my question is what exactly do aftermarket lower control arms and relocation brackets do? do the help with wheel spin, or just wheel hop? id like to drop my 60' times a little and am looking for the best way. thanks in advance

 

Aftermarket Lower control arms are much stiffer than the stock ones. If you are drag racing this is a good thing. If you are autocrossing it might not be. When the car goes around a corner the inside control arm goes up and the outside one goes down. With the stock control arms they twist to allow for this movement. with the aftermarket stiff ones and the harder urethane bushings very little twisting occurs and the rearend could bind causing eratic handling. If you go with stiff aftermarket control arms at least one end should have spherical rod ends to compensate for the lack of twist

Relocation brackets will improve traction by changing how the forces from the tires pushing the car forward reacts on the lower control arms. See pics below for explanation.

 

They will get rid of wheel hop, which will probably make the wheels spin more. Aftermarket arms are a great improvement. What does the car run now (60' and 1/4)?

 

best 60' was a 2.07 and best 1/4 was a 14.88

 

Get a set of arms with a bearing on one end as Ratchet posted if you drive hard around the turns. No need to buy new underwear after the rear binds with poly on both ends while driving it like you stole it. I would probably look into a converter next if yours is stock. Use some old leftover tires you don't care about at the track and burn 'em up.

 

ok, i dont do any autocrossing or anything, but every now and then i slide around a corner a little harder than i should. (im 19 just tryin to have a little fun ) are spherical rod ends a must? ive been looking at prices and i didnt really plan on spending that much. would the relocation brackets be a worthwhile upgrade without doing LCAs?

 

Only if your car is lowered. You could always box the stock arms and install poly bushings if trying to save $$. Would still be a nice improvement over stock. You can search for a "how to" on boxing the stockers.

 

Relocation brackets will benefit a non-lowered car aswell.

 

ok you explained how the lca's helped, mine will be just basically for drag racing, but what do the relocation brackets help, other than relocating them, o and are lakewood lca's good

 

Relocation brackets will change the angle of the rear control arms, making it so when the axle pushes the car foreward that it 'shoves' the rear axle into the ground, improving traction and reducing wheel hop.

 

where is a cheap place to buy them at

 

Spohn has them for $65 a set.

 

Summit has Lakewood boxed LCA's w/poly bushings and grease fittings for $90 plus S&H http://store.summitracing.com/defaul...h.asp&N=400272 on this page a.Probably one of the best deals.Poly bushings alone for stock LCAs go for around $40.And sometimes the stock LCAs give problems in pressing them in/out.Like Lo-tec said do a search on how-to box your LCAs if you want to go that way.

 

Chnaging the angle of the LCA with relocation brackets hurts cornering peformance. You ideally want the LCA set to a parallel position for both cornering and drag launching.

With the LCA angle upward towards the rear of the car -this produces roll understeer (axle steers towards the corner in a hard turn)

With the LCA's anglewd doward towards the rear of the car- This creates roll oversteer (axle steers outward away from corner) and causes the rear of the car to swing out easier on a corner.

Only buy LCA Relocators if you are experiencing wheelhop. And if you are getting wheelhop then just lower the rear LCA mount points one hole at a time until wheelhop is gone. This keeps your instant center low and helps with front to rear weight transfer pivot. Lowering the mount too low raises the instant center and weight from the nose passes to the rear under the IC rather than over it and does nothing for loading the rear wheels. This gets technical, but too steep of an angle only causes jacking of the rear chassis weight to initially load the rear tires- then that jacking suffersd the opposite effect a few feet off the line.

 

Hence why the Relocation Brackets are good for EVERY vehicle, gives you teh chance to find out which compliments your driving style best.

 

I agree 92maroRS. I always preach to everyone to buy any *adjustable* parts when availiable upon purchase so that you have to adjusting perameters to correct any ride and handling problems based on current ride or even future ride changes.

Here is a diagram showing how the angles of the LCA's change the roll oversteer/understeer of the chassis.

 

Another little example why adjustable parts are good- This is what would happen if you 1) have a stock height car and NON-adjustable LCA's with relocation brackets. Then 2) you decide to lower the car- see how the wheelbasde lengthens and the driveshft yoke pulls further out of the trans? Perfect example where adjustable LCA's will allow you to shorten them and bring the wheelbase back into factory length.

LCA's-red
TQarm-green
Driveshaft-purple

 

Dont waste your money on aftermarket LCA's at your power level. Buy a set of sticky tires - its all you need. Look at my 60fts my suspension is untouched.

 

Maybe you should buy a set and give them a try before you badmouth them.

 

bad mouth them? The guy has a 14 second car hes wasting his money buying them and they wont help out anywhere near as much as a set of drag radials would. Why should I try a set of aftermarket LCA's when my car dead hooks with nothing but a set of little DOT slicks? I'm not saying aftermarket LCA's are a waste of money in all cases I'm just saying for him it'd be money thrown away.

 

doesnt seem like his car is all drag, they serve a purpose other than making the car hook(which they really dont help that much in that aspect) they are stronger and dont deflect and are lighter.

 

i already have ET streets that havent been used yet

 

I got to agree with you telling the kid to put relocation brackets on a basically stock car is gettin ahead of yourself. Better LCA's and better tires is ALL he needs now. More power then go for the relocation brackets.

 

Lca's and Relocation brackets=$180ish

New tires= $300-400

I think ill take the cheaper route.

 

Excellent explanation of what is happening on the rearend of our cars. Anyone who is interested in tuning the suspension on their car will benefit alot from your sketch thanks.

 

One thing I didn't see mentioned is that from a handling perspective, you NEVER want roll oversteer. (On asphalt anway, dirt track racing is a separate case)

Ideally, you'd have no roll steer at all. However, that's usually not achievable over a useful range of motion, so you must ensure that any rear steer present is inclined towards roll understeer.

If you're drag setup produces roll oversteer, and you want decent cornering performance, consider resetting the LCAs back to a sensible angle when you're finished at the strip.

 

id like to thank everyone for their input to this, and thanks for the sketches drawn, they helped out alot.

Chad

 

hey. finally someone else with some smarts...

... i mean, besides the 1000s of 3rd and 4thgens pulling 1.5s on stock LCAs...


heres a tip to everyone else.

theres only one of 3 things your car will do when you floor it.

it will wheelhop.
it will spin.
or
it will go.

you can fix some wheelhop with stiffer arms... but its usually wheelhop caused by something else.. go look at the geometry above.

but lets pretend stiffer arms fixes all wheelhop.
it doesnt matter if you have a stock L03.... you're still going to spin unless you get some real tires under it.

stick some ETstreets under there, and put new shocks on the BACK only. cheapie $9 red ryder shocks will do.
the rear end wont squat... meaning your rear LCA angle wont go horribly bad.. and you will hook.....


but whatever... as soon as i post this, i will be flamed by the all knowledgeable guys above me... you know, the ones with all these boltons, and slow cars... compared to say... actual budget drag racers that spend their limited money only where it counts.....

 

Maybe some of us dont want an all out drag car?

 

If you left all of your suspension stock with the exception of aftermarket LCA's you would never feel or be able to measure any improvements made by them whatsoever. Your mind may trick you into believing the $100+ you just spent made a noticable improvement but the reality is that it wont. Like I said, aftermarket LCA's arent a bad idea for a car. They're stronger, typically lighter, and the expensive ones allow some adjustability but they are hardly a need-to-have item. You point out that not all people have drag cars and thats true but the original topic of this thread was CC89Formula asking specifically how to lower his 60 fts... The easiest method that would yield by far the greatest results are sticky tires.

If I can hit 1.5x 60fts with stock lcas, torque arm, shocks, and springs anyone can and I think it also proves that tires are about all you need on an 11's-or-slower f-body. I'll say it again... Aftermarket suspension can rarely ever do any harm but its not needed in most cases.

 

hmm. lets think about this.

i suggested stiffer shocks.
i suggested tires.


so, you swap tires at the track (obviously).


what i just said has not limited his ability to autocross, road race, open road race, or even rally the ****er.

its simple. perfect fix for the mild street car that just wants to be better on the 60'



now lets look at the other suggestions.
LCAs... hmm, some people argue they bind in autoX. i personally dont believe that, but whatever. in anycase, he can do them, but they wont help him hook. they may stop wheel hop, but they wont give more traction, so he'll just go from hopping to spinning.

relocation brackets:
hey, did you read any of the above? thoes help traction if you need it.. they help cornering if you need it.. but mostly, its a adjustment.. set it how you need it... if you're lowered severly, like a good autocross/road race car... then you'll still need that adjustment. that said, even if it plants the wheels hard, without tires, he'll still spin.


this is from the first post. the actual "what it does" questions were answered, now im trying to actually be helpful to someone.

why dont you go back to the front door.. i think you forgot to check your ego on the way in.

 

I know this is a somewhat older post but I have a question on the stock LCA's.On my '83 the LCA's have crossbolts,seem to be between 10MM to 14MM head(sorry not sure it started pouring rain when I noticed them),at 2 points on each LCA.Is this a common practice on all 3rd Gens,V8 3rd Gens or Z28/IROC/Formula & T/A suspension pkgs?

 

Not that common, but not at all uncommon either.

If you look at the control arm from underneath, you'll probably find a small reinforcing brace between those two bolts. That brace was actually a G-body part, and was used to reinforce the rear swaybar mounting points on that application. In theory, it should stiffen the control arm slightly, but I was never able to detect any difference.

Off the top of my head, I think GM stopped using those in about '85 or so...which might imply they didn't think they did much either. You might also note that when they put the 1LE suspension package together, they used a much stiffer rubber bushing in the control arm, but didn't bother with those braces.

 

i just replaced my rear end....axle, tq arm, shaft, AND LCA's. The drawings you guys put up were perfect. i didn't fully grasp the full function of it all till now. just wanted to say thanx

 

I dont want to hi jack anyones thread. Now im inthe middle of redoing the undercarridge. I picked up a posi unit out of an 89 gta. And i have eibach springs. now If i under stand all this it would be a waste of money to buy lower control arms and brackets?

 

It depends what angle your lower control arms end up at when you put the new springs in. If they are pointing up towards the back of the car you might want to install relocation brackets to bring them back down to stock.

Ric

 

My LCAs are stock, and "boxed". It dont get no easier, or cost effective than that! I just added solid bushings, and my 60's are 1.54.

 

My car has serious wheelhop problems and thanks to you guys I at least have a plan. I think I'll go with the Lakewood LCA's from Summit mentioned above and the relocation brackets from Spohn. Seems like a good way to go for about $155. (Car is lowered with 255s in back and probably in the 400 hp range - feels like all hell is breaking loose when I get on it!)

 

Actually, you left out the 4th possibility -

It will break!

(Sorry, I honestly tried to resist, but when this post resurfaced again...)

 

I can vouch for that one