Suspension Wallow Blues

[bacfire]

After quite a few handling mods (GT front coils, 4-leaf mid-eye rear springs, 1" front bar, GR2 shocks, export&monte carlo bars, subframe connectors, roller perches), I'm still not happy with my suspension. I wanted a nice street ride, but it's turned out a little softer than I'd hoped. The real problem, though, is the lack of suspension control in corners. I don't mind the body roll so much, but I can feel a "wallowing" or "pogoing" when the suspension is loaded in longer curves. Also, the rear end seems to roll about quite a bit more than the front in transitions.

Although I'm sure the 195/70-14 all-season tires that are currently on the car are contributing to the problem, I want to blame the GR2 shocks. I'm leaning toward Bilstein street shocks, but I need some reassurance before I shell out the $350+. What do y'all think? Is this the best money spent? Should I put that money toward 15" wheels and tires instead? I considered a rear bar, but pretty much wrote that off. Any other comments or ideas?

 

[Fstbk]

How stiff is your chassis? Do you have any rust in the floor near the toe boards or rear torque boxes? SFC's only do so much, many people think that connecting that thin front floor pan support to the rear torque box fixes a weak floor or poor patching in the floor.

I can tell you that if you held one of those frame extensions/front floor pan supports in your hand you would see how flexible that part really is. If I were doing SFC's I would eliminate those supports and go into the front frame itself.
But anyway..

Did you use the good export brace or that chrome one with the thin steel and shallow rib? I had the cheap one last season because it came with the car and switched during the winter overhaul....Get the good one.

That being said I have a new bottom on my 65 FB with torque boxes added up front and much of the same mods that you listed, except I went with the 4 1/2 leafs, Koni's and did the arning drop. I love those Koni's.
It is not bad, I dont have any real issues with pogoing or wallow etc.. but I can tell that my 14" tires are the weak link in my performance chain and will be figuring that out this winter. I am trying to decide on wheel size, its going to come down to what size has the most performance tire choices I guess.

 

[SoCalCruising]

Well, you can try the Del-Alum bushings from Global West. They replace the rubber bushings in the rear leafs and will reduce some body roll. Stiffer shocks will also help. 16 or 17" wheels/tires will (maybe) do the most. If you ever think you want to go to a big (13") front disc brake, then get 17s.

 

[rbohm]

installing stiffer springs means nothing in an aging chassis like the early mustangs. but since one of your goals is a good ride, stay with the springs and shocks you have now, but add to the package;

a 3/4" rear sway bar to help control body roll.

subframe connectors to stiffen the chassis, i prefer the weld in type.

upgrade the suspension bushings with either the energy suspension poly urethane bushings everywhere EXCEPT the strut rods, or the previously mentioned del-alum bishings.

for the strut rods go to an adjustable unit like the ones opentracker sells, our make them yourself with a kit that dazecars sells.

as for wheels and tires, this depends on what future upgrades you are planning. if you have drum brakes all around, and are planning an upgrade to factory disc brakes, then a good 15x7 wheels with a 205/65-15 tire will do nicely. remember that these cars are not that heavy, so monster tires and wheels really are not needed. if you want to upgrade to a 13" brake rotor, then go with 17x8 wheels with a 245/45-17 tire.

 

[fostereast]

I'd suggest skipping the rear sway bar and doing something to provide lateral control on the rear like a Watts Linkage (Fay's) or a panhard bar. The Del-A-Lum bushings would probably be a good move also. After solving this problem, you could see if a shock swap or bigger wheels is needed.

 

[bacfire]

It's a lifetime desert car. I've had the interior completely out and the floorpans are original and very solid. Subframe connectors are already welded in, a good export brace is in place, and I've done the Shelby/Arning drop. For whatever reason, I didn't feel the wallowing until I replaced the worn out springs (the GR2 shocks and chassis reinforcements came first). Maybe I'm feeling chassis flex, but if these things are that floppy after the reinforcements I've already done, maybe I need to build another Nova instead!

I was thinking maybe the shocks were a better match for the old springs than the new, hence consideration of the Bilsteins. It just drives like a car with worn shocks. My reservations come from the number of posters who have similar suspensions and like their GR2s. Anyhow, I'm in the process of building a new drivetrain for the car, so money is really tight (isn't it always) and I'd like to fix the issue without replacing something I don't have to. Lots of negatives from this list, along with prior experience from a couple of Chevys, put me off the rear bar, but maybe I need to reconsider.

 

[Falcon79]

WTH is wallowing?

 

[bacfire]

WTH is wallowing?

A southern term, I guess...pronounced "waller" around my parts. Like when a pig lies down in the mud and just kinda squirms around. Or for the city folks: when your dog rolls around in something smelly in the park. Gettin' the idea?

 

[Falcon79]

Yeah I know what you are sayin bacfire, I guess what I'm asking is how does that word relate to how your suspension feels.

BTW +1 for the panhard bar idea.

 

[Fstbk]

If I make any more mods to my car after the wheels, the Fays Watts link is the next big thing.

But, I really wonder if those GR2 shocks are really a good shock or just marketing? I wonder how large those shafts and bodies are on those? When I held my new Koni's up against my old shocks (cheapo's) there was a huge difference in weight and tube sizes.

Here, I found these.

 

[horse sence]

i think what he is saying in nasscar terms is his hoss is loose, can be as simple as one thing or a combo or several things ,soft shocks ,front end alighnment or soft springs
soft springs and shocks working against a stiff sway bar,if your shocks are adjustable i would set them at the stiffest point and try it ,then set them at there softest point and compare, i am voting for to soft front spring and shocks, a good set of adjustable shocks
will probably do the trick and front end alighnment, and i would ruel out body twist or flexing. also did you do the upper a arm lowering ?it makes a big difference in handling. and ah get that pig out of the mud

 

[Smitten65]

Do you have GR2's all the way around? Some find the GR2's too soft up front and do the KYB Gas-adjust up front and the GR2's in the back. With GT springs up front and 4 leaf in the back, both of which are relatively soft compared to what most are running, the Koni's are not a bad idea, tho'.

 

[bacfire]

Yeah, GR2s all around. It's an 50+ mile/day driver, so I was looking for comfort over sports car handling. A soft suspension is fine; an uncontrolled suspension is another matter. I'll probably eventually incorporate a lot of the ideas from this thread, but right now I'm becoming convinced that the GR2s are a $15 parts house junk shock with a good marketing plan. I'd like the adjustability of the Konis, but at nearly $250 per set more than the Bilsteins... I was hoping someone here might be running softer springs with Bilsteins, but as you say, most have 620s and 4.5 or 5 leafs.

 

[Smitten65]

I have seen a lot of folks on other forums that use the Bilsteins. They seem to be the second recommendation after Konis. I agree with the tires as a partial possible problem. You now have a better suspension (at least in theory) that the car came with but the same tires. What PSI are they running? Since you did the drop, I assume you have the performance not stock specs for that. Did you cut those GT springs?

One thing still strikes me as wrong. You mentioned that "I don't mind the body roll so much, but I can feel a "wallowing" or "pogoing" when the suspension is loaded in longer curves. Also, the rear end seems to roll about quite a bit more than the front in transitions.". I wouldn't expect that you should have much roll at all with a 1" bar up front and new rears, even without a rear bar. Since you say you didn't seem to have these issues before the spring change, is it possible that the springs themselves are the problem? Broken leaves, straps, loose shackles? What was the rear spring rate? V8 or I6 rear springs?

 

[65FBE2]

I have had Konis and replaced them in the rear with the Biliesteins. In my opinion there is no comparision. The konis are old school very stiff oil shocks with not enough travel for a Mustang. The shelby had a suspension limiting cable or something installed to keep them from over extending the shock. But to the point. Your tires are most of your problem. First off, do you have a 1" front sway bar? Then your tire selection will be the next big determining factor. I went from 15" 215.60 BFG TA tires to 17" 235.45 ultra HP tires and you couldnt tell it was the same car. The ride will suffer though. You have a soft rear spring and that is the main determining factor in ride quality. I would go with the KYB gas shock as a less expensive alternative and stiffer than the GR2s. The Blilistein shocks are great but over kill for a street car unless you are going to autocross it. If you must stay with stock tire size and want to keep ride quaility softer then a rear sway bar will help. No need for a watts link or panard bar for you application but I would add heavy duty rear shakels with poly bushings to help the rear from sliding sideway under the car. With the above mod's you should have a car that handles well and maintain great ride quality. If you really want a set of koni rear shocks, I have a set I will sell for about 1/2 price. Less than 800 miles on them

 

[65FBE2]

After reading you IP again, change shocks to KYB and it will stiffen up about right. The rest of your issues, I am 90% sure are the tires. Change them and you have a new car!

 

[rbohm]

I'd suggest skipping the rear sway bar and doing something to provide lateral control on the rear like a Watts Linkage (Fay's) or a panhard bar. The Del-A-Lum bushings would probably be a good move also. After solving this problem, you could see if a shock swap or bigger wheels is needed.

a panhard bar is not going to be that effective with the early style leaf spring suspensions, unless the leafs have some serious side flexing, and then you have other issues. a rear anti roll bar will do most of what a panhard bar will do in the rear, as well as limiting rear body roll.

 

[S-Car-Go]

I've used Koni's and Bilstiens (and host of other shocks, eddy's, KYB, etc). I say go for the street valved Bilstiens. Bilstiens are digressively valved so they are soft over bumps and firm around corners. Konis are linear but adjustable on rebound. BTW. What are your alignment specs? and did you drop your upper control arms? Too much pos camber could cause the "wallowing feeling". I say do the Shelby/Arning mod to your arms if you haven't and get the Bilstiens.

 

[bacfire]

Wow. Lots of ideas but all over the map! I do appreciate you guys a lot.

Control arms are dropped. 0 degrees camber, 2-3 degrees caster (tough time there), and 1/8 toe. Springs are new and undamaged. Front springs are uncut Grab-a-Trak "GT" that are supposed to sit 1" lower than stock. I did have to install the 1" poly cushions to get the ride height back up. The rears are Grab-a-Trak 4 leaf mid-eyes with all new rubber bushings. I think they're rated at 165#, but I'm more than a little dubious of comparing leaf spring ratings from different companies.

Tires are definitely an issue, but back in my younger and stupid(er) days I slung around a lot of cars with cheap, low-performance rubber. They just squirm a bit, then roll over and slide; not pogo around like I'm feeling. I've upped the pressure as high as 50 psi with no relief. I'll eventually go with larger wheels and tires, but they're just not in the budget right now.

 

[bartl]

If you are "porpoising" that means that you have a spring(s) that are loading and unloading in a continual cycle. My guess is that it's a combination of too little control by the shock absorbers plus the tires rolling over. There can be quite a difference in sidewall stiffness and you might find going to a different tire may help 90%.