mmt 14 Posted April 5, 2020 Hi guys, I guess the fat Front arb (21mm) from the 309 Will fit onto the 205? More important Will it make any improvements? My front suspension is rather hard and probably the arb do not do much work. Any thoughts? Race car only. Thanks Share this post Link to post Share on other sites
petert 549 Posted April 5, 2020 None of the 205’s I race against have a front ARB. Share this post Link to post Share on other sites
SRDT 146 Posted April 5, 2020 The ARB fits with the 309 clamps and bearings, you can't use the 205 ones as there is no other 21mm ARB. The clamps are also used on the Citroën C15 "760kg" with 24mm ARB. Share this post Link to post Share on other sites
petert 549 Posted April 6, 2020 So whilst it may sound like a good idea, because bigger must be better, it's not. It will just induce understeer. Just fit 500lb springs all round (or TB equivalent), the biggest rear ARB you can and leave the front ARB off. It will hook up better out of tight corners and be neutral. Share this post Link to post Share on other sites
Tom Fenton 1,524 Posted April 6, 2020 I guess it depends what you use the car for. I tried my road rally car without a front ARB as lots of folk seemed to like and I thought it was terrible! The arb provides stiffness in roll, this allows the main spring rate on a road going car to be softer for ride comfort and compliance over bumps. By removing the arb you need to up the spring rate as Peter describes, significantly, to take account of the arb no longer being there when in roll. The trade off is a much harder ride. This is fine on a car that sees smooth tarmac/race track. For a car used on bumpy roads it makes it not much fun to drive. Back to my rally car, a very stiff front spring would be a disaster for that on the bumpy roads its used on. It always makes me chuckle when folk talk about a set up for "fast road and track days". The setup ideal for each are almost mutually exclusive! Certainly on UK roads. Pick one or the other. 1 Share this post Link to post Share on other sites
mmt 14 Posted April 6, 2020 Thanks guys. I run 280 springs. Tried 340 and they were too hard for me. I’m amazed that you run the rates you do Petert must be that gravity is upside down Downunder. :-) I agree that track and Road are two different planets which requires two different animals. Share this post Link to post Share on other sites
petert 549 Posted April 6, 2020 It's actually 500 for AO50's and 650 on each corner for slicks. They're not too hard if your shocks are valved to suit. Share this post Link to post Share on other sites
billybluesky 1 Posted April 20, 2020 After fitting a 306 rear arb I found it made the car feel like i was going to lose the rear on fast {road} corners ,fitting a 309 front restored the handling and obviously reduced body roll , not sure whether just a beefed up front would help you, i guess its all personal choice. Share this post Link to post Share on other sites
mmt 14 Posted April 20, 2020 True. Personal preferrence is important. The Peter T built 205 I’ve seen on Youtube seems to be quite efficient though. Share this post Link to post Share on other sites
petert 549 Posted April 21, 2020 Here's one of my son chasing Parry in car 144. Share this post Link to post Share on other sites
Henry 1.9GTi 36 Posted May 12, 2020 I run the 309 bar with 400lb/in springs up front. No under steer for me. I quite like it and means you can run softer springs. The only way to do it is try both and see what you like. Play around with spring rates and geo on a test / track day, measure you tyre temps across the tread and just drive either what you think feels best, what the stop watch says its best, or a combo of both. I run 25mm rear bars with either 25mm or 28mm ARB depending on track. For me switching the rear dampers made more difference than going from 25 to 28mm. And a plate diff is a must! But going to aggressive on the decel ramp caused understeer for me on entry / mid. I now run 30/60 rather than 45/45 as this is my only option with the TranX diff. Front roll bar really is one part of the puzzle. But judging by experiences of different people I don't thing you'll go wrong either way. Got to find what you like. Enjoy racing it Share this post Link to post Share on other sites
mmt 14 Posted May 12, 2020 Thanks Henry. Indeed testing, trial and error approach is the only way forward. Lately I have been experimenting with front to rear rake but have not yet been testing it. What dampers are you using? Share this post Link to post Share on other sites
petert 549 Posted May 12, 2020 I should also add that we run fully adjustable custom front arms, thus we can't run an ARB. Share this post Link to post Share on other sites
Henry 1.9GTi 36 Posted May 15, 2020 AST 5100 fronts and Bilstein tarmac spec rears (B46-2313). Previously got confused with Bilsteins naming and had 1038s on the back. Going to the 2313 made a big difference but also compromised wet stability. A lot. Share this post Link to post Share on other sites
welshpug 1,621 Posted May 16, 2020 have you tried disconnecting the arb in the wet Henry? Share this post Link to post Share on other sites
Henry 1.9GTi 36 Posted May 17, 2020 I have not but its on the list. On race days its usually one panic after another so never had a chance to try it in a quali session. Only fixed the car late last year so have done 1 trackday in about 3 years and it was dry. Which was good for a shakedown so can't complain! Definitely want to play around with it though, the car was a weapon in the wet on a softer setup. Its a bit snappy now for sure but also a lot better balanced in the dry with more outright grip it feels. Next time it rains ill disconnect rear, then front as well and see how it goes Share this post Link to post Share on other sites
