Looking for some advice on wheels/tire sizes for autocross and track days. I'd like to run 17" RT660. What's the widest you can fit? I see alot of talk about 245/40-17, but from searching some of the facebook grups it also looks like rubbing is an issue (at least on track). I'm 100% stock right now. At some point I'll do some kind of coilovers, probably won't lower too much more than stock. I'll also likely run camber plates. For autocross events I'm running DS, which would limit me to a 17x7.5 wheel if I want to remain there. Kind of torn on whether to stick with a 7.5" width so I can stay in DS until I do coilovers and some other mods or just get a wider wheel now. I guess if I can only fit a RT660 in 225/45-17, I don't really need something wider than 7.5". Thoughts?
Track/Autocross Wheels and Tires
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I think you have some thinking to do. What is your goal, to be competitive in SCCA DS class? To go to track days? Daily driver with casual DS autocross for fun?
The DS autocross setup is very simple and affordable, lots of proven examples of how to setup the car. If your doing it for fun, just run a 225 and focus on improving driving. If you want to do track events the DS setup is not great as you’ll need much more front negative camber.
Once you go to wider wheels you will be classed in a different autocross class which requires more mods to be competitive…but it’s a more suitable setup for track use and time trials of your interested in that. But this setup is not as nice for daily driving compared to DS.
So the question is really for you to answer…I don’t think 225 vs. 245 tires is the question.
The DS autocross setup is very simple and affordable, lots of proven examples of how to setup the car. If your doing it for fun, just run a 225 and focus on improving driving. If you want to do track events the DS setup is not great as you’ll need much more front negative camber.
Once you go to wider wheels you will be classed in a different autocross class which requires more mods to be competitive…but it’s a more suitable setup for track use and time trials of your interested in that. But this setup is not as nice for daily driving compared to DS.
So the question is really for you to answer…I don’t think 225 vs. 245 tires is the question.
My goal is mostly to have fun with autocrosses and track days, but, being competitive and winnig is more fun than losing. I don't plan to stay in DS forever, but wheels and tires will be the first thing I change (well that and crash bolts for a little bit more camber). I'll probably do some track days on the stock suspension. So really it comes down to staying with a 7.5" wheel so I can stay in DS until I get to the point where I have to run STR. At that point I could keep running th 7.5" wheels, or sell them to get something wider. I'm tempted to get some RPF1 17x7.5's and and 225 width RT660's and call it a day for now. That way there is zero concern with rubbing and I can keep running in DS for the time being. Once I'm in STR I can figure out if I want to go to something wider. Open to suggestions though.
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Did you end up getting the RPF1's 7.5's and the 225 RT660's?
I'm going with RPF1 17x8 with same tire setup.
I signed up for FCP Euro Proven Grounds AutoX at Lime Rock. They have a very cool time trial competition and serious cars show up. It's all for fun but man is it competitive. So amazing. Nevertheless, I would like to be mid pack in this highly competitive group.
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My plan is 17x8.5 w 225 - looks like it's "faster" of the 3 available combos I am considering. 225 is tiny bit taller than stock, so slightly longer 2nd gear. 2nd choice would be 235/35 for even higher speed in 2nd gear. Wider may not be faster, as it add considerable weight.
| Section | Profile | Wheels | Diameter | |
| Pilot Sport 4 | 215 | 40 | 18 | 24.8 |
| RT660 | 225 | 45 | 17 | 25.0 |
| RT660 | 235 | 40 | 17 | 24.4 |
| RT660 | 235 | 45 | 17 | 25.3 |
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Probably the most comprehensive test to date, but still leaves some info to be desired.
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Classic Tirerack test- I loved this. I learned lot and it was cool to see our cars and the wheels and tires I wanted. Of course more info is needed...its a lot to take in, learn, understand. I'm learning...
I really would like to be competitive in the mid pack this summer so I'm going camber, wheels tires and strut braces and breaks. Really dial in my driving.
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Whoa!
simple math I didn't even consider. I would benefit from 2nd being a bit longer...I ended up buying a set of used 17x7.5 SSR competitions from a fellow BRZ/GR86 owner. He also had a used set of 215 660's that I mounted. I'll run these for little bit but will eventually get a wider tire. There is a guy local to me with a GR86 and it sounds like he plans to try to run 245's, so it will be interesting to see how well that works.
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245 on the 7.5 works very well. I ran that before jumping to STR. You just have to give the car a hair of time to react but as long as your conscious of it, its not a big deal.
I just put the RE-71RS's on a set of 17x7.5 in 245/40R17. They were 150 off at Costco, of all places.
Have you worked with these tires at all? I've heard reports from "ultra-meta for DS" to "eats themselves in 2 laps".
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Comparison of avg lap times amongst ten other EPS tires, though 225 on an 8" wheel.
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would you might sharing some pictures along with what suspension you are running (or stock?) thanks
edit
found your other post! disregard
I have RPF1s in the same size and offset. Only difference is that I my tires are 245/40. I am lowered on coilovers with -2.5 degrees of front camber and -2.0 degrees rear.
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That's a great color combo! Do you know how much you lowered? I'm really stuck between TS-10's and the RPF1's in 17x8. Trying to get an idea of the looks with my stock suspension (as of now).
TS-10s are great too! They still save quite a bit of weight compared to stock. That picture was taken after the coilovers settled and I have raised it since. Not sure on the exact numbers at that time, but it was probably around 1.3 inches in the front and 1.2 in the rear.
Here is how it looked on stock suspension.
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