Loose coming out???

[AVENGER29]

For some reason, we have always fought a loose out condition, car turn in great, awsome thru apex, but when i get on to it coming out,if i dont wait a little the car get loose, and sometime unrecoverable. tried softer rear spring, torsion bars, tried more & less stagger, compensating with different lowering blocks. tried adjusting with bias bar,proportioning valve to right front brake, tried different approach tapping the brake,feathering the gas.
54% rear, 54 left. 53.5 cross weight.Normally run between 2 to 2.5 inch of stagger,tried reducing stagger,didnt improved.
Had a very good friend, the current points leader crew chief, drive my car after the races sat nite. he told me need more bite, add at least 30 to 40lbs over left rear, easy enough, but most of all, told me to increase caster by a bunch, told me to measure left rear bumper to ground and should have at least 1.5 inch lowering effect when turning to the right, measure it barely get .25 inch movement.
front clip originally 66 valiant, most of the components are 73 duster, with power disc. Very difficult to gain much caster or camber in these cars, if you adjust for camber you loose caster, first im i going after the right thing?? if so short of cutting out all original upper a arm upper mounts and moving every thing, is there an easy way to gain a bunch of caster????????
This car rolls over beautiffully,hooks and has bunches of forward bite!!! But unless i wait until the last moment to get on it coming out its very loose,and if i push it too hard sometime breaks into an recoverable slide and spin.
avenger

[sanborn]

A loose out condition usually means the right rear tire is getting more traction than the left. But, there are a few things you need to check first:
1. Is the rear end square? If the right rear is trailing the left the car will be loose out(But it is generally loose in as well). If the right rear is leading the left, the car will generally be tight out.
2. More left rear bite does generally help to tighten the car out. But why add weight? You can accomplish the same thing by using two different thickness lowering blocks on the rear(I assume you use leaf springs). The thicker lowering block should be on the left rear. Start with a 1/2" thicker block on the left.
3. Positive caster also helps to load the left rear on exit but you must turn the wheel to the right well past center to have a lot of effect. Your friend is really referring to caster split between the right and left front. For example, you can run zero caster on the left front and 4 degrees positive on the right(4 degree split) and this will help to load the left coming out. If you must turn to the right much then you must really be loose.

[daveashsr]

hi guys !! just my 2 cents !!
i race a dart on pavement my self aand had a simular problem this year and had an old timer mopar racer help me out !!
he told me to relocate my rear spring hangers (shackles) higher !!
i use leafspring sliders and ended up plating the top of the frame rail and putting the slider there !! from what he told me the diff between the front spring eye and the rear should be 7-9" !! it sure made a big diff in my car !! we usted to flip the front hanger to get the car lower but with this setup u run it in the stock postition ! hope this helps u as much as it helped me !!
good luck
david

[AVENGER29]

Yes we are running leafs in the rear and we have tried a slightly smaller lowering block on right, maybe didnt go enough.
was not planning on adding weight, but simply shift weight around to gain 30 or 40 lbs over the left rear.We have over 250 lbs of ballast in car right now. We have to weight 3200 lbs.
We are also racing on dirt, have checked the rear, it is square, but will go back & recheck, we did hit the wall pretty hard early in season, the car is not loose going in.
thanks
avenger

[340king]

The caster gain/loading that the guy was refering to does occur. Typically, the need for it isn't crucial. The cars that run a bunch of this are the sprint cars. They use the high gain and loss of the severe camber to loosen the car going into the corner and tighten it up coming out. This caster gain is part of the reason that the sprinters carry the left front wheel.

In other words, when you turn left into the corner, the right front wheel goes up slightly while the left front goes down slightly. This reduces your cross weight allowing the car to enter the corner easier/looser. Then as you turn back to the right, the effect reverses, tightening the car back to where it was in the beginning. This continues as you continue to turn the wheel to the right, making the car tighter with oversteer.

This trick has its drawbacks though. It affects everything with geometry. Things like bumpsteer, straightline stability and bump sensitivity are all affected by using severe amounts of caster. Large amounts of caster split create some of the same things, but may not be as good one way or the other, ie not as loose in or not as tight out.

Since you are only complaining about one specific area of the track, I think the solution may be easier to find. I am tempted to suggest a change in left rear wheel offset. Tucking the left rear in a little while keeping nearly the same staic weights may give you the bite you desire. Since this is only on exit, I am going to only mention the location of the weight in passing. If you have the weight mouned too low in the rear, it could cause a problem like this. It may not be noticeable on corner entry due to driver preference/style. Also, if the weight is located too far to the rear of the car, it increases the polar moment of intertia, causing the rear of the car to try and continue in its previous direction(straight). I hope this helps.

[AVENGER29]

Thanks guys, have already made some changes, have decrease lowering block on right rear and slighlty raise the lead in the rear, have also relocated to gain 40 lbs over left rear.
Have mark the camber/caster bolts, and have made several marks as to preset settings,so that quick changes can be made at track,during hotlaps etc. Have also experimented with different wheel spacing, but will have several new tires mounted in different combinations.
car is awsome thru the begining and center of turn, but if i get it on it too soon, the car will break loose,and it seems like i go down the straightaway sideways, can never seem to recover.
But if i hesitate just a little, the car will come out alright and as soon as i get straight and on it,has extreme forward bite, have carried left front wheel down out of the corner. People have told me so, but never believe it until my wife accidently took picture of the car.
ps. i also get lots of comment on how different my car sounds compare to the chevies, never knew until watch my car last sat nite, their right, sound totally different and awsome. because engine move back 8 inches and down nearly 3 from original placing, the hedders have been heavily reworked, we reverse them, instead of out and down, very much like 180 degree, out and up and down in behind engine.
avenger

[WR70]

One more thought- Make sure the rear suspension isn't binding up in the turn. For example: as the car rolls about it's centerline axis, the right rear shock may be hitting the trailing arm, spring, mounts, etc. Or perhaps the left rear shock is in full extension at some attitude of body roll and unloading the left rear tire.
I find that when the car breaks loose and will not respond to any driver input during the slide, it is often related to suspension bind.
Good luck and have fun.

-Jeff

[FURY 66]

my ? is, this weekend plus last, going into the turn under braking the rear end wanted to come around. it would get a little sideways and the rear started hopping bad.asphalt track.would let off a little then punch it while it was still hopping.did that three times in the same turn.am i just getting in to fast/because i was flyin in on the others cars,2cd gear the car doesn't slow by it's self. i put a heavier duty shock on the right side.the rear is square. my brakes did start to go away (hot) could that have alot to do with it.do i want more rear brake or front.not aloud bias?
thanks mike