I only know of "companies" or "teams" who do this.

Multimatic was one of my customers before I retired. My contacts were on the manufacturing side, not skunk works. I've seen the innards of their DSSV spool valve dampers, but it's no help in understanding how they work.

Ohlins is another good one. I have Ohlins suspension front and rear on my roadrace motorcycle. Apparently they do some car stuff as well.

I'm sure other reputable manufacturers of high performance suspension also have good engineering teams. Bilstein. Koni. KYB. Sachs.

Then of course there are the specialists who work with race teams, of which there are many.

Perhaps if you provide us with some understanding of what you are trying to do, "the big picture", someone could provide some direction.

I'm looking for a consultant to help with a new chassis suspension design.

Okay.

Is this a hobby project, or is it meant to be a race car (rally? Dirt oval track? Paved oval? Road course?), or a production vehicle (how many? What type?) And is there serious money behind it, or is this someone scribbling on the back of a napkin? Objectives for the design? What do you want to do differently that hasn't already been done?

Careful reminders: "double wishbone suspension" can describe the front suspension of a Formula 1 car, and it can describe the front suspension of a 1955 Chevy. "You can make any bad suspension layout work if you don't let it move". Hydragas was a remarkable design.

Try mira UK or idiada spain, If you are in europe.

I really don't think here's a need for a suspension 'designer'. I believe all practical, durable, manufactureable and repairable suspension designs have already been published. Even active fluids and magnetism. What you might need is someone to assemble a kinematics & compliance model to evaluate ride, handling, loads, mis-build, off-road, and maybe a few other criteria. That leaves, Nastran, Adams, Solidworks, SuspensionSim, DYNATUNE-XL, just to name a few. Then you need to plug you new idea into a vehicle model of some sort and evaluate it's prowess where it's expected to have superior performance. That usually involves 'Integration' meaning how does your anti-proton beam suspension fit into your starship concept.`

Pratt & Miller and Roush are the two biggest doing this work stateside, but there are others. Both can take you from design sketch to production given proper funding.

Not to be disrespectful, but if you don't already have common knowledge like this then you shouldn't be trying to design or manufacture major vehicle components or systems. Developing major vehicle systems requires millions of dollars, mistakes are costly, and there are many frauds willing to take your money.