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The guy that has an "auxiliary man cave"- he's really got it all!
Take a look at the location for the tapered ball joint placement on the 993 vs the 964 upright and I think you may find a difference close to or equivalent to the difference of the 2 longitudinals. I may be wrong but just comparing the uprights by eye, the the location of the bearing relative to the female ball joint is different.
Take a look at the location for the tapered ball joint placement on the 993 vs the 964 upright and I think you may find a difference close to or equivalent to the difference of the 2 longitudinals. I may be wrong but just comparing the uprights by eye, the the location of the bearing relative to the female ball joint is different.
Pete
I really need to check this! I would like to use the 993 version as I believe the geometry of those is better.
I went through this back in 2015 and again recently. You did figure out what was needed for the most part. I am running the 993 longitudinal on my 964 wide body track build. I was running the 993 N/A uprights but recently switched over to the 993RS/EVO style. Even the stock turbo sway bar is less than perfect fit since you are pushing the front end out an additional 12.5 mm per side vs the 964 turbo So spacers will be required for the drop links. Less than ideal but the handling is worth the wider front track. I also had the 993 front hub issue. As you saw the 964 C2 front was the only hub on the 964/993 that used the setup that gave you issues. I was going to press off the ABS ring and swap it over but decided to cut up a set of C4 front axles I had lying around. I used the entire stub axle portion which worked perfectly. It would have set you up for the original center hub setup which I prefer over the 997 mess. I find way too many issues with the 997 units and Porsche requires and expensive rebuild every 4 k miles or so IIRC. We rebuild the locking mechanisms which is needed often if tracking as they don't pop out and lock properly given time. Also a huge PITA to torque down properly.
For reference this is a 993 ABS gear and mount left the 964 C2 front is above right and the 964 C4 I cut down and made for my car is bottom
993 vs 964 ABS rings
Before and after modifications
You will also need 993 tie rods vs the 964. If you have any questions I have been down this road before and happy to help.
Very nice and interesting video !
well Done !
It’s interesting to see you chose the standard 993 uprights rather than the 993 RS version.
Aparantly BBI in US came up with an upgrade of the RS version.
intrigued to hear your opinion
cheers
I went through this back in 2015 and again recently. You did figure out what was needed for the most part. I am running the 993 longitudinal on my 964 wide body track build. I was running the 993 N/A uprights but recently switched over to the 993RS/EVO style. Even the stock turbo sway bar is less than perfect fit since you are pushing the front end out an additional 12.5 mm per side vs the 964 turbo So spacers will be required for the drop links. Less than ideal but the handling is worth the wider front track. I also had the 993 front hub issue. As you saw the 964 C2 front was the only hub on the 964/993 that used the setup that gave you issues. I was going to press off the ABS ring and swap it over but decided to cut up a set of C4 front axles I had lying around. I used the entire stub axle portion which worked perfectly. It would have set you up for the original center hub setup which I prefer over the 997 mess. I find way too many issues with the 997 units and Porsche requires and expensive rebuild every 4 k miles or so IIRC. We rebuild the locking mechanisms which is needed often if tracking as they don't pop out and lock properly given time. Also a huge PITA to torque down properly.
For reference this is a 993 ABS gear and mount left the 964 C2 front is above right and the 964 C4 I cut down and made for my car is bottom
993 vs 964 ABS rings
Before and after modifications
You will also need 993 tie rods vs the 964. If you have any questions I have been down this road before and happy to help.
That’s really good info! I wanted to use the 993 longitudinal but was worried that I get a too wide track and that it offsets the scrub radius too much giving an unstable car. The other concern I have is how much of an outer lip I will have left once I get ahold of a BBS E88. I would love to have a set here to try!
I was also looking at cutting and using the front shafts. What I found was that the front shaft splines are smaller than the rear shaft splines and they would not lock up against the RSR hub. I also looked at using the rear shafts but then the ABS ring didn’t line up.
In my case and since I have a Motorsport ABS don’t bother about 45 or 48 teeth as it’s all configurable in the software.
Very nice and interesting video !
well Done !
It’s interesting to see you chose the standard 993 uprights rather than the 993 RS version.
Aparantly BBI in US came up with an upgrade of the RS version.
intrigued to hear your opinion
cheers
I think the BBS uprights are extremely nice options and they correct the bump steer as well as move the lower pivot for better geometry.
The only reason I wasn’t going that route was that I wanted to have the freedom
of making my own design of these in the next step.
That’s really good info! I wanted to use the 993 longitudinal but was worried that I get a too wide track and that it offsets the scrub radius too much giving an unstable car. The other concern I have is how much of an outer lip I will have left once I get ahold of a BBS E88. I would love to have a set here to try!
I was also looking at cutting and using the front shafts. What I found was that the front shaft splines are smaller than the rear shaft splines and they would not lock up against the RSR hub. I also looked at using the rear shafts but then the ABS ring didn’t line up.
In my case and since I have a Motorsport ABS don’t bother about 45 or 48 teeth as it’s all configurable in the software.
I run 9 X 18 ET 51 Fikse's, 9 x 18 ET50 E88's or 9.5 X 18 ET57 RSR factory Speedlines on mine with the 993 longitudinal. My fenders are factory steel and everything fit fine until I hit the track hard and sliced a new R7. I had rolled the fenders all but the last inch of the front. Ended up being a mistake and I used vice grips at the track to do a painful mod to the lip. It was that or miss three days of driving. Minor damage but worth the weekend of driving. Always something!!
Since we’re on the subject- the 964 hub and abs ring will fit the 993 upright-correct?
Pete
Not to step on any toes but yes they are interchangeable.
I chose to stay with the 993 hub for several reasons being a dedicated track car. I didn't want to go center hub which negates these concerns.
The 993 hub is a more substantial piece. I can't find the pics of them side by side but the areas where the studs mount have added material for greater strength. The 993 hub also interlocks the ABS ring with the hub instead of the 964 design which uses the ID of the bearing to center the ring. You can see the conical end of the hub in the picture where the 993 ABS or 964 C4 front axle lock into it and center the ring.
On the 964 hub the raised bosses the stud seats against are machined flat.
I've done this to and I did write a post about it here some years ago. And I do talk to Jonas since we know each other.
On my narrow body car I did end up with this set up:
993RS uprights
993C2/C4 longitudinals
993RS tie rods
964 cup sway bar/drop links
964 Hubs
993TT Rotors
964RSR struts/mounts
BBS E28 8" ET50
Front camber -3,5, Pirelli Trofeo
Front ride height is low, around 100 mm
And now the front end is really nice on the track. Very stable, lots of grip and no bump steer.
Not to step on any toes but yes they are interchangeable.
I chose to stay with the 993 hub for several reasons being a dedicated track car. I didn't want to go center hub which negates these concerns.
The 993 hub is a more substantial piece. I can't find the pics of them side by side but the areas where the studs mount have added material for greater strength. The 993 hub also interlocks the ABS ring with the hub instead of the 964 design which uses the ID of the bearing to center the ring. You can see the conical end of the hub in the picture where the 993 ABS or 964 C4 front axle lock into it and center the ring.
On the 964 hub the raised bosses the stud seats against are machined flat.
That explains it! The front 964 hubs have smaller splines. Then it makes perfect sense to chop off a shaft as that means you can hold the tire (or brakes) when tightening rather then crawl under the car with a tool.
Question for those that have moved to the outer mounting holes. Is it possible on a C4 with the requirement of wider front axles and sway bar or is this something reserved for C2s only?
02-02-2021, 08:51 AM
