Hi,
AlexGTT- I think you could achieve the
same results with less work.
On a Car that has not suffered any metal
fatigue then a 12.9 HT Bolt that has a fixing
point on the top when bolted up from underneath
[ie welded plate recessed into the boot floor]
would act as the dowel, then an alloy collar
fitted over the bolt that sits into the correct
sized recess in the subframe bush when tightened
up could act as the dowel peg.
The existing boot floor fixing point is 'spot' welded at the bottom
skin and then the metal tube extends upto the upper
skin with another flange, where its spot welded
to the upper skin.
The tube is to accommodate bolt length.
So by continuing the hole thru into the upper boot
floor skin you can weld in a fixing point below the
boot skin and cover with an access plate etc.
Nice thick plate welded at the top would allow the bolt to be fitted
from below as norma,l and then fit a large M12 flange bolt
tightened from the top, with or without access plate [if recessed]
Its basically what Merc did on the 190 etc, but there
access plates on the upper boot skin are tack
welded on, and sealed, more to stop condensation
causing corrosion.
This would give you a HT 12.9 Bolt fixed at top
and bottom with a alloy collar fitted over to
create the dowel/peg for the recess into the
alloy centre of the subframe bush.
Shear factor on a m12 12.9 bolt is way
above any lateral forces or spot loads
that the CSL will ever generate.
Could either make own subframe rear bushes with
shore 90 or 95 poly, [or delrin ?] and then have inserts made
to suit the new dowels/pegs, or if there is enough
meat on the std E46 bush insert, re-drill them and
use them for a little compliance on a Road / Track car.
I spent a long time fucking around under the
E46 CSL rear boot area cut much away and learnt that
BMW basically got it wrong and the design is
flawed regarding rear subframe mounts.
Given that the standard look was lost long ago
I have gone a different route to that above, but its a gamble,
so time will tell if the Primate's thinking outside the
box, is in the pound seats or not as the case may be.
When its finished and works will give the SP
and few pics.
Regards,
The Gorilla.
|