Discussion about Anti Roll Bars & Chassis Bracing

[Moff]

This is something which doesn't come up too often, but what are peoples opinions on Anti roll Bars and Chassis Bracing ?

I'm not concerned about how the handling will be affected.

My logical view is too brace the chassis and make it as rigid as possible, its the suspension which transfers the weight. and helps with the handling.

I have spoken to some suppliers and tuners, and have been told the following :

Don't brace the chasis too much, it will make handling crap

You want a thinner anti roll bar at the rear as its rear wheel drive.

Does anyone know the answer, or any of the technical stuff ?

Moff

[Bubble]

Don't brace the chasis too much, it will make handling crap

I can't see the logic behind that statement, as you only have to look at touring cars and see all the bracing that they have. I would have thought that the stiffer the chassis was, the better.

[Moff]

Thats exactly my thinking Geoff...

The suspension settings, plus any adjustment on the pillowball joints will decide on the levels of grip once the chassis regidity has been increased.
A Stiffer chassis means less flex, allowing the suspension to work more effectively I would have thought ?

Moff

[The Mad Welsh Man]

Don't brace the chasis too much, it will make handling crap

I would have thought that the stiffer the chassis was, the better.

I know this has naf all to do with Skylines but when i had my Turbo Mini i brace the chassis and the front and rear subframe to help the handling out and it did the job, Going around roundabouts at just over normal speed i was on 3 wheels

So i would say it makes the handling a lot better

[simon]

depends on application.

for a track car you want the chassis to be a stiff as possible to allow the suspension to do it's work.

for a road car you want it to move around more so to allow ride comfort.

the more stiffness you put into the chassis the more you will discover the weaknesses in the suspension components (bushes, ARB's etc)

Simon

[ivor]

i've seen some jap vids where they've put pot rivets every couple of inche's along the seams as well as filling them with polyurethane foam to get a rigid body.

This was only done on top track/drag cars as simon said if you plan to use the car for everyday driving i would leave a degree of flex in it just for sake of your teeth

[Moff]

I'm looking for the car to be more of a track car, so happy to sacarifice road comfort as its not an everyday car.

I already have some replacement poly bushes to go in.

Moff

[simon]

In that case there is a lot you can do to the chassis, I seem to recall Chris Wilson over on the GTROC refering to the R33 shell being as stiff as wet paper or something along those lines.

Getting it seam welded, put in a proper welded cage, front and rear strut braces will all stiff the chassis up. You will need to make sure that the suspension components are up to the job though as you will be making them work harder.

Think about things like your engine & gearbox mounts, steering rack bushes diff mounts etc as well.

Simon

[Richf]

Its a case of effort VS reward . If the car will NEVER be driven on the road and you need every 1000th of a second off your lap time things like this are worthwhile.

For a novice any available money should be spent on track time imo

Its true a stiff chassis WILL pick a wheel up more easily in the corners which isnt always a good thing especially for less experienced drivers as it makes altering the line harder

[Checkpoint]

It really depends on the application of the car, even to the point of "just" being a track car! Race teams will change suspension settings PER TRACK due to how bumpy or up and down the tracks are, this may include suspension travel as well as spring rates and damper rates.

As far as a road car is concerned, it could only ever be a compromise as what works well on a reasonably flat motorway will be way too stiff for a bumpy back road and what you need for a bumpy back road is too soft etc for a motorway (assuming you are pressing on )

Increasing bodyshell stiffness IS a good thing (thats why all manufacturers new models are always stiffer than the old models) as it reduces fatigue on the shell and vibrations etc as well as improved handling. (crumple zones and stiffer passenger cells are designed into this)

People referring to a car being too stiff and not handling well because of it are kind of right but it won't be due to the body being too stiff but the suspension instead.
Soooooooo many people buy the WRONG suspension for their cars application thinking that stiffer is better often because they want to say they have "Race" suspension etc when actually their car handles WORSE than before due to being too stiff!
This is because the suspension has to be able to move quickly to follow the changes in the road surface and it must also have travel to do this (something low stiff cars CAN'T do hence they are "too stiff" and "too low" to allow travel) otherwise they will skip across the road as the tyre looses contact. I have driven cars that are so stiff that they eject you from the seat on a bumpy corner and collect you by the handbrake somewhere near where a handbrake lever certainly should not be

Anti roll bars can usually be uprated from standard without problems as long as they do not start to inhibit the response of the suspension too much.

Another thing that has one of the most influences on how a car handles is the geometry set up...... but guess what...... it is another set of compromises between tyre wear and cornering speeds.
Also worth mentioning is that on a Skyline (as with a lot of cars) when you lower it too much the geometry of the lower arms go's tits up and the handling suffers as a result.

[Moff]

Thats the answer I was looking for

The plan at the moment is to get the Anti Roll bars fitted, with new standard droplinks, along with the Camber and Traction arms, Hicas Lock Bar and uprated Front and Rear Lower arms and uprated poly bushes. Once I get the Tein Monoflex, and the EDFC, car will then go to Abbey to have the Geometry set up.

Seam welding etc I think is a tad too far for what I am looking for, as I am far from an Expert, but having the right tools helps anyone do the job better

Moff

[Checkpoint]

Cool.
A roll cage (if you don't already have one) is well worth it, it will make a big difference to the shell's rigidity and it's protection is invaluable