Suspension setup

The super im talking about earlier is not on bump stops. my other car was.

If the car is tight on entry work on the front. if car has issues off the corner work on the rear. This is true in all forms of racing. If a car is tight on entry the first rule of thumb is soften front springs. and lower tire pressures. If your worried about bottom out dont just raise the car. it will be low racing. A 150lb spring compressed 6"s is as stiff as say a 300lb spring compressed 3"s but the good thing is its better on initial entry because the wait is not there yet with 150lb spring. as long as they dont coil bind your good.

I have to plug my new sponsor here and tell you Swift springs are lighter and have more travel before coil bind then convetional springs.

Adjustable shocks are nice. Rebound seems to be king any more in just about all forms of racing.

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First rally 2013
Rally car type AWD subaru
Total rallies as driver 6
Total rally cars built 2
Total rally cars caged 3
Total rally cars repaired from offs 4
Total years racing exp other then rally 19 yrs
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Quote
Reamer
A 150lb spring compressed 6"s is as stiff as say a 300lb spring compressed 3"s ...

Maybe you just worded that strangely, but a 150# springs that has been compressed by 6" is storing the same amount of energy as a 300# springs that has been compressed by 3", but the former is still only half as "stiff."

Quote
Iowa999

Quote
Reamer
A 150lb spring compressed 6"s is as stiff as say a 300lb spring compressed 3"s ...

Maybe you just worded that strangely, but a 150# springs that has been compressed by 6" is storing the same amount of energy as a 300# springs that has been compressed by 3", but the former is still only half as "stiff."

Correct. The stiffer spring is still stiffer---it still takes 300 additional lbs to compress it an addition inch vs 150 additional lbs for the softer spring.


Regarding softer always being better, there are always exceptions and in some recent testing we learned a lot about this. Soften the front enough to get good turn-in and it would understeer badly mid-corner and on exit of long corners. Going stiffer fixed the problem and even increased forward grip on exit. we suspect that the softer springs allowed the car to roll all the way over onto the bump stops in long corners and so, mid-corner effective spring rate of the loaded corner were made much higher by the bump stop and therefore induced understeer and a general lack of reactivity and feel mid corner or if a corner tightened.

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____________________________________________________________-

One. Class -- 2WD

www.quantumrallysport.com

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now your talking bump stops and bump timing. Timing is usally rubber stiffness and shocks not springs. When i first started playing with bumps that was the go to thing add spring to loosen on entry. This is a crutch for a person new to bumps. Last year I would of said the same thing as you did. Mid corner is roll center caster camber. entry is springs.If the car gets in good then you need to fix the middle. not with springs. the same goes for exit. now you are on the gas and wieght starts to move to the rear.

If a car produces 1000 lbs of load the car will stop traveling at a thousand pounds. in either 6"s or 3"s correct or am I not getting it? You set ride hieght by where you want to reach that load?

I have to say again im not an engineer that sits at a desk and calculates things. other wise the super would never have a 600lb rr spring. Ive been in the oval track car testing these very things for the last 2 weeks. With a $7500 to win show coming up next week i would like to win it. I wish!

Back to the VW is the rear bottoming out or are you hitting bump stops? what would it take to raise bump stops? To increase travel up.

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First rally 2013
Rally car type AWD subaru
Total rallies as driver 6
Total rally cars built 2
Total rally cars caged 3
Total rally cars repaired from offs 4
Total years racing exp other then rally 19 yrs
Like 31motorsports on FB!
Check out 31motor sales on ebay for used Subaru parts

Quote
Josh Wimpey

Quote
Iowa999

Quote
Reamer
A 150lb spring compressed 6"s is as stiff as say a 300lb spring compressed 3"s ...

Maybe you just worded that strangely, but a 150# springs that has been compressed by 6" is storing the same amount of energy as a 300# springs that has been compressed by 3", but the former is still only half as "stiff."

Correct. The stiffer spring is still stiffer---it still takes 300 additional lbs to compress it an addition inch vs 150 additional lbs for the softer spring.


Regarding softer always being better, there are always exceptions and in some recent testing we learned a lot about this. Soften (!!!??? from WHAT to WHAT!!!???)the front enough to get good turn-in and it would understeer badly mid-corner and on exit of long corners. Going stiffer (!!!??? from WHAT to WHAT!!!???) fixed the problem and even increased forward grip on exit. we suspect that the softer (Compared to???) springs allowed the car to roll all the way over onto the bump stops in long corners and so, mid-corner effective spring rate of the loaded corner were made much higher by the bump stop and therefore induced understeer and a general lack of reactivity and feel mid corner or if a corner tightened.

Numbers are good things, makes vague terms un-vaguer-er

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John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
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is 3 hours behind Eastern Standard Time.

Quote
Reamer
Back to the VW is the rear bottoming out or are you hitting bump stops? what would it take to raise bump stops? To increase travel up.

Mostly hitting the bump stops. They are just rubber snubbers that screw into the top of the trailing arm.


I don't have much more room to reduce the height of the bump stops before it totally bottoms out (having the top of the trailing arm hit the support)

Also, there aren't too many options for the front suspension (staying within stock setup). I already have new sway-a-way front torsion leaves. There is only one option, 15% stiffer.

For the rear I can get 7 different diameter torsion bars to adjust the spring rate. I'd have to look up what I previously bought.



Edited 2 time(s). Last edit at 06/20/2013 10:40AM by johnhuebbe.