Stiff suspension? No sway bars?

[Mrmaddbrad]

So I've noticed that the new McLaren has extremely stiff suspension but doesn't run any sort of anti-sway bars. This makes for a truely independent suspension and an amazing ride quality with "the ride quality of a Rolls Royce".

My question is, has anyone thought of doing this on a boxster? Coil-Overs destroy your ride quality when set on any sort of stiff setting and if set to stiff, you just understeer terribly....

But what if you had extremely stiff suspension and removed the sway bars? The stiff springs prevent you from any sort of body roll, and without the sway bars (especially the front), you shouldn't have as much understeer.

I honestly don't think this will save you're ride quality but curious if it will actually increase performance.

Just looking for thoughts. Maybe I'm forgetting something obvious.... But some one should try it :P. I know theres a BMW E46 M3 SCCA winner (in some prepared class) that runs no sway bars! So I know it can be done properly! Just looking for thoughts! Not to be destoryed with verbal abuse :P

[blue2000s]

The MP4-12C uses active hydrolic control to replace sway bars. There's no way you can build a traditional suspension that's stiff enough to control body roll but still soft enough to absorb road irregularities so that it maintains contact with the road without sway bars. Not that you'd want to drive on a regular road any way. That is why they exist.

[jaykay]

If you have springs and dampers controlling roll and ride, ride quality will be hurt dramatically; less tire contact with the road; less traction. Usually you want things as compliant as possible (without taking away from other things).

Roll control is best done/dominated by roll control devices...roll bars; or by setting roll centre geometry to minimize the roll moment

Of course other things can be made to work...but I would think think there would be a tight envelope for it.

Active suspension is whole other kettle of fish

[Mrmaddbrad]

I know the McLaren has active suspension. I'm not that ignorant, but its not the first car to have it, but it is one of the first cars to have literally no roll bars.

As i stated before, I don't think its changing ride quality. Lets just throw that whole sentence out cuz thats not what I'm getting out.

But roll bars aren't the only things that reduce body roll... Your shocks, springs, and even you're allignment change body roll. Along with weight distribution, and actually chassi stiffness.

If you made your spring rates stiff enough. And made your shocks soft enough to be able to take impacts to where you don't loose grip or upset the car too strongly. (assuming you don't only race on racetracks. Such as terrible autocross locations....)

[feelyx]

I had a 71 911T with no swaybars and stock suspension, while it was easy to toss into the corners, too many corners in a row you would start to loose control, and it was one car you could not brake hard in a corner without spinning it. I would experience so much lean in tight corners that I could pick up pebbles off the road. It would also follow the groves in the road like a train on a track. That T was the most fun of all the 911's I've owned.
feelyx

[stephen wilson]

Listen to Blue, you'd have to have springs stiff enough to knock your fillings out. The ride would be worse than a traditional setup with swaybars, and grip would suffer unless you were on a billiard-table smooth surface. The only place I've seen this successfully done is on very light Formula style race cars, and even then most still use small bars.

[MaxD]

I have an E36M3 race car and it is very common to run without a rear bar while running somewhat high spring rates. I do. This all comes down to driver preference and limitations of the outdated semi trailing arm suspension. The transition to putting power down mid corner to exit is the issue.

As designed the boxster suspension does a pretty good job. Feel free to to log some data without bars and a wide array of springs, would love to see the plots.

How much money and time did McLaren spend on the development of the suspension of the MP4-12C?

I bet the boxster is faster with bars.

Max

[stephen wilson]

It's common on front engine/rear drive cars to run without a rear bar to increase corner exit traction, but he's talking about eliminating front and rear bars. big difference!

[Mrmaddbrad]

I still feel like some one should try it :P It's not like it takes long to do it. Just for like 1, non points, autocross. Heck, maybe I'll do it lol. I do have access to a lift lol.