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I need help with Rims

2K views 14 replies 5 participants last post by  BlueBomber 
#1 ·
#2 ·
you have 5x100 lug nut pattern so the wheel HAS to have that.

16" to 18" tall would all work

6.5" to 8.0" wide is all fine. Wider and you get into grey areas where you might have problems mattering on your setup.

Offset should be 48mm - 53mm but people run 47 or even 45 mm sometimes. The top choice there would probably work, but to be safe you should get something with more offset.

if any of the terms I've used confuse you let me know
 
#4 ·
What do you mean by "backside"? anyway, mosc is 100% right, although 48-53mm offset is kind of a vague range. The wider rim you get, the lower offset you can run. So if you get 8" wide rims, 45mm offset would be ok, but 53mm wouldn't. If you get 6.5" wide rims, 53mm offset would be ok, but 45mm wouldn't. You get it? If you get too LOW of an offset (say 45mm on a 6.5" wide rim), you'll cause premature wear on bearings and such.
 
#5 ·
well WReXd, you've basically got it wrong. The offset is the distance from center. You'd always want that to stay the same in an ideal world no matter what width rim you use. However, it may not fit. My stockers were 6.5" wide at 53 offset and my new ones are 8" wide. Fitting 53 offset on there would make the rim 19mm closer to the car. It probably would rub.

In an ideal world, you'd want the center to stay exactly where it was... where the suspension wants to throw the weight.

this may help you:
http://www.americanracing.com/techcenter/techcenterdetail.asp?filename=wheeltech4&section=tech#
 
#6 ·
My reasoning is this: If you get rims that are .5" (12.7mm) wider than stock and the offset is 3mm lower, you've still got 3.35mm of more rim and tire on the inside of the hub mounting surface than before, so the suspension still has a bit more meat to "throw the weight" at: not just at the outside of the hub mounting surface, but the inisde as well. Now that I think about it, this may not be sound reasoning, but if that's the case I would have appreciated a thorough explanation of where I was wrong and why instead of a blanket "you've got it basically wrong" statement (especially since we seem to agree on these quotes):

The offset is the distance from center. You'd always want that to stay the same in an ideal world no matter what width rim you use. However, it may not fit.
Which is why I said:
The wider rim you get, the lower offset you can run.
You even say so yourself:
My stockers were 6.5" wide at 53 offset and my new ones are 8" wide. Fitting 53 offset on there would make the rim 19mm closer to the car. It probably would rub.
Which is why I said:
if you get 8" wide rims, 45mm offset would be ok, but 53mm wouldn't.
 
#7 ·
ok, let me explain in more detail.

Your suspension is intended to be directed down through the wheel and is balanced with an expected location of the center of the rim. The SUSPENSION dictates the optimum offset, not the rim or the tire. If you were going to run a 3" spare doughnut (assuming it's a 25" tire unlike the one in the trunk) and asked what offset would be best, I'd say 53mm. If you wanted to run a 12" wide drag slick, you'd get the same answer. Course, neither of those work well with the stock wrx suspension for other reasons but they are unrelated to offset.

The reason there's a range is nothing to do with rim width. A 45mm offset on an 8" wide wheel is no better than on a 6.5" wheel. They're both bad. 48mm is just an engineering judgment, a "fudge factor". Commonly, people tell you to be within 5mm of stock, that's all 48mm is. It's not some magic number that has anything to do with wheel width.

Now, since you really don't want to worsen the handling of your car (I'm assuming you value handling), you'll want to keep the center point of your wheel fairly close to stock. This, in effect, limits your wheel width because there is only so much room between the hub and the fender. Even swinging a 48mm offset (already 5 off), an 8" rim comes in 14 mm more (15mm is about all you've got to work with). Any wider and I'd a) have way too small an offset or b) rub.

Does this make more sense?
 
#11 ·
Just to throw some more numbers at ya, your stock rims are 16.5 lbs at 16x6.5 inches.

The ones you are looking at are 17.2 lbs at 16x17 inches and if you go with bigger rims, the 17's are pretty much 19 lbs. Now the new 16's would be 1/2 inch wider than your stocks, but they .7 more lbs. Rim weight is VERY important IMO. (The more the rims weighs, the slower you accelerate)

I personally don't put anything on my car that is going to make it slower =)

I did a lot of research before I bought my rims and Rota, Enkei, and 5Zigen all make cast aluminum rims that you can get 17" for close to the stock 16" weight; also the price won't kill ya. And since you will be running a lower profile tire with 17", there are many tire setups where you can save on overall rim + tire weight over the stock setup.

BTW, I love the black with polished lip look, try looking at Rota Subzero's in gunmetal (17x7 @ 16.5 lbs) also the 5Zigen FN01R-C in black polish can't remember the weight on these but I think are ~16 lbs for 17x7.

And one last thing, if $$$ is not a problem (for me it is always a problem... !Cry! ) get a forged rim. It will be lighter and stronger than almost any cast one of the same size. (probably looking at 1000+ for a set of forged rims tho) BBS, Volk, Advin, SSR, Work and many others make forged rims.

Hope it helps.
 
#12 ·
remember that you have less tire weight when you go to bigger rims while keeping the same diameter. My 18s weigh 18.5 lbs each (2lbs more than stock) but the tires came in within a pound of stock and that's with 225s instead of 205s as well...
 
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