Rear Control Arms Pushed Bolt Into Sub Frame??
09-21-2022 | 02:00 PM
#16
Track Day
Joined: Jul 2020
Posts: 18
Likes: 3
Adding camber with the eccentric while the car is loaded on the rack is very easy. Reducing camber on the other hand can be problematic as it oftentimes causes the eccentric bolt to go out of "square" relative to the subframe when you force it. This creates the inevitable problem which everyone complains about with the eccentric then slipping under load.
Whenever I'm doing an alignment and have to reduce rear camber, I normally lift the car off of the alignment surface until the wheels are in the air (last pic below) and then reduce the camber past where I want it with the suspension unloaded. After lowering and loading the car back on the platform, I then add camber to my desired target. Obviously you may have to repeat this procedure several times because as you adjust camber it will naturally change your toe and vice versa. Doing it this way precludes any eccentric slippage issues and as I mentioned above, I've never had one slip when following this procedure. The alignments we do are based off of the wheel hubs and NOT the wheels themselves which precludes any errors as a result of wheel run out that invariably you will always have with traditional alignment rigs that clamp onto the wheel lip.
I will caveat this with the fact that in order to do it the way described above, you need to have an alignment rig that allows you to lift the car off the platform during the alignment process. Not many do however. The rig we use is pictured below and allows for precise race alignment of the whole car including setting corner balance as the car is resting on scales which have a ball bearing platform on top of them. Each platform has adjustable legs and is leveled relative to the others with a laser.
As far as control arms and all associated hardware, I've found OEM Porsche Motorsport parts superior to anything on the market.
Whenever I'm doing an alignment and have to reduce rear camber, I normally lift the car off of the alignment surface until the wheels are in the air (last pic below) and then reduce the camber past where I want it with the suspension unloaded. After lowering and loading the car back on the platform, I then add camber to my desired target. Obviously you may have to repeat this procedure several times because as you adjust camber it will naturally change your toe and vice versa. Doing it this way precludes any eccentric slippage issues and as I mentioned above, I've never had one slip when following this procedure. The alignments we do are based off of the wheel hubs and NOT the wheels themselves which precludes any errors as a result of wheel run out that invariably you will always have with traditional alignment rigs that clamp onto the wheel lip.
I will caveat this with the fact that in order to do it the way described above, you need to have an alignment rig that allows you to lift the car off the platform during the alignment process. Not many do however. The rig we use is pictured below and allows for precise race alignment of the whole car including setting corner balance as the car is resting on scales which have a ball bearing platform on top of them. Each platform has adjustable legs and is leveled relative to the others with a laser.
As far as control arms and all associated hardware, I've found OEM Porsche Motorsport parts superior to anything on the market.
I think you just solved my alignment problems with my panny. The second i left the alignment place i would lose alignment. Been through 5 alignments at 2 different places and burned through 2 sets of front tires. Looks like i need to find a new alignment guy.
09-21-2022 | 02:06 PM
#17
Rennlist Member
Joined: Dec 2010
Posts: 7,229
Likes: 2,022
Yeah, this is all due to procedure. The hardware is not the problem but people who don’t know the mechanics of aligning these cars always blame it on that. You can visually look at the eccentrics to see if they are out of square or not. In many cases they will be with the inevitable results you experienced.
09-21-2022 | 02:08 PM
#18
Track Day
Joined: Jul 2020
Posts: 18
Likes: 3
Yeah, this is all due to procedure. The hardware is not the problem but people who don’t know the mechanics of aligning these cars always blame it on that. You can visually look at the eccentrics to see if they are out of square or not. In many cases they will be with the inevitable results you experienced.
09-21-2022 | 02:14 PM
#19
Rennlist Member
Joined: Dec 2010
Posts: 7,229
Likes: 2,022
The eccentric bolt needs to be “square” with the subframe. As you adjust it, particularly when reducing camber, it has a tendency to go out of square, meaning the bolt is not perpendicular to the subframe lugs but rather at a slight angle. It doesn’t take much but when tightened out of square, it WILL slip.
09-21-2022 | 06:42 PM
#21
Track Day
Joined: Jul 2020
Posts: 18
Likes: 3
I'm on my 3rd place. This guy does 911s so hopefully he can figure out the alignment. I'm with you I've never had issues with my other car until this one. Doesn't want to hold alignment at all. The weird thing is I took my wife touraeg to the same places and the suspension setup is the same. 2 eccentrics on the front and aligned no issue. Maybe the panny is too heavy.