Smoother Highway Ride for Coilover Conversion

[NOVA]

Originally Posted by dhutton

I built two Camaros. A 69 vert for my wife with full Ridetech, The Ridetech ride was harsh Biggest issue was any discontinuity in the pavement.
It’s a shame the Art Morrison IRS is so expensive because it could be a real game changer imho.
Don

I seen this post had come up to the top, and pretty much Don summed it up again....I have tried different things and I just do not see it getting a whole lot smoother, my bad for not riding in more similar cars with my set up and other suspension set ups before going this route.

[dhutton]

Originally Posted by NOVA

I seen this post had come up to the top, and pretty much Don summed it up again....I have tried different things and I just do not see it getting a whole lot smoother, my bad for not riding in more similar cars with my set up and other suspension set ups before going this route.

Only thing I can suggest is to significantly increase the rebound damping and see if it makes a difference.

Don

[pannetron]

IMHO too much rebound damping is sure to make the ride harsh.

[dhutton]

Originally Posted by pannetron

IMHO too much rebound damping is sure to make the ride harsh.

My thinking was that stored energy due to high spring preload was causing the harsh bang when traveling over drops in pavement. The spring fires off when unloaded over the drop. That’s why I suggested trying increased rebound damping. It’s just a theory and just something to try. Not a guarantee but I did find an improvement when I tried it on my wife’s car. Of course there is a sweet spot that may or not be easy to find. Ultimately I gave up and we sold the car.

Mandatory backyard hack disclaimer inserted here…

Don

[CraigS]

I find this thread curious. A given suspension style can't give a decent ride? What? First realize that one difference between an IRS and a solid axle is that the IRS will usually have some leverage built in so the spring or shock rate is not the effective wheel rate. The wheel rate will usually be much softer than the spring rate. The solid axle will have the two rates nearly identical. I mention this because (assuming the lengths would fit) a given coil over unit that rides great in an IRS car will be very much stiffer if moved to a solid axle car. Regarding ride comfort only, as long as both systems will allow 5-6 inches of wheel travel (without binding control arms or unwanted contact to frame or body) both can be made to ride well. The IRS will have the advantage when on rough pavement because of much less unsprung weight but, other than that ride can be nearly the same as IRS. There are a lot of other advantages to IRS regarding geometry but to say a solid axle car can not be made to ride reasonably is crazy.

[dhutton]

Originally Posted by CraigS

I find this thread curious. A given suspension style can't give a decent ride? What? First realize that one difference between an IRS and a solid axle is that the IRS will usually have some leverage built in so the spring or shock rate is not the effective wheel rate. The wheel rate will usually be much softer than the spring rate. The solid axle will have the two rates nearly identical. I mention this because (assuming the lengths would fit) a given coil over unit that rides great in an IRS car will be very much stiffer if moved to a solid axle car. Regarding ride comfort only, as long as both systems will allow 5-6 inches of wheel travel (without binding control arms or unwanted contact to frame or body) both can be made to ride well. The IRS will have the advantage when on rough pavement because of much less unsprung weight but, other than that ride can be nearly the same as IRS. There are a lot of other advantages to IRS regarding geometry but to say a solid axle car can not be made to ride reasonably is crazy.

I can only reiterate my experience building two 69 Camaros. The iRS car had a much better ride than the Ridetech four bar. Night and day. Even had Bret the owner of Ridetech ride in the car and suggest changes. No real difference. Maybe the solid axle cars CAN ride as well as an IRS but I’ve not seen any commercially available suspension kits that do….

I see that Roadster Shop is now offering a chassis optimized for ride called the Ride Line. I was contemplating buying one for my 59 Chevy pickup to compare to my C5 IRS equipped 56 Chevy pickup. Unfortunately they are now quoting 10 month delivery times which is a little bit crazy imho….

Don

[CraigS]

Don think back to a bone stock 69 Camaro. Did it ride OK? So what has changed? To me overall suspension design can get into a lot of stuff w/ roll centers, instant centers, etc. But ride is much reduced from overall design. You need 5-6 inches of wheel travel w/o anything hitting anything else, no control arm bushings binding, no geometric binding (an old Fox Mustang rear suspension would not roll if all bushings were replaced w/ spherical bearings), and reasonable shock and spring rates. The OP says his shocks are in the middle of their travel so that is good. I'd next disconnect, or remove if necessary, the coilovers to see if the suspension will move up and down w/o them. Next I think he also said the shocks are on #6 adjustment. Why? I don't know the specifics of those shocks but I have never seen any that #6 is the softest setting. Usually 0 or 1 is softest so that needs to be tried to see how it affects ride. And I may have missed it, but I haven't seen a spring rate # yet so we have no idea what he has. Based on your experience one other possibility is the shocks are completely wrong for the car. An adjustable shock has a range of stiffnesses available. The softest setting on these shocks could possibly be too stiff for this application. I once had the compression damping made softer in a pair of QA1 DA coilovers because it was too stiff for a good ride in a cobra replica. I figured that QA1 probably valved them more for something like a Camaro which would be 6-700# heavier.