BTW the Alfa 3.2 GT V6 has a 17mm one, slightly stiffer than the GTA.
Edward Have a look at posts from me about the Whiteline rear ARB.
I have the 20mm up from 16mm GTA one.
The eibach one is 18mm.
FWIW My personal view is that I really don't think you should increase the size of your front ARB, it will just add understeer..
On the otherhand whack up the size of your rear ARB.
So my 20mm whiteline one is 144% stiffer than oem, i.e. 2.44 times the rate of the oem bar.. ITs a noticable difference
No drawbacks.
If this is for track use, get the rosejointed droplink kit too, I have pics in the thread. Only drawback is that they squeak slighly occasionally as indicated in their blurb.
For track use, the whiteline rear ARB on stiffest setting (its 3-way adjustable) took 2 seconds off my lap time.
Understeer was huuuuugely reduced and the car was waaay more responsive in turn-in but also all the way through the corner.
Its the relative roll stiffness front to rear (including various aspects such as springs and ARB's) that determine how much understeer you have.
The stiffer the rear the less understeer..
Especially since there isn't much we can do to increase front end grip, unless we source big neg camber wishbones from N-technology or something..
The front still hardly rolls at all (my car is lowered 30mm in track season), and I defintely will not be increasing its size, possibly at some point even experimenting with disabling it since I have much stiffer springs than standard on the fornt.
I will shortly be putting way stiffer springs on the rear, probably twice OEM, and I reckon this would take another 1 or 2 seconds off my lap time, still keeping the car streetable though.
Cheers,
TB