Affect of Springs Asphalt vs. Dirt?

[SASPEEDRACER24]

Just curious if you were going from Asphalt to Dirt do spring rates change up or down at all to achieve more side bite? Ect. Or if your feel your car is sprung properly what are some other ways to achieve more side bite within the rules? I do know you want to move your weight higher which moves your roll center up but after that I am about clueless... Let the discussion begin...

[97car]

Softer springs usually, try taking out your sway bar and lower tire pressures. I remember at the start of TDS some of the asphalt cars still used the same set up. Observe the modifieds and other cars coming of the corners and make notes, remember foot to the floorboard does not always work if you're spinning you tires.

[abrungot]

Marc you taking your thunder stock out???

[Truck99]

Just curious if you were going from Asphalt to Dirt do spring rates change up or down at all to achieve more side bite? Ect. Or if your feel your car is sprung properly what are some other ways to achieve more side bite within the rules? I do know you want to move your weight higher which moves your roll center up but after that I am about clueless... Let the discussion begin...

 

Marc, side bite is a term you won't hear many asphalt racers use. It's an idea limited mostly to dirt racing because of the inherent lack of traction on dirt. You're right in that most dirt racers use higher weight placement to induce side bite and body roll, but moving weight higher does not really effect the roll centers. It effects center of gravity height.

 

Most dirt racers remove the sway bar and bump up the RF spring rate a little to compensate for the reduction in front roll stiffness, but I'm not sure that a sway bar couldn't be made to work just fine on a smooth track. Seems like most dirt setups also prefer less left side static percentage and more rear static percentage as compared to pavement setups.

 

Depending on the type of tire, air pressures are also lower on most dirt setups.

 

Take all that for what it's worth from a guy who's never tuned a dirt car.

[Nathan]

a smooth dirt track is a hard to find thing. you can run a sway bar on dirt but most everyone removes them because on dirt you want the car to roll harder to get the bite you need. shock play just as big if not a bigger roll on dirt. springs do play a roll but the springs don't change as much as you think a change in shocks can do just as much if not more for the car that springs can. you will also need to run lower tire pressures I ran anywhere from 10 lbs to 28 lbs.

 

on edit:

 

another thought the reason most all dirt cars run weight jacks is so they can easily change the weight distrubtion without changing springs.

[HiTech]

Take all that for what it's worth from a guy who's never tuned a dirt car.

BUT YOU DID SLEEP AT A HOLIDAY HOTEL RIGHT ...

[97car]

If the car is too tight put a bigger left front, throws more to the left rear and will loosen it up as well.

[BobbyJack]

I run the same springs, shocks, and sway bar dirt or pavement. but this is a 3300 lb purestock not a modified. the suspension doesnt have enough free travel to roll over and still get traction. this is just my opinion and what works for me. Bobby Jack