I've noticed the outside edge of my front tires are wearing much faster than elsewhere, is this due to a lack of negative camber? Or is there another cause, especially one that should concern me?

The car is a stock '06 Cayman S, tires are Michelin Pilot Sport 4 S, they have about 12 DE days on them and around 5500 miles total.

 

That is exactly what lack of sufficient camber looks like.

 

That blistering in the bottom pic is overheating of those tread blocks on the outside of the tire. Take a load off, please!

 

I ran a weekend where both days were ~100, could the blisters be from then?

 

That can aggravate it and cause it to occur when in lower temperatures it might not, but it's indicative of too much load presented to the outer quarter or third of the tire tread width. Additional negative camber could relieve that loading and actually improve performance by allowing more of the tread width to be fully utilized.

 

GT3 front lower control arms (+shims) are a common mod on 987 Caymans to allow neg 2deg or more camber. Stock parts usually are limited to about neg 1deg. For info, back in Dec I needed to replace mine and the Porsche parts were not available. I ordered some aftermarket control arms from Tarret but they were backordered, still waiting on them but hopefully will be here soon.

 

demonspeed has GT3 cup control arms in stock I believe

 

As stated more negative camber is needed which will required adjustable LCAs and/or camber plates. A near zero (some do a slight toe out) toe is also a part of a typical track alignment. The PS4S is a good starting tire for DE but a more dedicated track tire on separate rims is better. A symmetrical, non-directional tire allows switching side by side to balance edge wear. Remounting and flipping is another option to balance wear with the right tire.

 

+1 to everything above. Also, 12 days is pretty good for street tires and HPDE, even if you do the suspension work. I have killed new fronts in 2 - 3 days with the same issues (Cayman 718S, stock alignment). Part of this was a track hard on tires (Pocono) and part was my technique (overdriving the car), but the point is that HPDE kills tires in a few weekends no matter what.

 

If GT3 control arms are more then you want to spend I can highly recommend these Elephant Racing camber plates for $550. I used these on my lowered 986 with PSS9 and was able to achieve -3.3 in front, at stock height you'll prob be able to get 2+ negative. Their design allows more adjustment travel then some other brands.

https://www.elephantracing.com/porsc...s-for-986-987/

 

Need neg camber.

I have the LCA's on my 981S and run R-7's. Rarely do they wear like that before they cycle out (I know, much different tires, but same when I used to run the street tires).

Get the LCA's, change the pins once/season, and take that chit out to -3+ up front.

I also rotate my wheels left to right and visa versa between track days.

The only time I wore tires like yours, actually corded them in 1 day, was at an open lapping Friday at Pitt Race with Allegheny PCA. That is the toughest track on tires I have ever been on, esp T-7 to T-14. Crazy wear and tear on the tires.

There was also 5 hours of track time that day.

LCA's and negative camber and you should be set. Don't hesitate to rotate them between days, esp advanced days.

 

I'm going to be selling the car at the end of this track season, April/May, so I'm hesitant to put any money into upgrades. I have the potential to do 6 more days but I highly doubt these tires will make it through that many without adding some negative camber. I may run one day later this month and then replace them for the March/April weekends.