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Apr 07 2011
By: cantsteer Monster Hunter 42 posts
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Suspension tuning - spring rates and anti-roll bars

7 replies 2505 views Edited Apr 7, 2011

Could someone clarify a little better what the relationship is between them? According to the guide, increased roll stiffness should mean lower spring rates. After my previous car tuning mostly involved cranking up spring rates, I tried dialing that back a little and increasing the anti-roll bar number as the guide says. It seems to work brilliantly- I'm definitely faster around the Nurburgring, though just how much faster may be a result of increasing confidence about where the corners are as I run the track more often. I guess I'm mostly unclear on how far you dial back the spring rates compared to how high you push the anti-roll bar number to get the best results. I think with my Saleen S7 I increased stiffness by 1 and dialed back spring rates by about 2.0?

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I Only Post Everything
Registered: 03/13/2005
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Re: Suspension tuning - spring rates and anti-roll bars

[ Edited ]
Nov 19, 2012

Spring rates and anti-roll bars are primarily used to adjust two different motions of a car. Spring rates control up and down movement (result of front/back weight transfer) while roll bars control body roll (result of side to side weight transfer). A side effect of spring rates is that they also effect the side to side weight transfer as a softer spring will compress more in a corner than a stiffer spring. This is why the guide says that roll bars and springs should be adjusted together. Stiffer springs reduce the body roll, so smaller roll bars are needed to compensate. Softer springs cause more body roll, so a larger roll bar is needed is to prevent this.

 

Usually springs effect the car in a different part of the corner than the roll bars.  I've found that springs effect entry and exit while roll bars effect mid corner (usually). You can adjust both settings to get the best balance through a particular corner. Here's what I normally go by to adjust these settings:

 

 

Part of cornerCar TendencySolution
entry understeer lower front spring
entry oversteer higher front spring
mid-corner understeer lower front roll bar

mid-corner

oversteer higher front roll bar

exit

understeer higher rear spring
exit oversteer lower rear spring
on throttle understeer higher rear roll bar
on throttle oversteer lower rear roll bar

 

 

Hope that helps

 

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Sackboy
Registered: 05/22/2008
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Re: Suspension tuning - spring rates and anti-roll bars

Apr 7, 2011

When Gar speaks, it's probably a good idea to listen.  This guy is superfast.

DIsclaimer: My opinions are just that, MY opinions. They in no way shape or form express the opinions of anyone else unless they happen to agree with me.

Actual quote from a driver: "I never brake check anyone, but if I see you right behind me, I'm going to brake as hard as I can"
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Uncharted Territory
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Re: Suspension tuning - spring rates and anti-roll bars

Apr 7, 2011

Gar,

Thank you very much for posting this, I for one will be printing it out for future reference.

Still racing and ventilating the enemy from Edmonton, Alberta.




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Monster Hunter
Registered: 02/15/2011
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Re: Suspension tuning - spring rates and anti-roll bars

Apr 7, 2011

Thanks, that answer should help a lot.

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First Son
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Re: Suspension tuning - spring rates and anti-roll bars

Apr 7, 2011

Gar529 wrote:

Spring rates and anti-roll bars are primarily used to adjust two different motions of a car. Spring rates control up and down movement (result of front/back weight transfer) while roll bars control body roll (result of side to side weight transfer). A side effect of spring rates is that they also effect the side to side weight transfer as a softer spring will compress more in a corner than a stiffer spring. This is why the guide says that roll bars and springs should be adjusted together. Stiffer springs reduce the body roll, so smaller roll bars are needed to compensate. Softer springs cause more body roll, so a larger roll bar is needed is to prevent this.

Usually springs effect the car in a different part of the corner than the roll bars.  I've found that springs effect entry and exit while roll bars effect mid corner (usually). You can adjust both settings to get the best balance through a particular corner. Here's what I normally go by to adjust these settings:

Part of cornerCar TendencySolution
entryundersteerlower front spring
entryoversteerhigher front spring
mid-cornerundersteerlower front roll bar

mid-corner

oversteerhigher front roll bar

exit

understeerhigher rear spring
exit oversteerlower rear spring
on throttleundersteerhigher rear roll bar
on throttleoversteerlower rear roll bar

Hope that helps



nice write up gar. very simple, so even i can understand. i hope you get a team together for the tpra enduro. if not you can join team ftw. that'll give us 2 cars, we'll just split up the talent between the teams.

oh yeah i almost forgot what i logged in under. this is HEY.

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Keyblade Wielder
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Re: Suspension tuning - spring rates and anti-roll bars

Apr 7, 2011

agree with others, thanks for posting this.  it will probably help many people in many situations..

my question for you is, how universal is this table?  Are there things on there that would change for different drivetrain configs?  MR AWD for instance?

aka Ex_Stream_Tuna -FR's & Racing done here. ExXboxfan = Netflix only
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Wastelander
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Re: Suspension tuning - spring rates and anti-roll bars

Apr 7, 2011

Gar529 wrote:

Usually springs effect the car in a different part of the corner than the roll bars.  I've found that springs effect entry and exit while roll bars effect mid corner (usually).

Good stuff Gar.  I've been trying to increase neg camber on the front for mid corner understeer.  Too much screws up my braking...  never really thought of adjusting the sway bars.  Seems so obvious now.  Ha!

Good luck at Silverstone

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