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Author Topic:   dry slick problems
mudcrasy
Dirt Roller

Total posts: 9
posted August 15, 2005 07:16 PM  
Hi I am new to the forum.Ive done a seacher on car setups and havent found any that perticulary pertain to my problem but gave me some things to think about.My problem is that the dry slick gets the best of me.During the season the car has worked pretty well,no matter what changes I made I could enter the corner with no problems, middle and exit needed work.In working with that and getting it dialed in the track went dry and is here to stay.My problem now is in the feature it starts out good but tords the middle of feature it will not enter the corner,it just skate and pushes till it catches the slightly tack,then it will turn will good forward bite.Ill try to give all the info I can but I havent scaled it lately and Ive made lots of changes since the last scaling.It is a 81 metric chasey home built,lf 1100 rf 1300 lr 275 rr 225 car weights 3380, billisien shock all round, 2" offset in front,3"on lr 4" on rr,1/2 stagger in front,straight up in rear.Track is 3/8 mile high banked with wide sweeping corners. Thanks for any help. Sorry forgot the tires they are hoosier dirtstockers, a pretty soft tire.This might mean something also the tire were has been good all year till the last two races on the dry slick.Now the right side tires are fethered out really bad.

[This message has been edited by mudcrasy (edited August 15, 2005).]

Raz_900
Dirt Forum Champ
Total posts: 635
posted August 15, 2005 07:41 PM  
Even though the car is on the heavy side, those are some heafty springs. I run a 9/16 mile track that sounds close to yours and I've had the same issue at times this year.

The biggest culprit was the right front tire and/or spring. If the tire is wearing off, try grinding it to get some sharp edges back or re-siping it.

Try going to a softer RF spring. I run a 1000L and 1100R but with a 1.25" sway bar. Dropping to a 1200R will help loosen up entry.

Last is to add a shim or 2 under the RR spring. That will take some cross out of it and make it loosen up everywhere. Just watch, it doesn't take much to make the car feel evil. Been there, done that.

Last question is tire pressure and/or temps? Is the RF going up in flames?


mudcrasy
Dirt Roller

Total posts: 9
posted August 15, 2005 09:27 PM  
Thanks for the input.I also thought of the front spring rates but didnt know what it would change and how much.Also thought of adding stagger to the rear,but I really dont want to lose the lr bite.Ill have to investigate that a little more.Yes the right side tires are a lot warmer than the left.Last week after the feature the lr was luke warm to the right rear.Tire preasures are lf 14,rf 24,lr 19,rr 16 the track can get ruff ocationaly. Thanks again

[This message has been edited by mudcrasy (edited August 15, 2005).]

racer17j
Dirt Forum Champ
Total posts: 5390
posted August 15, 2005 10:00 PM  
Are you running a beadlock right rear? Your air pressures look a little weird to me. What class is this? Street stock/ factory stock or IMCA stock? I would think about softening up your front springs to 1000/1200.

mudcrasy
Dirt Roller

Total posts: 9
posted August 16, 2005 05:22 PM  
It is wissota street stock.WE are not aloud to run beadlocks.Thanks again for the input.Looks like Ill have to change front springs.Should I just change the springs or change the rf spring only? Do I need to keep ride hieghts the same?

[This message has been edited by mudcrasy (edited August 16, 2005).]

Raz_900
Dirt Forum Champ
Total posts: 635
posted August 17, 2005 07:09 PM  
I'd start with just the RF, if it gets better, then the LF.

And those pressures seem really high to me. I've used those tires before (255/60 and 265/60 in Med compound) and ran 19-20 RF and between 12-14 the rest of the way around. 19 on the LR must have it running in the middle of the tire only. I've run as low as 10.5 without beadlocks without problems.

By a handheld pyrometer for about $75 to check tire temps. Adjust air pressure to get them even on the LF, LR and RR then adjust pressure and camber to get the RF about 5-10 degrees warmer on the inside. You'll be surprised what tire temps can tell you. The rest of the chassis setup is a stab in the dark without them.

mudcrasy
Dirt Roller

Total posts: 9
posted August 20, 2005 12:25 PM  
Thanks for all the help guys.I changed the right front spring to a 1200,but do to the lack of time I didnt get to check ride hights and when I got to the track the right side of car was low.So at the track we changed the rear spacers from side to side raising the rr a 1/4 and lowering the lr 1/4.This made the car level with a 1/2 inch of rake front to rear.The car worked pretty well in the heat with a loose condition in the middle. The features dry out here so i put 3/8 shim under the lr and a 3/4 in larger tire( circumfrence Spelling ?able). This worked the same as heat race with the same loose condition.Adding the larger tire and shims gave me the same goofy ride hights.How would I go about fixing the loose condition without changing the enterence and exit? What do you think about the ride hights? In the past I have tried to get rr 1 1/2 in higher than lf,lr 3/4 in higher than lf,rf 1/2 higher than lf. Raz tire temps are as you said except rr was a little hotter on outside by about 10 degrees. Thanks for any addtional info.I would really like here about the loose middle condition.

    

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