Learn me on offsets

[BE-Fresh]

I have a bad case of ADD right now and can't seem to understand offsetting at all. Long story short, I want new summer wheels, but I want them to stick out a bit so they're flush with my fenders. Looking at 17X8 probably with a 225-235 tire width.

[Huffer]

Offsets:
http://www.tirerack.com/wheels/tech/tec ... techid=101 (http://www.tirerack.com/wheels/tech/techpage.jsp?techid=101)


Zero Offset: The hub mounting surface is even with the centerline of the wheel.

Positive:The hub mounting surface is toward the front or wheel side of the wheel. Positive offset wheels are generally found on front wheel drive cars and newer rear drive cars.

Negative:The hub mounting surface is toward the back or brake side of the wheels centerline. "Deep dish" wheels are typically a negative offset.

https://sl-i.net/FORUM/images/imported/2009/03/offsetgif-2.jpg

[Huffer]

I have a bad case of ADD right now and can't seem to understand offsetting at all. Long story short, I want new summer wheels, but I want them to stick out a bit so they're flush with my fenders. Looking at 17X8 probably with a 225-235 tire width.

You'll want a wheel with an offset of around +45 or even +42 depending on your wheel width...

Check out some posts from the "Aggressive Fitment" club on NASIOC. They're super flush running 18s at +35 I think.

[sybir]

Run coilovers before you start trying to get flush.

Here's another diagram that can help. Keep in mind this was laid out for WRX fenders, not Legacy fenders - on a BD/BG the outer lines are going to be moved in so that "inside of fender" is closer to where the dot ends for 7.5, 46 ET.

https://sl-i.net/FORUM/images/imported/2009/03/sti_offsetsgif-2.jpg

Also, not to scale, but it is relative.


This is what "herrafrush" crap looks like on my wagon. SSR GT2's, 18x8.5, ET48. Tires are Advan Neovas, 245/35/18. It'll fit, but it won't be easy to make it look right. Keep in mind that this is a "non-aggressive" offset, and my front and rear fenders are rolled AND pulled. This fitment would rub like hell (which is why I'm not running these tires or this camber once they go on). This isn't dumped, either, which is a whole different set of problems.

https://sl-i.net/FORUM/images/imported/2009/03/IMG_4657JPG-1.jpg

https://sl-i.net/FORUM/images/imported/2009/01/IMG_4667JPG-1.jpg

https://sl-i.net/FORUM/images/imported/2009/03/IMG_4668JPG-1.jpg

Now, below - this is the height you see all the "flush" cars running. This rubbed, badly, in the front, over any bumps, and that's an 18x8 ET45 with a 235/40/18. I rolled and pulled the fenders, which would be enough for cruising, and I raised it back up 3/8" from this pic so that I could beat on it with no worries about rubbing. Also keep in mind that this setup looks positively sunken on my STi. What fits a WRX easily will require lots of work, and money/time on our cars.

https://sl-i.net/FORUM/images/imported/2009/03/IMG_4675JPG-2.jpg

Now, look at that cute "little" wheel on my wagon.

https://sl-i.net/FORUM/images/imported/2008/08/IMG_4295JPG-1.jpg


Remember, rubbing in the rear might wear some paint on the inner fender, and chew up the sidewall over time - no biggie as long as you don't ignore it. Rubbing in the front means your tire is going to grab your fender and have its way with it, prison-style. The fender WILL buckle, and it WILL look like shit. Don't do it.

Before you go bolting on something aggressive, get your suspension set up, make sure you can add a little camber if you need it, then hit up local guys and try to test-fit wheels - what works on WRX's will not fit your car. Find your local Impreza community. Trust me, rolling up with a dumped Legacy will intrigue most wheel whores want to see what stuff will look like. You can also ask anyone local to me; I've had lots of cars in my garage testing sizes and colors from my collection. Lots of cool guys around who will help, especially if you've got something unique.

[BE-Fresh]

Sybir, just donate a set to me, haha.

I'm going to have to re-read this a few times to actually understand it lol. Thank you Huf and Syb, you guys know your shit.

Edit: I wasn't planning on going coilovers. I just wanted to keep my height now and go stiffer. If I go lower, I'm going to be very angry because I'll have to be very careful (I have low patience when driving).

[sybir]

Trying an aggressive fitment on springs is like playing craps. You might get lucky and end up with something that works well for you, but you're more likely to be throwing your money away on parts you have to off to get different sizes, etc. In all seriousness, no lowering springs are going to have the stiffness required to keep those kinds of setups off the sheetmetal, and not being able to adjust the ride height if necessary is an even larger issue, since you're basically trying to create something that looks like an interference fit without being able to adjust where the wheel sits in relation to the fender. A height adjustment to remove rubbing that takes 10 minutes on my car is something that at worst cannot be done, and at best has to be done with spring or tophat spacers on a spring/strut setup, which is sketchy and has its own issues.

Just my 2 cents. There isn't a way to do "fitment" on a small budget unless you have options to try a bunch of stuff first and then make a purchase. You're talking a lot of experimentation with wheels, tires, suspensions, etc. Most of the guys running aggressive setups on Subies are not DDing them, either. Subaru camber curves mean that the same fender profile that works on, say, a 240, will not work on a Subaru - you need a crapload of static camber because once your control arms go above level (like under compression) you are LOSING negative camber, not gaining it. You run out of camber you can realistically run on a street car used for commuting, etc, above 2-2.5 degrees.

I'm not trying to be negative - I'm the idiot running big wheels on a dumped OB with screwy suspension geometry, the guy running a RWD leg turbo, etc etc. Trust me when I say that the work involved in doing it correctly is both costly and time-consuming -go into it knowing that and I'll have a clear conscience.

In case any of you were wondering, this is also why I get hives when I get the question "what's the biggest wheel and tire I can run on my car".......it's not an easy answer :(

[BE-Fresh]

....shit

[jamal]

a 17x8 +48 with 225/45-17s should fit with a slight roll of the rear fenders. Going down to +45 requires more rolling. 225/50-16 on +53 wheels didn't rub at all but the tires were very close to my stock spring perches.