few questions about bushings, susp, roll centers etc

[overb0ost]

1) how are the FLCA ball joints supposed to operate? are they supposed to rotate and move very freely and smooth or should it take a little effort to move/rotate them. question i ask is because i disconnected my coils from the strut tower and 1 side the coilover would just limp over to whatever side it felt like (the ball joint would move so easily, it was a non-grease joint) and one side the coilover body would just stand still unless i pushed or moved it over. it seemed somewhat seized compared to the other side. this side the ball joint was a grease ball joint.

if a ball joint like mine that seemed a little seized, how would it affect my suspension and steering inputs etc?

2) how would the rear react to old worn out bushings in the rear lca AKA camber Aarm? in terms of hard driving grip or drift.

3) how much should i estimate to pay a shop to replace my worn out shot subframe/diff bushings? i know they are shot because the rubber is ripped to shreds and i can see the silver slotted spacers that are in my subframe.

since the subframe bushings are shot, does that mean my subframe has been experiencing more or less anti-squat than it should?

4) which is more important, front or rear roll centers? do the ball joints for the front and rear have different or the same pivot points inside the ball joint? i know one guy got them to fit but never measured if the pivot point is actually the same for front and rear. i do know that the higher the roll center, or i should say closer to stock geometry, it USUALLY means added grip because less binding. i've read somewhere that the front roll center should be slightly lower than the rear because it will load your outside front tire as the chassis rolls. true or should the be approximately the same height?

and yes i've searched around but these are pretty specific questions. any helpful information would be greatly appreciated! thanks

[racepar1]

1. New ball joints are not easy to move. The easy way to check ball joints is to jack up the car and get a big ass set of channel lock pliers and squeeze the knuckle into the control arm (squeeze the ball joint together).There should be very little or no play.

2. The bushings in the suspension arms themselves RARELY actually go bad. People ust replace them to reduce the slop in the rear suspension. Trust me on this I have done 4 energy kits in 240's this year alone. Also the rear LCA is not the camber arm the rear upper control arm is the camber arm.

3. Expect to pay A LOT of money to have a shop replace the subframe and diff bushings. For the subframe bushings alone you are probably talking over $500 because you have to remove the entire subframe from the car to do them. The diff bushings should be much cheaper because they are not that hard. If your subframe bushings are super shot then the whole thing will move pretty much anywhere it wants to. Every angle will be affected.

4. Both the front and rear roll centers are equally important, but their importance is not reducing bind. As you lower the car the roll center of the suspension drops more than the center of gravity of the car. This basically gives the body more leverage on the suspension, which causes excessive body roll. And yes the front roll center should be lower than the rear. You want it a bit lower in the front so the car can be tuned for slight oversteer at low speeds and slight understeer at high speeds.

5. It doesn't really sound like you know what you are talking about, it sounds more like you are just repeating things that you have heard (and it doesn't sound like your sources are very reliable). If you really wanna learn about suspension tuning go to sportcompact car magazine's website and read the MAKE IT STICK articles. They contain a lot of great information and they also have diagrams, which a lot of books about suspension tuning do not have.

[overb0ost]

thanks for the answers. yes you are right, i don't know exactly what i'm talking about hence me asking these questions to learn more. I've read a bit but obviously not books and books on this stuff since it gets too technical. I just read enough to understand the jist of things, or at least try to.

Some corrections on your post.

the rear LCA is also called the camber Aarm or at least thats what nismo calls it, "Nismo Camber Suspension A-Arm"

also, i agree with what you said about the roll centers, but if you replaced your bushings with roll center adjusters like MF-R, it would benefit raising the roll center and correct some of the binding issues resulting in more grip because of the added suspension travel. This would also allow the driver to have a better feel for the rear end, especially in terms of drifting.

correct?

[racepar1]

Read the make it stick articles. You said it yourself that you don't know what you are talking about and I obviously have at the very least a very good idea what I am talking about, so what the hell makes you think you have anything to correct in my post? A camber arm and an A-arm are TOTALLY different things. The camber arm would be the arm that controls the camber angle which is correctly called the rear upper control arm. The rear LCA can also be called and A-ARM. As far as the name in the NISMO catalog please remember that just because something makes sense in japanese does not mean it makes sense when translated directly to english. THE ROLL CENTER HAS NOTHING TO DO WITH SUSPENSION BIND, PERIOD. Get a clue before you try to argue.

[LongGrain]

thanks for the answers. yes you are right, i don't know exactly what i'm talking about hence me asking these questions to learn more. I've read a bit but obviously not books and books on this stuff since it gets too technical. I just read enough to understand the jist of things, or at least try to.

Some corrections on your post.

the rear LCA is also called the camber Aarm or at least thats what nismo calls it, "Nismo Camber Suspension A-Arm"

also, i agree with what you said about the roll centers, but if you replaced your bushings with roll center adjusters like MF-R, it would benefit raising the roll center and correct some of the binding issues resulting in more grip because of the added suspension travel. This would also allow the driver to have a better feel for the rear end, especially in terms of drifting.

correct?

the nismo camber susupension arm is the UPPER control arm, not the lower.

[BusBOy]

CORRECT..
i have spl subframe bushing on my car and the rubber around it is terring apart and im still hitting corners..

[overb0ost]

racepar1, when did i EVER say camber arm?

i think you misread my post and didn't see the "A" infront of arm

i said rear LCA, AKA camber Aarm

this is for all those who DON'T KNOW, LOWER CONTROL ARM
http://www.projectnissan.com/shopping/pc/viewPrd.asp?idcategory=234&idproduct=3962
http://www.projectnissan.com/shopping/pc/catalog/nismo/nmo-RearArmS14.jpg

but neways, thanks for the prompt answers.

on another note, since we're on this topic can you explain what suspension bind is and what causes it? yes i know its from excessively lowering the car.