Cant Decide, need help! 17" vs 18"
 

Hey all, here once again is another one of those 17 vs 18 inch threads... I am just having a hard time though.

Okay, I really dont like the look of 17's... But if I had to choose it would be 17x9 RPF1s with 245/40/17 MPSS.

Now 18's just really full out the car but I'd rather put performance in priority over looks. I am just a DD that wants quick acceleration and great control.
I keep reading that 18's will slow your acceleration down due to the rotational mass being elongated from the center. Then again TRD and Subaru have 18's on their special editions.

Cost really isnt an issue for me.

I just want to make sure if it is true that 18's will slow your acceleration or if not, what would be the perfect 18" for the stock power of the car. Obviously not 18x9.5 but yeah.

Thanks!!

If I were you Id go for the exact rpf1 setup you described. I went for 18x9.5 and there is a noticeable difference in acceleration. A buddy of mine and I have complete bolt-ons added to our cars and he pulls on me because he has 17 rpf1's and I have 18 nto3's.

Dude, you are way over thinking it. Pick the wheels that would put a smile on your mug everyday. I would consider another better tire besides MPSS, unless you can get them for under $130 any thing more is robbery.

As far as the weight of the 18" that all depends on the manufacturer. Yes there are 18" wheels out there that are lighter than most 17"s.
It's really your call

I would go for the 18". The steering is so much more weighty and feelsome. The car looks great and gets tons of compliments. I feel weird on the 17s. The diameter is smaller so you don't get as far with the same amount of wheel rotations, if you know what I mean. Bumps are more apparent. I'm not a happy camper with 17s

Almost everyone who seriously races this car uses lightweight 17" wheels. They're better for performance, period. Larger wheels rider harsher, are heavier, and have more rotational mass. The only benefit is looks which is subjective.

Wheel size has nothing to do with how many rotations the tires do. Only the OD of the tire. A 245/35/18 spins more than a 225/45/17.

Really??? so 18x9.5 is noticeably sluggish? damn. lol.

My choice for that wouldve been the Titan 7 T-S5, they are SEXY AF. But if thats the case... :(

Like I said my goal is to have a fun DD. Improvement upon the stock, better acceleration...etc.

It's easy to overtire this car. Remember how you bought a fun light sports car that didn't have a ton of power, with decades of chassis engineering expertise of multiple companies with trophy upon trophy of race heritage?

It's not a powerful race car, it doesn't have gobs of power to turn the biggest heaviest trendy instagram famous 19x12.5" wheels people put on them for some reason.

Unless you're making a bunch of extra power, try your hardest to not add extra weight at the corners. It makes a difference.

Also idk why people are saying to get a tire better than a PSS. I think the S-04 and PSS are wonderful tire choices at the top tier of a summer tire before you end up with a tire meant to stand up on the track.

Mine has the 18 x 8.5 and honestly I can't tell the difference between that and the stock wheel. Car is still fun

So its more so weight at the corners and not size?

What wheels and tires do you have?

Read this:
http://www.ft86club.com/forums/showthread.php?t=67345

A good lightweight 18x8 wheel can be fine...we did it on our shop car. But the same wheel in a 17x8 would be cheaper, lighter, ride better, and more fun.

Resist the temptation to go too big or too wide.

- Andrew

It's a lot of things.

Removing rotational mass as far away from the engine as possible then work backwards towards the engine is usually one of the very first things competent racers do to modify their vehicles.

This may be a good read for you in addition to the RCE post mentioned above.
https://www.tirerack.com/tires/tiret...jsp?techid=108

I have Enkei Raijin. They're the exact same weight as the OEM wheel so the extra weight comes from the tire, which is an MPSS. But the grip and the looks make up for all the shortfalls, which like I said before, I can't even detect. - especially for a daily driver

Okay awesome thank you!

And the tires are way cheaper! And you can get WRX take-offs for roasting for sub $100 for a decent set locally.

On your shop car do you have still to close to stock power? Just wondered how the 18x8 would effect a stock power car.

We had a mild increase in power. Tune, exhaust mods, etc.

18x8 with a quality wheel is fine. You just pay a little more. Small trade in ride for a small change in responsive-ness.

- Andrew

Okay.

Hell... great. I might just get the 18x8 RPF1's... since they are so light.