Originally Posted by
RedBullFiXX
While offset axles do shorten the wheelbase by 3.5mm, that is not the point of their use in tuning.
Offset axles locate the axle behind the kingpin to change the way a car turns, and have a profound effect on handling and added stability.
One can expect mid corner, to corner exit under-steer with this option.
Don't ask why, but this got me thinking about geometry. With offset axles, the effect of caster is amplified when turning. There is no caster difference when going straight.
To see what that meant to weight transfer, I threw my 104 with offset axles on the gram scales and got this:
LF RF
224 221 -- wheels straight
205 241 -- wheels right lock
259 188 -- wheels left lock
Obviously, I have more travel to the left than to the right. Guess I'll address that later. The point is that there is considerable weight transfer -- more than I'd expect from caster alone. If anyone has scales and a 104 with inline axles, we can see those numbers as well.
So the effect is that as I steer right, the right front loads up, but also sends weight to the left rear. As this dynamic happens, you'd expect the car to turn smartly to the right. As I exit the turn and reduce steering lock, the weight gets more neutral and the car wants to go straight, bringing on the corner exit understeer that RedBull mentions.
I'm new to pan car setup, but an experienced friend of mine tells me that you can never have enough caster. He may be on to something. The offset axle is a clever way to add needed caster effect when you can't get it otherwise.