1MeanZ

iTrader: (9)

hey guys i have been doin some reading about suspensions lately because i have been interested in making my own lower control arms, panhard rod, subframe connectors, and possibly a torque arm. i am installing a higher stall converter and am anticipating traction problems. my problem is, i do not truly understand the purpose of adjustable lower control arms. we dont have upper control arms so to adjust the pinion angle you adjust the torque arm right? are adjustable lowers used to somehow preload the rear suspension via the torque arm? i was planning on boxing a set of stock LCAs and calling it good. if i lower the car in the future i would get a set of relocation brackets and an adjustable panhard rod to center the rearend, and if i needed to adjust pinion angle(which is prolly not needed for the 1-1.5 inch drop i would be looking for) i could use an adjustable torque arm. at this point i just dont see the need for adjustable lower control arms. i know very little about suspension geometery and have little experience with it, so i may be off base here, but i still dont see the need. can anyone fill me in???

chevymad

I too dont see the real benefit to adjustable lca's.. The only thing i can see that it would change is the wheel base.. Maybe if the car is wrecked or tweaked somehow and the wheel base doesnt match from side to side, it could be adjusted by the lca's to make up the difference.

Thinking bout it a bit more.. since the rear moves in an arc as the car is lifted and lowered, the rear will also move forward and backward. So if you lower your car the rear end may no longer be centered in the wheel wells. Then you can adjust the lca's to center the rear again.

Well that's all I can think of.

AFreaknGoodTme

This is very important to keep the springs properly aligned in the cans as well as wheelbase.

Z28DJP1987

For the average guy the non-adjustable rear LCA's are a good supension improvement. If you are a serious drag strip racer you
may need adjustable ones.

1MeanZ

iTrader: (9)

so basically they are to center teh axle front to rear, just as an adjustable panhard rod centers it side to side? if that is teh case the only way to properly adjust them would be to put the car on an alignment rack.

AFreaknGoodTme

They are great for a car that has been in an accident and has alignment problems as well.

If the car is accident free, just match rodend to rodend centerbolt lengths on the adjustable arms with a tape measure before you install them. Then when they are on the vehicle and you need to make furture adjustments, just count the rotations made to one side and match the other.

SteveSpohn

We ship our adjustable LCAs set at OEM length. They allow you to center the rear front to back. Many people use them to push the rear front or back to get tire clearance when stuffing in big tires. They also allow you to get a 4 wheel alignment.

Steve

drop-top IROC

So, what I'm hearing is that 90% of the people out there will not really have a need for an adjustable LCA?

aklaim

Thats how I pretty much understand it to be. Unless you have frame damage or are pushing 9's or 10's, they arent really needed. I could be wrong tho.....

Dewey316

but if you want more than a poly/poly bushing, and you BUY them, you have to get adjustable

but as steve spohn stated, the come at stock length

although when it came to installing mine, it was really nice to have them adjustable that way i didn't ahve to wrestle with the rear at all, i just adjusted them slightly bolted them up, and adj. back to stock lenght

aklaim

See thats what I dont get. If your going to adjust them to stock lenght than why get adjustable ones to begin with? The non-adjustable ones are stock length.

Dewey316

beacuse the non adj. don't come with rod ends

aklaim

True. What is your main use for the car? Racing? Daliy driver? I just cant see putting rod ends on a daily driver. Too harsh and too much noise. And they wear out 5 times faster than poly/poly.
Im assuming you have the spohn lca's.....can you replace just the rod ends when they wear out?

Z28DJP1987

Previous Post is trying to confuse the issue for you. The Non- Adjustable rear LCA's will be find for your application. Installed on my car without a problem.

Justins86bird

To get rod ends, you need a adj LCA. Rod ends will not bind. Yes the make noise. Yes they wear out. But performance wise, you can't get any better then a rod end compared to rubber or polly, which will both bind under hard cornering.

1MeanZ

iTrader: (9)

thanks for the info guys. i think for now i do 90% street driving. i think the non adjustable lower control arms will suit me best. i am either gonna box a set of stock lowers or make my own from scratch, to the stock length. i am also interested in lower control arm relocation brackets, but i am almost sure i can make my own. does anyone have any basic measurements they can toss out here? basically i just need 2 measurements. the vertical distance from the stock bolt hole to the lower bolt holes, and the horizontal distance from the stock hole to the lower holes. i am assuming the lower holes are a little farther forward to make up for the shorter distance between mounting positions due to the fact that the arm wont be flat anymore. i am a junior in mechanical engineering here at university of toledo OH, so if it helps i am proficient with auto cadd and ideas so dont be afraid to send drawings either.

1MeanZ

iTrader: (9)

here is a very very rough sketch of my idea. my car is not here so i have no idea if the dimensions are right so i need you guys to help me out. i hope this attachment works

drop-top IROC

You're on the right track, 1meanZ, I have the Spohn LCA brackets and the holes in the brackets follow the natural arc of the control arm when positioned lower. Your drawings look like they take that into account as well. For the $60 I spent on them, it wasn't worth my time trying to get someone to design and fabricate a pair for me plus, the Spohn LCA brackets are quality units and much cheaper than competitor's models.

wdigitog

all i know is i corrected a rear toe in problem with the adjustable arms..the adjustment was just .5 deg., but at least i could do it easily.

1MeanZ

iTrader: (9)

well my drawing sucks, i drew one in ideas but couldnt get it into a form to post here. you guys get the idea. i may just buy some but they are so simple if i just knew how far down to put the holes. i can do the math and figure out the arc and position the holes front to rear, all i really need is one measurement.

hey wdigitog, how the heck did you have rear toe in with a solid rear axle????

Dewey316

are you running lowering springs?

if you are making them, i would look at YOUR car, and found out how much you need to move the rear of the LCA down.

1MeanZ

iTrader: (9)

no i am not lowering the car. it has teh stock "touring" suspension.

Dewey316

i would go look at your cars suspension, and make 1 set of holes at the point where the LCA is parallel to the ground. and then possible a set lower than that pair.

brodyscamaro

could you explain

1MeanZ

iTrader: (9)

yah thanks dewey316, i will measure the car when i go home for christmas and see what i can come up with.


yah wdigitdog, like i asked earlier, how do you get toe in with a live rear axle?

Dewey316

Bent axle? :shrug:

or one side has a toe IN problem the other side has a toe OUT.

Ukraine Train

you can export an ideas project as a .jpg file

AFreaknGoodTme

Technically you are correct to question him because he stated "Toe-In". What he meant is "toe to the left" or "toe to the right". Adjustable LCA's will correct rear toe-left or toe-right settings.

ronterry

You brought up a point where adjustable LCA's are used in circle track racing. You can shorten one side, which will help the car turn in easier. *** Turn in ONE WAY mind you ***

Technically you could stager LCA's even on road courses if turns favor one direction.

Ron