Hello everyone. I have read a number of threads on this topic across this and some other forums. There isn't a clear consensus on the best next step, so I have a couple of questions specific to my car that I hope you can help with.
It's a high mileage 3.4 Carrera 2 which I bought knowing it needed some work. Part of this was a complete overhaul of the suspension. My primary concern is for road use, so instead of getting carried away with monoball-type arms and exotic geometry I made the decision pretty early to stick to OEM rubber-bushed parts everywhere. So everything is standard but new, apart from the rear upper control arms which are old but showed no signs of serious deterioration. Anti-roll bars are standard, dampers are Ohlins Road & Track with standard spring rates and set to whatever height the book said (circa -30mm I think), tyres are Pilot Sport 2.
I love the way the car drives. The dampers make it remarkably capable and confidence-inspiring, I can get it to turn in where I want, it's fast, and it's comfortable. Could it be sharper? Yeah, sure. Do I want it to be? Not sure. Maybe not that bothered. I probably won't take it to the track but I might.
Here's the thing: I spun it. I'm under absolutely no illusion that it wasn't entirely my fault, and a Swiss-cheese model of things went wrong that day that led to what happened. But, I'm careful and I like to think of myself as a pretty safe pair of hands that generally doesn't crash things, even when driving a bit too much like a nob. Nonetheless it caught me out, somewhere I didn't expect it to let go.
I know what I did wrong, but I haven't been able to shake the thought that something doesn't feel right about the way it let go. It went too fast. As I've been working through the car repairing it and tending to some incidental work, I've been wondering if compromising the rear geometry by lowering the car was a factor. I was aware at the time that we might struggle to get the rear aligned, but we managed to get the toe within spec and so didn't worry too much about it. I was advised to keep an eye on the tyre wear and see how it went (for fear of disappearing into an American forum rabbit hole of very expensive parts).
These are the alignment results:
Camber -2*20' / -2*38'
Toe +0*10' / +0*07'
Here is the worse of the two rear tyres after 8k miles:

It's not so easy to see, but there is an even taper across the whole width of the tread, which I attribute to the camber and I'm not too worried about. What is more concerning is the wear on the inside shoulder, which I would have assumed to be toe; especially if I hadn't just had everything renewed and the geometry reset. I can take a picture of the new tyre I have waiting to go on for comparison, but I suspect these wouldn't have gone much further before they were done.
I have a good opportunity to replace some parts while the car is off the road, and whilst the price of Pilot Sports seems to go ever upward I'd rather not just keep throwing tyres at the problem. The European advice seems to be to first fit adjustable toe control arms in order to allow the camber to be brought back into spec with the factory eccentric adjustment on the lower control arm. The American advice however seems to be either to fit adjustable upper control arms to correct the camber in isolation, or to just throw $10k at Elephant Racing arms and build a cup car. Really, I'm trying to decide between:
Any and all opinions and experiences welcomed! Thanks much.
It's a high mileage 3.4 Carrera 2 which I bought knowing it needed some work. Part of this was a complete overhaul of the suspension. My primary concern is for road use, so instead of getting carried away with monoball-type arms and exotic geometry I made the decision pretty early to stick to OEM rubber-bushed parts everywhere. So everything is standard but new, apart from the rear upper control arms which are old but showed no signs of serious deterioration. Anti-roll bars are standard, dampers are Ohlins Road & Track with standard spring rates and set to whatever height the book said (circa -30mm I think), tyres are Pilot Sport 2.
I love the way the car drives. The dampers make it remarkably capable and confidence-inspiring, I can get it to turn in where I want, it's fast, and it's comfortable. Could it be sharper? Yeah, sure. Do I want it to be? Not sure. Maybe not that bothered. I probably won't take it to the track but I might.
Here's the thing: I spun it. I'm under absolutely no illusion that it wasn't entirely my fault, and a Swiss-cheese model of things went wrong that day that led to what happened. But, I'm careful and I like to think of myself as a pretty safe pair of hands that generally doesn't crash things, even when driving a bit too much like a nob. Nonetheless it caught me out, somewhere I didn't expect it to let go.
I know what I did wrong, but I haven't been able to shake the thought that something doesn't feel right about the way it let go. It went too fast. As I've been working through the car repairing it and tending to some incidental work, I've been wondering if compromising the rear geometry by lowering the car was a factor. I was aware at the time that we might struggle to get the rear aligned, but we managed to get the toe within spec and so didn't worry too much about it. I was advised to keep an eye on the tyre wear and see how it went (for fear of disappearing into an American forum rabbit hole of very expensive parts).
These are the alignment results:
Camber -2*20' / -2*38'
Toe +0*10' / +0*07'
Here is the worse of the two rear tyres after 8k miles:

It's not so easy to see, but there is an even taper across the whole width of the tread, which I attribute to the camber and I'm not too worried about. What is more concerning is the wear on the inside shoulder, which I would have assumed to be toe; especially if I hadn't just had everything renewed and the geometry reset. I can take a picture of the new tyre I have waiting to go on for comparison, but I suspect these wouldn't have gone much further before they were done.
I have a good opportunity to replace some parts while the car is off the road, and whilst the price of Pilot Sports seems to go ever upward I'd rather not just keep throwing tyres at the problem. The European advice seems to be to first fit adjustable toe control arms in order to allow the camber to be brought back into spec with the factory eccentric adjustment on the lower control arm. The American advice however seems to be either to fit adjustable upper control arms to correct the camber in isolation, or to just throw $10k at Elephant Racing arms and build a cup car. Really, I'm trying to decide between:
- adjustable toe control arms with or without toe adjustment lock-out,
- as above with adjustable upper control arms, with or without camber adjustment lock-out.
- I know that -2* camber is well outside Porsche's spec, but would those of you more experienced in fast setups consider this too extreme for the road? It does get driven quite hard, but it also has to do quite a lot of motorway miles.
- Are the static toe angle values concerning, am I right to think that this wear pattern is caused by excessive toe, and if so is this likely to be caused by the kinematics going to ***** because it's now lower than it should be during a static alignment?
- Is option 1 above enough / are the frustratingly expensive lock-out kits really necessary on a road car?
- If I go for option 2 above, can adjusting the length of the upper arms help counteract the geometry issues?
- If I lock out the camber adjustment, are the upper arms alone enough to adjust the camber or do I also need the GT3-style lower control arms?
- How do you set the length of the upper control arms if the eccentric camber adjustment is still in place?
- Does anyone other than the usual American suspects make cheaper lock-out kits?
- Do the Porsche GT / motorsport cars have eccentric adjusters? If not, do they have different subframes or is there a factory 'lock-out' kit?
- Is the best way to fix this issue to raise the subframe? If so, can this be done with factory parts?
Any and all opinions and experiences welcomed! Thanks much.