Tom Suddard
Tom Suddard GRM+ Memberand Director of Marketing & Digital Assets
10/10/23 8:50 a.m.
feature_image

Could stiffer sway bars make our GTI faster on track without hurting its street manners? In theory, yes—increasing roll stiffness to control body roll should limit dynamic camber loss and increase grip without the downsides associated with stiffer springs. As an added bonus, adjustable bars would let us tune the car’s balance to fix its tendency to understeer–but would it …

Read the rest of the story

Colin Wood
Colin Wood Associate Editor
10/10/23 9:42 a.m.

Alright, twist my arm, I'll start shopping for a rear sway bar for my Fit. wink

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
10/10/23 9:53 a.m.

The place you're most likely to notice a change in street manners is on pavement that's uneven from side to side. The car will rock more and you'll get more lateral "head toss".

In my experience, there's usually a threshold where the bars start having more impact on the ride (har har) than they do on the handling. A mild sway bar upgrade works well, an aggressive one may not.

Also, $1002 for a set of sway bars and end links. We're selling to the wrong customer base! You can get a set of FM bars and end links for less than half that.

CAinCA
CAinCA GRM+ Memberand Dork
10/10/23 1:50 p.m.

Interesting. I tried the 25.4mm 034 rear bar on my MK6 GTI. It was fine by itself but when I installed a 26mm H&R front bar it was way too stiff. I wound up running it on the softest position all of the time. I wound up swapping it to a H&R 24mm rear bar and it was great. 

 

Also, the 034 bushings dried out quickly and had to be relubed pretty regularly. The H&R bushings were teflon lined and never squeaked.

CrashDummy
CrashDummy Reader
10/10/23 3:01 p.m.

Curious how the rates compare to the stock bars....how much stiffer is the new rear bar? How much stiffer is the aftermarket front bar on full soft compared to the stock front? 

edmagoo
edmagoo New Reader
10/10/23 3:02 p.m.

I have always wondered why sway bar manufacturers add bends in the center section when there is nothing in the way of a straight bar.

I also wonder about cutting the center section of a stock bar and replacing it by welding a DOM center section like this:

https://forum.miata.net/vb/showthread.php?t=235046

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
10/10/23 3:47 p.m.

In reply to CrashDummy :

Because a sway bar is only part of the roll stiffness, it takes a fairly significant change to really effect a handling change. The new bars could easily be twice as stiff as the originals. It's an easy thing to misinterpret which is why we don't publish our rates, but we'll give them to you if you ask.

In reply to edmagoo :

Sometimes those bends are used as stops to prevent the bar from sliding side to side.

I would be very concerned about putting a piece of DOM in the middle of a sway bar and how long the joint would hold up. I would be more likely to try to modify a bar from another car to fit instead of splicing DOM in the middle.

CAinCA
CAinCA GRM+ Memberand Dork
10/10/23 6:22 p.m.
CrashDummy said:

Curious how the rates compare to the stock bars....how much stiffer is the new rear bar? How much stiffer is the aftermarket front bar on full soft compared to the stock front? 

IIRC: The 26mm rear bar is something like 1.75 - 2.25x stiffer than stock.

Pete. (l33t FS)
Pete. (l33t FS) GRM+ Memberand MegaDork
10/10/23 6:30 p.m.

It was my understanding that bars were made of spring steel and could not be welded.  Am I wrong?

 

Being wrong would be nice smiley

SkinnyG (Forum Supporter)
SkinnyG (Forum Supporter) PowerDork
10/11/23 2:29 a.m.

(I've fabricated quite a sway bars out of mild steel)

fanfoy
fanfoy SuperDork
10/11/23 9:58 a.m.
Keith Tanner said:

Also, $1002 for a set of sway bars and end links. We're selling to the wrong customer base! You can get a set of FM bars and end links for less than half that.

That price is pure insanity.

As for the material discussion, I see a lot of contradictory information, but an application like the GTI, there really is no reason to use any fancy alloy. The twist is so small that the stress is absolutely tiny. 

Maybe on an application that uses the sway bar to locate the lower control arm (like 80's Ford used to do), a stronger alloy might be needed? Maybe.

codrus (Forum Supporter)
codrus (Forum Supporter) GRM+ Memberand PowerDork
10/11/23 11:20 a.m.
Pete. (l33t FS) said:

It was my understanding that bars were made of spring steel and could not be welded.  Am I wrong?

Being wrong would be nice smiley

I'm a software guy not an ME, but my impression is that the reason welding is an issue is that it destroys the heat treatment in the zone that got hot.  In theory you can re-treat the entire part to address that.

Pete. (l33t FS)
Pete. (l33t FS) GRM+ Memberand MegaDork
10/11/23 1:41 p.m.

In reply to codrus (Forum Supporter) :

I'd be more interested in cutting the existing arms off and putting something else there.

karstgeo72
karstgeo72 GRM+ Memberand New Reader
10/14/23 9:40 p.m.

I run a front and rear sway bar (H&R) on my Golf Sportwagen among other modest suspension mods (additional camber/caster, sport springs + dampers) and the handling is fantastic.

karstgeo72
karstgeo72 GRM+ Memberand New Reader
10/14/23 10:04 p.m.
Keith Tanner said:

The place you're most likely to notice a change in street manners is on pavement that's uneven from side to side. The car will rock more and you'll get more lateral "head toss".

In my experience, there's usually a threshold where the bars start having more impact on the ride (har har) than they do on the handling. A mild sway bar upgrade works well, an aggressive one may not.

Also, $1002 for a set of sway bars and end links. We're selling to the wrong customer base! You can get a set of FM bars and end links for less than half that.

For sure.  See example towards the end of video here on my Golf Sportwagen.

https://youtu.be/DiAF0S9PxnI?si=tPcQN1Hr3GcY2pnk

 

You'll need to log in to post.

Our Preferred Partners
ciCYcArk0jJxNPopvj1QoWpugbTnlgtCIYjwQJd7Hb7tBjOR9OZErFP6wf5zON2V