not using it but are quick then they are the tunes I will use.

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My statement “false”, means this… weight bias is relevant to tuning whether you are aware of it or not. Look at your own tunes they must reflect weight bias in some way… At least relative to each other. Balancing springs was very helpful to me early on. And I still use balanced or close to balanced settings often. If someone very new to tuning were to read what you said it could very well be destructive to their process of learning in my opinion. Depends on the individual I guess. Also, using the tunes that you are fastest in kind of goes without saying… So I guess we agree afterall.

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+1

Tuning formulas stunted my learning process while learning to tune. Sometimes they spit out something better then what I had. Most times they were nothing special at all. At best you will get something easy to drive. Seriously, unless you are number 2 on a track, .050 from setting a number 1 time, you are wasting your valuable driving time setting the car up to these exact settings.

8

You must be right where I was 3 weeks ago tuning. Top to bottom:

Yes most times somewhat softer then stock spring is better

As far as weight bias percentages, be aware of them and use them to try and compensate somewhat. But do not rely on them giving you good numbers.

Road height being all way down works with tons of cars. Some cars need more suspension travel then the minumum though. And sometimes only front or back.

For rebound you can go 11 front and rear and bump go 2 front and rear and tune from there nicely most of them time. I tend to raise my rear bump higher then front. And I tend to lower my front rebound so its lower then my rear. Or Ill add some rear rebound.

Couldnt tell you about AWD as I dont drive them.

I would change that order to spring, then bump personally. And if that doesn’t fix it then in my opinion something is wrong.

I would try lowering my front rebound first instead of rear.

Having your rear too soft compared to front will eventually kill your stopping power. So “sometimes” stiffening the rear will help braking. You know, if it’s bad to begin with.

I never noticed a connection between ARBs and brakes unless Im braking while cornering hard. Sometimes too stiff will cause a tire to lift so it makes sense that there would be less traction for braking.

I quit using telemetry almost 100% of the time. And my satifaction with my tunes has been amazing. Believe me it is all too easy to look to telemetry for answers and the real truth is if the car feels good and moves fast when you make the right change then it doesn’t matter at all what telemetry is telling you.

Caster has mild effect on handling. Personally I notice caster when exiting turns. Sometimes you can feel the camber drop when coming out of corners. That to me is too high caster. When it is to low l feel less bite when turning in then when it is right. Too high and letting off steering slowly makes me feel a loss of grip that is not proportionate to how I am moving the stick.

The list of what causes oversteer looks good for the most part. BUT “Damping is also a cause but doesn’t affect the car too much…” is totally wrong imo. Damping is the holy grail as far as I am concerned.

Forget the Calc’s completely. They slow down the learning curve. They are all designed to reach a number that falls in range. On 90% of cars, soften that baby up 20 or even 30% and move it to what you need to help with over or understeering. Seriously there are calculators that factor in the constant for gravity and even atmospheric pressure. They work in the sense that most (only most) of the time you get a number that falls in range. Other then that pfft. Waste of time.

Build and driving is 90% of the battle. Maybe more when you factor out completely terrible tunes. Tuning makes a build feel good to run around the track. Obviously making it a little faster since you put the tires where you need them easier.

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Yeah these math based reasons for alot of things are a joke. “Is it more or less capable after I made that change.” Thats all you need to ask yourself.

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Calculations definitely have their place but they must be done properly, the ones bounced around by things like the ‘forza tuning app’ are not reliable because they’re based off things like the adjustment range available which is nonsense.

Half the problem with applying calculations to forza is that you simply don’t have the same information you do in real life, important things like: tyre spring rate, motion ratio, quantified unsprung mass, the camber gain in roll and bump, damper sizings and the internal shim stacks, etc. All that is missing and it makes it very hard to apply calculations reliably.

Also in relation to the op: An anti-roll bar should never be the cause of bottoming out as it only is in action during one wheel bumps or roll situations, not both wheel bump only situations whereby the car slams onto the ground. I suppose you can technically roll onto the bump stops but I assume this wasn’t the ‘bottoming out’ type situation that was referenced.

11

Great discussion guys, I’m learning here so Thanks! Keep it going and PM me to add statements to the OP on thread if you have something worth adding…

I’ve added more info about what works in Forza, handy tricks are useful in forza and the most experienced tuners know most of them. I only know a couple sadly.

12

Find what works for you and do that.

Everyone drives differently, some settings are not really universal and vary from person to person.

Math works for me but I also have a bachelor’s degree in Applied and Computational Mathematics… one could say that I know what I’m doing. I can calculate a base tune in less than five minutes, I then drive the car and adjust what needs to be adjusted by feel. I might not be at the top of the leaderboard, but I guarantee I’ll be in the top 500 or even the top 100 on tracks that I’ve really focused on.

I race a lot, hotlapping for the best time doesn’t really concern me (yet.) I build my cars to be stable and easily drivable so I can conquer online lobbies.

I often see on the forum “math has no place in video games” but you’re forgetting that the videogame is made possible because of mathematics. If you understand it, you can take advantage of it. I’m not saying you’ll be any better than others who tune by feel and experience, but it is absolutely possible to tune your cars using mathematical principles. And it is also possible to win lots and have lots of fun with cars set up using math. I do it every day.

1 Like
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Straightlaced84…could not agree more with you! Go Math!

Retired MSME…aka PRKid

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I use math to try to understand what is going on and bring consistency into tuning.

However, mis-used math can result in a whole lot of undesired results . . . consistently.

To effectively use math and correctly interpret the results, one must sufficiently understand the geometry and the physics involved in car tuning.

Fast drivers can take a poor tune and still turn a fast lap. A good tune just makes that effort easier and for more people. Tuning does not change the car’s power; it just makes it easier for the driver to make full use of it.

15

You are absolutely correct GRD…one must know the what, when & how to apply!

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Does the spring calculations work=Total car weight times the weight %? At least get you in the range and then can soften or stiffen up together as needed. What about roll bars? How do most of you go about setting a base?

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Most of the time I find the spring rates a touch on the low side but others are really close. Honestly after trying every witch way of setting a baseline tune including trying the app, it’s always going to need some fine tuning.

I have found setting up the car using the weight bias works best for me, I know exactly what adjustments I may have to make before I start driving. Trial and error and lots more errors have helped me figure out what I’m looking to get out of my cars. Quick with a bias on grip and stability.

Roll bars are tricky and some times the stock settings will work. I do try and balance the but only within a certain percentage range, just to keep the car stable. On mid and rear engine cars I flip the weight bias in order to keep the car stable. Then make adjustments as needed.

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CAUSES OF HIGH SPEED OVERSTEER

  1. Springs - Front too soft in relation to the rear.
  2. Aero - Rear downforce too low in relation to the front downforce.
  3. Too much Toe out in Rear.
  4. Rear Camber too low.
  5. Rear Tyre Pressure too high
  6. Rear ride height too high in relation to the front ride height
    Damping is also a cause but doesn’t affect the car too much…

Springs wont cause the high speed oversteer.
It’s rear camber too high NOT too low!
Hopefully this helps…
RR

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ONR RR – Do these apply as well for high-speed during turning a corner? Which one would contribute the most? Thx!