Tubular arms worth it?

[OCswinger]

I'm at that critical part in the bench build where I am trying to decide to drop money on tubular upper and lower control arms, or rebuild my existing ones now. The car is a 74 Duster, will have a 360 and a 727. I'm not into autocross are anything like that but, mostly just terrorizing the neighborhood. The body will need a patch in the lower quarters so I wont be dropping too much on bodywork (repair). She wont be a trailer queen but, wouldn't mind the suspension upgrade, that is if it is worth it.
For those of you out there that went the tubular route, was it worth it?
Thanks FABO

Jon

 

[abodyjoe]

rebuild and box the lowers ya have already. being a 74 i'm assuming it has disc brakes already? if so then you already have the large ball joint upper arms so just replace the bushings with moog offsets and replace the ball joint and be done..

 

[340duster340]

for an around town car, it really doesn't matter. the stock stuff is plenty strong.

 

[72bluNblu]

rebuild and box the lowers ya have already. being a 74 i'm assuming it has disc brakes already? if so then you already have the large ball joint upper arms so just replace the bushings with moog offsets and replace the ball joint and be done..

This. Unless you're going to run REALLY low with the torsion bar suspension, the tubular lowers aren't really necessary (they do add some additional suspension travel for lowered cars). Boxing the stock LCA's will be fine, and will allow you to address any play they might have developed. Jim Lusk has a great video on YouTube on how to do this.


For the UCA's, rebuilding with a set of Moog offset bushings will be enough to modernize your alignment specs, and will get you enough caster for a street car. If you're planning more of a corner carver, the tubular UCA's can get you more positive caster than the offset bushings will give you with the stock UCA's. But, really unless you're running 17" or larger rims with more modern tire compounds you won't need that much extra caster. If you are planning on 18" rims, the tubular arms do allow more rim to UCA clearance, which can come in handy for running really wide rims up front (18x9 or larger), but anything less than that doesn't really need that either.

So my vote is, as usual, depends on the application. For a basic street car with 15" rims and BFG T/A's you can keep the stock stuff and just reinforce the LCA's and run offset bushings in the stock UCA's.

 

[vitamindart]

Joe pretty much nailed it. Offset bushings in one arms are fine. No need for the extra cost.

 

[fratzog lover]

 

[kiss]

Fix/Box/Reinforce the lowers.
You will want to get tubular uppers. They allow for more caster adjustment at a better position. Stock UCAs won't allow for much positive caster at all, even with offset bushings, and even then your wheel/tire position in the fender will be sitting far back.

 

[famous bob]

Fix/Box/Reinforce the lowers.
You will want to get tubular uppers. They allow for more caster adjustment at a better position. Stock UCAs won't allow for much positive caster at all, even with offset bushings, and even then your wheel/tire position in the fender will be sitting far back.

you don`t really have to buy the reinforcements for the lowers either. if you can weld u can make your own, any meat on them will make them stronger.

 

[jbc426]

It helped me to think of the wobbling shopping cart front wheel versus the chopper images when thinking about caster with negative caster making the car twitchy like the shopping cart front wheel and the increased caster being akin to the straight line stability of a chopper front wheel.

On my A-Body, the potential added caster that quality tubular upper control arms add was less than pulling the lower control arm forward with an adjustable or modified stock strut rod. I had also raised the rear of the car slightly to gain rake. In my case with the added rake, Firm Feel tubular uppers brought me to 0 caster. I added a Hotchkis adjustable strut rod, and now have 5 degrees positive caster. The car has phenomenal high speed and open road tracking, and gaining the increased tracking does not seem to have a downside during any low speed driving either.

You do have to be careful not to let the shorter rod bind-up the range of motion or the lower control arm with the torsion bar removed. You must also take care not to pull the lower control arm so far forward that your front wheel hits the fender during it's turning range of motion.

On a related note, stay away from Moog ball joints. Mine fell apart in the box. I switched to using front end parts from these guys, and love them. The Moog offset bushings are still fine. If it were me, I would use the offset bushings, box the lower control arms and add some quality adjustable strut rods.

XRF Chassis | Automotive and Heavy Duty Chassis Parts | Canada and Unites States

 

[doug 371]

wow

 

[fratzog lover]

How the once mighty Moog has fallen. I'm guessing Chinese junk?

 

[GMachineDartGT]

There are pluses and minuses to your considerations.

Tubular Uppers

PLUSES

Increased caster using a standard urethan bushing
Required for high offset wide rims

MINUSES

Not necessarily stronger than OE

Cost

LOWERS

Pluses

Replace worn.out lowers with new tighter parts. Originals wear at T bar sockets

Increased bump clearance

Minuses

Cost
Cantilevered strut rod attachment looks funky to me. QA1 has in house engineering so Ill assume they are smarter than me.

 

[OCswinger]

Its looking more and more like the consensus is to rebuild the existing arms. Thanks for all the replies and thoughts. Not to mention that awesome youtube clip

 

[72bluNblu]

LOWERS
Cantilevered strut rod attachment looks funky to me. QA1 has in house engineering so Ill assume they are smarter than me.

QA1 may have in-house engineering, but their LCA design was obtained when they bought out CAP. Having had a set of CAP LCA's in the past, the design didn't change. There are a couple small details that are different, but those differences are very minor. The weld quality from QA1 is MUCH better though (of course!). They were a good design before, but CAP's production sucked. Mostly their welding.

As for the strut rod attachment, the strut rods bear very little load. The QA1 strut rods are aluminum tubes, and their CAP predecessors were the same and have withstood 60k+ miles on my Challenger. Heck they even survived one of the welds on my old CAP LCA's breaking.

 

[roccodart440]

I ran RMS uppers and QA1 lowers on mine. Function was 100%. Lighter and better looking to boot.

 

[345man2]

i know this is a dumb question but who makes the RMs

 

[TrailBeast]

i know this is a dumb question but who makes the RMs

Reilly MotorSports, Inc.

 

[345man2]

i see thanks

 

[Duane]

As for the strut rod attachment, the strut rods bear very little load. The QA1 strut rods are aluminum tubes, and their CAP predecessors were the same and have withstood 60k+ miles on my Challenger. Heck they even survived one of the welds on my old CAP LCA's breaking.[/QUOTE]

The strut rods are the only thing preventing your wheels and disc brake assembly from folding back under the weight of the vehicle when you get hard on the brakes at 60 miles an hour. What else would keep the lower control arm square to the frame? Certainly not the rubber bushing in the lower control arm. Just something to think about.

 

[gliderider06]

Strengthen the lowers and use the offset bushings for the uppers. Work fine for me on every one I've done.

 

[GMachineDartGT]

The only down falls to this is the offset bushings are still shitty rubber. Second, if you run a wide wheel (Im an 18x9), they wont clear stock arms. After examining all the tubular uppers on the market, the qa1s are clearly the beefiest and are the only ones who cared to put a droop bump stop plate.