2012 BRZ/FR-S Stock Class Autocross Discussion

[Getagrip]

This past Saturday I took my BRZ out for its first autocross. I consider myself a seasoned driver as I have been autocrossing since 1996. I’ve driven mostly Subaru AWD cars in stock or lightly modded ST classings.
The car is set up with 245/40-17 StarSpecs on 17x8 +48 Rota G-Force. I have not checked or messed with alignment yet.
The pavement does not get all that warm here so I started with about 32 PSI and ended up with 30 front and 29 rear.
The car did push some going into turns but was easy to rotate from mid-way through to the end.
I’d like to get a little more front bite without making the rear too twitchy.
I finished 3rd in PAX with 30 or so drivers.

Sorry for the quality on the left side, I found a smudge on the lense.
Here is my best run.

And my best run, although dirty.

Just realized this is a stock class thread, oh well the car is basically stock.

[AX_FRS]

The July Fastrack is out and it says CS for FRS and BRZ. I thought it interesting they didn't place it in any ST class though.

[Mitch]

Originally Posted by AX_FRS

The July Fastrack is out and it says CS for FRS and BRZ. I thought it interesting they didn't place it in any ST class though.

Last week I pre-registered for an autocross in CS. Glad I don't have to change! Curious on the lack of noise about ST. Where do most CS cars end up when they transition to ST_?

[Sccabrz192]

Rx-8 stx solstice/miatas str 350z/370z not classed

[FTD]

Originally Posted by dwx

I guess the stock wheels are +48 not 42. The section width of a 225/45/17 star spec is 8.9" on a 7.5" rim. A 245/40/17 A6 is 10" but measured on a 9" rim... My guess is on a +50 rim it isn't going to fit without a spacer, with more camber.

I tried running larger diameter tires on my old SM WRX to get some more out of 2nd gear and I hated it and it didn't keep me from having to shift into 3rd most of the time. I used to autox in milwaukee which has a large lot with fast courses. Now I'm in Atlanta where things are tighter and slower.

Phil, what didn't you like about the 245's?

From my testing on 17"x7" wheels the main difference between the 225/40's and 245/40's was the 'feel'. The 245's were more spongy and slower to react, but run times were on par. The MX-5 isn't gear challenged so sticking with the 225/40 was an easy choice (63.5mph in 2nd). On a gear challenged car such as this I would try to make the 245's work. Another upside for the 245's is they will last longer before cording/wearing out.

[AX_FRS]

It looks like the 350z is classed in STR (though it makes me wonder if only the roadsters run in that?)

I don't think a car can compete nationally in a ST class unless they are specifically classed in the rules, and I know there are people on this site that would like to do just that and have been pushing to get it classed. That's why I was confused as to why they chose a Stock class and not an ST class, aditionally.

Thinking about it though, most of the modifications that are allowed for ST class have yet to be released for the cars and so SCCA really has no way to judge (aside from pulling it out of the air) just how effective the car will be after modifications.

[xwd]

Originally Posted by FTD

Phil, what didn't you like about the 245's?

From my testing on 17"x7" wheels the main difference between the 225/40's and 245/40's was the 'feel'. The 245's were more spongy and slower to react, but run times were on par. The MX-5 isn't gear challenged so sticking with the 225/40 was an easy choice (63.5mph in 2nd). On a gear challenged car such as this I would try to make the 245's work. Another upside for the 245's is they will last longer before cording/wearing out.

I think there was some context missing in what I was saying. Another poster had talked about running 245/45. I believe 245/40 will be best tire for the BRZ in CS.

I tried 275/45 on the SM car and I didn't like it.

[jdrxb9]

Just another quick update from this past weekend. I decided to try a revised rear alignment AND the Cusco 20mm front sway bar.

Quick shout out to Circuit Motorsports who got me the bar on Friday with some quick service - very professional and reasonable shipping, considering.

I went from ~0.14 deg. toe-in to ~0.25 deg toe-in on each side in the rear. The bar went on with no issues. I felt the car drove more to my liking. I improved against the few folks that I've now run against more than once and PAX'ed well against a very small field, but that could just as easily be driving improvement. At this point, I've got no more changes planned and will just work on driving it better!

Video (sorry for the nasty audio) of my best run of the day here.

[EMguy]

A couple quick notes from this weekend in a BRZ:

1) A 245/40/17 A6 fits with room to spare on a +42 17x7. If Hoosier made a 255/40/17, I wouldnt be afraid to try that.

2) The same set of 245s (brand new, wrapped in storage totes) fits in the back seat area with room for a driver, passenger, and as much stuff as you can cram in the trunk.

3) The car is wonderfully balanced stock and tends toward the loose side of neutral, especially in quicker transitional elements. Sweepers are blissful. Slaloms could be improved, but are great for a stock car.

4) OEM crash bolts and a front bar will be magical. (I think)

[xwd]

Good to know on the storage! Did you fold the seats down to get them in there?

[feldy]

So this is a good read. While the zok and the msr are being moved. The mrs suspension and what not was also sold as a street package and those are not being moved. http://www.sccaforums.com/Forums/tab...s/Default.aspx

[ubersoph]

Originally Posted by feldy

So this is a good read. While the zok and the msr are being moved. The mrs suspension and what not was also sold as a street package and those are not being moved. http://www.sccaforums.com/Forums/tab...s/Default.aspx

I think you are referring to the Z0K package/Street edition solstice. Chances are good that it will get moved anyway if someone writes a letter.

[UncleFester]

Good thread.

I too experienced the loose rear-end this past weekend. I really had to watch throttling through and exiting turns. I got confident on my third run though and actually spun it.

My alignment was -2.2 front and -.8 rear. Zero toe all the way around.

Looks like I'll be trying .25 toe-in on the rear and perhaps a front bar next event.

I too have been looking for some of the wheels you guys have discussed. However it seems everything won't be available for months, which would be past the vast majority of the racing season. Perhaps I should hold off and get some Street Touring spec wheels over the winter as I don't see myself staying in stock class next year.

[simpleisbest]

Does anyone know if there is a hollow front sway available yet? If so, please post a link.
Thanks!