I'm not trying to beat an old horse, just posting up progress on rear tire wear.
Car is street driven, no track time or DE. What is on the car now:
H&R Street Coilovers
Tarett Parts below:
Front Monoball Camber Plate
GT Series Rear Swaybar
Rear LCA Monoball Bearing
Rear LCA Solid Thrust Arm Bushing

Suspension height measurements from factory measuring points (I'm going to remeasure tonight and update the post)
L R
F 5.56" 5.75"
R. 5.75" 5.75"

I don't have any concerns about the front. All numbers in degrees.
L-R
Camber -1.0 -1.0
Toe .07 .08

Rear
L-R
Camber -2.6 -2.3 (GT2 Range is -1.9 to -1.8)
Toe .22 .23

This car has always chewed up rear tires and I'm hoping to slow that down by eliminating any deflection in the rear suspension. The only remaining item that is out of spec is the rear camber. Is an adjustable rear upper control arm in my future?
My first impression of the solid bearing and bushing in the rear: a little more noisy and a little more harsh than before. Maybe it was always that way and now I'm listening for it?

 

Rear toe links and adjustable arms. I run a little more camber in the rear and have no tire issues. Also worth noting, no noises at all and everything on my car is heim joints from Elephant Racing. No rubber left except for the subframe.

 

Yep, the drive in to work today everything sounded normal, so perhaps I was tuned in a little much yesterday.
I should add that I have the RS Style motor mounts and 997 transmission mount. The driver side motor mount had failed and the transmission mount had failed in the rubber components. I feel that both of those changes have made a pretty big difference in keeping the car settled.

 

My experience over the years is rear camber as long as it is within the allowable deviation and close to the same side to side doesn't play a role in rear tire wear.

There was only one instance though this even was an issue. I had my Boxster in for an alignment, at an indy alignment shop, and when it came off the rack the tech told the rear camber was a bit more than called for but was still within the limits set by Porsche and both sides had the same amount of camber. Said this would not affect tire wear. This info proved to be correct.

Far and away rear toe is the culprit when there is accelerated rear tire wear and the wear is concentrated at the inner edges of the tires.

I don't have off hand what my Turbo alignment setting were after an alignment but I always asked the Porsche tech for a rear tire friendly alignment provided this alignment would not affect the car's handling/road manners. It never did and rear tire wear was even across the tread face and from side to side. More wear on the right rear tire is not an alignment issue, but an issue with how aggressive one drives. If one is overly aggressive with the gas pedal during right hand turns this can have the right rear tire wear faster. Lack of LSD and the right rear tire during a right hand turn can spin and this really wears out the tire.

Rear tire life of tires on my Turbo were in the 20K mile range with one set lasting nearly 23K miles and when one got a puncture because it still had 3mm of tread left was covered by a road hazard warranty.

I had 161K miles on my Turbo with its factory suspension and the alignment stayed very good for a long time. I only had the alignment done if tire wear showed some indication the alignment was out. The rear tire alignment was very stable, likewise the front tire alignment, but a nudge of the front tires against a low curb one night had the car howling at speed. Thought it was a bad wheel bearing (or front diff) but a Porsche tech checked the car over and reported the front tires were slighly out of alignment based on the feel and look of the front tire tread blocks. Signs of feathering and scrubbing. Drove 2K miles home and booked the car in for an alignment. Afterwards after a few hundred miles to give the tires time to adapt to the new and correct alignment the noise was gone.

Might mention to 20K miles was the rear tire life of the tires on my Boxster, too.

 

yes to toe links. a "must" for lowered cars. that will "help" for sure.

 

Zero inner tread wear with calculated settings based on ride height. https://rennkit.com/wp-content/uploa...-996-Turbo.pdf

 

Just from the driving pleasure point of view: maybe you should try to run equal or more camber in the front vs the rear

 

Wait, these cars get more fun to drive?? I have very few fun roads to drive on and everything feels good right now. So I'll hold steady on the alignment I have.

 

I replaced my chewed up rears 285/30R19 with 295/30R19 (both Bridgestone S04) and I noticed a smoother ride immediately. The tire looks better on the 11" rim also, so I'm assuming the sidewall was stretched. I think I could go to 305s and still be okay on the rim.

 

You should not have issues with getting rear camber in spec. If for some reason you can't get toe set properly to 15-17' per side (30-34' total), then get some adjustable Porsche toe links...

 

You should not have issues with getting rear camber in spec. If for some reason you can't get toe set properly to 15-17' per side (30-34' total), then get some adjustable Porsche toe links...

Is there a difference between fixing camber with adjustable upper control arm and getting toe back in spec OR fixing toe with adjustable toe links and getting camber back in spec? Doesn't fixing one allow the other to come back to proper spec?

 

Ideally you do not want to change the length of the upper control arms as that changes the suspension kinematics. I would stick with the stock for a street car for various reasons including NVH.

 

Okay, that makes sense. You have been pretty set on avoiding "dog bones" over all 1000 of your posts on this subject but I could never figure out why. Do you have a PN for the adjustable toe link? Thanks, I appreciate your reply.

 

The links just help to keep in in check too if the car has been losing it. I'd do it all, but again not required. I have rear dogbones, links, adjustable control arms, etc. all with heim joints and NVH isn't an issue at all and my car is a street car. I was expecting a little noise, but it's been silent. Running dust boots on all joints helps too.

 

Don't get me wrong, I use the RSR dog bones on my car but they are simply not necessary on street cars. Porsche used the same dog bones with the rubber bushings the are on the 996TT up through the 997.1 Cup car. If you want to reduce unwanted flex in the rear suspension, the greatest benefit will be through solid LCA thrust arm bushings and than the inner LCA bushings. The dog bones would be the last on the list and certainly not to change camber.