96powerstroke

Hi Folks,
I'm looking to do some minor suspension upgrades. 1970 Cutlass supreme. A pretty much original car with some bolt-on changes (like SSIII's and a Rallye steering wheel).

I don't plan on racing this car, I don't plan on upgrading the engine (it's a stock 2bbl 350) unless something catastrophic happens aaaaaand someone has a 455 big block that's readily available.

Anyhow.... I'm in the process of planning and budgeting/saving for my suspension upgrade. All of the rubber on the car is shot. It wouldn't surprise me if it was original.

While I would love to go urethane/polyurethane I've got mixed opinions on the product. While It'll stiffen the ride it can also lead to more squeaks in the car (like dashboard, etc.) however going with OEM style rubber would eliminate this, will the ride be that less stiff? As it stands the car handles like garbage. I'm sure that has to do with the fact it's a 46 year old car and not a late model German sedan i'm used to daily driving...

So I got to doing some research and it almost sounds like upgrading a bigger sway bar might be a better option than poly bushings.

Any thoughts on the topic at hand? Do I do poly bushing and bigger sway bar or stick with rubber bushings and still go bigger sway bar. For all intents and purposes lets just say money isn't a concern right now. I'm in the planning stages so everything must go on paper then I'll make cuts.

Thanks for the help.

RandyS

IMO you don't need the Poly bushings unless you desire a stiffer ride. Stock bushings work fine with a rebuilt front end (incl shocks).

oldcutlass

You'll be surprised at how much better the car rides once you replace all the worn suspension and steering components.

96powerstroke

Thanks thus far. The plan is to redo all the suspension, springs included. (ball joints, bushings, tie rods/steering components, shocks, etc.). While I would like the stiffer ride I'm thinking rubber is the way to go. I just hate taking a corner at 25 mph and being in the other lane because the car rolls so much. I was initially thinking the poly bushings would help this (in conjunction with other aforementioned suspensions parts).

RetroRanger

when i redid mine i put in a 1 1/4 fr sway bar (stock is 7/8") and add a 1" rear bar (stock was none) that along w new spring s and bushings and ball joints helped the car hold the road better.

VC455

When I rebuilt my wagon suspension, I put a 1 3/8 bar front and a 1" bar rear (wagons have a more rear weight bias) with rubber bushings.

Urethane bushings give quicker response but have the listed shortcomings.

Body roll was tightly controlled with this combination but I don't have that instant response you are accustomed to in a German sedan (if I move the steering wheel back and forth an inch or so very quickly, the car does not significantly change direction).

Before the change, I could move the steering wheel 6 inches back and forth very quickly and not only would the car not change direction, the only visible response was that the front fenders rose and fell in time with the steering input.

96powerstroke

thanks!

thanks! - I wish my cutlass could handle like my VW. I don't want to invest THAT much into suspension (Im sure I could get it to handle by throwing tons of money at it) nor do I want it THAT tight. I mean it is a big car. I like the big car feel but my car is just downright sloppy and potentially dangerous.

anyhow, since we're talking away bars, any suggestions on a vendor? UMI performance has front and rear sway bars but seem a little pricey. I haven't really gotten to researching other vendors. Thanks again

RandyS

I suggest you also swap your stock steering unit for a quicker ratio. Rock Auto has them at great prices, and no adapters are needed. That will get you a lot closer to that snappy steering that you are used to.

ELY442

Do not install front upper and lower bushings with polyurethane/urethane. It makes the car ride very hard once you hit a pothole or a bump. I wish I never install these bushings in the first place. I feel like changing it back to rubber. I did install urethane sway bar links and sway bar bushings with a grease fitting attached to the bracket with 1 1/4" sway bar and a 1" rear sway bar. The car handles very tight on street corners but rides very hard with the front upper/lower urethane bushings.

96powerstroke

Do you know off hand what the lock-lock is on a factory box? I think mine was upgraded already. I get about 3 turns lock to lock. A previous owner also replaced the P.S. high pressure hose so that further leads to my belief the box was swapped. It's too bad there isn't an easy way to swap in a rack and pinion.


This seems to be the general consensus! Besides Moog's are easy to come by and relatively inexpensive.

I never realized how much a 1/4 difference in the sway bar could make handling that much better. A colleague of mine even noted using a firebird swaybar is better and bigger!


For what it's worth I finally climbed under my car and noted that the prev. owner also has cargo coils. Any reason I should keep them? I think they make the front of the car look lower (too low in comparison to the rear) and change the geometry of the suspension. I had a suspicion there were CC's on the rear but never had the chance to look. I only just got the car last September.

Thanks,

70sgeek

Look at Moog's 5415 rear springs - they're variable rate and good for about a 1" or so lift over stock. Great for larger tire clearance but won't give you that hijacker look that the old street freaks used to have.


I overhauled my suspension using mostly Moog parts, Bilstein shocks + a 1-5/16" front and 1" rear sway bar combo. Urethane front end links and UMI Performance rear control arms. CPP steering box/pump combo which provides moderate firm feel and right around 3 turns L-to-L.


Rubber front control arm bushings all around is the way to go for street driver - still provides good handling with the right component mix and more forgiving on rough roads than urethane.

Jedidiah

Talk to Mark at Savitske Classic and Custom. http://scandc.com/new/

He literally wrote the book on muscle car handling.

I am running SPC springs coupled with Varishock SS shocks on my 72 Supreme. (I can't remember the spring rates exactly, but it was something like 550 lb/in front and 135 lb/in rear. I can look it up.). Rides like a Crown Victoria P71, so not harsh at all. It sits about 1.5" lower than stock. Good shock absorbers and springs are the best handling upgrade you can do for your car.

Using a different alignment on the front end can help improve your steering feel and make it track straighter down the highway. I run about +4 degrees of caster and -1 degree of camber. You'll have to shim the crap out of the upper control arms on the side towards the firewall to get that much caster. If you don't mind spending a little bit of money, you can get a steering box out of a Jeep Cherokee. It will bolt up, although you will need to get new fittings for your power steering pump. This will give you the quicker 12.7:1 steering ratio.

Go ahead and check your idler arm and ball joints. Jack the car up and shake the wheel from side to side; if it moves excessively, your idler arm is bad. Shake the wheel top to bottom; if it moves, then you have a bad ball joint.

Using a 1.25" front sway bar and a 1" rear bar seems like a good combo to me (at least in my mind). I'll be installing sway bars when the next paycheck comes around, so I can let you know how that goes. You will need boxed lower control arms if you want to install a rear sway bar.

Personally, I prefer polyurethane bushings. Rubber rots and there are various grades of polyurethane, some being more compliant than others. If you get a good polygraphite bushing, you should have nothing to worry about. Just grease them fairly often. However, I'd avoid running poly bushings on the rear end. The old triangulated four link has binding issues with bushings that are too stiff.

If you still are unsatisfied with the handling, get some adjustable aftermarket upper control arms and taller ball joints. That will allow you to correct the terrible factory suspension geometry without spending big bucks on aftermarket spindles.

Finally, after all of that, you should have a decent handling car. Sorry for the long post, it's just my two cents on things that I think can improve our cars' handling. I plan on doing this stuff to my car sooner or later, so maybe that can help give you some ideas. The members on this board are super knowledgeable and should be able to offer you insight for any questions you may have.

joe_padavano

Actually, Herb Adams wrote the book a couple of decades earlier...



One of the things he demonstrated is that the A-body cars are understeering pigs. If you really want neutral handling, you need a LARGER bar on the rear than on the front. Herb's setups went as far as 1.5" on the back and 1.375" on the front.