Most japanese cars use a coilover suspension, that is, where the spring sits AROUND the damper. However, most european cars (bmw, vw, etc.) use a different setup where the spring sits NEXT to the damper. What's the advantages or disadvantages of each? Or were the setups solely based on available space? I dunno if this is ITR related...if not, I'll add this: Does the ITR setup (coilover type) have any advantages over the bmw/vw setup? Thanks.

 

Um, anyone?

 

You can swap one without removing the other. Perhaps when switching out struts/shocks you don't have to realign your car. That's the stock setup, but I think all race cars switch to a coil-over systems. It's lighter and adjustable and many other reasons that I don't know about.

Don't know if I'm correct, but just some observations.

 

Thanks CB. I guess it is a lil lighter since you don't need the additional support for the separate spring and can just support it on the same axis as the damper. I know of many race BMW's that keep the factory setup, separate spring and damper. I'm still curious which is better. Thanks.

 

I think most serious racers switch to a coil over system. My reasons are. There are not many high performance struts that are separate. Eibach ERS spring are much smaller and lighter than spring for factory mounting points. Reduce unsprung weight. ERS has almost a infinite selection of spring rates, as opposed to car specific springs. You can not corner weigh your car if you have factory location mounted springs. I seriously don't think BMW race cars run stock mounted springs.

Again, there must be many other advantages that a coilover systems have over stock mounted springs that I don't know about.

 

Are you talking front or rear? On MacPherson struts the springs are clearly around the damper too.

In the case of the rears (at least with VW) the springs were moved seperate from the damper because of space. VW was able to add trunk room by having a smaller shock tower. It also allowed them to use a smaller length spring which the placed lower and more inward that the traditional spring over damper setup they used in the A1 - A3 chassis and created more trunk room. Space efficiency was there motivation much like the latest gen Civic and RSX utilizing a MacPherson strut design over double wishbone.

 

Thanks 801! I was talking about the rear, as I noticed VW's and BMW's use the separate spring/damper setup in their rear suspension. So, is it solely a space issue? I didn't actually see if the VW and BMW rears are MacPherson strut or double wishbone, I just got to glance inside the wheel well and see the separate spring/damper setup. Is this separated spring/damper setup only used on MacPherson strut-type designs? Or can it also be incorporated in double wishbone also? If it's only w/ MacPherson strut designs, than it seems like there's already a disadvantage there. Thanks.

 

I don't think this comment is accurate. Mustangs have MacPherson struts in the front and their springs sit separate from the MacPherson strut.

I think the definition of a MacPherson strut suspension is that it is an integral part of the suspension. If you remove the MacPherson strut the suspension will fall apart. The MacPherson struts have 2 functions.

1. Dampen the springs.
2. Locate the Geometry for steering.


I double control arm system like ours, the suspension does not rely on the spring/struts to maintain the assembly. It just dampens the car. That is why they can not make a Camber/Caster plates for our cars.

Not the best explaination, but I think it's close. Can anyone else explain it better?

CB