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iva failer
john pryor - 22/2/13 at 08:09 AM

Hi just failed iva test front wheels do not center i have just built a bog standerd locost used the origanal escort rack same
wheels over inflated tyres everthing seems loose help.
Also co gas was high 8.71 max is 4.58 have same carb webber has been factory o/h engine has been bored and o/h could
it just be air screw adj ?
HElp Thanks john.


designer - 22/2/13 at 08:52 AM

It's worth getting the suspension set up by a specialist.


panichat - 22/2/13 at 09:21 AM

Hi
My book locost failed on this. I got the tracking set up properly and it passed, but still didn't centre in the way I wanted.
I welded wide upper wishbone brackets on to give more castor adjustment and replaced the sierra steering column bearing with a spherical bearing which made a small improvement. The thing that made the most difference was adding a shim in the steering rack box to free it up.
If I was doing it again I would try the tracking set up and extra shim first before getting the welder out.

Good luck
Dave


snapper - 22/2/13 at 10:15 AM

The quick trick for IVA ( you should do it properly in slow time) is to pump up tyres to 30+ psi and put some toe out to the setup
This is only a temporary fix


big_wasa - 22/2/13 at 04:54 PM

Well known cock-up in the book that the 7deg of castor was only 3.5deg. Ive made mine with the full 7 and should be fine but it doesnt center like a production car.


PeterV - 22/2/13 at 06:37 PM

quote:
Originally posted by snapper
The quick trick for IVA ( you should do it properly in slow time) is to pump up tyres to 30+ psi and put some toe out to the setup
This is only a temporary fix


This tip worked for me.
I shimmed top wishbones back by 6mmm (Max I could do due to shock coils would touch) for a more permanent fix. Need to move bottom next to finish the job completely.


BenB - 22/2/13 at 06:46 PM

Other bodge is valve springs inside the steering rack boots limits the steering though when they get coil bound but does the trick.


Trollyjack - 22/2/13 at 07:19 PM

Not enough caster have it checked


40inches - 22/2/13 at 08:30 PM

quote:
Originally posted by BenB
Other bodge is valve springs inside the steering rack boots limits the steering though when they get coil bound but does the trick.


Used to be the case for SVA Ben, but the examiners now feel for the springs in the boot, fail if they can feel them