Ecosse911

Interesting, please do confirm as I was about to buy a set of 993 sensors. Thanks

dmaddox

@Ecosse911 I plan on sticking with the 964 control arms and longitudinal. My wheel is exactly where I want it to be....and further, I rebuilt them. So, with it in the car, I plan on pressing, drilling and pressing in the 993 stud for the 993 ball joint.

I'm going to update post #1 with the new plan. Feel free to correct me.

Peteinjp

While your pic shows that the shock mount is in line with the axle height on both (993 and 993rs) carriers is not the crucial measurement regarding the axle height the length from the ball joint to the axle center? If so that is obviously different between the RS and standard 993 units. It seems to me that there are 3 differences at least- steering arm height, axle height and shock height all relative to the ball joint height.

Pete

Bill Verburg

axle height is determined by the strut and springs and the relationship between the 2 bolts that fasten the wheel carrier to the strut,
the ball joint is passive wrt to height

the ball joint is pushed up and down by the wheel carrier, it only changes the angle of the A-arm, some shops actually mount the ball joint above the A-arm, this determines the angle of the A-arm wrt to the tie rods and ground

similarly the the geometry of the tie rod itself and any o/s at the tie rod ball joint(if any) determine the angle of the tie rod wrt to the angle of the A-arm and ground, at the inner end the steering rack also has a sya, in pre 1990 911s the steering rack is often spaced down to alter the tie rod angle

The angles of the A-arms determine roll center height, which largely determines cornering characteristics, the differential in A -arm and tie rod outer end arcs determines bump steer characteristics







964 w/ 993RS wheel carriers and o/s ball joint

J9277655

I'm very late to the game, but my car was purchased with a pretty exhaustive list of upgrades including the BBI Uprights. The listing is here with plenty of pics, but more importantly scanned copies of all the work orders & parts. Not sure if helpful but perhaps?

https://bringatrailer.com/listing/19...1-carrera-2-49

Peteinjp

Your right about all that. I’m was just trying to note that your previous statement that “the difference is solely in the steering arm extension of the carrier” is a little off as obviously the LCA is also adjusted for with the RS upright relative to the 993 stock unit.

I’ve seen pics of the ball joint mounted below and above the arm but I can’t wrap my head around how it would change the actual lower control arm angle- as the angle should be measured as a line from the center of the ball joint through the inner control a pivot. Even if the control arm and the ball joint had a 2 “ spacer between it the effective angle hasn’t changed as far as I can tell.

dmaddox

Does anyone have either of these two measurements:

1. 964 vs 993 uprights. The depth and diameter of the abs sensor holes. Or perhaps if easier the sensors themselves.

2. 964/5 vs 993 rotors. The difference in offset.

These two measurements might just solve this rather complex square filter, round housing issue.

Bill Verburg

on left is a 964t/RS 322x32mm rotor on right isa 993tt 322x32 rotor and hat, i forget the difference in height but 964/968/928 rotors are generally interchangeable and must be used w/ 964 wheel carriers on a 964, 993 rotors must be used w/ 993 wheel carriers

dmaddox

Exactly, wondering what that difference is. 5mm?

jeff33702

Are you trying to determine how much it will change the position of your wheel? If so, it will not. Bill is just showing you the offset of the caliper position - so if you're trying to determine caliper/wheel clearance, this makes sense ?

dmaddox

Thank you. Yes I trying to determine caliper placement in relation to my wheel, not wheel moving. As mentioned it is fairly close as it is but I can work with 5mm difference.

jeff33702

As I typed that last message, I was kinda putting that together, too

It's a great point though, some people are already running really close. What you're looking at there is the difference in offset which will end up being the centerline on the caliper - but does not take into account the actual thickness of the caliper. From centerline, I wonder what the difference is between the stock C2 and big red/turbo caliper face.
Did some measuring on the beater as it has big brakes - looking like @20mm from wheel mount face to face of caliper and 80mm from rotor centerline to caliper face. This is a 964 carrier...and I don't know exactly what these brakes are but likely 964tt. Prob not much help. I'm chowing some lunch but if you want anything else measured I can do it this evening.

dmaddox

Well I’ve ordered the 993T rotors so when they get here I’ll provide the measurements!

I’d think it would even help people with the math in doing any 993 upgrade/swap.

ThomasC2

Hi, here's a link to a thread I started when I did this upgrade (but with Porsche 993 uprights). It starts with the parts list and some other things I noted. Finally some comments about the result.

https://rennlist.com/forums/964-foru...ghts-long.html

Ubipa

Just got back from work travel, and had to re-measure. This is an interesting response since I inquired the same with BBI back in 2019 when I bought mine and they (Dmitry) said the 964 would. My measurement of the 964 taper and the BBI insert show a 0.75 to 0.675 taper over 0.625, 6.8 deg. With the BBI insert having a max seat of 0.75. Looking at a pic of a 993 and 964 ball joint side by side, the 993 joint seems to have a smaller end which would give it further seating (<0.125"). Not sure if that is significant enough to switch.

Hopefully, I am measure a 964 ball joint. I was told it was a 964-341-049-03, the hole in it is 0.425".