I am looking to run 12mm spacers on my FC because the wheels i have rota slipstreams are +48mm offset and way inward, I believe a 36mm offset 16x7 running 225 wide tires is ideal according to Fc3spro. Will this be safe? I have arp extended studs, and open forged lugs. The reason I ask is my car sees the track, as much as I can afford, repeatedly. (hpde) and road courses.

 

As long as you use a good hub centric spacer you should be fine.

 

im talking a plain, 12mm non hubcentric piece of stamped aluminum with some holes cut in it, as seen here
http://store.summitracing.com/partde...art=CAL-202372

I'm actually also reasonably sure that my wheels themselves arent even hubcentric.

 

If the wheels are not lug centric, then they NEED to be hub centric or you will get vibrations. You just won't be able to get them perfectly center.

Those spacers sould be fine for test fitting, but I wouldn't use them for racing.

 

Have any examples of a hubcentric stamped spacer? I understand what your saying about if the spacer is like a 1/8 of an inch lower on one side or something like that, but I doubt they have that much play in them. I was unable to find a 59.3 hubcentric stamped spacer in 12mm. From my understanding theirs tons and tons of racers who run lugcentric, thats the reason for higher tensile strength studs.

 

i just got done at a track day and had none eccentric spacers. and i will say that doing about 120 the wheel is just crazy. i dont rec them on track. riding around aily its ok but it is not great on a high speed track

 

Hubcentricity is for CONVENIANCE. If you make sure to torque the wheels IN THE AIR and do it evenly in steps, then the wheel will be quite well centered. There's absolutely nothing wrong with running non-hubcentric spacers. I've used those exact same type of spacers on track a number of times now without issue. Centering the spacer will also help reduce vibrations.

I've crewed for a racer that used 1" + spacers that weren't hubcentric and he never had any issues.

 

I run a 1/2" (12.7mm) spacer, non hub centric, on ARP studs with no issues. I've got +35 wheels and run a 225, needed the extra clearance because of the coilover spring seats.

This is the spacer I use http://www.southwestspeed.com/?sec=view_part&id=2572

 

A 12mm spacer on the front of an FC with the ARP studs is really cutting it close in terms of lugnut thread engagement. I've run a 10mm spacer with those studs and wasn't as happy as I'd like with how much thread of each nut was engaged. Be sure to pay close attention there.

The rear would be fine since the ARP studs have much more thread exposed (assuming that you use the same front and rear).

 

Those look like they would be ok. The ones from summit in picture did not look so good, oval holes??? Looks like they would fit loose on the hub, and you wouldn't be able to center them easily.

 

There's 2 lengths available. I tried it with the 2.5" ones with 7/16" spacers and decided to go with the 3.25" ones in front to be on the safe side. It'll depend on the wheel though, since some have a thicker hub area than others.

Put on the lugs just enough to keep the spacer from moving, then reach in and ceter it by hand. Not hard to do, and even it it's not 100% centered, it's so light and so close to the center that it shouldn't cause any real vibrations.

 

cool. I have http://www.rallysportdirect.com/shop...nd-p-2094.html
nuts, they are open ended and dont have a very large amount of thread, I would be a bit worried if they didnt thread 100% on their, The Arp studs are over 12mm longer then factory, why would it be a problem?