72 A-Body Geometry with Coilovers

[bainer1290]

Building a 72 Cutlass, 442 clone, big block. This will mostly be a street car but I want it to handle way better than it does right now with stock suspension.

Last year I installed a full poly bushing kit in the front and rear, all new complete moog steering linkage and balljoints and that helped a fair bit but its still not stiff enough for my liking with its stock springs, arms and shocks. My plan is to have Viking coilovers on the front, Viking shocks on the back with a set of rear lowering springs to drop it 2 inches all around. I also want to add Hellwig sway bars to the front and rear and eventually swap my current 15 tires for 18's or 20's.

Been reading lots about the front control arm geometry for a-body and how it has poor camber/caster mostly caused by the upper arms. There are lots of options out there and for a guy with a tight budget I have come across 2 styles but I am not sure if one is better than the other. Has anyone had any experience with either of these?

[Dc2x4drvr]

Glad to see another Olds here..I think most of the name brand arms are going to improve handling, try to stay away from no- name evil bay stuff. I just installed Ridetech arms and coil overs, easy install, and the Pro Forged ball joints look like quality pieces.

[bainer1290]

Thanks for the reply, nice cutlass!

Yes I see lots of negative feedback on the ebay stuff.

The ones above are from Speedmaster, looks like Jegs carry's them but it must be a new product as there are no reviews yet. I read somewhere that Speedmaster bought out ProComp, so no doubt the arms above are knock offs from China but I may give them a try to see. I can swap my existing Moog ball joints and poly bushings over easily if the bushings fit.

[csouth]

Welcome aboard.... Let me take a stab at it: The top arm you have looks like a tubular arm built on the same droop arm design of the factory arms. The caster settings may be different, but the camber will likely be the same because the pickup point seems to be in the same position. To change the camber on these arms it would still require a tall ball joint. You can just add tall ball joints without having to swap the factory arms.

The second pair of arms appears to be those typically used with a tall or b/f body spindle swap. With this arm you will have to change your spindle to B Body tall spindle to achieve the desired camber change. Keep in mind that when you change to the B body spindle your bumpsteer may actually be worse because they are designed for a different steering arm position.

[bainer1290]

Hey Chris, thanks for the insight and nice car!!!

I have ordered a set of the ones in the top pic to see, the description says:

1968-1972 Chevy Chevelle,Chevy Monte Carlo,Chevy Malibu,Chevy El Camino,Pontiac GTO,Pontiac Tempest,Pontiac LeMans,Oldsmobile Cutlass.
The upper control arms also utilize greaseable bushings which make for increased stiffness over stock to provide more consistent and precise handling.
Upper arms are 1.125" OD - .125" Wall Tubing.
This is for a set of upper heavy duty tubular control arms.
They are significantly stronger than stock.
Fit any A Body GM car.
Suspension geometry is improved over stock by increasing camber gain and improving roll camber. And have 4* Positive Caster.
Redesigned for better steering and suspension.
They utilize bleeding-edge manufacturing processes which include mandrel bends and precision cnc welding.
The highest quality DOM steel tubing has been used for their construction and have a chip and scratch resistant powdercoated finish.

So we'll see soon if all that is true....

I was thinking they look very similar to the Hotchkicks 1102 arms which are designed to correct geometry while using the stock spindles

[Marcus SC&C]

Bainer, sorry I`m a little too late! I was going to say to take a deep breath and step away from your wallet until you do a little research. :) You`re buying into some, um, shall we say very optimistic marketing. The A body platform has some very serious geometry issues up front and you`re right to want to correct them but no set of A arms from any manufacturer can or will fix them. A arms don`t define the geometry of the car, they only connect the points that do. At best even the finest upper A arms are only an alignment aid and at times and enabler for corrected geometry. In other words they play an important role (try driving a car without them!) but it is a *supporting role*. The geometry of the car is defined by the pivoting points (pickup points) of the suspension. To correct the geometry you need to move these points, on this car we start by having to move the upper / outer points vertically to make the changes we need. No A arm can do this. This brings us to either a "tall spindle" or "tall ball joint" solution. Done properly they can both be great choices. Once the pickup points have been relocated to fix the geometry issues we need to select a set of upper A arms designed to work with the *new* geometry. It`s not enough that they be "tooby", they have to have the correct length, offset and ball joint mounting angles to work with the new geometry. If they don`t specifically say they`re for your corrected geometry, they`re not. Selecting the wrong A arms will make alignment difficult and frustrating. You may want to buy the spindles or tall ball joints with matching A arms as part of a package such as our Street Comp AFX or Street Comp Stage 2-Plus packages to avoid any guess work. Think carefully before installing placebo parts on the car. You can always return uninstalled parts. ;) Mark SC&C

[bainer1290]

Thanks for the reply Mark, I appreciate the info and will let you know how it goes I should have the arms in a few days.

[Carguello08]

I'm in for an update !

[MonzaRacer]

HO racing used to make an upper control arm that fixed issues using the b car spindles.
But they kind of scaled back.
Not even sure if HO Enterprises is still around. Basically the fix was using tall gm spindle as at that time tall ball joints were unobtainium.
Honestly if I were to build another A body I would use ATS/Speedtech spindles.
Or go through Markus AAT SC&C with his kits.
As for coilovers look at Ridetech cause I can tell you I have three customers that switched from Viking to Ridetech and the say the Ridetech ride and handling is head and shoulders over the Viking.

[TheJDMan]

Are you just looking for bolt on upgrades?

[Staged 2Discover]

HO racing used to make an upper control arm that fixed issues using the b car spindles.
But they kind of scaled back.
Not even sure if HO Enterprises is still around. Basically the fix was using tall gm spindle as at that time tall ball joints were unobtainium.
Honestly if I were to build another A body I would use ATS/Speedtech spindles.
Or go through Markus AAT SC&C with his kits.
As for coilovers look at Ridetech cause I can tell you I have three customers that switched from Viking to Ridetech and the say the Ridetech ride and handling is head and shoulders over the Viking.

Keep in mind Bainer stated he would be mostly street driving. Specifically how does the Ridetech coil over ride better than vikings. Vikings are full dual adjustables and can be tailored. I've had Vikings on my A body for a few year now with no issues as have many others.

[csouth]

Keep in mind Bainer stated he would be mostly street driving. Specifically how does the Ridetech coil over ride better than vikings. Vikings are full dual adjustables and can be tailored. I've had Vikings on my A body for a few year now with no issues as have many others.

Personally on street car I would rather the single adjustable Ridetech. The double adjust Vikings offer more options, but I would venture to say most of us here won't get the most out of those selections on a street car. Just my .02 cents

[bainer1290]

Hey guys sorry for the wait! Glad to see some other A-body's on here.

So I got the upper arms installed along with the Viking coil-overs on the front and the viking shocks/BMR 2 inch drop springs on the back. Everything went together easily, the toughest part I have to say is adjusting the coilovers with the stamped lower control arms, not much room to get those wrenches in there to adjust... The stance is exactly what I was looking for dropped the back about 2.5" and the front 1.5". The Viking coilovers and shocks appear to be of real good quality and I have seen lots of good feedback on them, they are not the best but for what I had for a budget and for my needs I think they will work well.

From what I measured with my angle dial on the front brake calipers here's some numbers:

Stock Upper/lower arms & spindle (car on jacks & some shims installed from recent alignment)
full extension down
-4 Left -2 Right
almost full extension up
0 Left +1 Right

Tubular uppers & stock lowers/spindles (car on jacks & No shims yet)
full extension down
-2.5 Left -3 Right
almost full extension up
0 Left 0 Right

Specs say to align to:
-1 to -1.5 Camber
+4 to +5 Caster
1/16" Toe-in

I am not by any means saying this is a perfect solution but it does seem to be correcting the camber a little, but my measuring is by no means 100% accurate but the car did not move from start to finish and there was some change. I still need to get an alignment done but that will not happen for a few months as I am in the middle of prepping for paint too.

I appreciate everyone's input and I am looking forward to feeling how my baby handles with the changes compared to the original springs, haha probably going to feel way different.

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[Marcus SC&C]

Bainer, unfortunately you`ve just slightly changed the static alignment not fixed the cars geometry problems. To each his own though, the cars looking good. :) If you`d like to get the big picture on how the geometry is affected by different components you might pick up a copy of Chassis Engineering by Herb Adams or better yet, How to Make Your Muscle Car Handle by...um...me. :twothumbs

Lee, the only thing about the B spindle swap that A arms can fix is static alignment and that still leaves a lot of down sides on the table. Last I talked to Ken @ HO racing in the late `80s, shortly before they closed their doors, he was still recommending stock arms, near stock ride height and offset cross shafts from NAPA to get "the best alignment you can".

Tom, the Vikings are passable entry level shocks (especially for drag racing) but they have limited maximum rebound dampening for handling applications, much less than we normally see in modern performance cars. It`s also MUCH less than the available range in shocks like the Varishock and Ridetech. Both of these offer much more rebound control, even in a single adjustable vs. the Viking (or QA1) doubles. They also have more refined dampening curves and overall more refined construction It`s not that the Vikings are bad shocks, it`s just that (as always) you get what you pay for. FYI Viking doesn`t make a bolt in coil over for A body applications. They only make a hybrid, which is a different animal with different issues. I`m glad to hear you`ve had good luck with yours but the street reliability of all of the A body coil over/coil over hybrid conversions is much lower than the performance shock and spring format. They also have more potential tuning pitfalls. AT the end of the day regardless of true vs. hybrid format you`re still holding up the weight of the whole front end of the car with the two little plastic shock bushings. Coil over conversions are a much better choice for road race cars and hardcore auto cross cars where very high spring rates are the order of the day and increased maintenance is expected. Mark SC&C

[bainer1290]

Thanks for your insight Mark, I do appreciate it honestly. It will be a few months before I can road test the car (darn winter) but I am sure it will handle much better than my stock setup and I am very excited for that. Plus I can't wait to see it with some fresh paint, thinking of a metallic blue!

Here's a comparison on the stock vs lowered ride height, quite a difference.

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[HWYSTR]

.... Coil over conversions are a much better choice for road race cars and hardcore auto cross cars where very high spring rates are the order of the day and increased maintenance is expected. Mark SC&C

Very well put Mark, seems many don't understand this simple concept. Gross vehicle weight plays a big part here too.

Another simple concept is the diameter of the coil spring and leverage. The larger the diameter of the coil spring, the more linear the rate increases as it's compressed. Coil overs use a smaller diameter spring, so over a short distance of compression, the rate increases rapidly, and can cause a 'choppy' ride. Well, there's way more to it, but that's the simplest words I could put that in!

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