SCCA Solo C Street Discussion

[DylanFRS]

Originally Posted by Kido1986

215/45 RS3 vs 235/40 ZII is what we will be testing

235s on the 7" wheel? Are you suspecting it will be better than the 215 ZIIs? I just worry about sidewall stiffness with the minimal camber, especially in the front. I would be curious to hear your thoughts on it though since I am planning to get the 215s and didn't even have the 235s down as an option.

[jprice130]

Originally Posted by DylanFRS

235s on the 7" wheel? Are you suspecting it will be better than the 215 ZIIs? I just worry about sidewall stiffness with the minimal camber, especially in the front. I would be curious to hear your thoughts on it though since I am planning to get the 215s and didn't even have the 235s down as an option.

The ZIIs have the sidewall stiffness to handle this no problem. I ran 235/40 Z1s when I first got my BRZ in 2012 and they were great. The ZIIs are just as good. RS3s have softer sidewalls and do not like to be stuffed on skinny wheels, so that's why you see most folks running 215s with those tires on our 7" wheels.

The other thing to consider with this is that ZIIs don't like too much heat, so 235s have more width to dissipate the heat. The RS3s need LOTS of heat, so the 215s will heat up quicker, thus getting them to their ideal temp sooner.

[Rexpelagi]

Originally Posted by DylanFRS

235s on the 7" wheel? Are you suspecting it will be better than the 215 ZIIs? I just worry about sidewall stiffness with the minimal camber, especially in the front. I would be curious to hear your thoughts on it though since I am planning to get the 215s and didn't even have the 235s down as an option.

It actually doesn't seem to be an issue with the ZII, as they seem to have a stiffer construction than the other options. Also keep in mind that it is 40 series so there isn't a lot of sidewall there. That size is what finished 2nd at Nationals. That being said, I'm not sure why people jumped to that size other than better gearing, I just drove it and liked it.

[Kido1986]

Originally Posted by Rexpelagi

I'd be interested to hear if your results are different than ours, as our test was only a few runs with minimal setup changes on one surface.

I'm especially interested since we have nothing better to do for the next 5 months up here in the frozen tundra. :-)

Take a ride down here, we run ~20 events over 12 months (plus smaller groups like MSCC make about 30 autocross Sundays a year)

Originally Posted by Biggins

I'm not sure yet because I want to wait until late Feb/Mar to buy. It will likely either be the Sparco Assetto Gara 16x7 +48 with a 5mm spacer or the Focal F16/F09 16x7 +42 from Tire Rack. They're light but not super light, but I ran OEM wheels all last season.

My region should regularly have 5-8 full/mostly prepped FRS/BRZs running next year in CS and several well-driven/prepped 370Zs, MX5s, and RX8s, so I'll know quickly what works, also with DC Pro and NJ Tour early in the year. Plus, I have Strano's STX cars to baseline where I need to be throughout the season.

If they aren't that light, is there a real benefit to running 16s? You'll have more sidewall (which means more flex) and less choice of sizes. I understand slightly cheaper tires but if I'm wondering if you see an advantage that I don't. I was thinking of shorter overall height but 235/40/17s are almost as short as any 16 you can buy in ZII/RS3

[Kido1986]

Originally Posted by DylanFRS

235s on the 7" wheel? Are you suspecting it will be better than the 215 ZIIs? I just worry about sidewall stiffness with the minimal camber, especially in the front. I would be curious to hear your thoughts on it though since I am planning to get the 215s and didn't even have the 235s down as an option.

Jprice summed up my thoughts well. The ZII is stiff enough to handle it. I would have never thought of doing this myself (I would have bought 225/45s originally) but driving Trevor's car with them made me a believer. The shorter sidewall further strengthens it, side short sidewalls have less flex.

[DylanFRS]

Agh! Glad I talked to you guys then before ordering a new set. Thanks guys!

[Biggins]

Originally Posted by Kido1986

If they aren't that light, is there a real benefit to running 16s? You'll have more sidewall (which means more flex) and less choice of sizes. I understand slightly cheaper tires but if I'm wondering if you see an advantage that I don't. I was thinking of shorter overall height but 235/40/17s are almost as short as any 16 you can buy in ZII/RS3

First of all, I'm very jealous of how many events you get! We won't start up again until late March.

I'm not sure if there are any benefits to 16s, mostly I just want to try the R1R and AD08Rs to see if they could be relevant without spending more for how much they are in 17" sizes. Very few/no one seems to have given these tires a chance. Worst case, they suck in the dry and I have a rain set. I already know how great the 235/40 ZIIs seem to work.

I think the ideal sizes have been established:
Dunlop - 235/40
BFG - 225/45
Hankook - 215/45

[jprice130]

Originally Posted by Biggins

First of all, I'm very jealous of how many events you get! We won't start up again until late March.

I'm not sure if there are any benefits to 16s, mostly I just want to try the R1R and AD08Rs to see if they could be relevant without spending more for how much they are in 17" sizes. Very few/no one seems to have given these tires a chance. Worst case, they suck in the dry and I have a rain set. I already know how great the 235/40 ZIIs seem to work.

I think the ideal sizes have been established:
Dunlop - 235/40
BFG - 225/45
Hankook - 215/45

Hey, we'll never know for sure until someone trys! Look forward to your feedback! I noticed almost all of the "extreme performance" tires come in 225/50/16, so I assume that's the size you were looking to try? I also noticed that the ZIIs and R1Rs come in 225/45/16, so those might be worth a shot if you're looking to kill it on a small lot that doesn't get you above 59-60 MPH.

Also, you may know this already, but you might want to consider getting the R1Rs shaved if you go that route. At full depth, the treadblocks have a good amount of squirm and will not feel/perform very good in dry competition. I've competed on R1Rs in a Lotus Elise and the tires feel and perform much better when shaved down to about 5/32". A lot of people have a hard time doing that, but if you don't shave, the tires really won't last much longer because by the time you wear the tires to 4/32", they will be close to heat-cycled out.

[piknockout]

Originally Posted by AustinTX

I traded my STU STI in last Friday for a BRZ, and I plan to come play in CS next season - despite the PAX number

Why hello there good sir! I see you're just as lost as I am, how did we end up here? :p


With the crappy acceleration of the BRZ, I do wonder if going to a 16 with the shorter tire might not be the best idea. Coming from the STU STi, having to shift wasn't so bad and it's better than riding the limiter. I went to the 18's on the STi so that I didn't have to shift, but the car has more than enough torque to overcome the taller tire. If you're going to be on the limiter anyways and/or still have to shift on the 17's, might as well get the acceleration with the 16's perhaps. Only one way to find out though.

I'm not sure what I'm doing next year, but I am tempted to run C Street only because I'm feeling lazy. I kind of despise the fact that Street has destroyed Stock and really don't want to support it. I guess we'll see though. I might just run the car as STX with just wheels/tires/alignment and then find something to co-drive nationally. Still a lot of time between now and the start of the season to figure it all out. And of course worst case, I still have the STi...at least for now.

Edit: Yes, I did join just to post this.

[jprice130]

Nice to seem some NASIOC veterans join the fray! Welcome!

[G_Ride]

Originally Posted by jprice130

Hey, we'll never know for sure until someone trys! Look forward to your feedback! I noticed almost all of the "extreme performance" tires come in 225/50/16, so I assume that's the size you were looking to try? I also noticed that the ZIIs and R1Rs come in 225/45/16, so those might be worth a shot if you're looking to kill it on a small lot that doesn't get you above 59-60 MPH.

Also, you may know this already, but you might want to consider getting the R1Rs shaved if you go that route. At full depth, the treadblocks have a good amount of squirm and will not feel/perform very good in dry competition. I've competed on R1Rs in a Lotus Elise and the tires feel and perform much better when shaved down to about 5/32". A lot of people have a hard time doing that, but if you don't shave, the tires really won't last much longer because by the time you wear the tires to 4/32", they will be close to heat-cycled out.

I've tried 225/50/16 Rivals for three events locally. It's not that bad actually, except for mid corner push from sidewall flex. I would be interested in seeing how 225/45/16 will do on these cars, especially with the R1R.

[quiet-k]

Originally Posted by G_Ride

I've tried 225/50/16 Rivals for three events locally. It's not that bad actually, except for mid corner push from sidewall flex. I would be interested in seeing how 225/45/16 will do on these cars, especially with the R1R.

Yet you're going 17's with ZII's now, correct? So not that bad = non-competitive? ;-)

[Rexpelagi]

Originally Posted by piknockout

I'm not sure what I'm doing next year, but I am tempted to run C Street only because I'm feeling lazy. I kind of despise the fact that Street has destroyed Stock and really don't want to support it. I guess we'll see though. I might just run the car as STX with just wheels/tires/alignment and then find something to co-drive nationally. Still a lot of time between now and the start of the season to figure it all out. And of course worst case, I still have the STi...at least for now.

Edit: Yes, I did join just to post this.

Street's closed pizza boy, find another way home.

Welcome to the fantastic world of torqueless fuel economy Josh, enjoy your stay.

:-p

[G_Ride]

Originally Posted by quiet-k

Yet you're going 17's with ZII's now, correct? So not that bad = non-competitive? ;-)

You guessed it, lol They did pretty well, but with 17's it would be better. I just picked up a 17x7 RPF1 w/ 225 Z2 set from a member on this forum to test out.