| In
late 2008 we began developing a prototype that would allow a 924S or
944 power steering system to be bolted onto an early 924 or 931
chassis. The early steel cross member has different geometry for the
steering rack mounting points than the later aluminum cross members.
Power
steering on a stock early 2.0L car is not really necessary. However,
for highly modified cars with smaller diameter steering wheels, lowered
suspension, widened track, and wide sticky tires, power steering is a
welcome enhancement. We investigated a variety of alternatives,
including electric and electro-hydraulic hybrid setups. Ultimately, we
opted for the 924S / 944 setup primarily because it retains the correct
geometry for the tie rods. Other considerations were that the later
intermediate steering shaft is directly interchangeable with the early
cars, and 924S/944 power steering does not detract to much
from
driver feedback.
Construction &
Materials
These
adapter brackets were CNC machined from mild steel by 4M Industries. We
subsequently had them plated for corrosion resistance with Cad
DiChromate. The attachment points to the early steel cross-member are
counter sunk to provide the necessary clearance for the rack itself,
and the attachment points where the rack bolts to these brackets are
drilled and tapped to accept the OEM hardware.
Additional
Requirements
In
order to complete the conversion, a number of other issues must be
addressed. Eventually, we plan to develop a complete bolt-on kit for
the 931, and possibly the 924 NA. Each model presents a unique set of
challenges relative to space and the belt & pulley arrangement
for
the pump. We have sorted out a method of mounting the system on a 931
without removal of the A/C stystem. The 924 NA is a different animal,
which we haven't yet tackled. For now, the brackets are available for
purchase to DIYers who are capable of sourcing the following parts and
fabrication work:
- Power
steering rack from an early offset 924S or 944 (we recommend rebuilt)
- Power
steering pump (we recommend rebuilt or the rebuild kit from Rennbay)
- All
lines and the cooler circuit
- Fluid
reservoir (we recommend new from Rennbay)
- Intermediate
steering shaft from any 924S or 944
- 944
fender-mounted coolant expansion tank to replace the stock 931 unit to
make room for the pump and reservoir.
- Modify
stock 931 A/C compressor mounting brackets to raise the compressor (see
photo at right). This is required because the knuckles on the 924S/944
intermediate steering shaft are larger, and situated higher, and will
interfere with the compressor.
- Fabricate
a tensioning bracket and mounting plate to hold the pump in place.
- Have
a hydraulic line shop modify or fabricate new high pressure fluid lines.
- Custom
mounting bracket for the cooler circuit.
| | PSB-001
Power Steering Adapters
For
early 924 and 931. Sold per pair.
PSB-001
Power Steering Adapter Brackets
 Top
view of power steering rack mounted on an early 924/931 cross member Modified
A/C compressor brackets to raise the compressor for clearance with the
924S/944 intermediate steering shaft. Note the elongated slot on the
tensioning portion, and the extra mounting holes on the ends ofthe two
mounting brackets.
Development of this prototype is ongoing. As we
make progress toward a truly bolt-on kit, we will post updates here. |
