IVA/Sierra front uprights-mushroom fixing
 

I'm just finishing the preparation of my front uprights. Can anyone comment on the apparent need for a second fixing for the mushroom insert to satisfy IVA requiremts.
Is this a general requirement or just the opinion of certain examiners? I'm aware of previous posts that have touched on this subject under SVA rules which seemed to leave it open ended?

Not sure it's an absolute requirement.
But the examiner defo checked I had the second fixing.
Personally I would put the extra fixing in anyway.
I just tapped it out and put in a grub screw, so you can hardly see it anyway

I thought the original Sierra suspension strut had a "fin / gusset" on it, that went through the bolt hole. So although the base of the suspension was clamped in the hole, it was also positively held in with the bolt. Obviously on a kit car you also need to fix the upright in place to stop it riding out.

It is a requirement, although i think it maybe one of them that is down to the examiner, i had to put one in mine on the day to pass. Just drilled and tapped a 6mm allen bolt through them both. When i thought about it afterwords it is a good safety backup just in case the mushy comes loose.

AndyH

Yes it's the mushroom insert that needs fixing
Bum too slow !!!

I got a foto tho

Thanks for your response. I presume that they are concerned that the original clamp bolt can work loose? or that it could fail/fracture? or both?

Surely even if the existing clamp bolt failed the suspension forces would be tend to force the inset down into the upright anyway.

cheers
John

Andy,

This begs the question how the bolt itself is secured, does it have a lock nut or is it just loctited?

cheers
John

He was quite happy for a bit of loctite John....:)

Like I was saying, the original suspension was held in on its gusset. I imagine they want a positive fixing on the kitcar, because the donor had a positive fixing. You can see some after market coilovers have the tabs to be locked on on top of the hubs. I don't think any car has just a clamp to hold something as vital as a hub to the suspension.

That's an interesting pic Deezee. I'm wondering about making a set of mushrooms in steel, milling a slot in the side then letting in and Tig welding a piece of plate in. Assemble to upright and drill through. Job done :p