spring choice for 3 link?

[propit21]

trying a new setup for a new track. 3 link set up with soild upperlink and rear panhard bar. going to be the second time at this track which is third mile simi bank track, question is we run 225 springs across the rear with lr mounted in front and the rr mounted on top, running about 80 to 100 lbs of bite across the rear, to get more foward bite from mid corning out what would be the better thing to do, go 250lr or go 200 rr on spring?
what would be the effects of doing either?

also first race we were very very tight midcorner and we were running a pullbar and jbar set up, what will the difference be with soild upper and rearmounted panhard bar thats the same lenght as the jbar?
thanks for any help

[Dirtrunner35]

Need to fix the mid tight first, give more details about car.

[bushracing67]

if the lr is mounted on the trailing arm you will more than likely need o increase the rate, some of the 3 links around here are as high as 300# on the lr, if it is mounted on the rear end you should be close with what you have, im a fan of the big rr spring, i would prolly go 225rr and 175lr, my metric i am running a 100lr and 150-200 rr depending on the night, i can mat the throttle center off running under 60# lr bite

[steveshawjr]

mid tight is usually caused by to much pan-hard angel

when you run the rear pan-hard you cant go throw a bunch of angel to it like you would on a jabar .

under load on a jbar you actually lose angel during to axle wrap, this said on a pan hard you gain angel and faster than with a jbar due to axle wrap. try taking some bar angel out of the pan-hard and give that a try.


our 2 link we run a 200lf mounted in front ( not on the arm) and a 150 rr on top
jbar mounted 11" off the bottom of frame to chassis andeven with the pinion

about the same bite as you aswel. works good here but every driver/track is diffrent

[propit21]

car is a camaro front clip with fab rear 3 link
20 inch lr and rr trailing arms with about 1/4 of rear steer static, lr angle is 13.5 degree up hill and rr angle is just about level
upper link is soild 20" 14.5 degrees downhill toward the right front tire
panhard bar is 23" behind rear end with about an 1" difference in mounting height it frame mounted on the left and goes to the right side of the pumpkin housing.
225 springs across the rear
cross 49%
left 54%
Rear 53%
3040lbs with driver
about 80 to 100 lbs of bit
shocks are 5/3 lr and 6 rr

just looking to get more foward bit with this set up, mainly what will happen if we put a 250 in the lr with a 225 rr or if we 225 lr and 200 rr?

the rear end is not going to get alot of wrap because its soild mounted so whats good upper link angles and panhard bar angles to run. thanks

[Dirtrunner35]

What is your front springs and shocks ?

[propit21]

lf 900 with 5/2 and rf 925 with a 6

[Dirtrunner35]

1/4 of rear steer static, oversteer or understeer ?
How high is the panhard bar ? Left end is higher ?
On the lr shock, is that a 5 compression and 3 rebound ?

[propit21]

lr is futher foward
panhard bar left is 2" difference from the axle mount
its a qa1 5053

[Graff Spee]

Use you shock indicaters. Try to spring it get 4 inches of wheel travel. Thats wheel travel, not shock travel!!!

[DaveBauerSS6]

What is one basic adjustment for forward bite on a 3 link?

[Dirtrunner35]

Putting the left lower up a hole, just remember to put the axle back where it started.

[Graff Spee]

Upper third link angle deternines forward bite. Too much angle will loosen car going in. Too short of 3rd link will also loosen going in. 27 inches long and 18 to 20 degrees forward down angle works good. Run lower left link from 10 to 15 degrees up in front. This will promote hike up. It will also create roll over steer. Just be aware.

[propit21]

ran the car this weekend with a friday practice, did alot of tuning and adjusting on the car for the practice, change the rr spring to a 200 change the shocks to a 3 then to a 5 and back to a 4, change the lr shock from a 5/3 to a 7/4 moved the whole rear mounted panhard bar up an inch and it worked alot better, for the final main on sunday the track was glassed over so we lower the panhard bar to the bottom hole on the rear end which made the car way to tight in the center of the corner and wouldn't turn, also our cross was to high for those changes with the panhard.

[DaveBauerSS6]

So, no changes to the pull bar??

[propit21]

didn't run the pullbar had a soild upperlink