Spring time: Different suspension setups and how they differ from one another
Hello there! The suspension is a crucial piece in a car’s ability to accelerate, brake, and corner. It’s what keeps it from scrapping the ground causing a lot of damage to the underside. For this blogpost, I will be going over 5 examples: Macpherson Struts, Multilink, Double Wishbone, Torsten Bar, and Live Axle So without further delay, let’s get one with it.
Macpherson Struts
Easily the most common type (at least in the front) the Macpherson stir consists of a strut tower, a coil spring, a lower control arm, and a shock absorber. As it makes contact with a bump or obsticle in the road, the lower control arm moves in the direction of the obsticle (either up or down) and the strut follows suit, compressing the spring and the fluid in the shock absorber.
Advantages: Cheaper and narrower than a double wishbone as well as lighter
Disadvantages: taller, doesn’t absorb impacts as well
Verdict: The cheapest way to go, but there are better options if you want performance
Examples: Porsche Coxster, BMW M3/4, just about any non-supercar
Multilink
As the Macpherson strut is the most common front suspension setup, the multilink is the most common, non million dollar rear. Typically consisting of 4-5 different links, 3 link setups have been used before on older Toyota’s and Mazdas. Of those 4 links, they have a leading arm, control arm, camber arm, and toe arm. However manufacturers can adjust them as deemed necessary.
Advantages: more wheel control of strurs
Disadvantages: more expensive than struts, more complex to make
Verdict: A happy medium between struts and double wishbone while taking benefits from both
Double Wishbone
Commonly known as A-arms, unequal length control arms, or double wishbone, this setup is used quite frequently in the automotive industry, especially in higher tier SUVs and supercars. Consisting of two A-arms (or wishbones), these keep the shock absorber pointing inboard. This combined with how the upper A-arm is shorter than the lower one, it increases negative camber which increases cornering grip as more tire is in contact with the road.
Advantages: shorter than struts and providing more wheel control than the more complex multilink
Disadvantages: more expensive to make and also wider than struts
Examples: Any McLaren, Ferrari, or Lamborghini Huracan, Range Rovers, just about any off-roader or supercar for that matter, BMW M5
Torsion Bar
A torsion bar is similar to a live axle in that both wheels share the same point. Here’s what I mean: as one wheel goes up the other is affected too. It’s a live axle except with proper halfshafts and no leaf springs.
Advantages: sits great in economy cars without compromising space
Disadvatanges: can be difficult to make but really it depends on what car it’s going to be put in
Verdict: pretty basic, but if that’s what you’re after, go for the strut
Examples: Ford Fiesta, Toyota Sienna, Ford GT
Live axle
This has been around since the ox was still pulling stuff around. For this, it’s pretty basic: power is sent to the wheels through a solid beam on both sides accompanying by a leaf spring and shock absorber. The live (or solid) axle is quite old, that doesn’t mean it’s going anywhere. From drag racing to offroading, the live axle will be there until the end
Advantages: balanced power delivery, better off-road than an independent setup
Disadvantages: when one wheel goes up, the other goes down which messes with ride quality, hates corners because it can cause wheel hop
Verdict: quite good, but only for straight line stuff
Examples: Jeep Wrangler, classic muscle cars, Mercedes G-Wagon
Comments
Just the two?
Lol I posted it by accident before I finished
While a good effort, there are a few inaccuracies. Not all live axles have leaf springs- the Land Rover Defender and Mercedes G Class have suspension coils, as does the Ford Panther-bodies, except the Town Car, which has air suspension at the rear.
Also, Multilink is the best suspension type, because while the double-wishbone is good at controlling vertical movements and camber, it can’t control toe movements as well as a multilink.
Finally, in the Torsion Bar section, you described a Torsion Beam (confusing, I know). Whereas the torsion beam is semi-independent, the torsion bar is a simple fully independent suspension system. A torsion bar is like a horizontal L-shaped lever which twists up the way when the wheel moves up, and twists downwards if the wheel moves down (like if it goes over a pothole).
Yeah, I figured it would be easier to describe leaf springs
Definitely. No wonder so many use it front and rear
Oh ok, I thought t didn’t matter if t was bar or beam
Ford GT uses Torsion Bars?
Yeah, it uses controls arms and a torsion bar. Engineering explained made a video on it
https://youtu.be/L0rAU0or3rQ
that is pretty cool! Awesome! I’m hoping for an Editors pick!
Me too, but I wouldn’t count on it lol
An other thing to add is that in the multilink since there are different amgulation of rotation for the links the resulting rotation of all the suspension during compression generates also a variation in camber , you can easily see this variation in videos when people slams car like bimmer or audi that are bot multilink in the rear and when the air strut is completely lowered the wheel has a supernegative camber and is hidden partially under the fender :)