I am installing new wheels on my fc and they contact the suspension (17x9 +38) I know on the stock wheel/tire combo that the space between the tire and the lower spring perch is so narrow that I can't even fit my finger between them. so I'm guessing it's just under half an inch.

So If a lame straight walled street tired doesn't flex enough to make contact would I be able to run less clearance If I am running a stetched sporty tire that won't flex nearly as much?

I think I could get away with running a 5/16th spacer which would keep the wheel pretty close to flush with the fender.

That brings me to another question. How thick of a spacer can i use before I have to installer longer wheel studs?

 

You need as much clearance as will allow you not to rub, it'll be different for different cases. It will also depend on your suspension, as stock type springs get wider at the top, so you might be getting reduced clearances under compression. Pick a spacer that you think will work and try it out, if it doesn't rub then that's great, if it does, go thicker. It's not like spacers are expensive.

There is no hard and fast rule about spacers, because every wheel is different (some have thick hub faces), and anyone who tells you some arbitrary number is an idiot. Some wheels don't even get a safe amount of thread engagement without spacers, so longer studs are required right off the bat and any spacer will be unsafe on stock studs.

 

front
http://store.summitracing.com/partde...5&autoview=sku
rear
http://store.summitracing.com/partde...5&autoview=sku

and you'll need 10-15mm spacer to clear those wheels up front. you'll also need wide front fenders, or really skinny tires (the wheel stick out like an inch). if these are for the back, then you might need like a 5mm spacer at most.

 

15mm spacers will put these farther away from the suspension than the stock setup.

The wheels have 225 tires on them so there is quite a bit of stretch...

this is the front btw... the rears clear no problem

 

it depends, as you say stock is close, you can go a little closer, but your sucess depends on things like wheel bearings, and if you're on sticky tires, how strong the wheels are and stuff.

ive seen stock rx's that contact the tire to the spring, and it seems like a little isnt the end of the world

 

Similiar question, I know I'll have to get bigger fenders but I'm trying to run a 225/50 R16 up front (at least until I get the rest of the car situated then I'll put on lighter rims). The problem is the wheel is too big for the current fender and it contacts the coil overs (Tein Flex). I'm guessing I'll need about 15mm spacer and I plan on picking up the wide body fenders from AITracing.com, but what I'm wondering is if there's any big difference or if there's specific companies I should look at vs others. Right now I'm looking at the AutoRnD 15mm spacers for $110 but I'm wondering if I could pick up some cheaper ones and still be okay? (For instance I checked out advanced and they could order the ones for the mustang for about 70-90 bucks. But i'm not sure I'd want to do that.)

Cliff question: What brand spacer should I look at purchasing? Is 15mm going to be enough space or should I go to something bigger like a 20 or 25mm (The wheel contacts the spring already and cannot sit flush on the mounting surface, needs at least 5mm or so to do that)?

 

Can you get the offset on the wheel? How wide is the wheel? With the right offset, you shouldn't have any problems fitting them under the stock fenders.

 

I picked up a set of mr. gasket spacers 5/16th and they fit like ****. They are universal so all the holes are way too big for the fc hub and they are not hub centric. Now I am gonna start looking at H&R ones and also looking to have some custom machined so they fit hub centric on the hub and also into the aftermarket wheel.

 

Of course they're not hubcentric, they're universal for crying out loud! Spacers aren't meant to be hubcentric anyway, that's just extra, unneeded mass there anyway if they make the inner diameter that small. If you want them to be centered, then hold them in the middle while you put the wheels on. Maybe put them on with some gasket goo or something so they stick to the hub in the middle.

HUBCENTRICITY IS NOT NEEDED!!! I don't run hub rings on my street wheels, and I use universal spacers on my track wheels with no issues whatsoever. That part of the hub supports no weight and is only really just a conveniance thing to make putting wheels on slightly easier. The hubcentric part of the hub isn't big enough to reach the wheels with spacers anyway.

Sure having perfect spacers would be nice, but IMHO it's not worth the many times more expensive price tag compared to universal ones (unless you need some special thickness and MUST get custom ones or something like that).