Setup Question - mid corner steering force

[CtrMint]

Setup Question,

I’ve now had chance to track both my 420R and 620R, the 620R being my usual track car.

What I’ve noticed is that my 620R really wants to open the steering in any medium to high speed corners, and it requires a notable amount of steering force to stop it.  Which can become draining through the course of a day.  In comparison the 420R doesn’t, the effort required to hold mid corner just isn’t needed.  Both are running ZZR tyres.

I don’t believe my corner speeds are that different as I know its one of the areas I need to improve on.  I’m lacking complete confidence in terms of corner entry speed and faith in how much speed I can carry, and so I’m sure they’re at similar speeds, I’m also reasonably cautious picking up the throttle again off apex. The 620R turns in really well, as does the 420R, though I’m probably lacking sufficient experience and pace to really pick out any variance.

I’m assuming the difference will be down to the spacing on the lower wish bone?  I’d like the 620R to operate similarly to the 420R whilst not compromising straight line stability.

Unfortunately the 420R is at home, and the 620R is currently sat in the trailer, sorry I can’t state what the spacing is like on either Seven. But given the rain is pouring down I figured I’d post.

Although I might be barking up the wrong tree 🙂 Any recommendations?

[ScottR400D]

The ‘spacing on the lower wishbone’ could be the answer. That’s where castor is set and could be the difference  

Positive castor increases self centring which is what you seem to be describing.

To decrease the + castor you’d want to adjust the  washers to move the lower wishbones back.

Are the 420 wishbones set further back than the 620 is a the question. At least you’d need to see what the 620 is so someone who’s more familiar with the set up could comment.  

 

Edited July 9 by ScottR400D