You are correct that track enthusiasts do everything they can to eliminate rear steer, aka Weissach effect

for 964 a reduction comes from using the RS washers, but ultimately mono-balls are needed to eliminate it

the same happens in a 993, here there are 2 arms that control rear steer, the top rear and the rear of the A-arm, for 993 use the 993RS KT and A-arms which have stiffer rubber bushes these reduce rear steer similar to using the 964RS washers. And again the ultimate solution is t use all mono-balls

here's mine, using RSR A-arms which have mono-balls joints on both legs as opposed to only the leading leg stock and Rennline/Tarret arms for the other 3 arms




The main con is that all this hardware is expensive,

On track the RS setup is great it's only weakness is a tendency to lose alignment settings w/ hard use( the eccentric adjusters will rotate), The RSR w/ turnbuckle adjustment and locks at the eccentrics is the ultimate track solution

Maybe the ERP spring plate is not made of spring steel like the OE piece? The threaded portion welded to the plate (where the rod-end attaches) would definitely minimize any potential flex points on the spring plate.

Hi all,

I am trying to find out if I can replace wheel carriers on my 964t/3.3L (96534165619) with 993 ones (99334115803).

Can someone help? What modifications are needed?


Thanks,
Troky

Yes you can however you will need to replace the tie rods complete to the 993 version and use 993TT front rotors. I believe you may need to switch over to the 993 style toothed gear and sensors for the ABS as well but it might be possible to retrofit the 964 ones but I don't know for sure. Interesting the 993 aluminum carriers are around $400 new ea the 964 turbo units are around $1400 new ea. I would save the old parts.

As Anthony says
You will need to use the 964 45 tooth ABS gear
You will need to use 993 ball joints.
you will nee 2x 14x1.5x90 bolts and
2x 14x1.5mm nuts to replace the 2 lower strut nut/bolts

By far the more usual path is to use the 993RS wheel carriers w/ 993RS tierods which allow the car to be lowered more than the 964 or 993 ones.

In addition to that. 993 balljoint will have 2mm wobble sitting on 964 knurled bolt:


in details described in beginning of this thread:

http://forums.pelicanparts.com/porsche-964-993-technical-forum/693615-random-notes-964-993-suspension.html#post6903464

You may
1. bore out opening in 964 a-arm and press in 993 part
2. Machine 1mm wide washer to go between 964 knurled bolt & 993 ball joint.

Thanks for the information guys!

My mechanic said front right carrier is a bit distorted so I am looking for solution other than buying new for €1600. Not cool price :)


t.

Here's a narrowbody 964 RS running the longitudinal mounts in the widebody (Turbo) position.

Porsche 964 Cup Car :: Porsche 911 :: Porsche for Sale :: JZM Porsche

Thanks,*


Also good view of RS rear spring plates:


Heres reference pic

Interesting restoration. The cup cars used the outer mountings for more camber? Why would they not undercoat the wheel wells and undercoat the tub?

Some steering rack measurements to add to this excellent thread. Despite the Porsche TSB, the 993 rack will fit in the 964 C4 with zero problems. I can only guess that Porsche said that it wouldn't fit, because you need to remove the subframe longitudinals first in order to angle the 993 steering rack in to position around the C4 diff.

The two racks that I measured:
993 steering rack tag: 7832.955.169, K054690, 08.07, 2832.501.203, ZF rebuilt
964 steering rack tag: 7840.955.119, 964.347.009.02, 260046, 02.91

lock-to-lock turns, shaft travel, travel per 1 rotation
964 with 6mm steering stops (16" wheels): 2.81, 123.7mm, 44.0mm/turn
964 with 10mm steering stops (17" wheels): 2.64, 116.0mm, 44.0mm/turn
993 with stock stops: 2.47, 120.0mm, 48.6mm/turn

Just as the tech specs say, the 993 rack is faster.

Tie rods measurements:
M14 thread for all inner/outer along steering shaft axis
M14 into steering rack
M12 outer tie rod top nut, 964 and 993
964 inner tie rod -to- adjusting turnbuckle uses a reverse thread

Outer tie rod shaft height (above steering axis)
964 excluding threads=~39.2mm, length of threads=~18mm, to start of cone =~25.8mm
Outer tie rod cone diameters
964 min=14.53mm, max=15.93mm, m12 thread
993 min=15.16mm, max=17.11mm, m12 thread
Outer tie rod length (measured from cone bolt/mount)
964 =114mm, m14 thread end
Inner tie rod length (including steering stop)
993 =150mm steering stop to end
964 = ~100mm steering stop to start of threads, ~50mm length of threaded portion

Anyone know of a spherical inner tie rod replacement for the stock 964 inner? Seems that Porsche is a bit unique having rubber damping/isolation on the inner tie rods.