Sway Bar Sizes

[imwhyteyo]

back from the dead! was looking for this, great bit of info!

[carguy101]

I saw this too... Three posts above this. But thanks :)

I guess it was extra useful haha. I couldn't remember where I saw it, now I do. smh

[jeffnhiscars]

84 318i is actually 18.5mm.

Just sayin'

[Earendil]

I saw this and thought it would be useful here http://www.houseofthud.com/cartech/swaybars.htm

I saw this too... Three posts above this. But thanks :)

[carguy101]

I saw this and thought it would be useful here http://www.houseofthud.com/cartech/swaybars.htm

[pantelones]

As with most things, this "depends", right? I know the Pro-3 guys run hella stiff suspension with a larger front sway bar. That said, they run a stock rear bar (or in some cases no rear bar?). But back to the "depends", they also are trimming for race application, and have crazy [compared to street] camber, and sticky tires.

In general, I think you're right. But it's not an absolute if my understanding is correct.

Oh of course that statement is not an absolute. What size bars and how you have them adjusted all comes down to the specific application, and driver preference. Though general in a street application you really don't need that big of sway bars, but in an actual race car it becomes a whole other story. Sway bars do play a role in your over-steer/under-steer, and they can be used as a tool to correct one or the other to an extent.

[Earendil]

basically if you dont understand what makes a suspension feel stiff then you will probably buy aftermarket sway bars, ignorance is bliss i guess. bigger diameter bars are only necessary when you run really soft springs and you need the extra force of a bigger bar, it helps keep the wheels on the ground and reduce the added body roll from soft springs. if you run stiff springs (which most people who would buy aftermarket sway bars would be) you dont need bigger bars, the vert 21mm front and 14.5mm XI rear would be a perfect set up for a little stiffer suspension, and cost less than $100. i think its pretty silly to spend $300+ on new swaybars.

As with most things, this "depends", right? I know the Pro-3 guys run hella stiff suspension with a larger front sway bar. That said, they run a stock rear bar (or in some cases no rear bar?). But back to the "depends", they also are trimming for race application, and have crazy [compared to street] camber, and sticky tires.

In general, I think you're right. But it's not an absolute if my understanding is correct.

[NufnSus]

bump for a nice info resource

btw, can anyone confirm that the E30 320i came with an 18.5mm Front Bar?
...at least that's what my callipers say I've got, and it sure looks OEM (& in need of a new p/coat)

also, this;
How Sway Bars work
pretty sure I've seen it linked elsewhere within the cosmos of this forum before, but I figured this is maybe a more appropriate place.

[pantelones]

basically if you dont understand what makes a suspension feel stiff then you will probably buy aftermarket sway bars, ignorance is bliss i guess. bigger diameter bars are only necessary when you run really soft springs and you need the extra force of a bigger bar, it helps keep the wheels on the ground and reduce the added body roll from soft springs. if you run stiff springs (which most people who would buy aftermarket sway bars would be) you dont need bigger bars, the vert 21mm front and 14.5mm XI rear would be a perfect set up for a little stiffer suspension, and cost less than $100. i think its pretty silly to spend $300+ on new swaybars.

[jdog]

Sent you a PM on the rear bar.

[ieatpeople]

i have a new, never installed st rear bar (19mm) for sale, $40+ shipping. pm me if interested.

[blefevre]

I get what you are saying. I have never seen an ACS or Eibach bar. It is possible they are adjustable with different mounting locations for the sway bar link.

[Earendil]

stiffer isn't neccesarily better. especially the massive increases people like to go about.

I agree. But unless you had a 318, why would you buy a 20mm sway bar unless someone stole yours off your car? (Excluding the ix since it requires a different front sway entirely).

I guess I'm just puzzled why an aftermarket performance parts company would sell a part that is identical to the stock part. A stock part that doesn't really wear out. It seems they would attempt to sells something smaller or larger, anything but what most E30's have.

If a 20mm bar doesn't perform the same as every other 20mm bar, that would explain things, but you seem to be saying that isn't the case?

So if a stock E30 buys, say, the Eibach kit (20mm and 16mm) they will end up with a different rear bar, but they might as well be installing a freshly painted stock bar in the front?

I still feel like I'm missing something here. I can't believe that these companies are either that stupid/conniving, or that the buyers are that stupid/ignorant. Maybe when it comes to things I can't believe, I'm the one that's that stupid/ignorant :)

[nando]

So if they are all the same material, why the same size front aftermarket bars?

AC Schnitzer: Front: 20mm Rear: 16mm
Eibach: Front: 20mm Rear: 16mm
M-Technik: Front: 20mm Rear: 14.5mm

That little math bit, if correct (:)) is quite a useful piece of info that I hadn't seen mentioned in a swaybar discussion before. Make me think a 22mm upgrade from 20 might actually be worth something (46% increase).

stiffer isn't neccesarily better. especially the massive increases people like to go about.

[blefevre]

Because they run a business. They want to compete in the market of sway bars. You can take your pick on where you send your money.