IVA/Sierra front uprights-mushroom fixing

[jiwillia]

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?

[dogwood]

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

[deezee]

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.

[spud69]

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

[dogwood]

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

I got a foto tho

[jiwillia]

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

[jiwillia]

Originally Posted by spud69

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

Andy,

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

cheers
John

[spud69]

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

[deezee]

Originally Posted by jiwillia

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

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.

[davidimurray]

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