So I was strongly recommended getting control arms. I think someone said the uppers are the most important, if not, please correct me on that.

I have a couple questions about them.

1. Are these responsible for helping to prevent the *** drop when I launch or with WOT?

2. I am seeing a lot of arms, ranging in a pretty dramatic difference in design and price. I have no idea which ones I should be looking at.

3. I thought they were in pairs. Is there only one for each the upper and the lower? It looks as though they are being sold in singles, which is why i am asking.

This is my first time ever dealing with them, and know very little about them.

 

There is only one upper control arm. There are two lower control arms and they are sold in pairs. I think this is more what you're looking for. They won't prevent the rear end from dropping, but they will help keep the rear end planted for improved launches. They are typically sold with different types of bushings. Depending on your intended use, you will want to choose different bushings. The first type, mostly for daily driver duty, have regular polyurethane bushings in both ends. These are much better than the standard weak control arm bushings and will aid in keeping the rear planted. If you are looking at light track use, try something with a spherical-type bushing in one end. The spherical type will transmit a little (probably hardly noticeable) NVH (noise, vibration, harshness) but will allow the back end to articulate properly around corners. If you don't care about NVH and only want articulation, get LCAs with spherical bushings at both ends. These articulate the best while still keeping the rear end planted. It is generally recommended that you get non-adjustable LCAs and use the upper control arm for pinion angle adjustment (if you get an adjustable upper control arm).

If you want to go the upper control arm route, the same basics apply. A good UCA with a polyurethane bushing will be much better than stock. One with a spherical bearing will transmit more NVH but allow better articulation of the rear end. If you don't plan on lowering the car (which can change the pinion angle) then you can get non-adjustable control arms the whole way around.

At least that's how I understand it, hopefully we get some others chiming in. Hope this helps!

 

1. No. Rear end squat is a rear suspension geometry thing that depends on the exact control arm pivot point locations. Aftermarket brackets that revise either the axle-side LCA pivot point locations or the chassis-side UCA pivot point location are available, but may not actually require aftermarket control arms. FWIW, squat is not always a bad thing.

2. Waiting on your intended or expected uses of the car before adding anything.

3. CMcNam has this one covered. Adjustable LCAs will also allow you to correct thrust angle errors.


Norm

 

Will most likely not lower the car. It's for mostly street use, weekend driver. It's my "toy" and performance is my goal.

 

Can you narrow down what you mean by "performance" a little? Mods that help straight line acceleration don't always help cornering performance (and frequently hurt it). The opposite can be true as well.


Norm

 

Mostly looking for straight line acceleration.

 

Wider tires in the rear and CAI/tune would be the first step then. Mustangs are already set up pretty well for straight line acceleration as is. New control arms are only gonna do so much to help you hook up in 1st and 2nd, wider tires in the rear will do much more and a CAI and a tune are gonna do wonders.

 

Then for control arms it's not likely that you'll need to spring for spherical/spherical ended arms. Poly/poly will work, though poly/spherical will be somewhat better suited to cornering (and can also be good with respect to daily driving ride quality and noise concerns if you pick arms that don't feature all metal in the spherical ends - all-metal sphericals will eventually rattle).

It's all in the bushings . . . and if you aren't yet experiencing wheel hop you don't have enough reason to change out your OE's for anything firmer yet either.

But if you do, consider picking away at the problem in stages. The lowers are quite a bit easier to get at, so you might want to swap something better there first. If that cures your problem, you're done, so stop buying stuff to keep fixing it. If not, that's when you do the UCA. Past that there are several things to work with (shocks, springs, relo brackets, motor and transmission mounts).


Norm

 

Thanks so much. That clears up a lot! No, not really experiencing much, if any wheel hop. I was just under the impression that too much rear end drop would hurt performance, so I was looking at ways to fix that if I had to. The control arms came up in another thread, and was unsure if that's exactly what I needed.

So does the LCA or UCA possibly increase ETA/0-60 at all?

 

Squat implies a performance loss to the extent that the total rearward load transfer takes a little longer to occur, and acceleration will be slightly less for a fraction of a second.

Rearward load transfer has at least three paths, and they all peak at slightly different times (think in terms of a hundredth of a second at a time or less). Anti-squat, or geometric effects happen the soonest, and if all the load transfer was geometric you'd have no squat at all (and might even get rise/separation). Load transfer through the springs is the slowest, because it does not reach its final maximum value until the car has finished squatting. This might take half a second or less to happen. The third is through the shocks (compression or bump damping), which peaks in time somewhere between the other two.

Except for special circumstances like where the rear wheels encounter a dip in the road and try to drop out from under the body, the tail of the body dropping does not mean that load transfer has been reduced. Only that it's not finished happening.

I've never tried to estimate how much of a hit performance takes when a car has any given amount of squat, probably because I'm not nearly good enough at launching for it to matter.


Norm