What's this.....??
 

My earlier post, a few posts down from here, asked what did members recommend for replacement discs for my son's STI Prodrive. Ian at Godspeed is supplying exactly what I need.
However, the nightmare began when I busted the caliper to hub bolts for both the rear calipers, shearing them as I tried to gently persuade them to loosen. Now, both calipers are at the "caliper hospital" near me, but in removing them, I came acros this backplate.......

http://imageshack.us/a/img94/1903/p1050777v.th.jpg

What does that backplate actually do, other than reinforce the bolt connection through the hub and into the caliper? That looks like some sort of bearing at the bottom of it, but it's all seized up as though it has been laying at the bottom of the Atlantic for the last 5 years.

Could someone let me know?

Thanks if you can,

Mike

Its a mass damper, intended to dampen out resonance.

So what would be the effects of running without it, and why are they not fitted to the front?

Okey dokes, thanks for that. Strange device indeed. I'll just fit that back up as it is then, although a new one would be nice :p.
Calipers now back from stud machining, and caliper threads all in tact, thankfully. Does anyone know - just out of pure interest - how much I'd have had to pay for replacement rear Brembos?

New I'm not sure, 2nd hand around £150-£200.

Thanks Gaz. I guessed it was going to be quite expensive.

Ian Godney at Godspeed can probably repair them.

Worth asking.

Blimey, he's a gem. Never heard of him before all this, but now....what a find. I received some seriously good discs and pads for the boy's car bang on time today, all from Ian. The calipers are sorted, thank to a local fella who specialises in removing sheared caliper bolts from the caliper....I was very lucky to have managed to manoevre them clear of the hubs still with about 1/4" of stud protruding.

I'm now an Option 1 member, although I don't actually own one of these beasts myself.......but at least the boy's let me drive it a few times - his thanks to me for sorting the car out for him now and then. This Forum has been very helpful so far, so, nice to join up at long last :luxhello:

Mike