Front Suspension Advice

[70 Challenger Lover]

Just made some decisions on the rear suspension so I can get everything fitted properly as I finish up all the sheet metal work.

At some point soon, I need to think through front suspension components. I'm looking for stuff that will compliment what I'm already doing. Not going to compete but I'd like a tighter, more modern feel while still retaining driver comfort.

So far, I've done:

Complete US Car Tools stiffening kit (torque boxes, SFC, cowl braces, etc)
Ordered Hotchkis 160# rear composite leaf kit
Ordered Hotchkis front and rear sway bar kit
Welded up K frame and reinforced steering box gussets
Reinforced lower control arms with thicker sway bar tabs
Will be using Wilwood front power discs
Probably be sticking with 15" chrome road wheels but willing to spring for higher quality black wall tires.

There are so many posts here on components but I was hoping for advice on:

Power steering box (was considering the Borgeson)
High end shocks (adjustable yes but maybe not maybe not dual adjustable racing ones)
Pitman arm (stock? Longer than stock? 1 1/8 or 1 1/4 or does it matter?)
Upper control arms (the Hotchkis ones look great but are they worth the price?)
Torsion bars (was looking at the 1.1" Hotchkis ones just to stay consistent)
Poly or rubber bushings?
Any advantage of aftermarket struts or only in competition applications?

Again, not racing. Just want a nice streetable performer/driver/long trip cruiser. I like smooth if I can get it but I'm sure handling trades off comfort. Anything I'm overlooking? Need to map out all my spending now.

Thanks!

[Chryco Psycho]

Borgeson steering boxes are a good option .
Spend the $$ on good shocks , this is one of the most important & overlooked parts .
Pitmans arms change the rato # of turns lock to lock , the Borgeson steering  box already does this also .
I actually like stock control arms as long as you can adjust enough caster with offset bushings .
Either bushings are good , probably better off with rubber in the upper & lower control arms
Adjustable struts are much better than the stock non adjustable rubber bushed ones , worth the $$ IMO

[70 Challenger Lover]

What does an adjustable strut do? I've always thought of them as something to keep the lower control arm from moving forward or rearward. I'm sure they make adjustable ones for good reason but I've never really understood the advantage.

[Chryco Psycho]

Without rubber it is more rigid / fixed so less deflection but it can also help Caster a bit keeping the lower control arm forward a bit

[7212Mopar]

What I had  read. Adjustable strut rods is metal to metal at the attachment to K frame eliminating the rubber flexing and hold the LCA at the right position in its travel. The adjustable pivot can be set so to eliminate binding of the LCA going up and down. The adjustable length allows change in LCA angle that helps setting alignment.
I think the 1-1/8" and 1-1/4" are the steering box sector shaft size. Later years are 1-1/4".

[dodj]

If you go with longer pitman/idler arm, you may have header interference. Not a big issue, just dent the header, but just mentioning it so you know.
IMO, the hotchkis uppers are not worth the price. The MOOG offset bushings will do what you need for $50-$60. If your original uppers are not salvageable I'd look at buying new UCA's but I'd likely lean towards the QA1 piece. Same geometry 'correcting' for less $.
My preference for bushings is rubber for the control arms and poly for the sway bar.
I have no experience with Borgson but like my stage 2 Steer'n'Gear unit. Though, if I was ordering over again I'd go with stage 3. Same deal as Firm Feel boxes. Borgson is lighter I believe?
I just recently installed the adjustable strut rods from QA1. While they are not intended as a means of gaining more caster, I'm thinking I should be able to sneak in one more degree with these installed. Right now with the MOOG offset bushings I have 3.5*. The QA1 strut rods are metal to metal contact with a hiem joint.  I was changing the K anyway and thought I'd blow $200 more on the strut rods. It's a hobby..right?

[70 Challenger Lover]

My uppers were completely wasted so I had planned from the very beginning on getting new ones. Given the money I'm spending on the car, I don't want to go with stock uppers just to save money. I will look at the QA1 arms though as I'm not trying to waste money either. I am deviating from stock in so many areas so this is one place where I'd like to dial in more caster and the Hotchkis ones looked intriguing with their little bracket that's supposed to change a lot of the geometry flaws in the original design as the suspension travels up and down. They claim doing this increases traction in cornering by reducing bump steer. I don't know enough to analyze that claim but it sounds impressive.

On the adjustable struts, getting rid of the bushing doesn't increase vibration into the car? I plan to drive it regularly over rougher pavement.

[HP2]

Caster is best dialed in with the upper control arms.  Hotchkis control arms  have extra caster built into them, as do nearly every other aftermarket arm. Most tend to add 4*. Hotchkis also drops the front upper control arm mounting point. This is to accomplish a more linear arm movement that creates less caster change as the arm cycles up and down. Because of all the angles built into the front suspension, movement sometimes creates compromises from static position.  Mopars experience a negative camber gain in compression, a good thing, but also create negative caster gain, a less desirable thing.  IMO, most drivers won't really notice the dynamic caster change as much as they will notice the dynamic camber change.  The Hotchkis arms also have an un-intended side effect of reducing the anti-dive geometry built into the stock mounting location, but, with their suggested t-bar, the extra spring rate helps resist the anti-dive that is taken out of the geometry.

There are several other upper arm manufacturers you can evaluate; QA1, SPC, Performance Suspension, Firm Feel, Hemi-Denny, Magnumforce, Reilly Motorsports. Everyone but Hotchkis utilizes the stock mounting points and add caster with their arms. Yes, the offset rubber bushings are a way to add a couple of degrees to the stock arms if you plan on keeping the stock arms. Depending on the tolerance stack up, you may be able to get 4-6* this way.  The aftermarket arms can provide 6-10*. But, remembering the angle issue above, large amounts of static caster create large ranges of dynamic change.

The strut rod's sole purpose in life it to locate the fore/aft location of the lower control arm. Its highest stress occurs under braking when a large amount of compressive force is pitched forward into it, the bushing compresses and the lower control arm moves. Obviously the more rigid you make this part, the less dynamic change that is introduced into the system. Additionally, the more rigid parts are, the more noise, vibration, and harshness (NVH, the factories like to talk about reducing this)  that will be transmitted to the car.  A compromise here may be urethane strut bushing which are  more rigid but still have some measure of compliance. However,  a problem that has been discovered over the years with poly strut bushings is they don't exactly duplicate the rubber bushing's profile and the urethane can contribute to achieving LESS caster when assembled. Careful measuring and possibly reducing width of the rear bushing on a lathe can eliminate this problem.  Or....you utilize an adjustable strut rod that allows you to fine tune the arc of the lower control arm. Like upper control arms, there are numerous companies making strut rods. Some with more solid mounting methods. You can add 1-2* of caster with a shorter strut rod, but I wouldn't recommend going further than that as you can introduce binding in the lower arm motion by going too far with this.

Steering box creates driver feel and translates accuracy of driver input. Firm Feel can improve the feel and improve the input over a worn stock unit. But, it is still rebuilt on a stock box and will still lack some on center precision compared to  an entirely new box. It also is a very large piece of cast iron and has a built in ratio to it. This is why many add longer pitman/idler arms to them to speed of the ratio and reduce the turns it takes to move the tire relative to steering wheel input. Borgeson is entirely new and eliminates several of these issues. It is lighter, more compact and faster. It also operates on a different pressure which may require a new pump and it has a unique coupler, which will require mods to the steering shaft to connect it. More money, more time. Speaking of pump pressure, mopars are notoriously over-boosted. reducing pump pressure in your stock unit can improve feel of the stock box as well. Steering boxes in and of themselves don't necessarily improve handling. But they reduce effort and inspire driver confidence, which directly contributes to handling.

FWIW, Mopars were easily a decade ahead of their contemporaries in the suspension geometry department. Much of what we need to do with them today is simply refine what is there, not necessarily revise it all like what is necessary on other makes. That's what much of these aftermarket pieces do but how they package the marketing can change the perception. Think back, was Charmin really more squeezable than any other toilet paper or did they just capitalize on it? That isn't to say Hotchkis is all hype. They make very good products. But they also have a much greater marketing machine than all others.

Also, the Hotchkis leafs aren't composite. They are a multi-leaf steel arrangement, same as stock, but with revised construction.

[70 Challenger Lover]

Thanks everyone for the deep dive analysis. I'm going to look into all this stuff so I can make decisions on spending. You've all given me a lot to think about. I do like the sound of the adjustable strut rods, particularly if I can get a good setup using the poly bushings.

I'm pretty much talked out of the Hotchkis upper arms now but I would like to examine the other aftermarket uppers out there before making any decisions.

I see some manufacturers are using heim joints. Is this good or bad? I seem to recall seeing another post where someone complained they aren't durable enough over the long haul. Also, it appears as though a person would have to remove the upper to spin the joint for adjustments and then lock it down with the nut. Is that really how it works? That seems like it would be a nightmare to make adjustments. Especially with the suspension together and torsion bars loaded. What am I missing?

[dodj]

Also, it appears as though a person would have to remove the upper to spin the joint for adjustments and then lock it down with the nut. Is that really how it works?

Yup.

[HP2]

Heim joints are not a set it and forget it for years part. You can add dust shields to prolong their life, but you really should inspect them at least annually. Race cars inspect these as part of a track prep routing so they don't care how long they last. Rubber and urethane can be installed and forgotten until they fail.

Heim joint arms still install on the stock eccentrics so they have the same range of adjustment as stock before they have to be removed. After that, most heim jointed arms must be removed to adjust joint length, but not all.    Hotchkis and the Magnumforce double adjustables can be adjusted on the car.

[autoxcuda]

Also, it appears as though a person would have to remove the upper to spin the joint for adjustments and then lock it down with the nut. Is that really how it works?

Yup.

I have a complete hotchkis setup with 1.12" t-bars on my 68 Barracuda. Most of the heims are loose. About 10K miles and they all need replacing.  Before that (1993-2009) I ran .99" t-bars, addco sway bars, stock suspension components with poly bushings. Brakes have always been the larger 11.75" stock disk and calipers.

Taking a step back on the entire setup...  your 15" tires are your limitation on you handling.

Not that it can't handle good on the street with regular speed rated 15" tires. But the fine precision of something like a heim joint is not going to be realized.

I would go

1" torsion bars if you are street cruising
(1.11 will be noticeably harsher but helpful in extremely aggressive driving)

Bilstein non adjustable RCD shocks (not the fancy billet ones for $$$)

Poly strut bushings on stock struts
Firm feel upper arm
Or...
Adjustable strut
Stock upper arms moog offset bushing (you're just trying to get 3-4 degree positive caster)

Stock C-body 11/16" tie rods and stock C-body adjuster or most inexpensive tubular

Borgensen steering box (you probably have to change/rebuild box anyways and you will feel difference in precision and feedback from a rebuild box.)

[70 Challenger Lover]

Also, it appears as though a person would have to remove the upper to spin the joint for adjustments and then lock it down with the nut. Is that really how it works?

Yup.

I have a complete hotchkis setup on my 68 Barracuda. Most of the heims are loose. About 10K miles.

Taking a step back on the entire setup...  your 15" tires are your limitation on you handling.

Not that it can't handle good on the street with regular speed rated 15" tires. But the fine precision of something like a heim joint is not going to be realized.

I would go

1" torsion bars (

Bilstein non adjustable RCD shocks (not the fancy billet ones for $$$)

Poly strut bushings on stock struts
Firm feel upper arm
Or...
Adjustable strut
Stock upper arms moog offset bushing (you're just trying to get 3-4 degree positive caster)

Stock C-body 11/16" tie rods and stock C-body adjuster or most inexpensive tubular

Borgensen steering box (you probably have to change/rebuild box anyways and you will feel difference in precision and feedback from a rebuild box.)

I could see owning a nice set of larger aftermarket wheels just for a different look and road feel but I anticipate using the 15" wheels most often just because that's the look I want.

I have manual steering now but I will definitely not be keeping it. I was able to find a shorter power steering Column but would I still need to alter it for a Borgeson box? I thought only the longer manual columns needed shortening. I'm okay with that though. If I cut one, I'll cut the manual one and sell the PS version. The reason I was leaning towards Borgeson was mainly for a better design with less slop. I don't expect a handling improvement but I hate slop in my steering.

I'll probably go with the larger diameter tie rods and aftermarket tubular sleeves. I like adjusting those better than the stock style and they just seem stronger but probably doesn't matter I suppose.

After looking at the upper control arms out there, I can see I do not want heim joints. I'll go with the standard bushing style which is less expensive anyway.

When I start getting it all together, I'll want to really research the shocks. That alone could require some real thought to pick the right ones for my set up.

[autoxcuda]

Also, it appears as though a person would have to remove the upper to spin the joint for adjustments and then lock it down with the nut. Is that really how it works?

Yup.

I have a complete hotchkis setup on my 68 Barracuda. Most of the heims are loose. About 10K miles.

Taking a step back on the entire setup...  your 15" tires are your limitation on you handling.

Not that it can't handle good on the street with regular speed rated 15" tires. But the fine precision of something like a heim joint is not going to be realized.

I would go

1" torsion bars (

Bilstein non adjustable RCD shocks (not the fancy billet ones for $$$)

Poly strut bushings on stock struts
Firm feel upper arm
Or...
Adjustable strut
Stock upper arms moog offset bushing (you're just trying to get 3-4 degree positive caster)

Stock C-body 11/16" tie rods and stock C-body adjuster or most inexpensive tubular

Borgensen steering box (you probably have to change/rebuild box anyways and you will feel difference in precision and feedback from a rebuild box.)

I could see owning a nice set of larger aftermarket wheels just for a different look and road feel but I anticipate using the 15" wheels most often just because that's the look I want.

I have manual steering now but I will definitely not be keeping it. I was able to find a shorter power steering Column but would I still need to alter it for a Borgeson box? I thought only the longer manual columns needed shortening. I'm okay with that though. If I cut one, I'll cut the manual one and sell the PS version. The reason I was leaning towards Borgeson was mainly for a better design with less slop. I don't expect a handling improvement but I hate slop in my steering.

I'll probably go with the larger diameter tie rods and aftermarket tubular sleeves. I like adjusting those better than the stock style and they just seem stronger but probably doesn't matter I suppose.

After looking at the upper control arms out there, I can see I do not want heim joints. I'll go with the standard bushing style which is less expensive anyway.

When I start getting it all together, I'll want to really research the shocks. That alone could require some real thought to pick the right ones for my set up.

My biggest takeaway from your response was, " I hate slop in my steering. "

The borgeson box, 3-4 degrees positive caster, 1/2 deg neg camber are the biggest things to get you that.

A smaller Tuff steering wheel will give you a tighter feel too.

Also make sure the steering coupler sleeve to shoes are tight.

[70 Challenger Lover]

Now that I'm reading it, yes I guess that's the biggest thing for me in the front end. I know all the stiffening items welded in will give the car a tighter feel.

I have the next 9 days off so I'm going to get a ton of this metal work behind me. I'm getting antsy to putting the car on a rotisserie so I can put get som paint on it.