Rear Camber Question - 986 Forum - The Community for Porsche Boxster & Cayman Owners

JMP · 02-06-2010, 02:12 PM

Does anyone know if you can adjust the rear camber by moving the top strut mounts? I dont drive very aggresively and I want to have as close to a "zero" camber in the rear as I ccan get. I am getting an alignment next week and I want to advise the technician about this if he cant get the settings I want just by adjusting the camber eccentric. Thank you!

cvhs18472 · 02-07-2010, 03:59 AM

You might want to think about going to zero camber. There is a crown in the road which is used for draing the paved are and with zero camber the crown will move you around and you might find that distasteful considering you bought a car known for it's handling. I have mine set at 1 degree and still do some DE's, real rookie. The car still handles to my abilities on the track but I get a real 15-16K on the rear tires. Ed

Gilles · 02-07-2010, 07:09 AM

JMP;
If you want to change the camber because your inside of the tire is wearing more than the outside, why don't you try running an extra psi or two on the rears, this will move the contact patch towards the outside of the tire.

FYI I am running -2.5 camber on the rear and was using 37psi cold (with 19"), and my car was wearing more the center and outer portion of the tires, about three weeks ago I lowered 2psi (35-36psi) to get more wear on the inside (opposite to your problem) and that took care of it of course I did the same to the front ones to keep a balance.

IMHO you should leave the camber settings at the recommended OEM settings, you can increase them but I don't think you will like it at 0 deg.

Paul · 02-07-2010, 02:48 PM

Check the toe too, it can cause wear also.

JMP · 02-07-2010, 03:57 PM

Hi everyone, thanks for the information. I really just want to know if the rear camber can be adjusted by moving the top of the strut mounts like you can in the front. I am getting an alignment on monday and wan't to be able to tell the tech this infor if needed. I am going to run camber but at this time my left rear wheel has excessive camber and I just want it brought up to spec. If the tech can't do it by the main camber adjustment, I want him to check the strut mounts IF they can be adjusted. Thank you and I am sorry that I wasn't clear the first time, Jerry

jpeterson@petersonsoftwaresystems.com

Frank M · 02-07-2010, 06:12 PM

if the negative camber is excessive on one side only as you say, then probably a worn component may be causing it.
unless the vehicle was in an accident and something bent.

Roxy · 02-08-2010, 01:52 AM

Camber and toe are adjusted by the eccentrics on the inner ends of the lower control arms on the rear suspension. The top of the strut is non adjustable.
Tyre pressures will have little to do with tryres wearing on one side only.
This is normaly caused by the relationship and balance between camber and toe in. This also varies between the front and rear tyres.
On the rear I would look for some negative camber possibly -1/2deg. with .5mm toe in each side. As an example if you used -1deg negative you would use .8mm or 1mm toe in. each side. As there is 2 adjusters on the rear both have to be adjusted together to get the correct figures.
The workshop must have the machine to adjust front and rear together otherwise you are wasting your time and money.
I have been alighning cars (race and road) for over 35 years if you need any more info let me know.
I will be aligning my 986 2003 in the next week after just fitting some new Pirrelli Rosso's so if you want the correct figures to set your car to I will post them as soon as I can.
One of the most important things in the set up is if you want 1.6mm overall it is no good having 1.6 one side and 0mm on the other. The care will crab sideways and be nervous around corners. There is a lot more info I can give you I have to go. Roxy

syncspeed · 02-08-2010, 08:16 AM

No, they are not slotted like the fronts.

DamageINC123 · 02-08-2010, 11:14 AM

Quote:

Originally Posted by Roxy

Camber and toe are adjusted by the eccentrics on the inner ends of the lower control arms on the rear suspension. The top of the strut is non adjustable.
Tyre pressures will have little to do with tryres wearing on one side only.
This is normaly caused by the relationship and balance between camber and toe in. This also varies between the front and rear tyres.
On the rear I would look for some negative camber possibly -1/2deg. with .5mm toe in each side. As an example if you used -1deg negative you would use .8mm or 1mm toe in. each side. As there is 2 adjusters on the rear both have to be adjusted together to get the correct figures.
The workshop must have the machine to adjust front and rear together otherwise you are wasting your time and money.
I have been alighning cars (race and road) for over 35 years if you need any more info let me know.
I will be aligning my 986 2003 in the next week after just fitting some new Pirrelli Rosso's so if you want the correct figures to set your car to I will post them as soon as I can.
One of the most important things in the set up is if you want 1.6mm overall it is no good having 1.6 one side and 0mm on the other. The care will crab sideways and be nervous around corners. There is a lot more info I can give you I have to go. Roxy

Please post figures when possible. Thanks