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Author Topic:   need set up help
modman42
Dirt Roller

Total posts: 5
posted November 14, 2005 03:05 PM  
i have a 3 link car and know absolutely nothing about setting it up. i ran it about 5-6 times last year and when i would get on the throttle coming out of the corner the rearend would snap out from under me.

i am running it as basic as i can, i'm running the j-bar flat (no angle) and both straght bars flat (no angle). i have an afco 1095 shock on the rr, pro 94 on the lr and pro 74 across the front. i have a 750 spring in the rf and a 650 in the lf and 200 across the rear. the pull bar has a 60 lb spring. i was running any where from 1/4 to 1/2" stagger in the rear and 1/2" in the front.

any help would appriciated. if you need more info just ask. would i be better off running it as a 3 link swing arm. i know nothing so any info will be good.

chickenlittle
Dirt Full Roller

Total posts: 67
posted November 14, 2005 04:07 PM  
You might try the modified setup book by steve smith publications. Has good basic info on mod setups. You would probably need to put some angle in the j-bar. You raise it on the left side where it mounts to the frame. On the trailing arms, you want the left arm to be angled uphill towards the front about 5 deg and you want it point downhill on the right side about the same angle. The springs sound about right. You can put a heavier spring on the LR to get more bite comming off the corners. You can mount the spring in front of the axle on the LR and behind the axle on the RR. I hope the pull bar spring is 600 instead of 60 or are you talking about a 60 durometer bushing? You want to angle it down around 25 deg. The panhard bar can make a big difference. You would add more angle to it for more side bite. You can raise the whole bar and equal amount on both ends to loosen the car by raising the roll center. You lower it to tighten the car up around the corners. You need to get an idea about your cross, rear, and left side weights. A lot of the setup will depend on the configuration of your track and the conditions (wet, tacky, dry). There are a lot of other variable like your front roll center, tire pressure, wheel back spacing, etc. Look on e-bay and you can usually find that book. It should give you a lot of info on where to start. Best source would be to call who ever built your frame. They should be able to give you a baseline setup to start with. Hope this helps and good luck.

modman42
Dirt Roller

Total posts: 5
posted November 14, 2005 07:19 PM  
correction on the shocks it a 96 on the lr and 76 across the front. if i were to put a little softer rebound shock on the lr would that help?

donslink1
Dirt Freak

Total posts: 322
posted November 14, 2005 07:58 PM  
OH YA!!!!!!!

modman42
Dirt Roller

Total posts: 5
posted November 15, 2005 07:37 PM  
if i would run it as a 2 link swing arm and run my pull bar w/o the 90-10 shock would that free up the rear end a little bit and help with getting off the corners?

Kromulous
Dirt Forum Champ
Total posts: 802
posted November 16, 2005 06:58 AM  
How long are your links or bars? Both sides the same length?

How long is the pull bar, and what angle is it at?

200lb springs, on the housing? or on a slider on the back side of the housing?

2 Links are dependent on arm angle to get rear steer. Running the RR flat will make it awefully tight in and out.

Try setting it up with about 10* up angle in both sides, to get it to rear steer a little and pick up some drive on both rear tires.

Krom.

Dman
Dirt Freak

Total posts: 273
posted November 16, 2005 07:38 AM  
I wouldn't run without the 90/10 on the pull bar. You're flirting with disaster. The braking forces are what kills. There are many who have tried and have bent and/ or snapped the pull bar under braking. The damage is devastating when the rear end goes for a spin under the car. Real UGLY!

psycho47
Dirt Full Roller

Total posts: 51
posted November 16, 2005 07:38 AM  
Monitor your shock travel. I would suspect that you are getting very little travel with that stiff a shock package. Also put some angle in the j-bar to get a little more side bite. Usually 2-4" to start but could more or less depending on track conditions. The location on the pinion up or down always seemd to have more effect on my car than the location on the frame. The angle of your 2-links will depend on the length of the bars and how much rear steer you want. Adding rear steer on my car really helped with exit allowing the right rear to stay hooked up better. I fought a problem part of the year where I ran the right bar almost level but with body roll it was actually going past level and pulling the right rear forward. Move the bar up one hole and made a big difference.

cd2
Dirt Maniac

Total posts: 162
posted November 16, 2005 08:29 AM  
modmam 42
check your pm.
cd2

Dman
Dirt Freak

Total posts: 273
posted November 16, 2005 08:37 AM  
Get rid of the 96 LR shock.Too stiff. If you have a split valve for the LR make it an 8/2 other wise run a 93 or 94. Run a 93 or 94 on the right. It will help. As far as front springs go we need to know what kind of chassis you have.Chevelle or metric. A 60 or 600 lb. pull bar spring is just too soft.When it coil binds when you are on the throttle (bottoms out the spring) it will do the slide hammer deal and break the rear tires loose.Could be your loose on the throttle problem.There may be some tracks that are slick enough you can use a 600 but I don't know where. The softest pullbar spring we ever use is a 900. We had to run a 1050 on the hooked up tracks or the 900 bottomed out and bent the spring plates on the AFCO pull bar. As for the j-bar. The angle is a straight line projected through the heim joints/mounts, not the flat of the bar.Use at least a 4 in. difference.Set the frame side at 7 ins and the second hole up from the bottom on the pinion mount to start.Run your LR spring 50 lbs. stiffer than the right.We can't tell you the rates unless we know where the are mounted.Run 5 to 7 degrees angle on the RR lower arm and about 15 degrees on the left to start. More angle = more bite but also more rear steer so don't get carried away. Keep your LR bite between 80 to 120lb. split.If you are a rookie to the Modifieds start with a basic set up like this until you feel comfortable and are sure you are not the problem.Ask for advice from the guys who are consistently fast at your track.They will help you, (if they know whats good for them). There is nothing worse than sharing the track with a "spinner". Get a book and do your homework.There are alot of guys who could be fast but don't want to do what is necessary to be that way.They usually sell their cars(if we are lucky) and buy a boat, but not until they have torn us all up first.There is alot to keep up with. Good luck!

modman42
Dirt Roller

Total posts: 5
posted November 16, 2005 07:09 PM  
the car is an 01 predator w/ a chevelle stub. both bars are 18" long. the rear springs are on eliminators the rr is behind the rearend and lr in front of the rear end. the pull par is level.

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