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Author Topic:   tight in loose off 3 link
squid
Dirt Full Roller

Total posts: 57
posted April 12, 2004 05:59 PM  
little getting into the corner, but not terrible. Bigger problem is loose 3/4 to exit of corner.
running this set-up in a limited mod 360 Cu and 9:1 comp
Short arm 3 link
Lr 11in 225lb
Rr 18in 200lb
Lf 650lb
Rf 750lb
Pinion angle @ 8*, long panhard @ 7*
40 lb Bite, 57% rear and 49.5 cross


how much static angle do u run in a short arm set-up, dont know how much i have about 4 holes from the bottom.



cd2
Dirt Maniac

Total posts: 161
posted April 12, 2004 08:07 PM  
squid What is your wheel weights and your wheel off sets.Total weights with driver or driver weight in seat. Also check an give bar angles. cd2

zeroracing
Dirt Forum Champ
Total posts: 1875
posted April 12, 2004 08:15 PM  
stiffen rf spring, it will loosen entry, and tighten exit. also alot of people, even veterens, will enter tight and throw the car loose so it turns, but then it is loose off because the tires never get traction back.
so fix entry first. but a stiffer rf will help both overall.

xhubby
Dirt Freak

Total posts: 376
posted April 12, 2004 08:44 PM  
Would'nt a little more bite in the LR also help the tight in, loose off problem?

autoshop
Dirt Freak

Total posts: 298
posted April 13, 2004 12:11 PM  
stiffer right front spring or stiffer lf shock depends if the little push is a little push. the cross seems low for the amount of rear.

alias
Dirt Full Roller

Total posts: 43
posted April 13, 2004 12:20 PM  
Why does a stiffer right front spring loosen
entry? I am not arguing. I am just looking
to learn more about how a chassis works. I thought softer front springs made a car more
loose and that stiffer front springs made a
car more tight.
Thank you for any info.

zeroracing
Dirt Forum Champ
Total posts: 1875
posted April 13, 2004 12:40 PM  
The stiffer rf will help add dynamic wedge to the car, so that means the cross will go up as the car corners, which will loosen entry up, and tighten exit up.

juliaferrell
Dirt Freak

Total posts: 370
posted April 13, 2004 02:16 PM  
getting in a corner poses alot more questions than exiting one. brake? Do you use any?

alias
Dirt Full Roller

Total posts: 43
posted April 13, 2004 03:56 PM  
I understand that more cross will loosen the
car on entry and tighten it on exit. But
wouldn't a stiffer right front spring also
tighten the car on entry--So, which one overides the other? Would he be better off
to just add cross with weight jacks?

squid
Dirt Full Roller

Total posts: 57
posted April 13, 2004 05:00 PM  
i use 3" in offsets all the way around with 2" hub adapters in the front, metric stub.

I dont have bar angles for lack of gauge,
Lr in 4th hole from bottom
Rr in 2nd hole from bottom

car weighs 2370, half fuel, 160lbs lead and no driver. 150lb driver.

Wanted to know about putting more bite in the car or increasing angle of Lr which would give a little rear-steer ( short-bar)

Ego Racing
Dirt Forum Champ
Total posts: 724
posted April 13, 2004 06:42 PM  
The stiffer spring will keep the weight from rolling over as far on the right front and cause it NOT to side load as much.

cd2
Dirt Maniac

Total posts: 161
posted April 13, 2004 08:43 PM  
squid Could you put the car on scales with your weight in the seat and give the wheel weights? This will help someone to help you. When you say you have 40# of bite in the L.R. that weight comes from L.S.weight. Take the total of your L.R.& R.F. then the total of the L.F.& R.R. If the L.R- R.F. is more than the L.F.- R.R.you will have positive bite,wedge,or crossweight .If it is the other way you are negative & this will take out bite.The L.R.could weigh 100# more than the R.R.and still not have bite. Like zeroracing said a lot of drivers are too tight going in an most of them do not have enough crossweight.More L.S.weight,stiffer R.F.spring,softer R.R.spring or more crossweight will loosen you in & tighten you off. cd2

squid
Dirt Full Roller

Total posts: 57
posted April 13, 2004 11:02 PM  
i always thought bite was measured by Lr weight over Rr weight.

i take it this way is not true then and the way u described is the correct way to measure bite.


Lr+Rf/Rr+Lf= bite

and do u have to have driver weight in car, always thought scale #'s were a starting point and if u scaled one way and stayed with it would work out the same.

speedy79
Dirt Forum Racer

Total posts: 92
posted April 14, 2004 08:14 AM  
what track are you running at?

squid
Dirt Full Roller

Total posts: 57
posted April 14, 2004 04:48 PM  
southern Mn tracks

juliaferrell
Dirt Freak

Total posts: 370
posted April 14, 2004 05:47 PM  
For the getting in you need a shopping car lesson. "Throw weight on the left the shopping cart goes left when you give it a push." Go to your local grocery store, get you a couple three cases of pop. Load the left front and right rear, then load the rr and lf. Notice what happens when you push it. You can get you an old chevette or something and do the same thing with a couple quick built platforms on each corner to hold weight. Use enough weight so it really brings out the contrast in handling. Drive her around and test it. This will teach you more about what you need to do than 90% of the competition your racing against. Just get you some coil spring spacers to stiffen the spring rates on the corners and test away. (((My grandad taught me this way many years ago)) If you have scales you can really play til your CRAZY!!!

cd2
Dirt Maniac

Total posts: 161
posted April 14, 2004 10:07 PM  
squid This is the way we have done setups for years.Put the tires on with the stagger,wheel off set & air we want.With car on leavel floor add all fluids,set caster,camber,toe. Next set ride heights with driver or drivers weight in seat.Now the car is base lined this is a starting point that you can always return too if needed.now put car on scales and get L.S. weight,rear weight an crossweight.With car on scales your ride heights will be heigher by however much your scale height is.Exp. front 6" & rear 8" & on scales it is 8" on front &10" on rear then you will go by this on scales. If you add weight on L.S.check this measurement an if it is less raise the ride heights back up if you do not you will not get the correct weight.The same goes for the rear.When you change crossweight make your changes on all four wheels if you can.We run a 3 link with 54-56 % on l.s.& 56% on rear crossweight 52-54 % spring pullbar that can be centered or moved up to 4 " left an one 90/10 shock. To give an example of what i mean on bite lets try this. 2500# car set 53% L.S. 53% rear L.F. 623 R.F.552 L.R.702 R.R.623 L.R.702+ R.F.552 = 1254 L.F.623 + R.R.623 = 1246 if you subtract your R.F.from your L.F. the L.F.is heavy by 71# subtract the R.R. from L.R. an it is heavy by 79# 71+ 79 =150 # If you will check the L.S. weight it is 150# more than the R.S. weight an that is where the 79 # is coming from. Now take the 1254 # of crossweight an subtract the 1246 # an you have 8 # of C.W.or wedge or bite . Most times this setup will be tight in & loose off. Now we will adjust C.W. add weight on R.F.& L.R. take weight off L.F.& R.R. we will match C.W. to left & rear weight.Now we have L.F.588 R.F. 587 L.R.737 R.R 588 L.R.737 + R.F.587 = 1324 L.F.588 + R.R.588 = 1176 1324 - 1176 =148 # crossweight an the L.F. weighs 1 # more than R.F. an the L.R. weighs 149 # more than R.R. still adds 150 .This setup will be looser in an tighter off.You can keep adding C.W.an your left rear will get heaver than your L.S.weight an you will get looser in an start pushing at center an off If you do not think this is right then adjust the car untill your C.W.in down to 47 % an try that an then go up to 52-53% an try that an let us know what happens. Anyhow if 40 # is right for a heavy track an it goes dryslick by feature time it might take 140 # to be right. Hope this did not bore you or get you thinking wrong an if anything helped good. Good luck this year . cd2

jonniet
Dirt Forum Racer

Total posts: 92
posted April 14, 2004 10:44 PM  
Dude ,when is the chassis seminar?.....great lesson!...I wish I could explain things that clearly.

daddyrich
Dirt Full Roller

Total posts: 33
posted April 15, 2004 08:18 AM  
i see some good advise here guys but the one thing that stands out to me is the high rear percentage. at 57% it would seem to be on the outside limits of of what i i typically run and see with most cars of this type.to make a WAG - i would drop the rear weight percentage a bit and see if it doesnt alleviate the push going in. in so doing it will most likely fix the loose off condition.

Wauge28
Dirt Freak

Total posts: 262
posted April 15, 2004 01:33 PM  
The idea of adding LR bite to loosen a car going in is dependant on individual driving style and track conditions. Sounds crazy huh?

If you get off the gas and use little brake, the car will turn going in easier. Think of it as the opposite of forward bite. When you get off the gas, the harder the LR (bite) pressed into the ground, the more the car wants to rotate around that tire and steer left. Use the shopping cart again. If you're gliding down an isle with feet up and hair blowing in the wind, how do you turn left to miss the old lady? You drag a foot on the LR wheel.

If your driving style is the guy who won't lift going in, now you are tighter going in with more LR bite...hmmm.

If you are the guy who backs the car in the turn by mashing the brake, you lock up the rear wheels and now Bite makes no difference when sliding through the turn.

My simple suggestion with a 3 link...Way too little bit if the track is any bit slick. Adjust your bite with screw jacks to start. I would run 80 lbs Minimum and more like 120 lbs LR bite. Have ran more like 200 LR bite on many occasions. If that simple fix doesn't do it, then start changing RF springs. Stiffer RF is along the same lines of adding LR bite but you loose some side bite becuase of the lack of body roll.

squid
Dirt Full Roller

Total posts: 57
posted April 15, 2004 05:31 PM  
THANX a TON 4 the advice

i did get a chance to dig up my scale
sheet.

Lf 532 Rf 487
Lr 690 Rr 659
By this and your calculations i would have
Lf+Rr=1191
Rf+Lr=1177
So by that i have -14 lbs bite. tell me if this is right or wrong.

I have scaled the car and set ride heights.
But i was told that with that short Lr arm 11 in i shouldn't run alot of static bite in the car like 50lbs tops. Anyone else use this and know more detail about it, i think it would work if and when i get it sorted out.

thanx again for the help and info.

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted April 15, 2004 07:25 PM  
as it sits you have 31 pounds of left rear bite... using the rf, lr, rr, lf method doesn't help much... if we all did it that way our scales would read way wrong... its the most common method of left rear...
initially... from what i've seen thats not enough lr...
you dont have enough left side percent either... with those numbers you get
51.6 left side percent
just a hair under 57 percent rear
49.7 percent cross...

take your left up to 53, your rear up to 58 and cross to 48, get yourself about 90 pounds of left rear and start from there

irace74
Dirt Forum Racer

Total posts: 80
posted April 15, 2004 07:58 PM  
All of the advice sounds solid but, it kind of depends where your rear end is inrelation to the left front and the left rear. If the left side is lined up then the 53 left and 57-58 rear sounds good but... If it is a car with the left rear offset outside the left front then different thinking may be required. Generally moving the rearend to the left will tighten the car. You are moving the right rear closer to the center of gravity(more force on the tire)and you are moving the left rear further away (less force on the tire), Some cars with a great amount of left rear offset require rt rear static bite to make the thing work. When considering bite,or any other setting, consider the geometry of the car. If you square the left side and have the rt front 2" outside the the right rear(common seet-up), 53% left and 58 reat are good. To tighten the car offset rearend to the left, to loosen the car offset rear to the right. Always consider what is happening with rear steer( left side moving forward rt side moving forward or backward) during cornering. Short arm with alot of angle on the left rear for a trailing arm will induce quite alot of rear steer. Long arm with no angle on rt will induce very little rt side rear steer... this can go on and on but..

zeroracing
Dirt Forum Champ
Total posts: 1875
posted April 16, 2004 11:02 AM  
to get lr bite, take the lr wieght- the rr wieght=lrbite
its that simple. maybe someone else has a different way of doing it. but the lr-rr is what everybody refers too, and is the simplest way to do it.

Wauge28
Dirt Freak

Total posts: 262
posted April 16, 2004 11:49 AM  
I can not argue with "the theary" but I can tell you that for me..and everyone I know, we just take the LR weight compaired to the RR weight and that is your bite. I have owned 4 Dirt Works, a Harris, a Smileys and that is how they do it as well.

cd2
Dirt Maniac

Total posts: 161
posted April 16, 2004 01:24 PM  
squid In the post on setting wheel weight and crossweight what i was trying to do is get you to understand the difference between L.S.weight an crossweight. If you set your car 50% l.S - 50% R.S. an use the same front & rear % that you have now an rescale you should come out to L.F509 - r.f.509 l.r.675 r.r.675 that will be 1184 l.s. 1184 r.s 1019 front 1349 rear 1184 crossweight an no l.r. weight or bite now set your cross to the 49.5 % that you have an look at your wheel weights an you should be able to see why this will make you tight in an loose off. Now if you change your C.W. to 53 % you will have l.f.473 r.f. 545 l.r.711 r.r639 l.r.weighs 72# more than r.r Remember this all is with your same front an rear weight.Now set the weight 53 % l.s. use the same front an rear an set at 50% c.w. your wheel weights will be l.f.545 r.f.474 l.r.710 r.r.639 your c.w. will be 1184 50% an you should be 71# heavy on l.f & l.r. this comes from l.s. weight.The L.S.weight will make the car turn in better but a little tight in & loose off then adding C.W. will loosen in & tighten off.All i used the l.f. r.r. for was trying to get you to look at the over all settings an understand not enough l.f rear can make you tight in -loose off. Any car that i setup has no less than 53 l.s. 53 rear if possible an start at 53 crossweight an adjust to get what we want then rescale an log every thing in book.If it was my car i would go 53 left an 50 c.w.with the same rear an adjust from there. Good luck an let us know how it goes. cd2

tilley88
Dirt Forum Champ
Total posts: 879
posted April 16, 2004 03:04 PM  
On the short 2-link, set the left bar to 15*, and the right to 10*. Try to get your LBite between 30-50 lbs. Use a little brake goin' in, let it settle, then ease in to the throttle or hammer it depending on your track surface.

squid
Dirt Full Roller

Total posts: 57
posted April 17, 2004 10:23 PM  
thanx alot guys, i gotta admit to something pretty dumb on my part.

I am a rookie driver and have been around cars for quite a while and thought i knew somethings. well setting up the car and driving the car are 2 totaly different things. In putting my car together and put the steering wheel in my chest thinking it would be comfortable, after racing like this for 6-8 nites. i shortened the shaft about 3 in and amazing i can drive went from bein in the back and tryin to drive. To goin from 8th in a heat to 3rd in 3 laps.

Theres something to be said for bein comfortable in the car, But i am still fighting a little loose coming out, but i'm gonna add some more bite to it this wk and see what happens. I appreciate all the advice and have thought and read all ideas.


Thanx Squid

Dirt-Tracker
Dirt Maniac

Total posts: 182
posted April 18, 2004 08:45 PM  
Quick question.....over the winter I lost 45# due to a new fitness program. My car is very tight in and loose off. Should I add this weight back in car with lead weights or what should I do. I dont have scale weights in front of me. All I know is last yr I won 7 features and a track championship and now I look like Stevie Wonder is behind the wheel. This is the only thing changed.....I never scale my car with me in it. But we had the right combination last yr.

------------------
"Somedays your the dog, and somedays your the fire hydrant!!!"

www.geocities.com/albertson28racing

Dirt-Tracker
Dirt Maniac

Total posts: 182
posted April 19, 2004 06:25 PM  
ttt......help

zeroracing
Dirt Forum Champ
Total posts: 1875
posted April 19, 2004 07:18 PM  
crank more lr bite into it, just like you would add cross to the car. if you dont have scales just go a few rounds at a time and see how that works.
good luck
jason

Wheels47
Dirt Maniac

Total posts: 170
posted April 19, 2004 09:45 PM  
In Dirt trackers case should he also try to add left side weight to make up for his loss of weight or should he just add more bite and maybe a little more cross.

Thanks for the help guys this has been a great topic.

Wheels

zeroracing
Dirt Forum Champ
Total posts: 1875
posted April 19, 2004 09:49 PM  
i might add a little bit, but only if i had scales, i would be afraid to get too much. so i would leave it for now, and first attempt the few rounds of lr bite at a time. and try to hunt up some scales to borrow or loan.
plus a tight in loose off is textbook not enough left rear wieght. so add that first.
i would try to hunt some scales as soon as possible.

zeroracing
Dirt Forum Champ
Total posts: 1875
posted April 19, 2004 09:52 PM  
hey dirt tracker, i checked your profile if you want to drive down to marshall on this sat morn i can scale your car for you. mine are pretty good, not as good as some scales, but are digital.

Wheels47
Dirt Maniac

Total posts: 170
posted April 20, 2004 05:23 PM  
Zeroracing-- Dirttracker has scales. What we are have is a delima getting him set up this year since he lost 30 some pounds and we feel this is affecting our setup from last year. I know he will be on here after while and will very much appreciate the offer to scale him though.

We have both read this thread and will be trying some of the things mentioned on here to get him lined back out and tuned back in.

It's just getting us both frustrated cause our #'s worked so well last year and this year we haven't been able to get it right.

Thanks Wheels47(Dirttrackers Dad)

xhubby
Dirt Freak

Total posts: 376
posted April 20, 2004 05:48 PM  
wheels47, I know your frustration. We had the same problem a couple of years ago. Won 7 a-features & a track championship in 02, didn't change a thing over the winter, & only won 1 a-feature & finished 5th in 03. I've come to the conclusion that cold weather must affect spring rates.LOL. Good luck.

Dirt-Tracker
Dirt Maniac

Total posts: 182
posted April 20, 2004 06:35 PM  
Zeroracing---thanks for the offer but I have a set of scales. THats the frustrating part...we are setting the car exactly the same with alot different results. THe only thing we changed was me. I have lost 42# since last race season and was wondering if that would be contributing to the problem. My question is do I need to strap a 40# weight on my left side to fix this. We never weigh car with me in it, so we dont know what it weighed last year with me in it. Do I need to strap weight on to similate my lost weight or do I keep dialing in LR and cross to get it close. Thanks..

------------------
"Somedays your the dog, and somedays your the fire hydrant!!!"

www.geocities.com/albertson28racing

zeroracing
Dirt Forum Champ
Total posts: 1875
posted April 20, 2004 06:37 PM  
i am guessing you scale your car without you in it. i always scale mine with me in it, that way i know how my wieght change will effect. i would scale the car with you in it, and then make changes from there, but compensate for the lost wieght for now.

Wheels47
Dirt Maniac

Total posts: 170
posted April 23, 2004 10:01 PM  
Heres what we came up after setup. We set car up as usual, without me in it. Got it set and scaled it. Then I got in and set a 40# weight in my lap, to similate the 40# I lost this winter. This lowered my cross weight 1%, raised my left side 2% and raised my rear .9%. We took the weight out and my cross weight raised .3%, left side dropped .3%, and rear dropped .1%. Without the weight my numbers didnt really change that much. I got out of it and added about 40 more lbs left rear which raised my cross up about 1.3%. Hopefully this should help my tight in and loose out problem. Any suggestions. If this doesnt work I guess I will strap a 40 lb weight on car behind seat. Its really got me puzzled!!!

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