How much does suspension type really matter?
 

Double wishbone suspension is often lauded as the best suspension type there is. Lotus cars are famous for utilizing them, as well as other great handling cars like the MX-5 and S2000.
But other cars offer great handling with "inferior" suspension setup - the 911 has struts in the front (only changed to DW in the 992 GT3) and the Cayman has struts on all four corners. The Twins have front struts as well. Caterhams (and the original Lotus 7) have live axles or a De Dion setup in the rear. Obviously there are considerations other than handling to choosing one setup over another (packaging, cost, etc.).

This makes me wonder how much does the basic suspension setup actually matter for a car? Or put it another way, how much of the suspension details are there for a marketing on-paper advantage vs. any tangible benefit for the driver? Or #2 - does the particular setup of the car (weight, weight distribution, suspension geometry, etc.) overwhelm the basic suspension selection, making this point moot (or at least only relevant during the tuning process by the manufacturer)?

Putting some examples - would an MX-5 be significantly worse with struts in the front? Would the Twins be significantly better with DW in the front?

Bottom line, you can run less static camber with a properly designed double wishbone suspension. You always need to run ridiculous high static camber with a mcpherson strut. The real advantage of the double wishbone is more contact patch during braking/acceleration and a better contact patch on the inside wheel (during cornering, negative camber affects that wheel the wrong way, having less of it (double wishbone setup) will improve grip there, altho it doesnt do much.

Realistically speaking, its not a huge difference in many cases. The advantage of the mcpherson is simpler design, lighter (strut body replaces a whole control arm by itself) and requires a lot less space (thats mainly why some porsches have it).

In the real world, car setup, driver, and track/tires conditions will have a greater impact over wether you have mcpherson or a double wishbone (or a multi-link A-arm or a live axle) setup.

To add to that, the greater the total deflection in the suspension, the more it will benefit from having a more sophisticated setup. A Miata, which is designed to have a whole lot of suspension travel, benefits greatly from the camber it retains on compression. A stiffly sprung car like most McPherson Porsches or the BRZ don’t benefit as much from a double A-arm set up, because the camber they lose due to the deflection is smaller, because the deflection is smaller.

Porsche put double wishbones on the new gt3, and they gave up on struts decades ago for their serious racing efforts.
https://www.topgear.com/car-news/sup...t3s-suspension

https://www.total911.com/opinion-is-...-really-a-911/

https://en.m.wikipedia.org/wiki/Porsche_961

Street car? Fun weekend car? Nbd, 99% of car owners don't care and can't tell the difference.

Going racing, even at a grassroots level? Yeah, the suspension that controls the tire better will have more grip and better wear characteristics. Clean sheet of paper, it's going to be wishbones or multi link.

Double wishbone changes dynamically less camber and toe, that's gain .. even if one was to ignore higher production cost, but more space needed may hit in many cases and not be an option. For example, for cars like twins, due wide boxer engine, even with mcpherson struts there is not much steering angle. Or i heard that one of reasons S2K is underbraked due double wishbone suspension. Everything is compromise, and some may not be best for each and every case. Then there is bit of "many ways to skin the cat". At the end we value car as a whole, as package, and there might be cases where end result of whole car is better even if some of parts are not of theoretically best design.

There's a lot that goes into making suspension work. Bushings, valving, angles, materials, ride height, target ride quality, handling bumps vs smooth, straight line acceleration, downforce, weight, cost, active vs passive roll bars, rear wheel steering, active vs passive valving, what parts of valving can be adjusted actively, tire grip, target usage, and so on and so on.

The specific implementation matters far more than the underlying suspension type.

And when it comes to going fast, the driver matters far more than the implementation or the underlying suspension type.

I've had plenty of fun on torsion rear suspension.

In Formula 1, the aerodynamics of individual suspension bits matters quite a bit.

Off road, you might want something else.

@Icecreamtruk hit the nail on the head.

There's a reason why bespoke performance cars use double wishbone suspension designs while our car uses bargain bin parts like carry-over suspension from the econobox Impreza. Hell, even the ND Miata has a double wishbone suspension.

It wouldn't be possible to have a DW in the front , because of the limited space (boxer engine).

It's not a big deal. You do have to run a bit more static camber, not really a major prob. When I studied geometry of my 240Z vs my S2000, IIRC the Z's struts gained about 0.5 deg. camber per inch of travel vs. S2000 at about 1 degree per inch. So run a bit more static camber. Note that this doesnt really hurt braking as you don't gain as much camber as the front suspension is compressed as wishbones do.

I think the FT86's 55/45 weight distribution is a bigger hindrance to performance than front struts...

It would be better to have a bit more rear weight , but I guess you cannot have everything in life.

Be even better to have less front weight ;)

If they'd just make a short-wheelbase 2-seater version, with rear wheels moved ~8-10" forward, that'd put it about 50/50, with weight reduction...

And a 700HP turbo V8. And make the body out of carbon fiber. Hell, no passenger seat. Just driver. It should be carbon too. And...

:rolleyes:

Yes exactly.