Hi there, after some advice on what spring rates people are using? I've searched but there are alot of threads with a lot of different washers. The car is a 6k2 seat ibiza cupra, approx 300bhp and 320ft/lb, kwV1's, compbrake solid adjustable top mounts, H&R 28mm rear roll bar and neuspeed 25mm front bar, also run ball joint extenders and track rod flip (arms just point down), setup wise rear is shimmed to 2mm toe in each side and 2.5 deg neg camber and front parallel toe, 3degress caster (max on top mounts) and 2 degrees neg camber each side. I'm currently running 400lbs front springs (70nm) and 300 rears (50ish nm) tyres are 195/50/15 marangoni zeta linea sports semi slicks, I feel the cars still too soft and rolls, also squats a fair amount under acceleration, dive under braking is acceptable, now Is going to 500-400 to be too hard or 400-400 a better option, much appreciated
Personally i think 400 is enough in the front, but why not try 600/400 to match your weight distribution. Concern is that traction will suffer on front. I have had the same issue with my ibiza, felt like it rolled too much, but have resisted just upping the spring rates as this really does not help front traction. Ended up with a bespoke fron arb and some dampers tuned to give strong low speed damping resistance, which is what can help with counteracting roll.
Cheers for the reply rob, think I've seen your ARB, who produced that out of curiosity? I'm now more leaning to 400fr and 400rr or even 500rr to make the rear move a touch more front end grip is a little bit of an issue but the power delivery is a little aggressive so I'm probably going to turn down the revo boost setting to control that abit better
The 7-position adjustable ARB will be available from me once tested and I know all works well. Mk2/3 Ibiza, Mk2/3 golf fitment. Are actually in the process of engineering a whole front corner setup for our cars - wishbone with spherical bearings/ali upright/arb/damper/brake options. I reckon there is a market for these worldwide as nothing is available off the shelf and loads of people race/rally these cars. Personally I would not go that hard on the rear, if you want it to move more, up the tyre pressures / stiffen the damping. One of the fastest sprint hatchbacks I have ever seen used to run circa 300lb front and 200lb rear springs and went like it was on rails - no roll, just masses of grip. Owner was a PRO engineer at Mira. For grip, the tyre needs to stay on the road
Yes, but! - Camber control will be limited with the standard geometry up front even with 400lb springs! I found having a softer rear increases the inside front wheel spin coming out a corner, but then i have an open diff With ideal Geo, much softer springs can be used as your maintaining the contact patch with the Geo, not with limiting the camber loss as the wheel goes through its movement arc with a massive spring rate, and damper that can cope with that spring rate... As mentioned in previous threads, rear droop and tyre pressures can be a crude way of 'massaging' weight transfer when you are limited to what you can change :-) I do like a good converatsion about spring/damper settings with standard/restrictive geometry. More often than not it boils down to massive spring rates/tyre pressures to compensate for geometry inadeqancies!
RobT ... You mentioned about a Roll bar and full corner set up for Ibiza's... Any more info on this??
I've sold my Ibiza now but basically I ended up with about 400lb front springs, 250lb rears, 25mm Eibach rear ARB, and an adjustable front ARB which went from about 50-150% what a 28mm regular bar would do. About -2 front and -1.5 rear camber. Slight toe in at rear, parallel toe at front. Custom drop-pin in the upright to raise the front roll center. Car was set up on corner weight scales for even weight distribution. It drove lovely - plenty of traction, rode the curbs and bumps well, didn't roll much at all even on sticky slicks.
In 30 years of racing VW cars I have never run spring rates heavier in front than the rear and the 50 or 60 competitors I raced against did not either ( this was in S Africa) , A Golf likes to be over sprung at the rear 500 front and 600 to 650 rear . that was the average competitors choice although some went even harder on the rear , the Last car I built was a 6 R POLO Brand new body purchased from VW ran 120 n/m in front and 140 n/mm rear ( 680lbs front 800lbs rear ) this car won the SA VW Challenge in 2014 and was pretty much unchallenged the whole season. So I recommend you try this it might go against the grain with techno boffs who do the mathematics and engineering but it works and works very well . Also the rear axle will be dead stable under braking with toe in , BUT if you want the car to turn a little toe out on the back axle will work every time , If you go too much the car will get wavy on the tail under hard braking so watch for that . Limit droop on the back to get the inner wheel off the tarmac so the toe out doesn't pull the car into under steer. Can you get more camber or is 2 Degrees max ( you need more ) . Also what bushes are in the front? are they race ones with the Rose joint at the rear of the control arm . if they are, and you have pretty stiff toe control set the front toe to 15 minutes toe out !!! One last thing if you don't have a Limited slip diff pull the front anti roll bar off the car ( disconnect just to try if you want to save some time ) Most of my advise is probably strange looking at the points other people are making , but I have built many VW racing cars ( 4 last year alone ) and they have all been extremely successful and handle magnificent . I used KONI 28 Series dampers in our own car , these are in a league way above KW and proper custom Race dampers ( 4 to 5 K) but reasonably priced dampers will work with the set up I have recommended so don't stress about that . By the way some advise . try not to take a bit of info from one and a bit from another , Pick one set up and try it , if it doesn't work try someone else's recommendation just don't mix them . Ideally go to a track with the equipment to do back to back test as you carry out the changes , the problem is the rear toe as this really is a pain to do at the track . How do you do your wheel alignment, with a Dunlop gauge, or stringing the car , ( or a KWIK Fit ) . Corner weighting the car normally shows a 60 / 40 split that's normal but shouldn't influence the choice on spring rates , The stronger springs may start to fall out of the operating window if the C /Over kit if it is an off the shelf kit but it might still work and definitely worth a try ( are the dampers adjustable in rate ) ?? .
Is this a multi use car or dedicated circuit? Pretty much agree with most of that, few things around set up that are more personal, but there is one thing I really suggest DO worry about your front /rear weights, this will give you a ball park, in FWD start with 100% more rear spring PER KG than the front So, 1000 kg car with 600 front and 400 rear Say you are running 400 pound inch on the front the rear would start 550 on the back How do you work out the front starting point, well that comes down to your diff and the traction you can get. Open diff or something that can spin up like a Quaife will be a lot less than a plate style or a even a CIG Locker