Tubular A arm benefit

[gtome]

So I've been looking at coil over conversions for my 70 GTO and I was curious if there is a real benefit over the stock arms for a street car. I'm more after looks and adjustable ride height than I am actual performance. Is it worth the extra $1500 over using stock arms?

[boss_hoss]

Depends on what you plan on doing with the car. If you're just looking to do some cruising and light corner carving on backroads, a factory style control arms with good bushings and extended ballpoints are more than serviceable. If you're planning on getting more aggressive or tracking the car the tubular control arms are definitely stronger and offer several benefits. The better designed Tubular control arms are designed to fix some of the knows geometry issues present in A-bodies, they also have better mounting provisions for Coilovers and are just stronger overall. Maybe others can chime in, but I'd bet in a lot of situations you wouldn't notice the difference under most driving conditions.

If I was starting a new build and I was on a budget I would stick with stock style control arms and add the taller ballpoints and better bushings then you can replace them with tubular down the road. If you're really itching to get the tubular control arms but don't want to spend $1500 two options, I'd look at are BMR control arms which are about 1/2 of what you were looking at or Speedway Motors offers some house branded ones for even less. The speedway ones are most likely Chinese and very similar to the ones you can get on Ebay so I'd look at changing the ballpoints on those immediately, but I've run similar ones on my car and had no issues.

https://www.bmrsuspension.com/?page=products&productid=2714&superpro=0

https://www.speedwaymotors.com/1964-72-GM-A-Body-Chevelle-Tubular-Upper-and-Lower-Control-Arms,81680.html

[gtome]

Thanks for that. This truly will just be a driver, no racing at all. I live in the middle of Daytona and I get stuck behind old lady's going 38 mph pretty much all the time. So this will be just for looks. Maybe a burnout here and there.

[andrewb70]

Thanks for that. This truly will just be a driver, no racing at all. I live in the middle of Daytona and I get stuck behind old lady's going 38 mph pretty much all the time. So this will be just for looks. Maybe a burnout here and there.

Refurbished stock control arms with bushings are fine for that.

Andrew

[gtome]

Great. I will probably just do a coil over conversion then, and rebuild the stock A arms and control arms. We do powdercoating at work so I will powder the frame and the suspension stuff.

[Mkelcy]

Depends on what you plan on doing with the car. If you're just looking to do some cruising and light corner carving on backroads, a factory style control arms with good bushings and extended ballpoints are more than serviceable. If you're planning on getting more aggressive or tracking the car the tubular control arms are definitely stronger and offer several benefits. The better designed Tubular control arms are designed to fix some of the knows geometry issues present in A-bodies, they also have better mounting provisions for Coilovers and are just stronger overall. Maybe others can chime in, but I'd bet in a lot of situations you wouldn't notice the difference under most driving conditions.

If I was starting a new build and I was on a budget I would stick with stock style control arms and add the taller ballpoints and better bushings then you can replace them with tubular down the road. If you're really itching to get the tubular control arms but don't want to spend $1500 two options, I'd look at are BMR control arms which are about 1/2 of what you were looking at or Speedway Motors offers some house branded ones for even less. The speedway ones are most likely Chinese and very similar to the ones you can get on Ebay so I'd look at changing the ballpoints on those immediately, but I've run similar ones on my car and had no issues.

https://www.bmrsuspension.com/?page=products&productid=2714&superpro=0

https://www.speedwaymotors.com/1964-72-GM-A-Body-Chevelle-Tubular-Upper-and-Lower-Control-Arms,81680.html

What geometry issues do tubular arms fix?

[dontlifttoshift]

The good ones add caster and keep the wheel centered in the opening. They will also have the proper angle in the mounts for the tall spindle or tall ball joints.

[gtome]

Are tall spindles better than what I have stock?

[Josh@Ridetech]

The good ones add caster and keep the wheel centered in the opening. They will also have the proper angle in the mounts for the tall spindle or tall ball joints.
This.

Are tall spindles better than what I have stock?
Yes. With the factory spindle, you will see positive camber gain when you go into a corner, and the car will want to push. With a tall spindle, you will see negative camber gain as the suspension compresses, keeping more of the tire's contact patch on the ground under compression/lateral forces, and it will handle much better. This picture will help show the differences :cheers::

215005

[gtome]

That's interesting. I will have to do more research on that.

[Mkelcy]

You can also get there with tall upper ball joints on your stock UCAs: http://pozziracing.com/first_gen_suspension_geome.htm#Geometry discussion. Ball joints are, I think, cheaper than tall spindles.

[gtome]

I think I've seen 1/2" over ball joints around.

[cdrod]

Howe Racing makes rebuildable ball joints that can be assembled with longer studs that move the suspension pickup points to improve suspension geometry. You can also get tall ball joints made by ProForged from Holley but these are not rebuildable or as customize-able. These taller balljoints don't always work well with the stock upper arms; the tubular upper arms are typically shorter to allow the negative camber gain during suspension compression.

I used the Howe ball joints with stock lower arms and stock spindles with adjustable upper arms from SPC. Ball joints: +.3" lower, +.9" upper. I was able to set alignment caster at +6 degrees with -.5 degrees camber. The car isn't a corner carver but it tracks sooo much better than the stock suspension geometry.

Here's some links:

https://howeracing.com/collections/howe-precision-ball-joints

https://www.holley.com/products/suspension_and_chassis/ball_joints/ball_joints/parts/101-10473?srsltid=AfmBOoo2zB1hxXjxJBITfEQHHZDNzbPk-IskbOdP9lJhsYTxAyh_Ti9g

Rodney

[68Formula]

Great. I will probably just do a coil over conversion then, and rebuild the stock A arms and control arms. We do powdercoating at work so I will powder the frame and the suspension stuff.

Two concerns if you were to use the stock control arms with a coil over conversion.
1. The shock mount location is not designed to take the full load of the vehicle. It's only designed to support the load of shock compression. The large o.d. is what supports the coil and thus the front weight. The pocket would need to be reinforced.
2. Since the coilover rides on the shock body, the available travel until the spring bottoms out is significantly less compared to the stock setup. And then most will lower the car a couple inches, reducing it further. This is why some companies offer a pre-fabricated upper mount that actually sits higher than where it would if it used the stock setup.

Many aftermarket tubular lower control arms solve both issues by reinforcing the shock mounting to support the full load of a coilover setup, and they use a drop pocket to increase suspension travel.

If you're serious about coilovers I'd strong suggest going ahead with tubular control arms. If you get the right setup not only will it facilitate the use of the coilovers, but as mentioned, some increase built-in caster at the same time. The car will feel more stable, and provide better feedback through the steering.

[gtome]

Thank you guys for taking the time. Seems that the more I read, the more I realize how little I know about suspension stuff.

[gtome]

If I went with the BMR arms (with tall ball joint), are the Viking coil overs as good as these others? (I don't see a rear offered on their site.
https://www.bmrsuspension.com/?page=products&productid=2715&superpro=0
https://www.bmrsuspension.com/?page=products&productid=1413&superpro=0
Or
https://aldanamerican.com/product/coilover-conversion-kit-level-2-pontiac-gto-1968-1972-front-rear/
Or
https://www.performanceonline.com/1968-72-Chevy-Chevelle-GM-A-Body-Front-Coil-Over-Conversion-Kit/

[twilightTA]

For those of you who have upgraded the arms have you noticed an increase in NVH issues? Thanks

[gtome]

What's the thoughts on Aldan products? I see they have a black Friday sale.
https://aldanamerican.com/product/coilover-conversion-kit-level-2-pontiac-gto-1968-1972-front-rear/

[68Formula]

Not familiar with their kits, but 2* added caster isn't much. It's most likely built into the upper-only, so in addition to being somewhat limited in total caster you can achieve, the wheel will be pushed more back to the the rear of the fender. They also don't mention a taller ball joint, so it's probably stock height. Unless you've changed or are changing the spindle for a taller one, that kit doesn't address the camber gain issue.

[gtome]

Yeah lack of a tall balljoint is for sure the downfall. I have a cart built with BMR stuff too that has the longer balljoint that is similarly priced. I belive they have 2 degrees in the top and 2 degrees in the lower for a total of 4 degrees built in.
This is also 100% just a street cruiser.

[gtome]

So i started my own business and I'm trying to get back on this car. I want to get the rear end and suspension ordered. Do you think this one would be a good option? This is nothing more than a street car. No racing.
https://www.bmrsuspension.com/?page=products&productid=2715&superpro=0

[boss_hoss]

I like BMR and have used their parts before. Price and quality are definitely good. The other Plus about the BMR lower control arms is that they are set up to run both a standard coil and shock or Coil over set up without any modification. Thats not necessarily the case with some of the cheaper ones. Also Looks like they use a Pro forged or similar balljoints which is pretty good quality.




So i started my own business and I'm trying to get back on this car. I want to get the rear end and suspension ordered. Do you think this one would be a good option? This is nothing more than a streetcar. No racing.
https://www.bmrsuspension.com/?page=products&productid=2715&superpro=0

[gtome]

Only real downfall for me with those is that they are red and that won't work for me so I will have to have them stripped and re-powdercoated.

[OLDFLM]

You can also get them in black hammer tone... it's the second picture in your link.

FWIW I've had BMR suspension on my car for 15 years now and couldn't be happier with their product or service!

Front: upper & lower control arms and their sway bar. Rear: Torque arm with watts link. AFCO coilovers.

[gtome]

Your right i see the hammer tone now. I'm not in love with that either, but at least it isn't red!

[OLDFLM]

They used to do a light grey but I'm not sure you can get that as an option any more...

[gtome]

Yeah if I'm not happy I can always have them done. Not that big of a deal. I just want to get something decent that isn't outrageously priced.