Have searched thru the various threads on this, and am now confused. There seems to be some variance in views on tyre pressures needed to procuce
IVA-satisfactory self-centring effect.
Possibly some differing views depending on whether Sierra or Cortina hubs are used. I have used Cortina uprights, with upper wishbones giving what
seems to be approx 3 deg castor. Had the car front end fully tracked, camber angles adjusted and toe-in set at Procomp. Matt and Ivan did a great job,
and offered useful advice; big thanks to them.
So, the question is - what tyre pressure should I set for the fronts? One view suggested low pressure e.g. 16 psi, another view reckoned it should be
40 psi, just for the (re-) test.
Your suggestions please.
I increased my tyre pressure from 28psi to 35psi for the IVA and noticed an improvement (all be it not that significant) and mine passed OK; that said - could have been fine on the normal pressures.
I was wondering the same thing prior to IVA and I was told (by someone on this forum) they recommended 8psi at the front to get a J15 thru (because Bently do that). On the day I forgot to lower them and it passed anyway. The self centring on my car is barely perceptible only if the camber is in my favour. My pre-prepared excuse was "that all the bits are new and a bit sticky".
The best way is to get a new set of top wishbones with the full and designed 7 deg.
Replacing the rubber bush on the steering column with the bearing mod also helps no end.
[Edited on 24/7/13 by big_wasa]
Good tip on the steering bushes, the more free running they are the better for self-centering and general feel.
quote:
Originally posted by big_wasa
The best way is to get a new set of top wishbones with the full and designed 7 deg.
Replacing the rubber bush on the steering column with the bearing mod also helps no end.
[Edited on 24/7/13 by big_wasa]
- check the free movement of the steering rack - if the damper is too tight it can make it too stiff to center well (particularly if you only have 3
degrees of castor). You can add another shim very easily.
Dave
quote:
Originally posted by big_wasa
Replacing the rubber bush on the steering column with the bearing mod also helps no end.