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Author Topic:   4 bar lr / 3 link rr help
droper23
Dirt Freak

Total posts: 233
posted April 12, 2005 11:02 AM  
I am having trouble getting it to turn going in, in the middle and off the corner.
my left rear is 4 bar with spring (175)on eliminator behind housing
rr is 150 on top of housing
53% LEFT
57% rear
about 51% cross with about 80 lbs of left rear
front springs are 800 both sides on a metric frame
trying to get some suggestions on how to loosen it up some. Left rear hikes up really high. If I sling the car in it will turn on entry and in the middle, but coming off it wants to drive straight to the wall, where if I did not lift I would hit the wall head on. My shocks are 75 on front and right rear and 953 on left rear. Any suggestions would be helpful.

dirtywrench13
Dirt Freak

Total posts: 324
posted April 12, 2005 12:02 PM  
you may want to try more spring on the right rear,lead the rr, or add some stagger.

FlyNLoIMCA17
Dirt Forum Champ
Total posts: 753
posted April 12, 2005 04:39 PM  
check your stagger. Front and rear. I run this same type rear suspension and really got it working this year so far. My car is a metric also. Here's my setup
springs:
LF- 850 RF-800
LR- 200 RR- 175

shocks:
front- 75
rear- 94

left - 52.1%
rear- 55.8%
cross- 50.4%
left rear bite 61 lbs.
total weight - 2417

the weights are without the driver and about half full of fuel. I weigh 140 lbs.

tire psi
LF- 10 RF- 13
LR- 9 RR- 11

RR lower link is level, spring is mounted behind the axle.
LR lower is 5 degrees up and upper is about 20 degrees up spring behind on the cage.

I run a 19" shorty bar from behind the driver to the left side of the pinion. Pinion end is one hole below even with the pinion shaft. I have about 3-4" of rake in the bar up to the frame.

Pull bar is an AFCO progressive bar. Mounted 20 degrees downhill and 1/4" of preload. I don't run a 90-10 shock.

If you want to loosen your car then drop the upper LR 4-bar down a hole. This will help loosen it up off the turn. Last year my car wouldn't hit water if it feel out of a boat! Over the winter I set the front roll center, which made the car turn alot better. But the car just slid up in the turns still. So with the advice of the great people on the dirt forum I moved the RR spring behind the axle. The car went from a barely top 10 car to running in the lead! The car is fast now. I hope this info. helps you!

Dale

FlyNLoIMCA17
Dirt Forum Champ
Total posts: 753
posted April 12, 2005 04:40 PM  
Oh yeah I run on a 1/4 mile track. Usually gets slick by the end of the night.

topnotch
Dirt Full Roller

Total posts: 30
posted April 12, 2005 10:33 PM  
i'm running a similar setup on my car as well. It has 3 nights on it and i have had similar problems first the setup. chevelle stub, lf650 rf700 lr200behind on the cage rr150 on top. the car turns in well with a push in the middle. changed it to a 175 in front of the housing on the right rear on a coil over. maybe it will help both cars

Dman
Dirt Freak

Total posts: 270
posted April 13, 2005 07:46 AM  
Try dropping your cross to 49.5 . The 4 bar LR should keep it tight coming off on the throttle if you have enough angle in the top bar.It could also be you don't have enough rear brake to get a good "set" on entry.

[This message has been edited by Dman (edited April 13, 2005).]

MIDWEST MOTORSPORTS
Dirt Full Roller

Total posts: 50
posted April 13, 2005 08:17 AM  
i agree with d-man. take some of the left rear out, and im pretty sure 49-50 cross will give u about 35 lbs of left rear. i think the springs need to be heavier on the rear and lighter on the front, because the i feel like with your setup, its not letting the car get on the right front so you can steer the car, just an observation.

rpm20
Dirt Freak

Total posts: 338
posted April 13, 2005 09:06 AM  
i believe you would lead the lr not the rr. if you lead the lr it will loosen you up coming in, also if you lower your bars on the left side, then it wont hike up so much. the other thing is if you put angle in the lower rr bar up to the front then it will induce rear steeer on body roll, thereby helping loosen you into the corner but you will want to keep it over on the rr when that happens by using maybe a 3 compression and a 5 rebound to keep you over.
i have also lead my lr by about 3/4" and that will make you turn, then theres always more stagger too.

quote:
Originally posted by dirtywrench13:
you may want to try more spring on the right rear,lead the rr, or add some stagger.

[This message has been edited by rpm20 (edited April 13, 2005).]

MIDWEST MOTORSPORTS
Dirt Full Roller

Total posts: 50
posted April 14, 2005 08:12 AM  
RPM20 IS CORRECT!

dirtywrench13
Dirt Freak

Total posts: 324
posted April 14, 2005 12:18 PM  
oops, my bad! itchy trigger finger.

FlyNLoIMCA17
Dirt Forum Champ
Total posts: 753
posted April 14, 2005 09:18 PM  
TopNotch..... try the car with the spring in front on the RR then move it to spring behind. I think you'll like the spring behind better than in front. Remember the RR is a 3-link. And on a normal 3-link you run the RR behind, LR in front. So with the 4-link LR 3-link RR run both springs behind the housing. It really helped mine!

droper23
Dirt Freak

Total posts: 233
posted April 20, 2005 06:24 AM  
We put the right rear back on the swing arm (3 link) in front of the rear end, pulled the rear end to the right about 1/2" and dropped the cross to 49.1% which came down to about 35 lbs. of LR. The car turned a whole lot better this weekend. We are going to change the right front spring to a 750 to see if it will help some more. But all in all I could actually race this weekend.

droper23
Dirt Freak

Total posts: 233
posted April 20, 2005 06:25 AM  
We also changed the LR spring to a 250 and the right rear to a 225 both on eliminators

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