gt3 lca and caster
 

anyone running an adjustable gt3 lca with a big shim say 15mm? what impact on caster? my rudimentary qeometry says that a 15mm shim in the lca means that the caster/thrust/track/trailing arm has to get 10mm longer to maintain same caster - is there enough adjustability in the eccentric thrust arm bushing to get a 10mm offset? thanks.

I think so, on my gt3 lca with the two fixed holes (that slightly overlap), i bet the centers are close to 10mm apart and the adjustable center puck has holes even more offset.

thanks. hoping to get around 15 mm in the front and ditch the spacers (use the lcas for track width and camber plates to set camber). and if i can get 20 mm in the rear i can run 996 wheels.

Use the off center hole in the lca puck up front to correct caster with that much shim. You will have a lot of neg camber in the rear if you put 20mm shims.

i'm too not worried about the rear - i appear to have enough adjustability in my camber plates to compensate for the wider lcas, and the trailing arms are much longer in the back so less impact on caster (20 mm longer lca means mebbe 5 mm longer thrust arm - well within the range of the eccentric TAB).

the question was regarding the front - if there was enough offset in the 'off center' (eccentric) hole in the 'lca puck' (thrust arm bushing or TAB) to compensate for the wider lca. my math showed that the hole needs to be off-centre by around 10 mm to accommodate a 15 mm longer lca. steve confirmed that centres are offset by around 10 mm. presume anything more than 15 mm wide lca and the thrust arms will start pulling the caster less positive.