Soft Springs/shocks Stiff Arb

[number2301 1 1 Cars]

I had this suggested to me the other day, and with my limited knowledge of suspension sounds like it'd work well. The idea is you have reasonably soft springs/shocks to soak up the bumps on your typical english road and a stiff arb to stiffen things up just when you need it round corners.

 

Anyone got any thoughts on this?

[TEKNOPUG 3]

Go for stiffer springs with standard shocks. The ARB with adjust the understeer/oversteer characteristics of the car but it will stiff suffer from excessive weight transfer if the springs/shocks are soft.

[Grim.Badger 15]

I had this suggested to me the other day, and with my limited knowledge of suspension sounds like it'd work well. The idea is you have reasonably soft springs/shocks to soak up the bumps on your typical english road and a stiff arb to stiffen things up just when you need it round corners.

 

Anyone got any thoughts on this?

 

From the way that it has been described to me this is exactly what the standard setup is; the GTi apparently has softer springs than you would expect but a much thicker and stiffer arb.

[chownr 0]

I think there is some mileage in what you propose but you have to make sure that you retain the harmony between all three elements. It would be foolish to run say a 50 ilb spring and try to accomodate this with massive damping and or a thicker ARB and visa versa.

 

Remember that springs control essentially vertical movement, dampers control the srping compression and rebound, and the ARB controls body roll/stiffness in the corners (think thats right!). A thicker ARB will alow you to run softer springs to accomodate bumpy surfaces without compromising cornering ability but I wouldnt go overboard.

 

If your normal roads are extremely bumpy then there may be some mileage in running slightly softer springs and an oversize ARB

[Sandy 189]

I've tried alot of set ups and the best 205 I've driven, by far, had no ARBs. It did however have properly revised geometry.

[VisaGTi16v 1]

What a rough point of view, what did you do to the shocks and springs on that car? Stiffen up one or both? One end more than other?

[Sandy 189]

Colin's your man (eeyore), but basically coilovers front and back with pretty tame spring rates. But gettting the track/roll axis/bump steer and castor right, seems to be the key.

 

The trouble with ARBs is that they unload the inside and overload the outside tyres, which reduces overall grip and over bumps they can make loss of grip sudden. They don't help traction either. What they do, is reduce body roll, which makes the car "feel" like it's handling better, or reduce the effects of undesirable geometry changes on smooth surfaces.

[number2301 1 1 Cars]

Oh its nothing I've actually done, just had it suggested and was interested in discussing it to help me understand suspension a bit more.

 

Wouldn't the soft springs and long suspension travel keep the tyres in contact with the road regardless of bumps?

 

Interesting that someone mentioned it sounds exactly like the standard set up, as the person who recommended it is quick to criticise the 1.9 for having too stiff suspension.

[welshpug 1,628]

yep, softer springs = more contact with the road.

 

 

I remember a test of the 206 gti180 and civic type R a few years ago, they said on pan flat smooth tarmac the Civic pulled away easily, but throw in some welsh hillside with tight bends and hairpins and the more supple pug suspension did its thing and more than made up for the 20 bhp deficit.

 

similarly Citroen have recently been out in ireland testing prior to WRC Ireland, and they found that the suspension they usually use in france is simply too stiff and short to deal with the terrain out there!

[Sandy 189]

Of course softer springs (up to the limit of travel) cope with bumps better, but stiff ARBs make matters much worse, because when one wheel hits a bump, it transfers the same load (to a lesser extent) to the wheel on the other side, which means both wheels suffer a loss of grip. With a softer or no ARB and stiffer springs, this does not happen, only the wheel that's hit by the bump is affected and so the loss of grip is less and less dramatic.

 

The Civic Type-R (old shape) is pretty stiffly sprung and I was thrown clear of the seat once over a bump (held down by the seatbelt). But it is exceptional in that respect and to say it's inferior to the 206GTi is either creative journalism or a joke. Try the Accord Type-R on the other hand, there's a car with amazing bump absorbtion and the steering remaining consistent and true over pretty extreme surfaces.