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Stability / Handling
pk - 7/6/06 at 12:24 PM

I lost the original - so here we go again!

My Blade engined, book car seems to be unstable at speeds of over 60 mph. It’s got the book caster – all of it, 5.5 degrees I seem to recal, a live axle and a quick rack fitted.

It tends to get into a bit of a “tank slapper” that feels like it could be the rear tyre side walls flexing / moving around, but I note from an earlier thread that the caster angle seems to be the usual suspect.

So what’s the consensus for caster angle and are there any other areas that I should look at?

The corner weights are all OK
The tyre pressures are all at 20psi.
I have between 2 to 4 mm of toe in.
Bump steer is very very small if any at all – special steering rack.
It's on straights that it seems to be moving around, bends are OK.

Any ideas? How stable should it be?


iank - 7/6/06 at 12:30 PM

It's over in 'Locost Related'


nitram38 - 7/6/06 at 01:16 PM

I still would suspect rear wheel toe-in or rather the lack of.
You need to get the car suspension measured properly.
A small tweek here and there will make a big difference.


SeaBass - 7/6/06 at 02:35 PM

quote:
Originally posted by nitram38
I still would suspect rear wheel toe-in or rather the lack of.



Aye - but pretty difficult to adjust on a live axle... lol


nitram38 - 7/6/06 at 05:36 PM

quote:
Originally posted by SeaBass
quote:
Originally posted by nitram38
I still would suspect rear wheel toe-in or rather the lack of.



Aye - but pretty difficult to adjust on a live axle... lol


It could still be bent


SeaBass - 7/6/06 at 05:51 PM

quote:
Originally posted by nitram38
quote:
Originally posted by SeaBass
quote:
Originally posted by nitram38
I still would suspect rear wheel toe-in or rather the lack of.



Aye - but pretty difficult to adjust on a live axle... lol


It could still be bent


Let's not bring sexual orientation into this...

Live axle cars do have a certain amount of 'jitter' to them when they are as light as a seven. You can really feel the weight transfer lighten up the front wheels when blasting up hills round here.


David Jenkins - 7/6/06 at 07:43 PM

quote:
Originally posted by SeaBass
Live axle cars do have a certain amount of 'jitter' to them when they are as light as a seven. You can really feel the weight transfer lighten up the front wheels when blasting up hills round here.


Great, isn't it!

David