I was looking at getting some lower control arms for my car. I have heard both good and bad things about both spherical rod ended LCAs and polyurethane LCAs. Anybody have either one and what do you think of them? Are the rod end/urethane combo LCAs from Spohn better? I want good performance (bind=bad), but I also want them to be reasonably quiet.

Will they help my car hook up better? Right now it just spins the tires through first. Any suggestions on this problem also?

 

I would suggest getting lower control arm relocation brackets first,they will help your problem with spinning before tubular control arms will.They are around $70 thru Spohn.

 

How much would it cost to get a shop the weld these up and all fer ya?

 

There was a discussion on this when I shaped my suspention nicely..

https://www.thirdgen.org/techbb2/sho...threadid=78632

I desided on poly/poly for panhard/lcas, since its my daily driver.

 

Poly is good enough. I also agree with the relocation brackets too. Our cars have a terrible angle on the lower control arms if you takre a look and realize that they should point at the center of the car ( rightaround the tranny tail housing ). When I put in the poly bushings, panhard and control arms it took ALL of the slop out and improved handling so well.

 

Does the poly/poly sacrifice handling though? It seems like they'd bind real bad. Does anyone have the poly/spherical combo, and if so, how are they? I'm looking to get into autox/SCCA, so I don't want to sacrifice much cornering capability.

Thanks for the "relocation bracket first" recommendation. I was curious which would help the most and spending $70 vs. $150 is always nice--buying something sooner will make my part time pain in the ars job feel more worthwhile.:lala: ---what the f is this thing? lol

 

Another thought... when I had my SFCs welded in, the LCAs (factory) were in place(bushings behind the welded metal). This probably fried the bushings didn't it?

 

Yes,if the arms were left bolted in when the connectors were welded,I would say there is a real good chance they torched the bushings.The stock bushings burn easy,this will definitely give you slop and kill any hopes of traction,you may want to unbolt an arm and take a peek.

 

Poly poly should not bind at all as long as you keep them lubed. I have lakewood's which have zerk fittings. no squeeks and no binding. It's tight enough so if you and a couple buddies push the car side to side the rear housing stays still and only the side walls flex. Before the rod and arms, the housing moved back and forth in excess of an inch

 

I don't get it.

I'm thinking of the poly as reacting like solid bushings would. Obviously it's not quite as rigid, but still Much more rigid than the factory rubber. The rigid design restricts the movement of the rearend. Look at the car from the back. Now, when you corner, the car body rolls somewhat (and one of the springs has a greater force acting on it). This roll and force causes one side of the car to move down over the wheel and the other side to lift. This motion is natural and designed into the suspension. The stiff poly (and super stiff solid) bushings restrict this movement, thereby putting the entire cornering force (centrifugal force, weight of car, etc.) into the tires alone, rather than transmitting it into, and making use of, the suspension geometry. Think about an independent rear, and its travel. Maybe I'm all wrong on this, but engineers at companies like Spohn & Global West seem to recommend spherical for performance, while enthusiasts recommend poly.

It probably sounds like I've already made up my mind, but this question has me downright perplexed. As an enthusiast, and an engineering student hoping to get into this field, I'm trying to figure this out.

 

I don't know. My car with poly is more predictable than stock. It reacts the same to bumps weather doing 60 on a 25mph on/off ramp or 60 on a strait road. I think the improvement comes from the suspension doing all of the work, instead of the bushings absorbing shocks and flexing and distorting. The engineers designed it with specific travel and angles, which stays more consistant with poly compaired to stock (if you can push the car back and forth and see the axle shift, think about what the force of a 3600 lbs car does to the suspension when going around a sharp turn at a high speed). This deflection and movement is what the poly gets rid of, it does not actually restrict the designed mvement of the suspension, just the unwanted flexing and deflection.

 

They had to compromise some with the factory rubber because many customers prefer a smoother, quiet ride over performance.

I'm talking about poly vs. spherical rod ends.

I am still curious if anyone has the combo LCAs from Spohn. What are these like?

It pretty much sounds like rod ends would give the best performance, but on daily drivers they're too noisy and the poly doesn't hurt it too much. Seems like a combo would be a good compromise, but I thought the rod ends on both ends would have been best before I started asking message boards. Thanks everyone.

 

They had to compromise some with the factory rubber because many customers prefer a smoother, quiet ride over performance.

I'm talking about poly vs. spherical rod ends.

I am still curious if anyone has the combo LCAs from Spohn. What are these like?

It pretty much sounds like rod ends would give the best performance, but on daily drivers they're too noisy and the poly is an improvement over rubber. Seems like a combo would be a good compromise, but I thought the rod ends on both ends would have been best before I started asking message boards. Thanks everyone.

 

BMR Fabrication just cleared up my lingering questions. Thanks for your help everyone.

 

What did you decide on, just because I've just started to mess with handling this past year (for about 6 years all I cared about was power). What did bmr say? the relocation brackets improve the instant center, which you referred to as independent center ( i'm pretty sure, but not 100%). Suspension is the most complicated thing on any car, and the more I learn the better.

 

As for the "independent" instant center, I was way off. I've had dynamics, but I must have brain farted bad because my post on that stuff was way off. Sorry for any confusion. (Where's the smilie face that's pulling something out of his ***?)

As for what bmr said, basically, the rod ends aren't lubricated in any way. The metal on metal wears and creates play between the pieces, resulting in noise. The teflon lined ones delay this, but before too long, the teflon wears and falls out creating even more slop than if it was metal on metal. He said that the poly binds the suspension a little, but not enough to be noticeable to most anyone but a professional racer. The rubber is almost no bind, & I found that his "rubber" is actually Neoprene, so it lasts longer than the factory rubber. Furthermore, his bushings are smaller than stock which helps eliminate any compression of the bushings (especially the Neoprene). While the rod ends transmit the most noise, poly transmits some noise. This can be deadened by getting his poly/rubber combo because the rubber absorbs nearly all of the noise. For a comparison of poly vs. rubber, visit his website at www.bmrfabrication.com and look under the FAQ section. Hope this helps.

 

Thanks for the link, it sounds like it makes some sense. Good luck.