Which wheels/tires for '17 PP in DS (autocross)

[RT-BRZ]

Originally Posted by Balefire

So for better or worse I purchased a set of light weight 18x7.5 wheels for my sons 2017 PP in DS.
I now realize my 200TW for autox in 18", 25" diameter tire selection is pretty limited.
Any recs on size and tire for DS in 18s?
Besides my +1" wheel 2017 PP, this would also pertain to the BRZ tS, and the 2nd gen BRZ that runs 18"x7.5" et48 oem sizes.

Here are some choices I'm considering .

245/35/18 Conti Force. Close to OEM diameter. But wide on narrow wheel.
235/40/18 rt660. Nankang cr1. V730. These are all taller than stock, probably worse gearing
225/4018 rt660. Z3. Close to OEM diameter but narrow.

He will have limited DD use and primary autox use for these wheels and tires.
My son is learning, so no AD08.

The bright side to a taller tire on a 2017+ is that you get more headroom in 2nd gear since it effectively numerically lowers the FD. I did this on my STX '13 BRZ (255/40-17) and I feel like it hurts me but I never had a problem bouncing off the rev limiter even on bigger courses. Unfortunately it made my car slower at the big track too but that's my prison.

[cmiovino]

Originally Posted by Balefire

245/35/18 Conti Force. Close to OEM diameter. But wide on narrow wheel.
235/40/18 rt660. Nankang cr1. V730. These are all taller than stock, probably worse gearing
225/4018 rt660. Z3. Close to OEM diameter but narrow.

He will have limited DD use and primary autox use for these wheels and tires.
My son is learning, so no AD08.

Number one, compound beats all (given you're not comparing a 205 to a 245). I'd reckon a 225 RT660 is going to trump a 245 ContiForce.

The two main leaders are still the RT660 and A052. The Nankang CR1 isn't too far behind, nor the V730, but no one in our big region is running these. The Conti's are too new, but are an endurance tire.

I'd go with an RT660 even if it meant a narrow "225". The Falken's run wide anyways. A 225 is virtually fits like a 235 despite the number.

With that said, being your son is learning and doing daily driver duties, I don't think putting him on the fastest tire is the best way to learn. I tell everyone who's picking up the sport to run on something like a Conti ECS.... 300-400TW, not top tier tire for a year. Get the driving down a bit, a good line, all that... then increase mechanical grip. I see too many newbies run out and order the best tires and then rely on those for a decent time, but not improve their driving for a long while.

[cmiovino]

Originally Posted by cmiovino

I have two options for wheels:

• STI 5x100, +53, 15.7lbs - these barely cleared the front struts and I fear with RT660 or A052 that run wide they won't. A 3mm spacer might allow clearance, but can't confirm.

• Stock performance pack wheels, +48, 20.8lbs. Heavier by 5lbs, but give an extra 5mm clearance without a spacer. Would easily fit 225's.

The difference is 5lbs per wheel in weight, or 10% of the overall mounted wheel/tire together. This might affect handling and power, but might be negligible.

Not looking to go all in and buy new wheels with a lower offset as I'm probably going to STX long term.

Tires:

• Safe: 225/45/17 RT660 - baseline and safe choice. Should get through the 20+ event calendar, $200 cheaper.

• Risky: 225/45/17 A052 - The quicker tire. May not make it through 20 events, $200 more. A guy running 0.6* camber on a GS Civic did get 150 runs last year before they literally disintegrated.

• Wildcard: 235/45/17 in either on the PP wheels only. I'm not sure these would clear with the PP +48 offset and a 3mm spacer combined. Not sure if it's worth the extra increase in diameter, reducing the effective gear ratio, but increasing top speed in 2nd.

Since this thread got bumped, I figured I should update it with my choice and how it panned out.

I ran the 224/45/17 A052's on the stock PP wheels. I did add the 3mm spacer and I had plenty of room left between the strut and sidewall. Much more than the RE-71R's in 225 on the +53 wheel.

I got 149 runs out of them exactly. They have a few more in them, but that was my run count for the year. They're below the wear bars, but the outer edges held up with -1.3 degrees camber.

On a good note, I moved up from 37th to 31st in a highly competitive region. Our 10 top were just about all winning at nationals this year.... so yeah.

The A052's worked, but I don't know if they were the best for the car in DS. My main grip was they overheated quickly. My morning runs were good, but afternoon once it heated up, I rarely improved. Many times I was sitting in the top 15 (out of about 100) going into the afternoon, but ended up falling to around 25.

I'll likely try to RT660's this year as most in my region have switched to these for prices and their ability to take more heat. Price-wise, the A052's in 225/45/17 were $800 last year and $1000 this year. RT660's are up, but now those are ~$650 ($550 last year).

I'm up in the air again with wheel choice. The PP wheels worked last year with the A052's being 21lbs. The RT660's are 24lbs, so the1 15.7lb weight of the STI wheels would be ideal. The 660's run wide, probably wider than the Yoks, so we'll see which I decide to roll the dice on. The good news is once I fit the 660's on the PP wheels with the 3mm spacer and find I have more than 5mm of clearance, that confirms they're fit with the lighter STI wheels.... for the year after.

I still think the 660's will work better for our climate and the BRZ in street class with limited camber. The Yoks worked ok, but didn't seem ideal - likely due to the lack of camber. But they made it and didn't disintegrate in <50 runs like many said they would. They would be AMAZING on an STX setup with -4 degrees of camber and 245's.

[RT-BRZ]

Originally Posted by cmiovino

.......

I'll likely try to RT660's this year as most in my region have switched to these for prices and their ability to take more heat. Price-wise, the A052's in 225/45/17 were $800 last year and $1000 this year. RT660's are up, but now those are ~$650 ($550 last year).

I'm up in the air again with wheel choice. The PP wheels worked last year with the A052's being 21lbs. The RT660's are 24lbs, so the1 15.7lb weight of the STI wheels would be ideal. The 660's run wide, probably wider than the Yoks, so we'll see which I decide to roll the dice on. The good news is once I fit the 660's on the PP wheels with the 3mm spacer and find I have more than 5mm of clearance, that confirms they're fit with the lighter STI wheels.... for the year after.

I still think the 660's will work better for our climate and the BRZ in street class with limited camber. The Yoks worked ok, but didn't seem ideal - likely due to the lack of camber. But they made it and didn't disintegrate in <50 runs like many said they would. They would be AMAZING on an STX setup with -4 degrees of camber and 245's.

One point of note for my on my RT660's in 2021; I found that the first 7-8 events I ran didn't actually seem to "break in" my tires. While the tires seemed to perform just fine for me, they never really seemed to get "hot" to the touch at any of our local events. At the end of August I ran a track day at Mid Ohio and the first session they seemed a little slippery which really dampened my confidence for the rest of the day. However, all the sessions after that were just fine and they seemed to stick great. The first session issues could have just been that it was not super warm but I'm not really sure. I ran one more event in September and they were amazing with crazy grip everywhere. It wasn't until after Mid Ohio that I noticed any real wear at all. YMMV

[Aroundomaha]

Originally Posted by RT-BRZ

One point of note for my on my RT660's in 2021; I found that the first 7-8 events I ran didn't actually seem to "break in" my tires. While the tires seemed to perform just fine for me, they never really seemed to get "hot" to the touch at any of our local events. At the end of August I ran a track day at Mid Ohio and the first session they seemed a little slippery which really dampened my confidence for the rest of the day.

This thread was a great read as I consider wheels and tires for 2022. I enjoyed RT660s last year on my GTI but this is a different situation. My emphasis is on seat time, learning, and fun so the 225/17/45s are my probable choice. I'll also likely go with the Kumho V730 since the Grass Roots Motorsports test showed them wear a little better than the RT660.

I've not had any issues with RT660 break-in but am running on concrete in Lincoln. I got about 90 runs out of the RT660s even with rotation and flipping on the wheels. But the GTI's brake vectoring heat-cycled them pretty hard. A seam was showing on one tire when i sold them, so though still safe, delamination was beginning.