Your opinion: stock upper control arms vs. Firm Feel tubular

[firefighter3931]

Never have been a fan of lightened weight bearing suspension components on street cars. The stock stuff has allways served me well ! 

Some interesting reading on this very subject in the thread below :

http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Number=5210269&an=0&page=2#Post5210269


Ron

[b5blue]

I think the narrow front rims spaced outboard on that car would put allot of stress on that upper ball joint by transferring the load in and up? Shame to see such a nice car eat a tree!

[Hemidog]

Never have been a fan of lightened weight bearing suspension components on street cars. The stock stuff has allways served me well ! 

Some interesting reading on this very subject in the thread below :

http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Number=5210269&an=0&page=2#Post5210269


Ron

That thread was mentioned on page 1 

[69bronzeT5]

I'm going for tubular on my Charger. I've heard they're better than stock ones. I'm pretty sure Mike runs tublular's on Mr Angry and Angrier if I'm correct.

[NorwayCharger]

I do repair crashed vehicle for a living and i see that kind of damage all the time.
The car hit something hard and front suspension and LCA/UCA´s break.
This happend to BMW, VW, or any other make.
To me i looks like the car hit something hard in the left front corner and made the UCA break.
Do you think the UCA broke and made the car crash?

[firefighter3931]

Never have been a fan of lightened weight bearing suspension components on street cars. The stock stuff has allways served me well ! 

Some interesting reading on this very subject in the thread below :

http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Number=5210269&an=0&page=2#Post5210269


Ron

That thread was mentioned on page 1 

Yep, i noticed that after posting the link. 

[firefighter3931]

Do you think the UCA broke and made the car crash?

My guess is that the UCA broke first then steered the car off the road creating the damage to sheetmetal. 

I've been to many wrecks as an emergency responder and work on an extrication pumper with hydraulic tools (jaws/spreaders/cutters/rams) and have not seen a "stamped" stock style UCA broken like that. The stamped stuff tends to bend but not break. 



Ron

[Mike DC]

My guess is that the UCA broke first then steered the car off the road creating the damage to sheetmetal. 

I've been to many wrecks as an emergency responder and work on an extrication pumper with hydraulic tools (jaws/spreaders/cutters/rams) and have not seen a "stamped" stock style UCA broken like that. The stamped stuff tends to bend but not break. 

The broken A-arm causing the wreck is certainly a possibility, but I don't see how it's an automatic assumption judging by the wreck. 


I agree with you, the stock A-arms are liable to bend like hell and maybe even peel all the way off the balljoint without ever snapping apart.  But that doesn't mean the tubular A-arm on his car failed before the hit.  He hit something with that corner hard enough to break a good solid aftermarket A-arm. 

The aftermarket parts don't need to be unbreakable.  They just need to be strong enough so they don't become a weaker link in the chain than the originals were.  This hit remains inconclusive IMHO.


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I also wonder about the type of steel & the type of welds we're dealing with here. 

A thin-walled chromemoly A-arm with TIG welds holding it together is one thing.  A thick mild steel A-arm with gas torch (oxy/acetylene) welds is something very different.  These cases would produce two parts with similar final appearances, but with VERY different failure characteristics.

[bull]

In the end though I have to wonder if the added expense will really offset the improved handling.

[HPP]

In the end though I have to wonder if the added expense will really offset the improved handling.

Depends on what your doing with your car. IMO, no, there is not $300 worth of improvement in tubular uppers.

[NorwayCharger]

The true story is here..

http://www.bigblockdart.com/index.php/topic,38494.0/topicseen.html

[Mike DC]

Depends on what your doing with your car. IMO, no, there is not $300 worth of improvement in tubular uppers.

What's several additional degrees of caster worth?  Maybe a whole lot, depending on the guy & the car setup.

 

[HPP]

Yes, a few extra degrees of caster is important, but when that same imrorvement can be had for $30 for offset bushings compared to $300 for arms, then the value ratio changes, dramatically.


Something a lot of people tend to overlook is that there is only $50 worth of material in these things, so even with development costs, labor, overhead, etc, I don't see six times margin as a reasonable cost for these items. However, many, many people do or otherwise the price of these arms would have dropped because of no one buying them. Simple supply and demand. IMO, there is not $300 worth of improvement that is received by using these arms. For example a local shop builds tubular arms for many of the area oval track racers. Their price, $175. Granted those are chevy arms, but it doesn't take much alteration in design to fit the mopar layout and I could have some simialr arms for nearly half of what most compaines are selling them for.

[bull]

I hate to do this but maybe someone could explain their theory on what added caster does to improve handling and why the stock caster is inadequate? I'd like to go back to basics here if possible.

[Ghoste]

Not unlike the casters on a piece of furniture versus just a straight up and down mounted roller.  One has a tendency to try and stay neutral and going in the direction it's pointed (high speed stability) and the other is easier to turn at low speeds.

[bull]

Right, so positive caster would be backward angle on the wheel's center point, correct? What is the stock caster angle and how much more angle do these tubular upper arms create? The chopper pictured below has what looks like nearly 45-degrees of positive caster. Is it measured in degrees on a Charger? If so what's the number?

[Mike DC]

 
Stock caster was essentially zero.  I don't remember what the technical specs were but it's little or none.  Maybe 1-2 degrees.  (Factor in the car having a non-stock raked stance, and your caster is potentially going all the way into the other direction past zero.)


I don't know about the specific Mopar A-arms in question.  But geometry-corrected aftermarket arms for muscle cars are generally something like 8 degrees.  That's the kind of number that tends to be favored by modern sports cars. 

 

[b5blue]

My recent Goodyear alignment spec. is 0.3 to 1.3 (+) just remember if you increase that angle you also angle the part of your lower ball joint that goes to your outer tie rod, too much + = on a manual steering car hard steering, on power steering indirect cause of low-speed shimmy, increased road shock and high-speed wander. (per MoPar chassis book)  If you really want to get into this look up "steering axis inclination" and check out "slip angle" as camber has an effect on "the angle of steering axis inclination" and that effects "lateral load deformations of tires" 

[HPP]

Stock alignment spec called out negative caster to a lesser or greater degree depending on power or manual steering, and a camber that was zero to positive. Don't forget that these specs were for rock hard bias ply tires and that radials will tolerate a wider range of adjustment than a bias ply. Currently with radials, you would want as much positive caster as possible up to around 5 degrees with a slight amount of negative camber to improve road holding capability. Geting caster out beyond 5-7 postive degrees in a vintage mopar puts unusual stresses in the steering linkage that could possibly create premature wear.

Steering axis inclination is going to contribute to high speed stability and return to center capability to a greater degree than caster will. Greater SAI will also provide a greater "jacking" effectas the wheel is turned and more dynamic caster is introduced in to the set up. This jacking effect will reduce the amount of lateral deformation of the tires and help reduce slip angles by raising that corner of the car slightly during cornering. 

The only way to icnrease SAI is to swap out the early style disc brake spindles for the later B, FJM spindles or go with a custom design spindle $$$.

[b5blue]

If I'm not mistaken if you raise or lower the rear ride height you will "change" S A I. The issue is the arch that the spindle makes as it turns, too much and that sweep plows down on one side and up on the other. That's why jacking up the rear end of a car is a no no. 

[Mike DC]

 

To understand how raising the rear end affects the front end's aligment, think of the way that raising the rear end makes the headlights point farther downwards.

The camber & toe & SAI are relatively unaffected (as long as the amount of rake is within reason) but it causes a caster problem. 

[b5blue]

Right, the chassis now has the front suspension moving up and forward in jounce if the rear is up too high. 

[kcederwall08]

I'm using some tubular adjustable controll arms form Magnum Force, and I think there pretty good. I was running a rediculous amount of negative camber in the front due to me lowering the car, but now its much better. As for an performance incease, I cant say I have really noticed anything, other than high speed stability, which is probably due to a new good alignment.

[b5blue]

Did you lower the rear also?

[Mike DC]

other than high speed stability

A gain in caster will do that. 

It increases the front steering's tendency to center itself whenever you're not putting pressure on it one way or the other.  Like because of the vehicle's speed.  The same way a shopping cart's swiveling back wheels wanna fall back to being centered whenever you push the cart and let it roll.