Slotting strut mount in Street
 

can someone translate this for me? My poor understanding is we are allowed to remove the alignment pin and slot the towers up to the max camber the OEM allowed, and I'm not really sure what that number is for a 2005 R53


2016 street current rules...


13.8 SUSPENSION
A. Standard, as defined herein, suspension springs must be used. They may
not be cut, shortened, or collapsed. Spring perches may not vary from the
OE shape within the working part of the perch.
B. Both the front and rear suspension may be adjusted through their designed
range of adjustment by use of factory adjustment arrangements or
by taking advantage of inherent manufacturing tolerances. This encompasses
both alignment and ride height parameters if such adjustments are
provided by the standard components and specified by the factory as normal
methods of adjustment. However, no suspension part may be modified
for the purpose of adjustment unless such modification is specifically
authorized by the factory shop manual.
C. Suspension bushings, including but not limited to those which carry the
weight of the vehicle and determine ride height, may not be replaced with
bushings of a different material or dimension.
D. Replacement control arms for vehicles having integral bushing/arm assemblies
must be standard manufacturer parts as per Sections 12 and
74 — 2016 SCCA® National Solo® Rules
13. Street
13.0.
E. If offered by the manufacturer for a particular model and year, the use of
shims, special bolts, removal of material to enlarge mounting holes, and
similar methods are allowed and the resulting alignment settings are permitted
even if outside the normal specification or range of specifications
recommended by the manufacturer. If enlarging mounting holes is specifically
authorized but no material removal limits are specified, material
removal is restricted to the amount necessary to achieve the maximum
factory alignment specification.

The short answer is "consult the factory shop manual" for your car.

Here's the much longer and possibly more useful answer:

"However, no suspension part may be modified
for the purpose of adjustment unless such modification is specifically
authorized by the factory shop manual."

"If offered by the manufacturer for a particular model and year, the use of
shims, special bolts, removal of material to enlarge mounting holes, and
similar methods are allowed..."

Factory shop manuals will include crash repair techniques. If these have been applied to a car it will not be disqualified upon protest. A factory shop manual used to be required to be in your possession at National events. Probably still is.

Conversely, and perversely, an unauthorized type of repair that brings an alignment back into factory spec is illegal.

The removal of pins is widely accepted as allowed on MINIs. I've never heard of being able to enlarge slots. You would have to produce a factory manual specifying it to convince me that your car was legal if I was on a protest committee reviewing a protest against your car.

I autocrossed for 23 years and had a fine old time doing it. I never competed seriously at the national level because, to my taste, the allowed (and necessary) modifications were something of a bastardization of normal motoring. I had the opportunity to closely inspect the most winning Lotus Elan in Solo history. I counted a total of five parts that I could recognize as identical to the ones on my car.

The original street classes (street touring, modified, not the stock classes renamed "street") were created to provide a venue where common street modifications would be allowed. These quickly became just more bizarre modification classes because of the nature of what works best on an autocross course.

The best people to ask if something is legal (or works best) are the ones running in your class with you. They are the only ones who can protest you and are most likely to know what agreements/decisions precede you.

I was informed by a national Solo officer that the intake manifold could not be ported on my car because past protest committees had decided that it didn't have an actual intake manifold due to it being cast as part of the head instead of being separately cast and bolted on. The Solo Events Board whom I had formally asked chose not to respond. There are a lot of group politics and secrets in human endeavors. Make friends.

A shorter answer:

The good news is that you don't need to limit camber or any other setting to what's specified by the manufacturer -- any setting that's achievable with legal parts and modifications is legal.

The bad news is that you're not allowed to slot your strut towers unless, as hsautocrosser pointed out, it's explicitly described in the manufacturer literature as an approved repair procedure. I don't know R53s well, but I'd be surprised if they're allowed to slot strut towers.

I've not had any luck finding out if the factory repair manuals allow it, the R56 is slotted from the factory