I am trying to resolve excessive inside wear on my rear tires. I put on PS2s (315/25/19, sitting on H&R coil overs, at a a "one-finger" gap) about 2k miles ago and they are pretty worn out in comparison to the rest of the tire. I did some searching and some recommend dog bones and/or control arms, some didn't; case by case. I got an actual alignment when I got these tires (2k miles ago), and here are the readings.

If raising the car higher will solve most of this wear, how high do I need to go? Dog bones or control arms? Can someone help me pin point what actions I need to take to correct my inner tire wear? Thanks!

 

Kind of the nature of the beast.You could bring the rear camber to -1.5 to help some and raise the rear ride height for a better camber curve .But with all that weight back there kind of have to run some neg camber. Dog bones could be installed to get the camber to 0 but it won't like going thru turns.Who buys a 911tt that doesn't like to carve a corner ?

 

Neither. It's your toe. Incorrect toe will eat the inside 1" or so of the tire. Look how much toe you had prior to the alignment! Too much camber will wear the inside of the tire but it will be more gradually across the whole tire tread. Here is a picture of my rears with -2.25deg camber and toe set at 0.17' per side, 0.34 total. Tread is totally gone but wear is even. Installing solid thrust arm bushing in the rear LCAs HELPS A TON with tire wear as it helps lock down your toe settings. You'd be surprised how much your toe moves around under braking and acceleration with the rubber bushings compressing. When you accelerate, you can get as much as an extra 1/4" of toe as the bushings compress. Same under braking. All this tears up the inside of the rears. I know people, especially those that have spent the money on them, will disagree, but dog bones are a waste of money for the most part. I tried dog bones, hated them and ended up going back to the stock pieces. Even 996 Cups use the stock parts sans monoball. Unless you are low rider slammed, your camber eccentrics should get you in the ballpark of -2.0 camber or less.

 

This issue has been discussed a lot. I've got 19" wheels and am lowered on 1" springs. I got a good alignment from TC design in Milpitas and have not had an issue with tire wear. They are a great place to get a good alignment. If you are lowered more than 1" you probably need either adjustable dog bones or toe links in order to get your alignment in spec but talk to TC design and see what they can do. They are well versed in Porsche cars and highly recommended on this forum. I have no affiliation with them but just a happy customer.

 

Thanks guys...I think it is not my camber, but my toe. So I hear mixed comments regarding dog bones. Also, is the solution solid trust arm bushings or toe links? I just don't want to be throwing suspension components at the issue.

 

pwrhound - Where/What brand solid thrust arm bushing would you recommend? Does this work with the OEM LCA or is a different LCA required?

 

I understand your dilemma. I am just stating though actual experience what works and what doesn't.

 

I like the Tarett thrust arm bushings because on the adjustable ones they are the only company to use two securing bolts which prevent slippage. Most other companies only use one bolt. For the rear, you only need the non-adjustable ones which are cheaper. The Tarett toe arms are a good product. No fluff, they just work. Reasonably priced, track proven. Yes, all these parts work with the stock LCAs. You simply press the factory rubber thrust arm bushing out and install the solid one (you do have to remove the LCA from the car to press the bushing out).

Here is a pic of the rear OEM LCAs with the Tarett adjustable bushings. In this case, monoballs were also installed. The car already had toe arms but just adding these two components drastically improved rear tire wear in addition to getting rid of some of the squirliness the car had in the rear. All a function of locking down the rear end... PM me if you have any questions..

 

Thanks everyone! Do you think if I raise the car up .5-.75 inch, I can achieve anything significant using stock suspension components?

 

Is there any substantial noise associated with the use of the solid thrust arm bushings vs. the stock rubber? I guess my rubber bushings are still in good shape as I don't drive my car easy and the wear across my tires are pretty much like yours.

 

No extra noise. If your car is mainly street and not subjected to frequent hard cornering, max brake stopping, full out accelaration, etc., then you won't see the big benefits of the solid TA bushings. The solid bushing really help with sticky tires where you are subjecting the suspension to high loads. Either way, they do help and there really is no down side. They make a HUGE difference on my car but I do about 30 track days each year...

 

Anybody able to point me to a guide for taking some negative camber our of my rears (996t cab) using the factory cams on the lower links? I'd be happy at about-.5

 

Go to the 6speed Technical Information Forum and ask your question. You would go crazy if you knew the make up of the Tech 411 advisors who are answering your questions.

 

We make an Eccentric Monoball cartridge kit for the lower control arms that can be used to reduce, or increase rear camber close to .9 degrees on the 996.





Works by shortening or extend the effective length of the control arm.

More information here

 

Will do thanks!