I understand that increasing the stiffness of the rear ARB promotes oversteer and increasing the front promotes understeer. For this reason it obviously makes sense to stiffen the rear ARB on the Coupé. My question though, is what is the best way of going about this?

I’m wondering if the best option is to get a moderate increase in stiffness on the rear bar or to get a moderately stiffened front bar with a huge increase on the rear.

Looking at the Eibach kit, it appears that the front bar is 26mm and the rear 22mm. I believe that the Whiteline is available as a 22mm or 24mm rear and I’m sure I’ve heard that the standard rear bar is only 12mm. Can anyone confirm these and tell me what the standard front bar is? Also, it would be handy to know how thick the Dedra front bar is too!

It stands to reason that the ratio between the two is the important factor. For me, the Coupé is quite well balanced as standard. The tail will slide if provoked quite easily but it rolls too much, allowing too much weight to come off the inside wheel when cornering hard. I wouldn’t want to fit a rear ARB and find that it oversteers too much. Nor would I want to fit both front and rear and find that the balance stays the same or, worse that it understeers more.

Has anyone had experience of playing with different combinations also?

I fitted the whiteline 22mm rear ARB from http://www.balancemotorsport.co.uk/products.asp?subcategory=Anti-Roll+Bars&category=Suspension they also do a 24mm one, which I believe may increase oversteer, the 22mm should, in my opinion have been fitted as standard as it really does improve the handling no end.

I believe the standard rear ARB is 19mm, though I am sure I read that it may be 16mm, (Maybe on the 16v?)

Just for information, I've been digging and have come up with the following list of permutations for Anti-roll bar set-ups on the 20v along with the approximate stiff increases over standard. I've also sorted in order of (my understanding) of understeer vs oversteer bias.

Standard 24mm front and 19mm rear set up
Front- 24mm
Rear- 19mm

Eibach 26mm front and Eibach 24mm rear
Front- 26mm 38.00% stiffer than standard
Rear- 22mm 80.00% stiffer than standard

Dedra 25mm front and Whiteline 22mm rear
Front- 25mm 18.00% stiffer than standard
Rear- 22mm 80.00% stiffer than standard

Standard 24mm front and Whiteline 22mm rear
Front- 24mm
Rear- 22mm 80.00% stiffer than standard

Dedra 25mm front and Whiteline 24mm rear
Front- 25mm 18.00% stiffer than standard
Rear- 24mm 155.00% stiffer than standard

Standard 24mm front and Whiteline 24mm rear
Front- 24mm
Rear- 24mm 155.00% stiffer than standard

19mm rear ARB is just part of the Tipo platform. All 2L models have 19mm ARB. Tipo 1.6 has 16mm etc. Not sure about 1.8L Coupe

Dedra front arb is 24mm, isn't it?!
Juergen

so come on best mix and match as i have the eibach front and rear bars