AdamP 0 Posted December 20, 2008 I'm looking to upgrade the rear ARB to try to dial out some understeer on my roland garros. Its running Spax springs and shocks up front (I know...) and standard 18.1mm TBs. I was thinking of a 21/22mm one, but was informed that it would make hardly any difference and I really want a 23/24mm one. Opinions? And a quick picture of my problem.... Share this post Link to post Share on other sites
Tom Fenton 1,541 Posted December 20, 2008 Get hold of a 306 GTI6 24mm arb, cut about 3" off it, then weld one of the end plates to the bar to make a budget 24mm ARB. Share this post Link to post Share on other sites
Anthony 1,003 Posted December 20, 2008 Are you still running the standard 16mm XS rear ARB? If so, even a 19mm GTi one will be noticeably stiffer and they're easy to obtain. (indeed, if you get stuck, give me a shout as my parents live just outside Newbury so I'm in the area fairly frequently) I suspect your problem is more that you've stiffened the front spring rate and left the rear untouched - an stiffer rear ARB will help to a point, but really IMO you want to uprate the torsion bars to GTI spec (19mm) as a minimum, if not a bit thicker. You could also try changing the front ARB for a softer one - I believe that the 1.0 models have the thinnest, followed by 1.1's, and XS's the thickest (23mm IIRC) Share this post Link to post Share on other sites
AdamP 0 Posted December 20, 2008 (edited) Are you still running the standard 16mm XS rear ARB? If so, even a 19mm GTi one will be noticeably stiffer and they're easy to obtain. (indeed, if you get stuck, give me a shout as my parents live just outside Newbury so I'm in the area fairly frequently) I suspect your problem is more that you've stiffened the front spring rate and left the rear untouched - an stiffer rear ARB will help to a point, but really IMO you want to uprate the torsion bars to GTI spec (19mm) as a minimum, if not a bit thicker. You could also try changing the front ARB for a softer one - I believe that the 1.0 models have the thinnest, followed by 1.1's, and XS's the thickest (23mm IIRC) Yep, still got the standard ARB in there, whatever that is. So my best option would be to find a knackered 1.9gti beam and switch the bars into my decent beam? Edit: Found a pair of GTi torsion bars in the for sale section, would they match well with a 21/22mm ARB on the rear? Considering it is only for track work and there is absolutely no weight in rear. Edited December 20, 2008 by AdamP Share this post Link to post Share on other sites
pug_ham 244 3 Cars Posted December 20, 2008 Found a pair of GTi torsion bars in the for sale section, would they match well with a 21/22mm ARB on the rear? Considering it is only for track work and there is absolutely no weight in rear. They'll match up fine imo, I used to run my STDT with a set of GTi TB's & swapped between standard GTi (19mm) arb & 20mm & 22mm ones with no detrimental effect but all made it corner tighter & turn in slightly nicer. A cheap & (very) effective upgarde over a standard XS rear beam. Graham. Share this post Link to post Share on other sites
AdamP 0 Posted December 20, 2008 They'll match up fine imo, I used to run my STDT with a set of GTi TB's & swapped between standard GTi (19mm) arb & 20mm & 22mm ones with no detrimental effect but all made it corner tighter & turn in slightly nicer. A cheap & (very) effective upgarde over a standard XS rear beam. Graham. Thats great. Thanks for the advice guys. Share this post Link to post Share on other sites
AdamP 0 Posted December 21, 2008 Next question... where is the best place to purchase a 22mm ARB? Seen them advertised for £130, can they be found any cheaper? Share this post Link to post Share on other sites
Tom Fenton 1,541 Posted December 21, 2008 24mm 306 ARB, cost about £40 and 1/2 hr to modify it to suit a 205............ Share this post Link to post Share on other sites
AdamP 0 Posted December 21, 2008 What size torsion bars are you running with that? Share this post Link to post Share on other sites
Tom Fenton 1,541 Posted December 21, 2008 Standard GTI, works a treat. Share this post Link to post Share on other sites
AdamP 0 Posted December 21, 2008 Thats tempting.... how did you weld it onto the end plate? I haven't actually taken an end plate off so i don't know what it looks like behind there. Share this post Link to post Share on other sites
Tom Fenton 1,541 Posted December 21, 2008 Get a 24mm ARB, cut the end off, you will find it sleeves nicely into a 306 end plate (which fits a 205 beam) then weld round the join and robert is your mothers brother. Only tip is to make sure you weld it in a position so that the plate the other end sits level on a spline. Share this post Link to post Share on other sites
AdamP 0 Posted December 21, 2008 So will I need 306 end plates for both sides? Or just the one I'm welding? Share this post Link to post Share on other sites
Tom Fenton 1,541 Posted December 21, 2008 Both sides, the 205 end plates are too small to fit on the 24mm bar splines. Share this post Link to post Share on other sites
