Is it the same? the 147's and 156's anti-roll bar

Pls Help! I got a 156 Eibach ARB. Can it also fit my 147GTA?

I think (but not sure) that you can fit all the ARB on any GT/147/156....but what you will get as an end result will be different.

Mine has the 24mm ARB at the front...the GT 3.2 has 23mm....the 156 2.4JTD has 22mm....most of them have 22mm....I am not sure about the GTA....

Many people say that my car shouldn't have the 24mm bar at the front...as it is for the GTA....not sure about that either. But I am happy that I have the 24mm....I will be fitting the polypro bushes at the front ARB monday. The rear one on mine is 14mm...the Q2 and GTA have the 18mm....I have the Q2 fitted to my bella, so soon the 18mm rear ARB will be fitted to my car.

Or I might go directly for http://www.whiteline.com.au/

Hi KGB, just so you are aware (if the sniper kitties haven't got you yet ) that the effect of increased diamater is alrger than you might thing.

14mm to 18mm is a 173% increase in stiffness.

14mm to 20mm is a 316% increase in stiffness, this would be way too stiff for road use without other major changes to your car.

Whiteline have a full matrix of stiffness increases on their catalog pdf.
Or I can root out the formula somewhere if you need it.

Cheers,
TB

thanks kgb, my major concern is whether the shape of 156 and 147's ARB the same or not. EB spare told me that the front bar is same but the rear is different.
I also fitted a Q2 recently, improvement is significant. I found that my GTA is stiff enough for road use now, still thinking to keep the ARB or sell it.

A 147 GTA rear ARB can fit a 156 GTA with trivial adjustments of spacers, and some very minor sensor cable rerouting.

I think the 156 GTA ARB very likely would fit a 147 no problem at all, but have not tried it.

Cheers,
TB

thanks TB, anyway EB will exchange me the correct ARB. They made mistake in my order.

OK, thats better!

Thanks TB,

So I should fit the Q2/GTA rear ARB 18mm???

ps: as you probably know, I have Koni-FSD, powerflex all around, and superpro polubushes on the front ARB which is 24mm.

I would say go for the 18mm rear ARB, since if you just upgraded the front ARB that will have added understeer to your car I suspect, although I'm sure it feels very stable.


Perhaps go for an adjustable one though and start off at the softest setting, only slightly dearer (three holes).
Definitely be more cautious in the wet especially while you get used to the new handling of your car, it will feel much more taut and alive and you need to be smoother with the steering than without it unless of course you are deliberately trying to "adjust" the cars line.

Cheers,
TB

Originally Posted by Trailbraker

...since if you just upgraded the front ARB that will have added understeer to your car I suspect, although I'm sure it feels very stable.
Cheers,
TB

That I will know Monday, when I hope to get them installed finally.

My rear camber angle has changed with the koni-fsd...most of the garages over here are saying that they can not adjust it (most of them have never seen alfa in their garage anyways). But there was a thread around here, with follow AO that fixed his camber....I asked him how...but he never replied.

KGB I got my rear camber adjusted to increase rear camber at the rear.
Apparently you just elongate some bolt holes, obviously an experienced mechanic should do it.

Cheers,
TB

is the improvement significant if upgrade to Eibach ARB? that is only 2mm thicker than original

The effective stiffness is proportional to something like the diameter to the power of 4, so yes, 2mm is a big differecne.

From the Whiteline chart the jump from 16mm to 18mm is 60% stiffer.

Cheers,
TB

Originally Posted by Walfa

is the improvement significant if upgrade to Eibach ARB? that is only 2mm thicker than original

yes, thanks TB, I read the chart. Just wonder the actual feeling is noticeable. any GTA here using Eibach here?

Just a thicker rear bar would be most beneficial to get a better balance, what that translates to driving is weight being shifted to the rear, improving cornering agility. The front bar's adequate really, bit of a job to change too as it involves dropping the sub frame.

That said, you can't go far wrong installing a thicker front as well, the bushes on the original will need replacing at some point, also if the difference is 2 mm, proportionally the increased stiffness won't be as much as the rear. Fitting both, the stiffest rear setting and if it has the option softest on the front should work well.