Strut/shock, brake pad replacement...staying in stock class

[hderr]

I'm going to replace the brake pads, and shocks on my late 85, 944 Porsche. I'd like the replacement to be as close to "performance" without changing from stock class.

Can I use any brand brake pad?

I'm guessing there is more restriction on the shocks? What do I look for or where do I find info on this?

Hank

31 ES 944

[kirstein]

Hank,
In Stock classes any brake pad is allowed, and any shock or strut that's dimensionally the same as the original, doesn't alter ride height, and doesn't allow more than 2 seperate types of adjustment. There is a link on the left side of the web site called National Solo Rules. Click that an it will take you to the SCCA website location to download the entire rulebook.

[Eric Pollock]

Hank,

If you were to look at the rule book the following is stated:
13.5 SHOCK ABSORBERS
A. The make of shock absorbers may be substituted providing that
the number, type (e.g., tube, lever, etc.), system of attachment
and attachment points are not altered, except as noted below.
The interchange of gas and hydraulic shocks absorbers is permitted.
The following restrictions apply:
1. No more than two separate external shock damping adjustment
controls. This permits the use of shocks which originally
came with more than two external adjustments, which
have been converted to double-adjustables, only if the additional
adjustment controls have been permanently disabled
(e.g. via welding, epoxying, grinding off). Gas pressure
adjustment is not considered a damping adjustment.
2. Suspension geometry and alignment capability, not including
ride height, may not be altered by the substitution of alternate
shock absorbers.
3. Adjustable spring perches are allowed, but the spring loadbearing
surface must be in the same location relative to the
shock mounting points as on the standard part. Shims may
be used to achieve compliance.
4. The fully extended length must be within plus or minus one
inch of the dimension of the standard part.
5. Electronically controlled shocks may not be used on vehicles
not originally equipped with such units. Vehicles originally
equipped with electronically controlled shocks may use the
standard parts or non-electronically controlled alternative
shocks subject to all the requirements of 13.5. Non-standard
electronically controlled shocks are not allowed.
B. The mounting hardware shall be of the original type. The use of
any shock absorber bushing material, including metal, is permitted.
Pressed or bonded bushings may be removed from standard
parts to facilitate the use of alternate bushings which fit in
the original location without alterations to the part. This does
not permit the use of an offset shock bushing. A shock absorber
bushing may be implemented as a spherical bearing. The bushing
attaching the end of a strut to the body or frame on a strut
type suspension is a suspension bushing, not a shock bushing.
C. To facilitate the installation of commonly available aftermarket
shock absorbers, struts, or strut inserts whose shaft size is larger
than the center hole of an upper shock mount assembly, that
hole may be enlarged by the minimum necessary to accommo64
date the shock shaft size, provided the following restrictions are
met: (1) the enlarged hole must remain concentric with the original
configuration; (2) the enlargement of the hole does not require
modification of a bearing (as opposed to a washer, sleeve,
or plate); (3) neither the hole enlargement not the location of the
shock shaft changes any alignment parameter. Provided these
constraints are met, this permits enlarging of the center hole in
an upper shock mount with an integrated rubber bushing, where
the bushing is integral to the mount and bonded to the plate and
the mount is provided by the OEM as an assembly. This includes
drilling out and/or removal of the metal sleeve.
A bonded shock bushing/plate assembly is considered a shock
mount assembly and not a bushing. It may not be replaced with
an aftermarket performance part. It is not permissible to replace
the bonded bushing material.
D. A suspension bump stop is considered to be performing the
function of a spring. Therefore, the compressed length of the
shock at the initial point of contact with the bump stop may not
be increased from the standard part, although the bump stop
may be shortened for the purpose of installing non-standard
shocks. Bump stops installed externally and concentric with the
shaft of a shock may be drilled out to fit a larger diameter shock
shaft. Bump stops may be substituted for the purposes of installing
non-standard shocks.
E. A hole may be added through the bodywork to route the line
from the reservoir to the shock absorber body. Such holes may
serve no other purpose.
F. A hole my be added to an interior body panel to provide access
to the adjustment mechanism on an allowed adjustable shock
absorber. The hole may serve no other purpose. Interior panels
are defined to be those pieces which cover the interior of the
vehicle and are accessible from inside the vehicle. They do not
include structural panels, such as wheel wells or inner fenders,
which may also be accessible from inside the car but which
actually form part of the body of the vehicle.

Basically you can use any shock or strut.

13.6 BRAKES
A. The make and material of brake linings may be changed.
B. Substitution of clutch and brake hydraulic lines with solid metal
or braided metal is allowed on all cars manufactured before
model year 1992.
C. Alternate brake bleeder fittings such as “Speedbleeders” are
permitted. They may serve no other purpose.

Brakes is pretty clear.

[hderr]

Thanks, that helps.

Hank
31 ES 944

[mdahl]

Replacement Bilsteins will firm up your ride nicely. Koni Adjustables are pretty nice too, but I find that it's a pain to adjust the inserts correctly to your liking. (Some are cool with a knob, but most likely.. -you'll have to do the rotation of the shaft fully compressed, set, install on car, then repeat ad nauseum to dampening perfection)

With the dreaded "while I'm in there" you might want to look at the state of your suspension bushings.. I'm sure the rubber has flowed enough in 20 years to warrent replacement. Those worn bushings can cause unpredictable handling at the limits. Also, If your rear torsion bar bushing have worn enough, you can cause rubbing of the t-bars against the tube. That can lead to corrosion and possible breakage.
Be forewarned, due to old Porsches being how they are, you may not be able to find OEM replacement bushings for all parts. Sometimes you'll only be able to find poly or monoball bushings. Stay away from poly bushings. They're fitment is usually crap, and you car will sound like people 'wrassling' on a cheap motel bed.

For brake pads, any sport offering from Mintex, Ferrodo or Hawk will work nicely. I would do a strong flush also, with some high temp fluid.

[jhadler]

Shocks...Koni shocks are your best bet. It wont be too hard to find externally adjustable Konis. And they're legal for stock. You can go nutso on shocks if you want, but I'd start with the Konis.

Bushings... Yep, your bushings, if they're not already shot, they're well on their way. In most cases with Porsches, there are no "stock" bushings you can just pop in. All of the aftermarket bushings are not legal for stock anyway. The only "stock" legal bushing replacement is the OEM bushing, and many times that means replacing the whole suspension arm...

Brakes...Pretty much any pad you want. For autox, a nice soft pad will give you better modulation and performance. Carbotech is a good choice. For the track, then a race pad is better. Porterfields are pretty popular in the P-car camp. Hawk makes some rippin' good pads too.

One thing you can, and should do, is get a good frony swaybar. Yes, front (not the rear though) swaybars are legal in stock.

-Josh2