Are there downsides to using spacers? Less bite on the lug, more torque against the wheel housing, etc?

Also, can you add spacers after alignment and adding camber, or does that have to be redone after adding spacers?

 

Small spacers should not change much. It should have no effect on camber, caster or toe. You must be sure that you have adequate thread exposure to allow the threads to protrude through the open nut. Don't use the stock, aluminum enclosed ones, or, if you do, make sure you have enough length on the bolts. Make sure you do not have any rubbing issues. If you go with bigger spacers requiring their own bolt extensions, you may find your bearings wearing out a lot faster.

 

I think that's what I was trying to get at. Anyone know at what size that starts to become an issue? How thick can you go using just the stock lugs?

 

I use steel lugs and the max I can go while still getting full engagment is 4 mm. I have a set of 4mm spacers at home that just barely leave me enough stud to get the entire lug around.

If you installed longer studs to use a thicker spacer, then you'd have the problem of your setup no longer being hub-centric. There is a little hub that the wheel rests on, and if you installed probably a 8mm spacer (guessing), you'd no longer have any hub for the wheel to center on, which would be no good.

 

anything beyond a 5mm spacer should have longer studs or integral studs (as part of spacer).
There may be other opinions... like, "no spacer at all with stock studs"...

 

I've ran 7mm spacers in the rear using original studs and had no issues. General rule of thumb (so I've been told) is to get at least 8-10 rotations on the lug. I tighten to 96 ft/lbs.

I've also ran up to 30mm adapters in the rear and aside from the added weight noticed no problems. Was advised by our Porsche Tech I didn't need to adjust alignment specs.