What is the Key to good Ride Quality vs a Harsh Ride

[ryeguy2006a]

This is sort of an open ended question as I'm very likely going to be selling my pro-touring Camaro with a tight and rougher suspension and I've been giving a lot of thought to my next project. I'm not sure what it will be but my focus is going to be on ride quality vs. handling. I want to have a car that will glide across the road and give that "Cadillac" feel. I do still want the car to handle well, just with more of a cruiser mentality. I've been looking at wagon's from the 50s and 60s, and was wondering what I should do. air ride, Shock waves, coil overs, or just a good shock/spring combo with different rates.

Would love to hear some thoughts/opinions.



Thanks,
Ryan

[dhutton]

I can tell you that my 69 Camaro with an Art Morrison IRS is the nicest riding first gen I have been in. It also has their subframe that uses stock C6 arms with rubber bushings which also make a big difference imho.

Avoid heim joints and Delrin bushings if you want a decent ride imho….

Roadster Shop introduced a line of chassis focused on ride quality. Check it out.

Don

[ULTM8Z]

My 1971 Camaro has just your typical basic bolt on suspension pieces...

Hotchkis front springs
Factory Z28 5 leafs in the rear
Larger sway bars
Bilstein shocks
Tubular upper control arms w/ factory lowers
Y-braces (or G-braces as they're also known)
Subframe connectors
Urethane body bushings

It definitely won't win any autocross competitions, but it handles and rides really well for a 100% street driven car. My wife even commented on how well it rides and she's not even a car person (she was expecting a much harsher ride given it was an old muscle car).

[FORDvsCHEVY]

ridetech shockwaves… rides great and looks cool.

[ryeguy2006a]

I appreciate all of the feedback. Gives me a lot to think about. As much as I'd love to get an RS chassis, I know that will be out of my price range. I'm personally leaning towards a good tubular front a arms, and shockwaves, but the rear is still TBD. My main focus would be on a comfortable ride for the family.

[Jk918]

Something to keep in mind when looking for a new project such as a wagon from the 50/60s, depending on model the availability of aftermarket stuff to create that comfortable ride your looking for maybe difficult, without some serious modification .

[marolf101x]

Ride quality is simply the measurement of how much the passenger moves, or what the passenger feels inside the vehicle. . .what forces are transmitted to the person.
Ride quality is also subjective, with each person having a slightly different expectation of what it should be.
However, NASA provided some useful data during early astronaut training on things the human body just doesn't like. . .certain frequencies, for example induce nearly instant vomiting.

So look at anything that causes a direct and sudden "jolt" to the passengers.
The suspension should dissipate the slow undulations in the road via the wheel moving up and down, thereby not moving the cabin.
This is done mostly with shock/spring force and travel. Enough travel provides enough time to slow the wheel/tire before it transmits into the vehicle.
If the spring rate is not terribly stiff the tire, shock and bushings are mainly responsible for quick but short events (cracks in the pavement, bridge expansion joints, etc). This movement is very low, maybe only 1/4", but the speed is high, maybe 1M/second (32 inches/second).
Did the tire soak up some of the force, or is it a very short, stiff sidewall?
What's the shock graph look like? If it has a ton of low speed force it'll feel much more "rough" than a shock that has low force in low speed and slowly ramps up in force as speed increases.
Were the bushings "soft" with a lot of movement so they could slow down and neutralize the motion, or were they stiff and transferred that motion into the solid structure of the vehicle?

All that being said, the things that make good ride quality hurt performance.
Performance is the tire sticking to the pavement regardless of driver input. Quickly turn the steering wheel and the car darts in that direction. The rapid change in direction imparts a force into the passengers and can feel unsettling.
But the biggest thing for ride quality (to me at least) is the quick stuff. It's what sends that shock through the passenger when you hit a pothole or crack in the pavement.

[ryeguy2006a]

Something to keep in mind when looking for a new project such as a wagon from the 50/60s, depending on model the availability of aftermarket stuff to create that comfortable ride your looking for maybe difficult, without some serious modification .

That is a great point and I have looked into the few platforms I've been considering and there aren't nearly as many options out there. Aftermarket companies make it almost too easy to upgrade most of the muscle cars from that era. But that means that we get to be more creative right?

[Hotwire]

I have a 64 chevelle 4 door that mainly rides like stock until you hit a sharp bump in the road.

When Mark Savitske was still in business (SC&C) I called and sat through his long winded sales pitch. He had a lot of great information that he would openly divulge. Basically mimic modern suspension. Good shocks, moderate spring rates, aggressive sway bar, good bump stops.

I'm running stock moog springs, cheap KYB gas-a-just shocks, tubular arms w/ upgraded bushings (delrin/poly/solid heim), and large sway bars. In a straight line it feels like a well controlled 64 chevelle, ride is smooth, but controlled, no lateral movement. Roll into a curve going hot, the car will just start to lean then the sway bars catch it and stays flat. I'm not running some level X package, don't have a ton of money thrown at it, just some good parts that I purchased second hand for the most part. At some point I will be upping the spring rate as I have the car low and if I have 3 large guys in the car it does squat and rub, but that will increase the car's harshness.

I'm running 500 treadwear tires (Bridgestone Potenza RE980AS) so I'm not really competitive when it comes to events, but damn if I don't get the most I can out of it and have more smiles per mile than I should. I've taken the car through Tail of the Dragon in TN, Suches Loop in GA, do a couple of SCCA autocross events, and drive the country backroads around my home with little concern. With the above suspension, 2007 Nissan Maxima seats, this car drives, rides, and is more comfortable than my daily driver. It makes me WANT to drive it not just because of the power to weight ratio (No where near your Camaro!).

[Hotwire]

PS, if you do go with an a-body, you HAVE to correct the horrible factory geometry of the front suspension. They have positive camber gain on compression which just rolls the tire over like a windshield wiper. This was when I had just rebuilt the factory suspension and thought it'd be fun to run at the Summit Racing Autorama in GA. A photographer with UMI took this picture to show how bad it was. The top of the tires were leaning so far out it was scrubbing the inside of the outer wheel well rubbing the lettering off of the sidewall.

[stab6902]

So look at anything that causes a direct and sudden "jolt" to the passengers.

If the spring rate is not terribly stiff the tire, shock and bushings are mainly responsible for quick but short events (cracks in the pavement, bridge expansion joints, etc). This movement is very low, maybe only 1/4", but the speed is high, maybe 1M/second (32 inches/second).
Did the tire soak up some of the force, or is it a very short, stiff sidewall?
What's the shock graph look like? If it has a ton of low speed force it'll feel much more "rough" than a shock that has low force in low speed and slowly ramps up in force as speed increases.
Were the bushings "soft" with a lot of movement so they could slow down and neutralize the motion, or were they stiff and transferred that motion into the solid structure of the vehicle?

This is exactly it. You'll notice new cars with the same goals (good handling with decent ride comfort) such as modern BMWs, Cadillacs, etc, have giant "ride control" bushings that are carefully tuned and like 3+" in diameter to soak up that initial impact harshness from hitting expansion cracks, pot holes, and so forth. They have complicated multi link independent suspensions to ensure this compliance doesn't completely ruin the steering feel, camber curve, etc. Short of putting modern subframes under an old car, the best we can do from a practical standpoint is use stock-type rubber bushings.

Using a premium "touring" type tire will also help, as will taller sidewalls, and light wheels to minimize unsprung weight. Avoid huge cast wheels and no-name "performance" tires with stiff sidewalls.

Minimizing noise will also help the human perception of harshness. Insulating the cabin properly, and there's a lot more to it than sticking 150 lbs of Dynamat everywhere, will also make a big difference. Again, "cheat" by poking around newer luxury cars at the salvage yard or whatever and copy what they do.

Seats make a big difference too - again, go with something from a modern luxury car, not a bouncy stock seat or stiff race type seat.

But the biggest thing for ride quality (to me at least) is the quick stuff. It's what sends that shock through the passenger when you hit a pothole or crack in the pavement.

Agreed, focus on the bushings, wheel/tire selection, and NVH treatment of the cabin first.


Regarding lower frequency ride quality, meaning undulations on an otherwise smooth road, going with a relatively soft spring/big bar setup is a good idea. If you want to be super low, air bags are a good option - you want as much travel as you can get, especially with relatively soft springs. Bump stops are important too. I'm a big proponent of the modern "foam" progressive microcellular polyurethane bump stops. These offer a lot more cushion than hitting a rubber, or worse yet, stiff poly bumpstop.

The long wheelbase of a wagon will help. It's good to have your head about half way between the two axles rather than biased toward the rear axle like in most muscle cars. The stiffer the chassis the better - you want the suspension to do the work, not a wet noodle chassis. Adjustable shocks are the way to go on any custom car you really want to dial in. There are too many variables to assume an off-the-shelf shock will be close enough. Plus, this will give you a quick way to "stiffen up" the car if you ever go to an autocross or track day.

As you can see there's no silver bullet. You have to keep the goals of the car in mind throughout the build and make wise decisions.

[ryeguy2006a]

All great info, keep it coming!

[TheBandit]

Decades ago when I rebuilt the stock suspension on my Nova, the only changes I made from stock were poly bushings and KYB shocks. The thing rode great - very smooth and comfortable going down the road. Over time as I've changed things piece by piece I've come to recognize some of the tradeoffs between ride quality and performance. Above anything else, the wheels/tires were the single biggest factor. Going from 15" wheel with ultra-tall 60 series sidewalls to 18" wheels with 35 and 40 series sidewalls was a game changer for handling while simultaneously introducing ride harshness and noise. Stiffening up the suspension with heavier springs and swaybars certainly took some "Cadillac" out of the car, but it still rode pretty well and I think was worth the tradeoff. For what it's worth, I ran my stiffened and lowered suspension on 15" wheels/tires for about a year and the ride was still pretty smooth compared to when I put the 18s on. That's not to say that low profile tires can't provide a smooth ride when combined with a modern suspension - obviously there are lots of cars on the road now that achieve it - but I think the easy button for getting a decent ride out of an old car is to plan around taller profile tires. I would still shoot for higher spring rates and consider adjustable shocks, but keep all the bushings rubber. And while it should go without saying, I think it's important to emphasize for any project car you should start by getting everything into good repair and safe - putting kickass shocks on a car that has worn out bushings, sloppy steering, or crap brakes is not going to help anything.

[WildCherry66]

I put ridetech's street grip suspension kit on our 66 Chevelle and the ride quality is amazing. BEST riding vehicle in our household now including a 2019 and 2020 in the fleet. Going over railroad tracks is surprisingly smooth where I still brace for impact like with a typical car and it floats right over them. Awesome. And it still is able to corner well with the larger sway bars and camber gain correction achieved in this setup using taller upper ball joints. Very happy with it and stance looks right to me as well.

[dueling73s]

I am getting older and also wanted to improve the ride quality of my 2nd Gen. I installed ridetech Composite leafs with delrin bushings and dual adjustable QA1 shocks. These replaced dropped leafs from Eaton with poly bushings and Edelbrock shocks. The ride is much improved and very enjoyable to drive. I am not sure what your rear suspension is, but if you are still on steel leafs and don't want to go with a more exotic suspension, I would highly recommend taking a look at these.

[pitts64]

The 68 to 72 el Camino. it comes with a very strong and massive frame that no other Chevrolet has. The roof, pillars and doors are from the stronger sedan models they close like a bank vault door. The cab is quiet and the ride is smooth but handles like its on a rail. Surprisingly the front to rear weight is balanced.
My 69 SS396 el Camino is such a joy to drive! I updated the suspension with one of Mark Sevetskes stage three set ups with the Howe .9 and .5 ball joints. Lee 14:1 box with a 30 pound torsion setting. I have Spohn Del Spheres in the rear.
This is one of the best cars I ever drove.
It has a stock 1968 427 truck motor, TH400 with a Hurst Autostick shifter and a 2;73 rear end. This drive train has an amazing amount of torque that just keeps on coming.