A-body priority list

[Olds.PhD]

I'm looking to finally upgrade the suspension in my 68 Cutlass. Car already has Hotchkiss 1" drop springs, so I'm leaving that part for now.

I've been through Savitske's book, and obviously the #1 priority is the front end geometry. So my plan for that is UMI arms with tall ball joints. I also planned to get front and rear sway bars (rear chassis-mounted). I'm also planning on Ridetech's single adjustable shocks.

Question is, how high of a priority are the rear control arms? I don't need to change my pinion angle, so that adjustability isn't really needed. The factory suspension has already been rebuilt - so the rubber bushings are in good shape. Are new arms with the roto-joints (or r-joints or whatever brand name manufacturers slap on them) a night and day difference? Or are they something you notice once you really get some seat time and start pushing the car?

This is a street car first and foremost, but my C3 is about to go under the knife, and I'd like something that I can autocross here and there while the C3 is being built. That said, the upgrades here are going in stages. Suspension first, wheels and tires next, then a brake upgrade.

[raustinss]

Id be looking at speedtech.. afx spindles,control arms set upnfor the front ... they offer a swivel style control arm for the rear . Start small and simple, upgrade as you go . You already said it's a street car so no need to go crazy into debt to impress no one you know with parts they can't see

[FORDvsCHEVY]

I went almost full ride except my chevelle already had Rear Hotchkis control arms so I added there sway bar.

If your steering they will help with driving the twisties.

Als will improve straight line and launch if you like to launch your car.

I personally would do it but just put it to the back of your list.

[Olds.PhD]

Id be looking at speedtech.. afx spindles,control arms set upnfor the front ... they offer a swivel style control arm for the rear . Start small and simple, upgrade as you go . You already said it's a street car so no need to go crazy into debt to impress no one you know with parts they can't see

I'd love to run the AFX spindles. They were in my trade space for this build. Unfortunately, they very much don't allow me to start small and upgrade as I go. They require a lot of things to change at once, mostly because of the brakes. I'm currently running 15s and Corvette brakes will not fit. So to run those spindles I'd be getting a-arms, front springs (to maintain my 1" drop - don't want 2"), new wheels, new tires, and new brakes all in the same hit. Sticking with the stock spindles and running tall ball joints lets me do this in smaller chunks. Maybe someday I'll upgrade to that spindle, but I think it'll have to wait.


I personally would do it but just put it to the back of your list.

That's what I'm thinking. It'll definitely happen, but my initial impression is that they can wait until some of the other items are checked off. Just want to be sure I'm not missing something big back there by delaying them.

[andrewb70]

Before doing anything, I would think about what you actually want to do with the car. I see all too often people making upgrades that are overkill.

Andrew

[Olds.PhD]

Before doing anything, I would think about what you actually want to do with the car. I see all too often people making upgrades that are overkill.

Andrew

I thought I made that clear; “This is a street car first and foremost, but my C3 is about to go under the knife, and I'd like something that I can autocross here and there while the C3 is being built.”

Apparently not clear enough so here it goes: car will never be a track car, as the engine oiling isn’t up to sustained high g loads (just a canton road race pan). The C3 will eventually be the track monster. That said, the handling is god awful in this thing and needs substantial improvement. Even for tooling around backroads. I will be auto crossing this, probably once every two months or so. It’s not a daily driver, but gets driven frequently for fun.

The C3 will be out of commission for a very long time, and this thing will need to fill in during that time.

[Hotwire]

I pretty much went the same route on my a-body. It was undrivable to begin with due to sitting and lack of maintenance. I rebuilt the entire front and rear stock suspension to see what it was about, then started upgrading little by little.

The rear bars do make a difference. Will make the car go from riding something squirmy, like riding a horse with a loose saddle, to actually feeling like a machine. Add control arm braces and it just heightens that effect. I could launch off the line and the rear bars would absorb some of the initial hit (T56 w/ LS7 clutch), but it was also unpredictable. Now the rear is solid and I can feel the tire bite, launches require a little more accuracy as the tires get shocked much easier but launches are reliable and I know where the car is going when I let off the clutch.

The biggest eye opener for me was tall upper and lower ball joints. Correcting the front geometry and getting rid of bumpsteer made the car so much more enjoyable to drive. I really liked the thumbs up and cruising, but driving without having to correct every nanosecond and about having the wheel ripped out of your hands going over bridge abutments was sketchy. Not to mention the threading the needle feel going around curves as the camber and toe changed..

Car is budget build. I'm running chinese lower tubular a-arms in the front (with proforged balljoints) and SPC fully adjustable uppers. They work but offer NO added caster. To dial in caster it pushes your wheels backwards in the wheelwell, tires scrub rear wheel well on full lock turns, and looks a little goofy, not ideal. The adjustable uppers are great, can dial in whatever you want.

I'm running a SC&C front frame brace, if you can find one, I recommend it. Made a difference in the overall feel of the car as well as helped with hard driving. Before the floorboard would move under your feet, now it's solid like riding in a newer car. I bolted in a S10 ZQ8 steering box (SS/Xtreme), quicker ratio, funner to drive, other guys have gone w/ Jeep Grand Cherokee boxes, pretty sure they're the same. I'm running stock tahoe hydroboost with my LS swap, factory lines bolted right in, you will need adapters if running older powerplant.

Have a Hellwig solid front sway bar, it works well, but is stupid heavy, would be better w/ hollow. Running secondhand rear sway bar that attaches to control arms, it works but would love to update to chassis mount.

Still running stock moog springs and cheap KYB gas-a-just shocks. Rides stock but goes flat in corners. In the process of upping the spring rate to try and keep the car firmer in corners without going straight to kidney blaster race springs.

If you haven't already, replace your body bushings. These cars are wet noodles and need everything they can get to "triangulate" the structure.

https://static1.pt-content.com/images/pt/2022/11/52420043616_8812b22334_c-1.jpg

https://static1.pt-content.com/images/pt/2022/07/52030600457_27bde824c1_c-1.jpg

[Olds.PhD]

Still running stock moog springs and cheap KYB gas-a-just shocks. Rides stock but goes flat in corners. In the process of upping the spring rate to try and keep the car firmer in corners without going straight to kidney blaster race springs.


Thanks for all of the feedback, Jeff. Very helpful. I am also trying to be mindful of spring rate. I've seen some coilover options that are really high rates compared to the drop springs. Figuring it best to start with what I have and get the geometry correct before worrying about higher rates.

I do have a G-body Monte SS steering box in the car, which is a quicker ratio than stock. We'll see how the increased caster feels with it once the new arms are installed and alignment done, but I may want something with a bit quicker ratio.

Also appreciate the insight on the easier chassis reinforcements (control arm brace and front frame brace). I was thinking of those a bit further down the line.

[Hotwire]

You're welcome, hopefully it's helpful. I'm like the junkyard dog trying low cost solutions before giving in to the high dollar parts. Unfortunately it comes with some learning lessons.

I'm running an LQ4 that's set back so the pass head is about 3/4" from the firewall, takes some weight off the front end, but is still heavy. The stock 290lb/in moog springs (pn 6200) have held up well. I did cut them to lower the car along w/ 2" lowering spindles. The car rides fine but if I get a bunch of people in the car or some big guys I do bottom out.

I don't think I need the full on 500lb/in rated springs the aftermarket offers? I used Moog's spring website: https://www.moog-suspension-parts.com/universal_coil_springs.asp and did some snooping around. Punching in the installed height and inside diameter of our stock springs I found Moog 6033 springs may work.. They're 370lb/in rating, may not be direct bolt in, but I have a set in the garage that I'm going to try whenever I get free time. Got them off amazon for $100. They're for the rear of a 58 Impala, but look like they'll work. If I get them installed I will give you feedback if interested.

*EDIT* - note, if you go w/ coilovers, any angle from straight up and down changes the spring rate, so if yours are not straight up and down when installed, the advertised spring rate will be less. Not critical, but may need to be factored in when you're setting it up.

You have hotchkiss springs now which are 500lb/in springs, looking at their site. What engine are you running?

[Olds.PhD]

You're welcome, hopefully it's helpful. I'm like the junkyard dog trying low cost solutions before giving in to the high dollar parts. Unfortunately it comes with some learning lessons.

You have hotchkiss springs now which are 500lb/in springs, looking at their site. What engine are you running?

Been there on junkyard diving. I put this car together with my dad way back in high school and college, and we spent a lot of time scouring junkyards for parts. Didn’t have the money to just buy everything new. Now I’m lucky enough to be able to spend some money on the car.

Car currently has an Olds big block. Aluminum heads and intake, but still relatively heavy. Especially with the factory AC compressor and the battery still up front. Plus the Tremec 6-speed isn’t exactly lightweight. I’ve been pretty happy with the ride on the Hotchkiss springs. It doesn’t do great over really rough roads, but I think that comes down to the cheap shocks. It definitely bottomed out in the rear when I had the trunk full for a cross country trip a few years back. Don’t think it could handle actual people in the back seat.

[416velle]

Starting with front, from my experience.......I've done a handful of different things with my rig....Stock front lowers and spindles/SPC uppers/hellwig 1-3/8 sway bar/SPC springs, then upgraded to UMI rod end uppers/CPP tall spindles/stock-style tube lowers to now (hasn't run yet) keeping UMI rod end uppers/QA1 coilover lowers (because UMI is backordered), Speedtech aluminum AFX spindles, ABC performance sway bar and Ridetech triple adjustable coilovers.

I can attest to KYB Gas-a-just Shocks, some lowering springs, polyurethane bushings and any decent sway bar to be SOLID for ALL street driving and OK for an autocross event once or twice a year. This is a relatively inexpensive option as well. You aren't going to turn many heads on the track but itll at least not be a handful out there.

That setup above upgrades with tall spindles and rod end uppers/poly lowers on coil springs, with UMI tubes out back got me 16th overall in the Grand Champion class at LS Fest 2020 on my second ever racing event, so I'd attest to that being a OK setup for autocross once or twice a month. But its a little more expensive, and I wont even touch on brakes/wheels and tires which were a HUGE difference.

As for steering....highly recommend the tried-and-true jeep cherokee box. Quick ratio with internal stops. Cheap and available from oreillys/napa/autozone, requires a different rag joint. I also recommend a flaming river intermediate shaft and bump steer kit (if the cars lowered), both of those things do HUGE HUGE things for wheel feel and smoothness......

TLDR::: Front upgrades come first, and if you run out of budget then put some poly bushings in your stock rear arms, or BUY MY OLD STUFF and some new bushings for em, UMI adjustable uppers/stock length lowers. Serious about this, i want them gone. Also have CPP spindles, C5 brakes and some other crap too.

It depends on what you do with the thing! For a driver you don't need to go crazy whatsoever.
I personally strive for some Ultimate Streetcar events and autocross every week if I can so I went with the best I could up front and built a custom 3 link/Watts link for the rear to maybe compete with some camaros and corvettes.
Just my .02

[jetmech442]

Same page as Hotwire and 416Velle here.
I'll add that the stock D52 calipers are very capable, solid pieces that generate great force numbers, especially with good pads. I ran the same stuff for many years(tall upper/lower BJs, SPC uppers, hotchikis drop springs, hellwig front and rear sway bars(big bar, soft spring theory works great). I'd say after that, legit shocks allow you to create the behavior you want out of the system, and then laterally locating the rear end. Even a simple panhard bar mounted to the rear will stop it from shifting about 2 inches side to side in and out of turns. In Autocross, that side to side of the diff causes most of the spin outs IMO.

[Olds.PhD]

I ended up going ahead and grabbing the rear control arms too.

Parts list:

UMI front upper and lower control arms with tall ball joints (0.9" top, 0.5" bottom). The uppers are adjustable.
UMI front splined sway bar.
UMI rear chassis mounted sway bar.
UMI adjustable upper control arms with roto-joint on the body side and rubber on the axle (I have roto joints for the axle, but haven't installed them).
UMI fixed lower control arms with roto-joints on both sides.
Ridetech single adjustable smooth-body shocks.
Reusing my Hotckiss 1" drop springs with 3/8" spacer added up front (spacer compensates for the lower ball joint and adds another 0.25" to prevent high centering myself on the headers)


Install notes: if you have an Olds with Hooker long tube headers, the lower control arm bolts are pretty much impossible to remove/replace. I unbolted the engine mounts and used a very very long pry bar to physically move everything as much as possible to get the bolt to barely come out and barely go back in. Not fun. Not UMI's fault - just life with long tubes. The front lower control arms also contacted my disks with full weight on wheels. Factory disks and factory spindles. Talked to UMI and they recommended grinding the ends. Wasn't hard, but kinda sucked to have to do it. The rest of the install was really easy. Helped that the suspension wasn't 50 years old and rusted to hell.

Alignment: Did it myself and ended up at -0.5 degree camber, +6.5 degree caster, and toe-in at 1/16". Required a .063" shim on the passenger side, even with all of the adjustment available. The joys of old frames.

Test Drive: First drive was brief, but a noticeable improvement over what I had before. Didn't notice much difference on turn-in with the easy cornering I was doing, but significantly more competent mid corner and accelerating out of the corner. Ride quality is pretty similar to before. I have heard people describe the stiffer bushings as having a similar impact as increasing tire pressure, and I'd definitely agree with that.

Supposed to rain here a bunch over the next week, so I won't get much seat time. But first impressions are positive. Once I've got a few miles on it, we'll try for an autocross.

[Hotwire]

SOLID list man, congrats! Hope you enjoy the upgrades. You'll notice it first time you hit a bump or go around a corner you used to have to correct on, life changing.

[SPLATT71MC]

Improving the front will make the most difference but doing the rear as well just rounds out the package. I'm to the point with my Monte Carlo where the next step will be bracing up the frame.