Increasing Negative Cambers
02-24-2015, 11:06 AM
#16
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As an update, I was advised to stick with the Porsche Motorsport shims, and stay away from the Tarett shims because the material is too soft.
Also, there was an issue with measurement of camber on my car, and turns out they can get about -1.6 F, not -1.4. They still say they can get -2.3 R without shims.
If my track event this weekend isn't cancelled, I may just try -1.6 F and R for now, if I can't get shims in time, then adjust after this event based on the tire wear (assuming the tires make it through the event!).
Also, there was an issue with measurement of camber on my car, and turns out they can get about -1.6 F, not -1.4. They still say they can get -2.3 R without shims.
If my track event this weekend isn't cancelled, I may just try -1.6 F and R for now, if I can't get shims in time, then adjust after this event based on the tire wear (assuming the tires make it through the event!).
02-24-2015, 11:10 AM
#17
Nordschleife Master
As an update, I was advised to stick with the Porsche Motorsport shims, and stay away from the Tarett shims because the material is too soft. Also, there was an issue with measurement of camber on my car, and turns out they can get about -1.6 F, not -1.4. They still say they can get -2.3 R without shims. If my track event this weekend isn't cancelled, I may just try -1.6 F and R for now, if I can't get shims in time, then adjust after this event based on the tire wear (assuming the tires make it through the event!).
02-24-2015, 11:15 AM
#18
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Apologies. Must amend. I just read y notes from Chuck and there was no mention of maximum negative camber for rear struts. We only talked front, shims, LCA.
My camber guy IIRC gave me a verbal on the rears saying -2.0 max. My memory may be fading so that could be wrong.
the PMS shimms were $15 USD each and required ordering.
For your first track say I wouldn't worry. Ive run all mine on factory fluid, pads and near factory camber so far all fine. I have all that stuff on my list to do after Ive used up the pads and tyres the factory fitted to the car after the next few track days in April.
My camber guy IIRC gave me a verbal on the rears saying -2.0 max. My memory may be fading so that could be wrong.
the PMS shimms were $15 USD each and required ordering.
For your first track say I wouldn't worry. Ive run all mine on factory fluid, pads and near factory camber so far all fine. I have all that stuff on my list to do after Ive used up the pads and tyres the factory fitted to the car after the next few track days in April.
02-24-2015, 11:16 AM
#19
Rennlist Member
Agreed. Very odd, not heard this issue before. Suggest Tech needs to compensate for top mount. Chck eyeballed the system and said initial thoughts were max -1.75 but myself and another came out above -2.0 so shows eyeball not as good as laser align.
02-24-2015, 11:54 AM
#20
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I checked my alignment the other day and found -1.5 both front with 0 toe and 1.8 both rear with 4mm total toe. I was able to get -2 in front did not do the rear yet.
02-24-2015, 12:48 PM
#21
Rennlist Member
As an update, I was advised to stick with the Porsche Motorsport shims, and stay away from the Tarett shims because the material is too soft.
Also, there was an issue with measurement of camber on my car, and turns out they can get about -1.6 F, not -1.4. They still say they can get -2.3 R without shims.
If my track event this weekend isn't cancelled, I may just try -1.6 F and R for now, if I can't get shims in time, then adjust after this event based on the tire wear (assuming the tires make it through the event!).
Also, there was an issue with measurement of camber on my car, and turns out they can get about -1.6 F, not -1.4. They still say they can get -2.3 R without shims.
If my track event this weekend isn't cancelled, I may just try -1.6 F and R for now, if I can't get shims in time, then adjust after this event based on the tire wear (assuming the tires make it through the event!).
I aligned 4 991 GT3s and all had -1.4 - -1.5 stock camber n all 4 corners and we were able to get -2.0 - -2.2 in the front without shims.
The rear camber can be adjusted to -2.3 - 2.5 range without adding shims.
Porsche Motorsport shims are not cheap but made from an appropriate alloy and won't flex under load. Going with cheaper shims might be a better option but your camber setting might change as well when driving due to a softer material.
02-24-2015, 12:53 PM
#22
Rennlist Member
Guys, took delivery of my 2015 just before the snow arrived in the Mid Atlantic so only have a few hundred miles on the car and of course as you all say it is wonderful. Now in garage on lift keeping warm so have taken time to check alignment, and inspect. My car came dead on to factory specs== -1.5 degrees camber all four wheels, front toe 0.5mm in on both wheels, 1.5mm in on both rears, ride height within a few millimeters of spec front and rear.
So now my question; does anyone know how to set rear toe?. This will need to be done if changing rear camber. For years I have done my own alignments on 996 Cup, 997 cup and GT3RS so understand the kinematics, but with the motorized adjustable rear toe, how does one either lengthen or shorten rear toe link when changing camber? (Front looks pretty straight forward and like prior models with adjustable length steering arms.)
Thanks, Tom
So now my question; does anyone know how to set rear toe?. This will need to be done if changing rear camber. For years I have done my own alignments on 996 Cup, 997 cup and GT3RS so understand the kinematics, but with the motorized adjustable rear toe, how does one either lengthen or shorten rear toe link when changing camber? (Front looks pretty straight forward and like prior models with adjustable length steering arms.)
Thanks, Tom
02-24-2015, 12:53 PM
#23
I just had my track alignment done. I went with -2.3 all the way around. The problem my guys ran into was the thread length on the toe links. I was not willing to push the thread engagement to what I felt was an unsafe number. As far as I know no one makes toe links yet with a longer shaft.
02-24-2015, 01:01 PM
#24
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I just had my track alignment done. I went with -2.3 all the way around. The problem my guys ran into was the thread length on the toe links. I was not willing to push the thread engagement to what I felt was an unsafe number. As far as I know no one makes toe links yet with a longer shaft.
02-24-2015, 01:01 PM
#25
02-24-2015, 01:02 PM
#26
Yes we used shims on both front and rear
02-24-2015, 05:35 PM
#27
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After some fiddling around, my dealer was able to get -2.0 at each corner, without using shims. Seems good enough to try for a first event.
02-24-2015, 05:37 PM
#28
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02-24-2015, 08:13 PM
#29
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If there is ride height variation between cars that might explain some of the variability on maximum camber without shims.
02-24-2015, 08:56 PM
#30
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Makes sense. Related to that, putting someone in the driver's seat caused the front left camber to increase (more negative) by about 10' (0.17 degrees) - more than I would have guessed.