I've never seen a Westfield do this ...

[cng1]

Adding a stiff ARB _reduces_ so you'll be going slower and will delay the transition of weight till later in the corner (may or may not be a good thing on any given corner).  

Not sure I get the logic here, can you expand what it reduces that would make you go slower.

Have a read of "Competition Car Suspension" by Allan Staniforth for chapter and verse.

The simpleton explanation is that an ARB is primarily an aid to help you adjust balance the amount of grip between front and rear where for whatever reason you are unable to do so by other measures.  An ARB cannot "invent" grip at one end so can adjust balance by reducing the grip at the other.  So, given two identical cars, one balanced correctly by geometry/CoG/spring/damper setup will be quicker than the one that has to use ARBs to archieve the correct balance.

[SteveD]

a r b = anti roll bar ,reduces body roll

[cng1]

a r b = anti roll bar ,reduces body roll

You might naively think that mightn't you.  The ARB connects the wheels on either side.  Under hard cornering where the suspension on the outer corner is being compressed the ARB will endeavor to also compress the suspension of the wheel that's already flapping in the breeze.  Of course it won't actually lift that wheel further off the ground as even stiff ARBs are flimsy when compared to your coil springs.

[SteveD]

its not called an arb because its a shock absorber is it !

who says the inside wheel will be flapping in the breeze ! and i fail to see how the arb will compress the suspension on the inside wheel tbh but still in no suspension god

off to find my staniforth book and post some quotes from it

[cng1]

who says the inside wheel will be flapping in the breeze ! and i fail to see how the arb will compress the suspension on the inside wheel tbh but still in no suspension god

off to find my staniforth book and post some quotes from it

We were referring specifically to the picture posted at the head of the link.  The wheel there is up in the air, which is just fine.  My point was that adding an ARB is not going to somehow bring that wheel in contact with the ground.

In terms of how an ARB compresses the suspension on the inside wheel what do you think an ARB does?  An idealised ARB has close to zero friction on the mounting links.  For now imagine that you've not got any springs/dampers on there.  Pull up on one side (lets call it the outside wheel) with 1 Newton of force (as would happen during cornering) and that 1 Newton is transferred to the other side, pulling that up by an equal amount.

If your ARB was infinitely stiff then you could apply a few thousand Newtons to compress the outside then that too would be transferred to the inside, compressing that by a similar amount .  Clearly your ARB isn't infinitely stiff so can only transfer a small amount of force but what happens on one side will happen to a lesser amount on the other - compress one side and the other will too.

[SteveD]

who says the inside wheel will be flapping in the breeze ! and i fail to see how the arb will compress the suspension on the inside wheel tbh but still in no suspension god

off to find my staniforth book and post some quotes from it

We were referring specifically to the picture posted at the head of the link.  The wheel there is up in the air, which is just fine.  My point was that adding an ARB is not going to somehow bring that wheel in contact with the ground.

the car in the pic has no arb ,assuming the shocks and springs are in the right ball park ,fitting  properly set up arb's front and rear  to that car would reduce body roll therefore keeping the inside wheel on the ground     cant say i have seen any westfield with arb's and half decent set up lifting a wheel ever

[markcoopers]

I yumped mine off a bridge a while back to see what it felt like flying......cracked the sump, so i'll be keeping all 4 on the black stuf now.

[SteveD]

I yumped mine off a bridge a while back to see what it felt like flying......cracked the sump, so i'll be keeping all 4 on the black stuf now.

did you have arb's fitted  

[cng1]

the car in the pic has no arb ,assuming the shocks and springs are in the right ball park ,fitting  properly set up arb's front and rear  to that car would reduce body roll therefore keeping the inside wheel on the ground  

No, it really wouldn't and even if it did you wouldn't be substantially better off.

Just imagine that you can get it so that the inside wheel is touching the ground, the peak corner speed will be when you are using the complete limit of lateral grip.  Your mass is fixed so the roll force is proportional to corner speed, hence force acting down on the tyres to give grip.  So, speed is proportional to grip which is proportional to downward force.   Take force (weight) from the outside tyres and give it to the inside ones and you're no better off.  So lets say you get a few 10s of newtons of force between the inner tyre and the tarmac - how much good do you think that does compared to the thousands of newtons that are helping thrust the outer tyre onto the tarmac.

Have a read of Stanniforth though, I am sure that he explains better than I that peak grip and hence speed is when the car is set up so it is dancing the line between being on 2 wheels and pushing the outer tyres beyond optimum camber.

[SteveD]

so your saying basically that having two or three wheels on the ground when cornering is better than having four ,and you dont need arb's on a car

your making out as if everyone is a driving god ,this is the real world not a book  

[cng1]

so your saying basically that having two or three wheels on the ground when cornering is better than having four ,and you dont need arb's on a car

No.  I am saying if you can get things right without degrading grip by using ARBs then you are better off.  How many wheels are on the ground is irrelevent as under hard cornering the inner wheels have no weight on them anyway.

[SteveD]

how many cars do you know of that race on circuits that are set up somewhere in the ballpark and are on the pace  that work without arb's  none and the inside wheels will have weight on them in cornering conditions just not as much as in a straight line

and how the chuff can a arb degrade grip when set up propa they will allow you to corner faster as it cuts body roll and stabilises the car

[cng1]

SteveD, happy to continue the discussion if you are serious however I beginning to think you are trolling - am I wrong?

[SteveD]

no honestly im deadly serious for once ,im failing totally to understand why all the racecars out there are running around with  arb's fitted if they dont need them according to you

and cars that have them must be set up incorrectly then

[stephenh]

Why do you say anti-rollbars degrade grip, cgn1?