Question about lower control arms

Bronco2Fan

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So, my 03 GT Vert is due for a suspension overhaul. I've been researching and see basically 3 kinds. Stock, tubular, and tubular with spring perches. If I do coil overs, I wouldn't need spring perches correct? If I do shocks, struts and springs I need the kind with perches? If I do coil overs, can I still use the stock arms or tubular with perches?

I know that's a lot of questions. But I want to keep the ride stock for comfort, and it doesn't see a lot of use nowadays. Plus, I want to try to get everything from 1 vendor if possible. I'm leaning towards coil overs just for the ease of getting it lowered some and comfort.

I read the stickies and they're informative and confusing, as they deal mostly with track set-ups. Any info and insight are appreciated.
 

Warhorse Racing

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Are you looking for front control arms or rear lower control arms? Either way, aftermarket tubular front/rear control arms don't usually come with rubber bushings. Poly/Delrin/spherical bushings will add NVH. If you are focusing on ride quality, you might want to stick with rubber bushings. You can find replacement rubber bushings for the front and rear control arms, or you can find OEM-style replacement arms with rubber bushings. In some cases, those rubber bushings can cost as much (or more) than poly bushings. For your application, you might want to consider a (relatively) inexpensive set of adjustable shocks & struts (like KYB AGX). You'll be able to adjust the ride quality easily. If you decide to install lowering springs, progressive springs will be better for comfort.

Late Model Restoration should have several options to choose from for all of the parts you are looking for.
 

Snorky

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I enjoyed the ride of my green mustang the most on eibach pro kit lowering springs, then less with the h&R SS springs, then even less with a upr tubular K with stock A arms. And now the least with my upr K member and A arms with my maximum motorsports/koni yellow coilovers. With torque arm springs out back on my MM xd lcas panhard bar torque arm.

All thr setups I used the koni yellow shocks. If you're looking for ride comfort I would suggest stock A arms with rubber bushings. A minor lowering spring(no it won't sit remotely flush) it'll still look tall to most young car guys. A ford racing B spring or eibach pro kit with good shocks will ride closer to stock with improved handling. As you get progressively closer to race car handling or being stanced. Your ride becomes progressively less comfortable.

Another person to ask is white with his panhard bar torque arm setup lol
 

PNW Mike

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You may want to ask the folks over at Maximum Motorsports for their recommendations.

I chatted with them about my goals for my '97 and I was very satisfied with the process and how much time they invested in working with me to sort out the right options for "phase 1" of what I should do, with future phases of improvements I could add on later. I also learned a lot from their tech pages - they have great insight into the nuances of the options and a solid understanding of what works and why. I have a parts list from them that is in the queue for projects to get done as soon as I have time - and after I stop finding other random fun new projects to spend my time and money on. :)
 

shovel

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If your plans include a lower ride height from stock you'd do well to get the BMR arms with tall ball joints. That's going to correct roll center for around 1" worth of lowering. It's not quite as good as spindles or not lowering but it's better than stock ball joint geometry on a lowered car.
 

MachSVT

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Front Control Arms

1. Stock - Can utilize coil over conversion. I used this setup when I converted to a koni coil over setup utilizing Maximum Motorsports (MM) coil over kit. Note: requires camber plates!

2. Aftermarket tubular with coil spring bucket - I'm not really sure why these are ofered as they don't offer any mprovement over stock (geometry / weight savings). Can also utilize coil over setup, but I'm not sure why someone would want to do so.

3. Aftermarket tubular WITHOUT coil spring bucket - Coil over applicable ONLY. Note: requires camber plates! Many suppliers supply these, which offer weight savings and (depending on manufacturer) offer geometry changes. For example MM arms can be purchased with forward offset of 3/4 inch. This is ideal for a stock subframe because it centers the wheel in the wheelwell, which both is a visual improvement, but also moves your weight balance slightly rearward, which is an adantage for our nose heavy applications.

What is ideal about #1 and #3 is that you can upgrade your front suspension in steps BUT keep your #3 selection in mind if you have asperations to eventually upgrade to a MM crossmember. The reason this is important is that MM offers both offset arms and stock geometry arms. Why that's an important callout is the MM crossmember ALSO offsets the control arms 3/4 inch.

Said another way:

If only wanting 3/4 offset, either utilize the 3/4 arms, or the non-offset arms with MM crossmember. This offset does not have inner fender interferrence with (up to) a 275 width tire ON MY CAR. Keep in mind this is ride height dependent.

If wanting 1.5 offset (this would be race ONLY as your front tires WILL interfere / rub the inner fender) could also be ride height / tire widt dependent.

All of this said, I upgraded a part at a time in steps:

Step 1: MM coilovers /Konis
Step 2: MM non-offset control arms
Step 3: MM Crossmember

I hope this helps!
 

shovel

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Tubular arms with coil buckets
1. can be available with tall ball joints which correct roll center for about an inch of suspension drop (or can move roll center closer to center of mass on a stock ride height mustang for track tuning)
2. are torsionally much stiffer than open plane stamped arms for less fore-aft deflection which also improves strut linearity by eliminating bind
3. have more firm pivot bushings which can mean more steering feedback in competitive driving (and more NVH when driving in the real world, can't have everything)
4. weigh around 20% less (10lb vs 13lb)
 

MachSVT

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Disclaimer: I never really researched, so I am honestly asking...not meant as a "counterpoint" for arguements sake...

Your #1 & #3 can be accomplished with stock arms, yes? Defiitely more convenient to just bolt them up vs. needing a press, etc. So I get that point. They certainly would not need to be as strong when moving the spring on the same axis as the strut.

It's the #2 that I'm really after. Are stock arms really that weak? They appear to be overly robust by comparison to the aluminum arms I see on many vehicles.

I guess I'm approaching this from a "what would I REALLY gain over the stock part" as the divorced spring / strut setup is rediculously inefficient from a spring rate required / weight perspective. It's the cost of said arms that makes me say "why would I want that?".
 

shovel

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Disclaimer: I never really researched, so I am honestly asking...not meant as a "counterpoint" for arguements sake...

Your #1 & #3 can be accomplished with stock arms, yes? Defiitely more convenient to just bolt them up vs. needing a press, etc. So I get that point. They certainly would not need to be as strong when moving the spring on the same axis as the strut.
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It's the #2 that I'm really after. Are stock arms really that weak? They appear to be overly robust by comparison to the aluminum arms I see on many vehicles.

I guess I'm approaching this from a "what would I REALLY gain over the stock part" as the divorced spring / strut setup is rediculously inefficient from a spring rate required / weight perspective. It's the cost of said arms that makes me say "why would I want that?".

I don't know if tall ball joints are available to fit stock arms, never looked into it myself. Cost no object the three best ways to address this would be spindles (maintain the already very good stock arm geometry and retain full strut travel) or a tubular K-member that compensates for lower ride height by relocating the inboard pivots upward (and forward, in at least one application) or keeping the car at stock height because the folks who engineered it did a good job and compliance does not equal bad handling.

Tall ball joints are mostly a budget-conscious way to still do a better job than just lowering ride height for cosmetic reasons with stock geometry.

Ford Racing M-3075-D control arms (stock on 03-04 Cobra, OE performance upgrade briefly available in the Ford Performance catalog) have slightly stiffer rubber bushings to increase steering feedback and reduce deflection. Aftermarket tubular arms like BMR have urethane bushings that also are smaller in diameter for much higher stiffness - this is always going to communicate more of the road to the chassis and steering wheel which might be better in competitive scenarios but worse in everyday road driving. I think a lot of people aren't honest with themselves about how they're going to actually drive and don't give the rockstar engineers who developed the car enough credit for the balancing act of making a sellable product.

The stock arms are not weak but they are also not as rigid as a tubular arm because ultimately they are a flat piece of steel that's had a texture pressed into it. You can imagine the difference between a piece of paper you've folded a couple times vs. one you've carefully rolled into a tube and taped - same idea here. The stock arm is a lever with its fulcrum in the middle (the bottom of the spring) and it's held in tension vertically but stiffness in every other direction is kinda hamfisted and probably accounts for the manufacturer just throwing steel mass at it. The ball joint prevents direct twisting force but since the bottom of the coil bucket, the center of the ball joint and the instant center of the pivot bushings will almost never be directly inline with whatever force is acting on them they will always twist a little bit and that means deflection.

This is of basically no importance to actual handling but can mean a lot to steering feel and communication. The weight saving and possible reduction in strut bind of going to a tubular arm would likely be responsible for most or all improvements in lap times, if any.

I speculate they were designed that way for economy, somebody could throw a sheet in a press and pull out a formed arm in 4 processes (stamp, fold, coat, insertion) , probably under 30 seconds net work per arm vs 10+ minutes per arm manufacturing welded tubular ones. I do not know enough about the state of aluminum casting in the 90s but I think it's likely even if material cost is identical there's no way you could manufacture aluminum arms with as little labor or process cost as stamped steel.

To give the original engineers credit the divorced spring and strut arrangement means that the coil spring is traveling half as fast as it would on a coilover and since kinetic energy scales logarithmically your net (dynamic) unsprung weight on a divorced spring can be potentially less than on a coilover even if the actual spring is heavier. This also makes the K member the main stressed element in holding up the car's weight which (likely) provided some weight savings in engineering the firewall/pan/fender structure and brought some of the twisting forces acting on the chassis inboard to make the whole chassis torsionally stiffer. 70s car engineers might have been under a lot of economic constraints but they weren't dummies.
 
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Bronco2Fan

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My car will never see the track and only occasional spirited driving. I haven't driven it over 20 miles at a time since I retired in 2012. And less than 200 miles a year put on nowadays. I just know that the OE stuff is original and never replaced, so it needs done for sure.

I appreciate the input and knowledge you guys are sharing.
 

shovel

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Overwhelmingly the main reason I would consider replacing original arms is that the ball joint is under tension and while it does communicate impending failure a little bit, we all have different nervous systems and plenty of people have been caught by surprise.

Since the ball joint is under tension and the whole car is hanging off it, when it fails it fails all the way. There is no partial failure and limp home.

If you're in a parking lot when it fails you get a dented fender and a towing bill, if you're on the highway when it fails you may get to meet doctors or God.
 

MachSVT

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Please delete....double post
 
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MachSVT

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Overwhelmingly the main reason I would consider replacing original arms is that the ball joint is under tension and while it does communicate impending failure a little bit, we all have different nervous systems and plenty of people have been caught by surprise.

Since the ball joint is under tension and the whole car is hanging off it, when it fails it fails all the way. There is no partial failure and limp home.

If you're in a parking lot when it fails you get a dented fender and a towing bill, if you're on the highway when it fails you may get to meet doctors or God.
Great point!
 
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Bronco2Fan

Bronco2Fan

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So, MM suggested I go with Bilstein's all around, front coil over conversion with 275 in/lb 12 in long 2 1/2 in dia. springs, adjustable rear lower control arms with MM road and track springs (no coil overs). Caster camber kit. They also suggested the pan hard kit. But that looks like way too much work. And I don't think I actually need it.

What's funny is the didn't mention front control arms. I guess I'll call them back today and ask.
 

Musturd

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Like others mentioned simple lowering coils and quality shocks and struts . No need for all the mm bullshit . Especially coilovers unless you want your car to ride like complete dog shit . Eibach pro kit is always a good option . Mm stuff is great for a race car but sucks dick for daily usage . Rides like a skateboard
 

Snorky

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Like others mentioned simple lowering coils and quality shocks and struts . No need for all the mm bullshit . Especially coilovers unless you want your car to ride like complete dog shit . Eibach pro kit is always a good option . Mm stuff is great for a race car but sucks dick for daily usage . Rides like a skateboard
A strong degree of truth in the background of this statement. If you want it to handle our hookup. Mm has you covered. If you want it to ride "good" for a race car. They've got you... but it isn't saying much next to an oem or an eibach prokit setup. But those obviously trade off with handling for ride comfort....
 

shovel

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It's basically impossible for any two people to agree on what constitutes the proper ride height, the most comfortable ride, an acceptable compromise, good or bad amounts of NVH, or even "good" handling - except at least on the topic of handling it's possible to produce empirical answers with a stopwatch. And then ignore them because these cars tend to return better times near stock ride height and looking fast is way more important than being fast.

 
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Musturd

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Was hard to beat the ride quality and handling when my car was setup like this steeda springs , Koni adjustables , steeda lower control arms factory uppers 03/04 cobra front control arms steeda bump steer kit 13” brakes all around car rode similar to factory for a smooth ride and handled exceptionally well with the steeda front and rear sway bars .
IMG_1572.jpeg
 

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