Having staggered offsets

[89lude]

Hey guys,

I was reading about a bmw putting spacers on the rear to make the rears have a lower(wider) offset and he was wondering how this affects handling.

That caused me to think. I know that lower(wider) offsets make the car more stable at higher speeds due to it decreasing the rolling angle but will having staggered offsets, say a wider offset on the rears (WITHOUT changing the tyre width - so fronts and rears are same width) cause the car to oversteer or understeer? Hows it affect the handling in a fwd. Sounds interesting.

Discussion time!

[yah mum]

google.com

[vinnY]

just something to note, you'll find your cars front track width is already wider than the rear track width out of factory

[89lude]

Come on, wheres the big physics discussions that i see for other topics from i think its JonhL and ChargeR....? They always make a good read.

[Zilli]

an interesting topic... i would say having a wider track at the rear would promote traction for the rear wheels (as driving wheels) which is why you see it on RWD cars... but you would also think that it promotes understeer on the front with the trakc being narrower and there being more "push" particularly with a fair bit of lock dialled in

[rk 86 wa]

Putting spacers on the front of your car allows for wider track width as mentioned before.

Your car will "understeer" or "oversteer" when you overload the tires load as they are what is essentially in contact with the road surface.

Every system has equilibrium, the easiest example is when you have the same offset front and rear the load "ideally" is being shared equally.

When you shift the offset on the front or the rears you are applying a different moment about the changed "corner" and therefore changing the characteristics.

The weight distribution is over a larger area when the track width is increased and therefore increases the load capacity on the fronts.

From my understanding and perhaps someone can correct me if I am wrong, a larger front track allows the load to be shared of a longer axial length where as the rears are still confined to the "stock" or narrower axis.

Hence in Leymans, with a wider track, the load capacity across the axis is increased and therefore as understeer is when the tires are overloaded, it will give better traction as a result. Similarly if you decrease the track width you will decrease the load capacity on the rears and therefore it will be more likely to oversteer.

Having a staggered offset will change the above mentioned equilibrium within the system to allow for a better front bias if the fronts are wider than the rears.

This however is all under the assumption that the car is under steady state cornering of course.

Now just be mindful that if you widen your front track width your turning circle will decrease.

At the end of the day "wider front offset" arguably won't make your car "better" unless the driver is aware of what will change and desires the results.