For stock power and street driven: 17x8 vs. 17x9 and +35 (245/40) vs. +45 (225/40)?
 

I'm about to buy RPF1s for a stock, street/twisty-driven twin and I wanted to get clarification on a few things before purchasing. I've seen a couple forums on these topics but I'm trying to narrow in on a firmer consensus. My primary concern about upgrading wheels/tires is retaining stock acceleration and throttle response while increasing grip and improving handling characteristics.

I've already decided upon 17 inch RPF1s with MPSS tires. I will likely do a 1 inch drop using Eibach Proline Springs. I prefer the flatter face look of the 17x9 RPF1s, but is 17x9 noticeably too wide for stock power? Also, would I be best served with a +35 offset (245/40) or +45 offset (225/40) on a 1 inch drop? I've been reading that +35 (245/40/17) is the way to go for RPF1s but I was told in a previous thread that 245 might be too much tire for stock power. I wouldn't be able to go with 235 since MPSS aren't manufactured in that size. If I go +45, I think I would go with 225/40. Thoughts?

Lastly, what camber settings would be best for the recommended set up? Thanks!

Lots of variables there but first, 17x9 without coil overs will probably rub a little. So why stuck on the MPSS tires? A 17x8 with a 225/45 is a nice stock"plus" setup. 245/40 running on a daily will just generally be extra grip and decreased gas mileage

And not sure what you have to adjust camber, but camber bolts will get you -1.5 ish

I can almost guarantee that 17x9 +45 will not fit. They certainly would not fit on my car with stock struts, camber bolts will make this worse at the front which is where the least clearance is.


With coils, yes they will fit, but may touch at the front on full lock..


My setup with 17x9 +35 RPF1 was for track, and even then there were limiting factors other than tyres.


Personally, I'd be tempted to got 17x8 for a daily driven car (which is what I run with 225/40) as it keeps the agility of the stock car that you can lose with wider rubber (ie Twisties) Grippy 225s will be plenty at sane speeds for a street driven car on stock struts.

What other limiting factors were there for 17x9 +35? I really like the look of the 17x9 RPF1 over the 17x8 :/

@RedBRZ80 I'm sold on the MPSS because of glowing recommendations from friends in addition to what I hear on these forums. I didn't realize that they're also sold in 235/45/17, so I suppose if I went with 17x9 +35 I could get that tire size. I'm assuming that 17x9 +35 (235/45) and a spring kit would fit? Sorry for the noob questions, this is the first time I've ever upgraded wheels.

Yup 235/45/17 is pretty nice on 17x9 +35 rpf1's, I run them daily at the moment Federal 595 RS-R on HKS Sp coils 24mm drop front and 18mm drop rear no issues. Will prolly switch to MPSS or something similar next in the same size.

Edit: I did run the same setup with stock suspension and swift sport springs and never rubbed at all if that answers your question.

My friend has 17x9 +35 RPF1 + 245/40 on stock suspension, standard factory alignment, no rubbing.

Limiting factors in that tyre width/grip was not what was making the difference to outright performance (in this case I had more tyre grip than the suspension could handle). 17x9 +35 RPF1 is a great choice light, strong, and sensible fitment with a little camber (but you'll need tops to get it at the front, because bolts won't work with these and sensible tyres)

A 9 inch wide wheel without a little negative camber will poke a bit in the front.

I run 17x7 02 WRX BBS wheels with 225/45-17 Bridgestone S-04's.
Mods are simple, Swift springs, camber bolts up front, drop in filter and an axleback.

The S-04's are, in my opinion, a fantastic tire to match to this car. Very stiff sidewalls, but some compliance in the tread itself. Lots of grip, but not so much you can't get it sideways when you want.

I would go with a R compound tire and the smaller rims (less weight). Cost alot more in the long run but tire compound > tire width.

Also with a 225 R compound I am sure you will overload stock suspension haha. 225/45R/17 is my plan when my current tires die, I just need to find light rims I like.

17x8 can clear BBK ;)

Thanks for the helpful input guys. I don't think I would go with R compound tires because of cost. At this point, the wheel depth I choose really depends on the optimal tire size for my needs. I'm most conflicted about 225/45/17 vs. 235/45/17. I'd be forced to go 235 if I choose 17x9 RPF1s.

I've been reading that 225 would feel more nimble than 235 on stock power. Is the difference between 225 and 235 actually that noticeable for street/canyon driving?

arguably no. especially because some tires "run" wider or skinnier than their markings.

Im kind of in the same boat, except with a different set of wheels lol.

Its either 17x8 +45 or 17x9 +42, I'm leaning more towards the 17x8 with 225s square setup. Lowered around 1.2" front and about -1.5 deg of camber. If I go 17x9 with 245s I think I'll definitely need to run a 5mm spacer at least up front to the clear the stock struts. I don't think going 235s is a good idea since there aren't alot of options to choose from.

I'll probably get some cheaper tires like Yokohama S Drives that arent so grippy so I can still slide around a bit. Only problem is I dig the meaty tire look :P