What kind of suspension do DSMs have?

It looks like a type of multilink with the upper arm mounted very high. What is this called?

MacPherson strut style suspension up front.
Independent upper and lower control arms in the rear; for AWD models.

Lowering a vehicle with a Macpherson style suspension actually raises the center of gravity.:eek:

The reason so many vehicles come with this type of suspension is because it is quick and easy to assemble in the factory. Bolt the shock to the spring and half the setup is already finished.

Originally posted by Dyesin
Lowering a vehicle with a Macpherson style suspension actually raises the center of gravity.:eek:


Could you please elaborate on this? If this is the case why do people lower their car for performance reasons?

Yes please do elaborate. It just doesn't make sense. It decreases suspension travel in some cases but I can't see it raising the center of gravity as the weight of the car is closer to the ground. Please explain :confused:

I think he probably meant the roll center, but i'd have to do reasearch to see if it actually does raise it.

Originally posted by streetlethal976
Yes please do elaborate. It just doesn't make sense. It decreases suspension travel in some cases but I can't see it raising the center of gravity as the weight of the car is closer to the ground. Please explain :confused:

Think of the MacPherson strut setup as a triangle.


/\ The top point is where the upper spring perch is.

The point on the right is your steering knuckle.

The point on the left is where the lower control arm pivots on the car's frame.

If you shorten the distance between the top point and the right point, with shorter springs, you have altered the center point of the triangle( the point is vetically higher). The vehicle's frame isn't going to move. Your lower control arm will move upward, thus, the center of your steering axis is raised.;) The "center of gravity" acts in relation to centrifical forces. The gravity keeps you in the center. The forces on the wheels now are pushing on the car and across the car at a higher point than they were before. Does anyone understand that? For performance, I'd say use a STIFFER spring, not a shorter one. Not all cars were meant to be lowered. I never could understand why people always wanted to lower their car just because everyone else did it and it looks "dope dude".:rolleyes:

Originally posted by Dyesin
Lowering a vehicle with a Macpherson style suspension actually raises the center of gravity.:eek:
No. Center of gravity is not defined by the type of suspension used by any means. By your own definition, raising the vehicle would lower the center of gravity in which case monster trucks would be more stable than F1 cars.
Originally posted by Dyesin


Think of the MacPherson strut setup as a triangle.


/\ The top point is where the upper spring perch is.

The point on the right is your steering knuckle.

The point on the left is where the lower control arm pivots on the car's frame.

If you shorten the distance between the top point and the right point, with shorter springs, you have altered the center point of the triangle( the point is vetically higher). The vehicle's frame isn't going to move. Your lower control arm will move upward, thus, the center of your steering axis is raised.;) The "center of gravity" acts in relation to centrifical forces. The gravity keeps you in the center. The forces on the wheels now are pushing on the car and across the car at a higher point than they were before. Does anyone understand that?
I'm sorry to say this, but ALL of the above is 100% wrong. I think you're trying to define the roll center of the vehicle, not its center of gravity. The vehicle roll center is controlled by raising or lowering the inboard anchor point of the lower A-arm, and by varying the steering axis inclination. First of all, the control arm doesn't move upwards while the frame doesn't move (as you stated) when the vehicle is lowered. Actually, it's the inboard anchor point of the control arm that moves down together with the frame. The ball joint is not going anywhere. Although the pivot radius (defined by the inclination of the steering axes and centerline of the tire) decreases, the decrease of inclination of the control arm has much greater effect on location of the roll center. The vehicle's roll moment depends on the vertical displacement of the center of gravity above its roll center, but, simply said, lowering the vehicle will result in lower roll center AND center of gravity at the same time. ;)

Originally posted by Taboo

I'm sorry to say this, but ALL of the above is 100% wrong. I think you're trying to define the roll center of the vehicle, not its center of gravity. The vehicle roll center is controlled by raising or lowering the inboard anchor point of the lower A-arm, and by varying the steering axis inclination. First of all, the control arm doesn't move upwards while the frame doesn't move (as you stated) when the vehicle is lowered. Actually, it's the inboard anchor point of the control arm that moves down together with the frame. The ball joint is not going anywhere. Although the pivot radius (defined by the inclination of the steering axes and centerline of the tire) decreases, the decrease of inclination of the control arm has much greater effect on location of the roll center. The vehicle's roll moment depends on the vertical displacement of the center of gravity above its roll center, but, simply said, lowering the vehicle will result in lower roll center AND center of gravity at the same time. ;)

:happy:

Hey Taboo, check this out.:cool:

http://e30m3performance.com/myths/Weight_Transfer/weight_transfer.htm

Why? :dunno: The article just proves exactly what I said:
Originally posted by Taboo
The vehicle's roll moment depends on the vertical displacement of the center of gravity above its roll center, but, simply said, lowering the vehicle will result in lower roll center AND center of gravity at the same time. ;)
Id doesn't say that "lowering a vehicle with a Macpherson style suspension actually raises the center of gravity" (as you claimed) because the statement is simply incorrect. Center of gravity and roll center are two completely different things. :dunno:

I'm WRONG about the center of gravity.
Why is the roll center raised? Interesting.
My original idea remains. Once I have the geometric info to properly elaborate this theory, those who who drive my cars will be the first to know.:eek: Why not?

"MacPherson strut style suspension up front.
Independent upper and lower control arms in the rear; for AWD models. "


Thats 1g

IGS is rollin a 2g.


It looks like a type of multilink with the upper arm mounted very high. What is this called?

It's called double wishbone. More or less. Our cars use two seperate lower front control arms.

Originally posted by Dyesin
Why is the roll center raised?
The roll center is not raised after lowering the vehicle. Actually, it's lowered - just like the center of gravity, but the distance between the roll center and center of gravity increases - which promotes body roll which is compensated by stiffer springs for. Of course, if someone just simply cuts a couple of coils off the stock springs, it will drop the car, but will result in increased body roll at the same time.

http://www.dsmtalk.com/forums/showthread.php?s=&threadid=80729&highlight=DG%2A%2A%2A%2A+suspension

All about 2g suspension setup.