New shocks, struts and alignment - now horrible handling

I replaced shocks and struts with bilsteins HD (yellow), H&R lowering springs, two new rear tires on my 2006 Cayman S , 130K miles with horrible results. I took the cayman for alignment after all the work was done but now the car is not handling correctly at all. The PSM ( porsche stability management) kicks in frequently when driving at freeway speeds for no reason, mainly above 65mph or faster turns, not at low speeds. The alignment shop gave me the print out of the specs and I did notice that the rear camber is out of specs. I asked and the answer that they gave me is since I used the lowering springs the car can't get the right camber otherwise the toe would be out of spec too. By the way, the car had stock shocks and lowering springs all its life without any of these problems. Any insight on the problem? Rudy

The PSM kicking in is a concern. Have you checked to make sure the new rear tires are the correct size? If they are more than a couple percent off of stock diameter that would affect PSM. Also check inflation pressure.

thanks for the reply. I did checked inflation and size, all good. The rear tires were replaced with identical brand and model as the ones removed. I also checked all lug nuts for proper torque. The car is wandering back and forth on the freeway, PSM kicks-in during fast freeway turns and brakes to correct vehicle. The car is not even close to drifting or breaking loose but the PSM thinks that the car is out of control. tonight I will turn-off PSM to see if anything feels different. I will post a picture of the alignment sheets, I have two.

Full disclosure: I am not a member of SAE...I'm not even an engineer. As I understand, when you lower your Cayman , the OEM rear control arms are not able to compensate enough, resulting in excessive toe-in. This causes poor handling and rapid tire wear. You may want to consider installing rear toe control arms like these from Tarett . I had similar rear toe control arms installed on my Cayman when I had coilovers installed.

this makes sense now. this is what the alignment shop was trying to explain to me. Thank you for the link 808croc, more money for cayman fund...

As its been about 7 years since I had the work done, I do not recall the specific toe control arms that I had installed, but these look like the ones I got from Rennline .

I will most likely go with Tarett mainly due to pricing. thanks, will order and install next week.

Post the alignment. Something is definitely wrong. No point in buying parts until you understand the issue. Sent from my iPhone using Tapatalk

I have made a note to post the alignment sheets tonight that I have.

here are the alignment sheets that I have (two). My rear camber is off and can't adjust anymore with the current OEM arms is what I was told.

Just to clarify, did they say the couldn't make the rear camber more negative or less negative? It looks like the rear camber is maxed out while the front camber is close to zero. I'm no alignment expert but I'd start by getting the front and rear camber closer. Most people run close to the same or half a degree off one end or the other. It's definitely increase negative camber up front to -1.8 at least and then get to rear close to the same. If you cant get the rear and lower then go even farther up front. Toe looks fine which is surprising given the handling you're experiencing. Sent from my iPhone using Tapatalk

the rear camber specs listed on the sheet are: -1.75 min to -1.25 max; preferred is -1.50 My camber is -2.30 left rear; and -2.90 right rear So I would need to get the rear closer to -1.50, in your words go "less negative." the alignment shop said that there is no more adjustment left on the camber without affecting the toe. In any case the car continues to activate the PSM on turns and that is a clear indication that something is not right. I will personally put the car on a lift to check all bushings and arms to check for wear. Hard to believe that after replacing all new stuff the car is not working properly. I'll report back with any updates. thanks for all the valuable feedback.

Okay, thanks for clarifying. It is odd to me that the rear camber is that extreme after your lowering. Do you have any measurements from before the suspension changes? Can you confirm the ride height all around? Most people measure from the center of the wheel to the lip of the fender (not technically correct, but easy). Even given the extreme camber you have in the rear I don't think that alone would cause the handling problem. I'd personally start by getting more camber up front (max it out but keep it even). See how that feels and if PSM settles down. Ultimately you will probably want adjustable toe links in the rear to get the camber and toe where you want it, but for a 1" drop it just seems odd. Sent from my iPhone using Tapatalk

I don't have measurements from before but I know that the car was even lower before the new stuff was installed and there was no handling problems prior to this. I will take measurements and post them tomorrow as you suggest. I have ordered the Tarett toe links as I can't drive the car with the PSM activating like it is, very annoying.

I was just thinking that if you're going to replace the rear toe links you might want to consider locking plates as well. The more I think about it if your plates are slipping it would explain the discrepancy between your measured alignment and the driving experience. https://www.tarett.com/items/993-96...ension/993-964-control-arms/locking-plate-kit-996-993-t-link-lkplt01-detail.htm Sent from my iPhone using Tapatalk

I placed and received the order but unfortunately didn't include the locking plates. I will install the links this Saturday and take it for yet another alignmnet. I will ask the shop to mark those areas and then monitor to see if they move. Since I'm not autocrossing or racing it I hope they don't move. If they do then...here we go again. thanks for the recommendations and I will report back.

I got my control arms installed in 2012 and I don't recall having locking plates installed at the same time. I've not experienced any handling issues in the past 7 years.

808, it's not require during the installation. For people that have settings that are slipping the installation of the plate resolves the issue. Installing the plates require you to realign things. So I was just suggesting that while he's changing parts and realigning he might want to consider it. It's unclear if his alignment is actually slipping. But it's also unclear while his car is handling so poorly. Sent from my iPhone using Tapatalk

I'm not an alignment expert either but agree, more camber up front or get F&R closer together. The Front will have a better contact patch as weight transfer is initiated than Rear. As the turn progresses, you'll get more grip in the rear when power on (neutralising the camber) which I feel will result in more of a Front push. With the camber difference so large, I also think the Front and Rear won't feel in sync as you turn in, almost pitchy ... I've moved between F2.5 & R2.0 at a lowered right height with GT3 LCA 's as an aggressive road set up to a more streetable/comfort F1.2 R1.2 which I think is still pushing a little at the front, snaps quite quickly in the rear on power so will probably go back up again, at least in the front camber (looking for more rear slip in corner on power). Let us know how you go!