I plan on getting some wheels from IForged. Does anyone see a problem with going 8inches in the front and 9inches in the back?

 

You will destroy something, most likely your center differential.
You have an AWD car, not a rear drive car. You cannot mix and match wheels and tires and sizes. If you want to do that, buy a Mustang or Camaro, not an STi.

 

I know the aqua car has 18x9 in the front and 18x8.5 in the back.

I have 18x8.5 in the front and back

 

If anything, you want the wider wheel in the front.

But i would HIGHLY advise against mismatching sizes like that.

-Gagan

 

Thats what I thought I was just making sure. But I would be fine with 8inches all the way around.

 

As long as you use the same tires and size of tires.

 

What size tire do you have?

 

Why is it bad to have different tire widths in the front and in the rear? I understand if the tire thickness or wheel size was larger, then the circumference of the tires will be different, thus destroying the differential. But the different tire widths? I don't see how having for instance a 18x7.5 with a tire width of 40 in the front and 18x8 with a tire width of 40 in the back, could hurt the differential, since the circumference of the wheels/tires are the same in the front and in the back. Somebody fix me if i'm wrong.

 

It's because the circumference is "close" between the front and the rear. In reality, for different widths of the same tire, the RESULTANT outer diameter after putting them on is never the same - maybe it's better to say that it will always be further off than if you got the same size front/rear.

It also doesn't help performance-wise because our cars' cornering is limited by understeer. Wider tires in the rear will be solely for looks because you'll be limited to the same corner speed regardless of rear tire size.

 

As long as the rolling diameter is within X percentage between the front and the back, no harm will come to the differential. Depending on who you talk to, X will change. Some say 1%, some say 2%. The larger the difference, the more heat created in the center differential, the smaller amount of time your diff will last.

Fitz

www.Flat4Racing.com