stephen grant Posted June 18, 2007 Share Posted June 18, 2007 I've got the green ARB and it's too understeery. What would the panel recommend as a sensible replacement? Mostly road use, couple of trackdays a year. 160ish bhp k. Yoko 032's. 13x70x185 all round. Widetrack. Thanks in advance stephen Link to comment Share on other sites More sharing options...
Area Representative Richard Price Posted June 18, 2007 Area Representative Share Posted June 18, 2007 What springs and dampers? Do you run a rear ARB? Link to comment Share on other sites More sharing options...
stephen grant Posted June 18, 2007 Author Share Posted June 18, 2007 I do have a rear ARB. I'm on adjustable platforms. Roadsport 'A' spec circa 1997. Spring rates unknown. I think the dampers are Bilsteins, but there's nothing written on them; they just look similar to pictures i've seen of Bilsteins. Sorry, i'm probably not helping myself hugely am I.... stephen Link to comment Share on other sites More sharing options...
Peter Carmichael Posted June 18, 2007 Share Posted June 18, 2007 Thinking of ARBs as the principal controlling factor of understeer/oversteer is an oversimplification. There are many factors at work. A car with the green 18mm ARB can work well. Rear ride heights can be crucial in getting the balance right. Consider this often overlooked effect... The rear of the car is a de Dion axle, so the camber at the rear is not affected by roll. The front of the car is double wishbone and the camber is affected by roll. Reducing overall levels of roll can increase levels of grip at the front. The only sure fire way to use ARBs to control under/oversteer is to increase/decrease the rear ARB stiffness. Increasing the rear ARB stiffness puts more of the weight transfer at the back (decreasing back end grip) and holds the car flatter, (increasing front end grip). So... ... take stock of your current suspension. In answer to your original question, don't go smaller than a 16mm ARB at the front otherwise you will have a roly-poly mess of a car. Consider that with attention to ride heights/camber etc. you can probably get the handling you want, even without changing the front ARB. Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted June 18, 2007 Share Posted June 18, 2007 Slight thread hijack here (sorry) .... Having found play in my front ARB ball ends, have bought spares from CC. Numpty newcomer question - to remove the ARB, is it simply a case of unbolting the clamps at the front ? Is there anything under tension that needs to be restrained ? ****************** And you run and you run to catch up with the sun, but it's sinking... And racing around to come up behind you again. photos Link to comment Share on other sites More sharing options...
Grubbster Posted June 18, 2007 Share Posted June 18, 2007 Nothing to restraint but it is quite a tug to remove (after undoing the bolts of course) as it is sprung into place. For a short while only - the Silverstone grid girls here (and a few nice cars!) Wightblat 2007 pictures here Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted June 18, 2007 Share Posted June 18, 2007 That's what I thought. Assume it can be deflected by hand to get the ends back in again. Is it a case of inserting both ends, then screwing clamp blocks back in place to pull bar into position ? ****************** And you run and you run to catch up with the sun, but it's sinking... And racing around to come up behind you again. photos Edited by - Stationary M25 Traveller on 18 Jun 2007 21:01:19 Link to comment Share on other sites More sharing options...
simonbell Posted June 18, 2007 Share Posted June 18, 2007 I've currently got a red front ARB, 250lb/in front springs and 165 or 175lb/in rear springs with no rear ARB. While the setup is generally quite good compared to some std Caterhams I've driven it does still understeer a bit. I'm going to fit a rear ARB as I think its the roll at the rear, combined with the stiff front which is causing the understeer. Simon Bell - Caterham 7 Duratec R I`ve seen the future.....and it`s powered by duratec Check out the website here Link to comment Share on other sites More sharing options...
Alex Wong1697456877 Posted June 18, 2007 Share Posted June 18, 2007 The Freestyle adjustable seems to work well if you want to have a play with different settings. Link to comment Share on other sites More sharing options...
stephen grant Posted June 18, 2007 Author Share Posted June 18, 2007 I was a bit put off that by recent reports of the Freestyle arb breaking..... Link to comment Share on other sites More sharing options...
Alex Wong1697456877 Posted June 18, 2007 Share Posted June 18, 2007 This wont help you...... I've broken a caterham one (one front and one rear) and the freestyle has lasted pretty well so far including an endurance event and a handful of trackdays (touch wood). Edited by - Alex Wong on 18 Jun 2007 17:14:59 Link to comment Share on other sites More sharing options...
MikeW Posted June 18, 2007 Share Posted June 18, 2007 I think a green front ARB is too stiff for a Roadsport A spec car. Try removing all together or go for an orange one (or the freestyle adjustable) Most guys seem to run between orange and red on the front and soft to second softest on the back (orange ARB) You want 2 -2.5 deg of camber as well MikeW Mega Grad Race No 9 Link to comment Share on other sites More sharing options...
DMT Posted June 18, 2007 Share Posted June 18, 2007 How old is your car? In the academy we were told the green bar would be a waste of time as it is too stiff for the grip the tyres we use can generate - but a couple of the serious ones out there found it took a second off their lap times - helpinh to eliminate alot of tthe understeer. As the only difference to last years cars is chassie maker I ca only think the new chassies react diffrently. I found once my ride heights were sorted front to rear I can effect the ballanceof the car just using tyre pressures - but we are using CR322's. Anyway I talk rubbish Peter is the man to listen too. Link to comment Share on other sites More sharing options...
Trevor Newman Posted June 18, 2007 Share Posted June 18, 2007 Green isnt too stiff on Academy cars i won in 2005 using a green bar, if you get understeer using a green ARB then you ought to take stock of the rest of your car set up, and academy is run without rear ARB's I currently running a live axle car on a green ARB again with no rear ARB and suffer no understeer. The majority seem to regurgitate hearsay that the stiffer the front the more understeer you get, personally i think/know its the opposite. but then again what do i know about driving quickly 😬 Link to comment Share on other sites More sharing options...
DMT Posted June 18, 2007 Share Posted June 18, 2007 Thats good to know steve - Nick potter - Another Academy champion advised of the none use.... so anyway I think i will try one. Any advice on Mallory in an Academy car - we are there in 2 weeks - never been there before - but I guess that long corner must be a place akin to understeer?? What kind of lap times should we be aiming for?? Link to comment Share on other sites More sharing options...
stephen grant Posted June 18, 2007 Author Share Posted June 18, 2007 Hi DMT; it's a 1998 I think, was Roadsport A but the engine output has gone up a fair bit since then. I think the message i'm getting is not to treat the ARB in isolation, but to get the whole package looked at, ie flat flooring etc. So that is what I shall do Cheers stephen Link to comment Share on other sites More sharing options...
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