Alot of Z owners put bigger wheels in the back, I believe for better traction (some probably do it for looks). While I am waiting for their responses to my questions, I figured I'd see what you guys think.

What are the advantages / disadvantages to doing this?

I am either going 17" all the way around, or 17's in the front and 18's in the back.

 

same circumference? wider traction pads in the rear will give you a bit more traction for car with oversteer. Having like a 15" front and a 18" rear for wheels would allow the front to "roll" a little more and give some crazy understeer if i factor it right. Not what you'd wanna do in a RWD car.

my guess is the looks.

 

My s13 has 195/75/15 in the front but 205/75/15 in the back, STOCK. Although the wheel radius same, I'm sure the difference is needed for RWD cars.

 

i dunno what an S13 is (240 Silvia? trying to remember inital_D) that setup is probably to help the RWD cars be more street-safe with the understeer FWD cars are known for. Oversteer can be dangerous to the "normal" driver ...

 

The only true reason is looks.

It depends on the traction were talking about. If its for drag racing its worse, the less sidewall you have the less traction on launch. Also width plays a bigger roll then Height. You have a 16" wheel thats 25" tall and you can have a 19" wheel thats 25" tall so size of rim really isn't a factor. The sidewall might shrink which would help in handling but going bigger then the front won't make a differnce.

MY 2 cents:

the Drag look has always been bigger in the back smaller in the front so you have this rake look, I think the import scene has adapted this idea and instead of changing tire size there changing rim size.

I disagree with the rolling better. Again Diamter plays ZERO roll in this. Width plays a roll, you can get any width with any diameter.

there is no performance in running 1 size bigger then the other. Changing widths is different story.

 

The bigger the rim/tire in the back the more unsprung weight. The speedo gets thrown off if the actual tire size is taller. Slight power loss is seen but if you are having traction problems and are using the bigger tires to help gain it its worth the weight.

Get some good rims that are a good bit lighter than you current rims and your good to go. Then get the speedo recalibrated after your first ticket. : )

Looks is ok but thats Ricey. HEHE Just kidding.

 

I don't think he was talking about just a bigger rim.

 

"I am either going 17" all the way around, or 17's in the front and 18's in the back."


I think he was

 

HEHE
Both are valid points but from different perspectives either way he has good explanations.

 

Hum. I guess we'll have to wait and see. : )