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Rank: C-Class Racing License
 7 users liked this post.
#1 Posted : Friday, February 28, 2014 10:59:43 AM(UTC)
Greetings Community!
Need a little help tuning your damping settings?
Hopefully with the use of my formula, you'll be able to quickly get some settings which work for you!

Damping Formula(s):
Front and Rear Rebound = ((WB% (LBS) * 9.8) / (LSR * RH^2)) + 1
Front and Rear Bump = ((WB% (LBS) * 9.8) / (USR * RH^2)) + 1

abbreviation meanings:
WD = Weight Distribution
LBS = Weight of car in pounds (Only pounds!)
USR = Upper-Spring-Rate (Maximum stiffness the spring(s) can go)
LSR = Lower-Spring-Rate (Minimum stiffness the spring(s) can go)
RH = Ride Height
9.8 is a constant which must NOT be changed!

*Note*
When finding Front Rebound or Bump, use Front Weight Distribution and Front Ride Height
When finding Rear Rebound or Bump, use Rear Weight Distribution and Rear Ride Height


Example:
In this example I will use a 2013 Lotus E21 (F1 car) just because it's light.
Weight Distribution: Front - 46% / Rear - 54%
Weight: 1422 lbs
Upper-Spring-Rate: 589.3 lb/in
Lower-Spring-Rate: 73.7 lb/in
Ride Height: Front - 3.5 in / Rear - 3.1 in
Once you have got your values substitute them into the formula...

Front Rebound: ((46% (1422) * 9.8) / (73.7 * 3.5^2)) + 1 = 8.1 (to 3 significant figures)
Rear Rebound: ((54% (1422) * 9.8) / (73.7 * 3.1^2)) + 1 = 11.6 (to 3 significant figures)

Front Bump: ((46% (1422) * 9.8) / (589.3 * 3.5^2)) + 1 = 1.9 (to 3 significant figures)
Rear Bump: ((54% (1422) * 9.8) / (589.3 * 3.1^2)) + 1 = 2.3 (to 3 significant figures)

Taking Mathematics to the game!
"The true sign of intelligence is not knowledge but imagination" - Albert Einstein

For my open source tunes please click 'here'

Hope this helps!
Enjoy,
RR

Edited by user Monday, March 03, 2014 8:47:26 AM(UTC)  | Reason: Not specified

Rank: B-Class Racing License
#2 Posted : Friday, February 28, 2014 1:55:07 PM(UTC)
The ^ symbol. What does that represent - To the power of? e.g 3.5 to the power of 2?
Rank: B-Class Racing License
#3 Posted : Friday, February 28, 2014 2:00:49 PM(UTC)
got it. 3.5 * 3.5 * 3.5.

cool
Rank: Racing Permit
#4 Posted : Friday, February 28, 2014 4:19:09 PM(UTC)
is there a formula for the roll bars ?
Rank: C-Class Racing License
#5 Posted : Friday, February 28, 2014 4:52:53 PM(UTC)
Originally Posted by: ToOSk3tChY Go to Quoted Post
The ^ symbol. What does that represent - To the power of? e.g 3.5 to the power of 2?


This means to the power of 2
Example:
If the ride height is 4.5, put it to the power of 2 so - 4.5^2 = 4.5 * 4.5

Originally Posted by: oldmanpork Go to Quoted Post
is there a formula for the roll bars ?


I have one but it needs tweaking. Been using the same formula for years. But you have to remember that the anti-roll bars are mainly a tailor tuning aspect...

RR

Rank: C-Class Racing License
#6 Posted : Friday, February 28, 2014 5:03:16 PM(UTC)
Can u do a spring and diff. formula?
Been racing since Forza 1...2005... NOT 2007 like it say's above.
Rank: C-Class Racing License
#7 Posted : Friday, February 28, 2014 5:18:48 PM(UTC)
Originally Posted by: joediesle Go to Quoted Post
Can u do a spring and diff. formula?


The Diff and springs are tailor tuning aspects. How you drive makes the tune!
Rank: Driver's License
#8 Posted : Friday, February 28, 2014 11:52:27 PM(UTC)
Doesn't seem to work on my E21 but awesome job might be better for lower classes
Rank: C-Class Racing License
 3 users liked this post.
#9 Posted : Saturday, March 01, 2014 12:40:14 AM(UTC)
All of a sudden, I regret leaving school at 15.
Wornburner says NO.
Rank: C-Class Racing License
#10 Posted : Saturday, March 01, 2014 4:26:08 AM(UTC)
Originally Posted by: SPxUMADBROYOLO Go to Quoted Post
Doesn't seem to work on my E21 but awesome job might be better for lower classes


You sure... I tried it on my F1 tune and took off 0.2 seconds.

Originally Posted by: BIGpoppaKEGdog Go to Quoted Post
All of a sudden, I regret leaving school at 15.


I'm 17 so not a big difference =P

Rank: Driver's License
#11 Posted : Saturday, March 01, 2014 10:54:20 AM(UTC)
thanx for this post. i am working on a tuning spreadsheet in xcel. i will try this out and add the math to my spreadsheet.
Rank: Driver's License
#12 Posted : Saturday, March 01, 2014 11:59:46 AM(UTC)
Thanks for posting this, the damping is my ugh problem child. Are you using the actual curb weight of the vehicle or what you have figured the sprung weight would be? I have a ARB formula and a second way I figure them also and sometimes you just wing it LOL. Question at the end of your calculations you had this "(to 3 significant figures)" can you explain? Is that meaning constraint of up or down only by 3 from original answer or something else?
Rank: C-Class Racing License
#13 Posted : Saturday, March 01, 2014 4:29:19 PM(UTC)
Originally Posted by: AlphaPD331 Go to Quoted Post
Thanks for posting this, the damping is my ugh problem child. Are you using the actual curb weight of the vehicle or what you have figured the sprung weight would be? I have a ARB formula and a second way I figure them also and sometimes you just wing it LOL. Question at the end of your calculations you had this "(to 3 significant figures)" can you explain? Is that meaning constraint of up or down only by 3 from original answer or something else?


"Are you using the actual curb weight of the vehicle or what you have figured the sprung weight would be?"

I'm using a bit of both...

Three significant figures: This means 3 consecutive numbers which doesn't start with a '0.'
Example:
If you had:
i) 15467.2 = 154|67.2 (Round up) = 15500.0 (to 3 s.f)
ii) 0.0010234 = 0.00102|34 (Round down) = 0.0010200 (to 3 s.f)
Hopefully you get what I mean...
RR
Rank: Driver's License
#14 Posted : Saturday, March 01, 2014 11:33:08 PM(UTC)
Originally Posted by: ONR RoadRunner Go to Quoted Post
Originally Posted by: SPxUMADBROYOLO Go to Quoted Post
Doesn't seem to work on my E21 but awesome job might be better for lower classes


You sure... I tried it on my F1 tune and took off 0.2 seconds.



yea i couldn't get it to work i would try to take turns like i normally do especially for some high speed turns and it will lose it, i think unless there was a way to include aero because that adds weight and maybe the individual spring rates that are already tuned it would be more accurate in giving a basic damper setting, but i'm no mathematician

Rank: B-Class Racing License
#15 Posted : Sunday, March 02, 2014 4:23:40 AM(UTC)
What can I say? This formula is terrific. With Damping & Tire pressure dialed in based off your 2 formulas, that took my car to a different level. Great work!
Rank: C-Class Racing License
#16 Posted : Sunday, March 02, 2014 7:20:02 AM(UTC)
Originally Posted by: SPxUMADBROYOLO Go to Quoted Post
Originally Posted by: ONR RoadRunner Go to Quoted Post
Originally Posted by: SPxUMADBROYOLO Go to Quoted Post
Doesn't seem to work on my E21 but awesome job might be better for lower classes


You sure... I tried it on my F1 tune and took off 0.2 seconds.



yea i couldn't get it to work i would try to take turns like i normally do especially for some high speed turns and it will lose it, i think unless there was a way to include aero because that adds weight and maybe the individual spring rates that are already tuned it would be more accurate in giving a basic damper setting, but i'm no mathematician



I see what you mean... for the Mazda 787B and F1 car, maybe some others, high bump rates and lower rebound rates ate better =/ I might have to do some tweaking... Thanks for the info!
RR

Originally Posted by: gangrel Go to Quoted Post
What can I say? This formula is terrific. With Damping & Tire pressure dialed in based off your 2 formulas, that took my car to a different level. Great work!


Thanks gangrel!
RR

Rank: Driver's Permit
#17 Posted : Sunday, March 02, 2014 8:05:56 AM(UTC)
At the risk of sounding dumb, how can i figure out my lower spring rate?
Rank: Driver's Permit
#18 Posted : Sunday, March 02, 2014 8:13:54 AM(UTC)
How exactly do i find my lower spring rates
Rank: C-Class Racing License
#19 Posted : Sunday, March 02, 2014 9:25:18 AM(UTC)
Lower spring rate is the minimum rate the springs can go...
Go to your tuning setup > go to springs > and put one of your springs value all the way to the bottom and remember it > then put it back to the value it first was...

RR
Rank: Driver's License
#20 Posted : Sunday, March 02, 2014 3:50:50 PM(UTC)
Do we assume the maximum spring stiffness for the front and back are the same? I believe in most situations they are. Also, 3 significant figures of 15467.2 becomes not 15500.0 but 15500. <---- Notice there is no zero after the point. You could also easily say 1.55E4 or 1.55 x 10^4.

Also, do we ignore aero or are these for 50% front and rear aero? I've definitely noticed a slight difference in the suspensions dampening when throwing the aero up or down.

I look forward to trying out your equation, thanks!
Rank: C-Class Racing License
#21 Posted : Monday, March 03, 2014 8:46:20 AM(UTC)
Originally Posted by: BigRunnyDump Go to Quoted Post
Do we assume the maximum spring stiffness for the front and back are the same? I believe in most situations they are. Also, 3 significant figures of 15467.2 becomes not 15500.0 but 15500. <---- Notice there is no zero after the point. You could also easily say 1.55E4 or 1.55 x 10^4.

Also, do we ignore aero or are these for 50% front and rear aero? I've definitely noticed a slight difference in the suspensions dampening when throwing the aero up or down.

I look forward to trying out your equation, thanks!


BTW these are all the same Number...
15500
15500.
15500.0
15500.00000000......................................................................................................
1.55*10^4
1.55E+4 <---- Notice it's E+4!
Mathematically when round a number to a certain amount of significant figures or decimal points, you include the amount of significant figures originally! Therefore 15500.0 would be the correct answer.
My little rant over...
Read the information it's all there, if not stated then not used. I would include the aero but the equation would be too long for some people hence why I haven't included this into the formula!


Rank: D-Class Racing License
#22 Posted : Monday, March 03, 2014 11:39:02 AM(UTC)
Could someone put the math into a spreadsheet for me its doing my head in trying to get to grips with the math lol.

P.S same with the tire presure math would love a spread sheet for that aswell thanks.

Clean Racing with the AI VIDEO
Rank: C-Class Racing License
#23 Posted : Monday, March 03, 2014 11:58:56 AM(UTC)
Originally Posted by: Duke Odyssey Go to Quoted Post
Could someone put the math into a spreadsheet for me its doing my head in trying to get to grips with the math lol.

P.S same with the tire presure math would love a spread sheet for that aswell thanks.


You only need a calculator, preferably a scientific calculator or graphical calculator and a pen + paper!
=/
RR
Rank: Driver's Permit
#24 Posted : Monday, March 03, 2014 12:15:59 PM(UTC)
Thank you very much Roadrunner. I'm going to have fun with these formulas of yours. Using the min and max spring settings was very clever by the way.
Rank: Driver's Permit
#25 Posted : Monday, March 03, 2014 1:33:57 PM(UTC)
Hi,

for the Ferrari 312T i get a Rear Rebound value of 30, but i can only set it up to 13. What now? :D

Greetz

Edit: Equation: ((0.63x1263x9.8)/(65.4x2^2))+1=30.8

Edited by user Monday, March 03, 2014 1:41:13 PM(UTC)  | Reason: Not specified

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