2012 BRZ/FR-S Stock Class Autocross Discussion

[Vanguard]

You probably can get away with 245 on the front in R888s. Id suspect any bigger than that and you will rub the strut.

[Sccabrz192]

Originally Posted by Racecomp Engineering

A bilstein would be nice so you could turn up some gas pressure. I think the BRZ would be the best subaru yet due to the low roll. Add a rear bar and some billies and of course hoosiers and i think you'll be in good shape. Camber bolts would be extremely helpful if that's workable but I guess the jury is still out on that one.

- Andrew

Have you started pursuing this with Bilstein yet? I would be very interested in a set if you provided something similar to the GTWORX WRX cup sport dampers for the BRZ.

[jdrxb9]

Originally Posted by jdrxb9

I just talked with my local Subaru and Toyota/Scion dealers today. Subaru says they don't think they'll be able to order parts until late next week. Toyota showed the bolts as available and ordered me a set - only catch is they have no idea when they might come in. If worse comes to worse, I figure I'll pull the bottom one, verify it is a normal M14-60 and get some high strength equivalents for the uppers. Not technically legal, but I'd replace them with the official parts before it mattered.

Well, I won't be sourcing any alternate bolts, genuine OEM are in hand:
(sorry for the cell phone pic)

Two day turnaround was surprisingly quick!

Also, the car is at the dealership , but no pics of that yet (probably tomorrow).

[Racecomp Engineering]

Originally Posted by Sccabrz192

Have you started pursuing this with Bilstein yet? I would be very interested in a set if you provided something similar to the GTWORX WRX cup sport dampers for the BRZ.

Yes, very much something we are planning on doing! The process is unfortunately pretty slow, so I can't even begin to estimate a time frame. Not this year at least but we are going to be pushing for it with Bilstein.

- Andrew

[Sccabrz192]

Originally Posted by Racecomp Engineering

Yes, very much something we are planning on doing! The process is unfortunately pretty slow, so I can't even begin to estimate a time frame. Not this year at least but we are going to be pushing for it with Bilstein.

- Andrew

That is good news! Keep us updated if/when this materializes

[MTeator]

Originally Posted by jdrxb9

Well, I won't be sourcing any alternate bolts, genuine OEM are in hand:
(sorry for the cell phone pic)

Two day turnaround was surprisingly quick!

Also, the car is at the dealership , but no pics of that yet (probably tomorrow).

With luck my bolts will be here tomorrow. Have wheels in hand.... waiting on the tires too, but those are tomorrow or Wed.

[simpleisbest]

Has anyone with the new bolts figured out the maximum range of camber adjustment?

Time to start thinking about possible alignment configurations...

[jdrxb9]

Originally Posted by simpleisbest

Has anyone with the new bolts figured out the maximum range of camber adjustment?

I've not seen any experiences with the OEM bolts posted. I'm scheduled for the alignment rack Friday and will post up my results afterward unless someone beats me to it.

[jdrxb9]

Well, had the BRZ on the alignment rack this morning and installed the OEM camber adjustment bolts.

Stock upper attachment bolt right, OEM adjustment bolt left:



And here are the results:


Overall, I'm pleasantly surprised with the front. The stock alignment was at least slightly negative already. The bolts gave about a whole degree of additional camber. FYI, a quick check with both stock bolts loosened and camber maxed out showed -0.4 deg., so nut much there.

In the back, despite the FSM saying:

Inspect the toe-in and camber. If the values are not within the specified ranges, adjust the installation bolt holding the rear suspension member to the vehicle body, or the bolt holding the upper control arm and rear suspension arm so that the values fall within the specified ranges.

No adjustment other than the cammed bolt at the inboard end of the toe control link was evident to myself or two techs. So, rather than just start loosening every bolt, I decided to leave it as is. We'll see how the balance feels and go from there.

I've only driven it a couple miles, so I can't yet give any impressions on the driving feel with these settings.

Cheers!

Edit: All measurements are without driver weight.

[MTeator]

Cool thanks. My bolts went on backorder :/

[simpleisbest]

Originally Posted by jdrxb9

Well, had the BRZ on the alignment rack this morning and installed the OEM camber adjustment bolts.

Stock upper attachment bolt right, OEM adjustment bolt left:



And here are the results:


Overall, I'm pleasantly surprised with the front. The stock alignment was at least slightly negative already. The bolts gave about a whole degree of additional camber. FYI, a quick check with both stock bolts loosened and camber maxed out showed -0.4 deg., so nut much there.

In the back, despite the FSM saying:

No adjustment other than the cammed bolt at the inboard end of the toe control link was evident to myself or two techs. So, rather than just start loosening every bolt, I decided to leave it as is. We'll see how the balance feels and go from there.

I've only driven it a couple miles, so I can't yet give any impressions on the driving feel with these settings.

Cheers!

Edit: All measurements are without driver weight.

Thank you soo much! Great info! I was expecting much less available neg camber. Still not great, but better than I expected.

[feldy]

Ran in Cstock today. This car is no where near being c-stock maybe d stock. 350zs doing 56s today on rcomps we were doing 61s. With rs3s even with rcomps I don't see us catching up.

[des]

Originally Posted by feldy

Ran in Cstock today. This car is no wear nearing being c-stock maybe d stock. 350zs doing 56s today on rcomps we were doing 61s. With rs3s Even with rcomps I don't see us catching up.

Very different experience here in SF today -- a second off the C-Stock winner on Hoosiers and on the same tenth as an MSR-package Miata on Dunlops, both driven by talented veterans.

The FRS -- even on the oversize Dunlops I chose -- slaloms as well as or better than any stock car I've ever driven, including RX-8s, S2000s and Miatas.

Wheel width will be a problem but otherwise car was right in there. Hope you keep plugging away.

[feldy]

How low on fuel did you run it? I was having other problems as well today. Going from a FWD car in autocross to this. I spun it drove it slow ect. But my co-driver is a quick driver and he was still 4-5 seconds slower then the 350z today on rcomps. I did take the auto thinking it would be nice not to miss shift in turnarounds ect. It was fighting going back into first when we wanted it to. Couldnt launch the car even with the nannies off. Had torque converter stall at 2k rpms. I spun it in the finish on my 2nd run. I had never spun in the finish before so I got a tad discourged. I was 2 seconds behind my co-driver who has a stx prepped RX8. And he was the one 4 seconds behind the z.

[Vanguard]

So it appears you have an automatic. I don't care what others might say in regards to the auto being really good compared to the manual...it will NEVER be as quick in an autocross setting.

I started autocross in an AT Saturn Sky Redline and thought I was quick. Once I finally drove a manual, I realized that you will be at least a second faster on a 40second course with a stick. Torque converters always asking you "are you sure you want to accelerate now?" coupled with being in the wrong gear will add up to being 5 seconds slower than a 350z on rcomps.

Des has it right...keep plugging away and you'll close that gap quick.

[carbonBLUE]

Originally Posted by Vanguard

So it appears you have an automatic. I don't care what others might say in regards to the auto being really good compared to the manual...it will NEVER be as quick in an autocross setting.

I started autocross in an AT Saturn Sky Redline and thought I was quick. Once I finally drove a manual, I realized that you will be at least a second faster on a 40second course with a stick. Torque converters always asking you "are you sure you want to accelerate now?" coupled with being in the wrong gear will add up to being 5 seconds slower than a 350z on rcomps.

Des has it right...keep plugging away and you'll close that gap quick.

actually in sport mode the ecu forces the car in the smallest gear possible when you are pressing it downshifting into corners as you brake, and throttle response is instant, the auto isnt something you would normally find in a 25k car period, its got the same sport tech as the ISF and LFA when it comes to sport mode

Originally Posted by feldy

Ran in Cstock today. This car is no where near being c-stock maybe d stock. 350zs doing 56s today on rcomps we were doing 61s. With rs3s even with rcomps I don't see us catching up.

you never know, try with better tires, maybe its not the tires for a technical course you need, i noticed in the frs needs a slightly bigger rear sway bar for low speed stuff

[Kido1986]

Subscribing to follow this thread. I am trying to get into a BRZ now and I plan on running a lot of local events in stock. We have multiple autocross groups and one doesn't allow rcomps in stock so I will be doing R-S3s (also so I can do roadcourse days as rcompstires would likely overheat quickly in 20 minute sessions at Daytona and Sebring).

As for the camber bolts (Im new to a lot of this), what do I call and ask for? Will Toyota know what I mean if I just call and ask for camber bolts? Or does someone have the part number I can call and ask for?

Thanks guys!

[des]

If you're still on stock tires, don't make any judgments. On real tires, the car isn't tail-happy, and you can get on the gas much earlier.

[des]

Originally Posted by feldy

How low on fuel did you run it? I was having other problems as well today. Going from a FWD car in autocross to this. I spun it drove it slow ect. But my co-driver is a quick driver and he was still 4-5 seconds slower then the 350z today on rcomps. I did take the auto thinking it would be nice not to miss shift in turnarounds ect. It was fighting going back into first when we wanted it to. Couldnt launch the car even with the nannies off. Had torque converter stall at 2k rpms. I spun it in the finish on my 2nd run. I had never spun in the finish before so I got a tad discourged. I was 2 seconds behind my co-driver who has a stx prepped RX8. And he was the one 4 seconds behind the z.

Nearly full tank -- I wasn't competing, just shaking down the car.

We're not even trying to go super fast at this point -- it's more about finding what works and adding speed from there.

No one is fast the first time out in a car. You have to know what you're working with before you make decisions -- if you drive FWD even remotely competitively you've been through this process before.

[jdrxb9]

Well, I ran the BRZ both yesterday and today at two different autocrosses. FYI, my previous autocross experience was fairly extensive, but ~10 years ago in a Neon. I ran fairly competitively locally, but just ok nationally. My only RWD experience is just scattered fun runs, so I've got a lot of learning and re-learning to do with the BRZ.

Sat was a very low key local event and I was really just starting to brush the rust off. Car felt good and I was pretty amazed with the grip from the AD08 'street' tires.

Today was a slightly bigger event at Cumberland MD airport. Again, I'm still just learning the car and my times were pretty far from competitive. My best was 50.7XX vs the top SS cars at 45.XXX. If you pax my time on a CS index and allow an additional .98 factor for the 'street' tires, I was ~3 sec. off.

Some random observations:

VSC off is really all the way off, even with the TPMS light on - witness my spin on the last run.

The car transitions really well, but I need to learn how to rotate it a bit more on entry to the longer turns.

As reported elsewhere, the rev limiter is very 'soft' - just kind of backs you off a bit from redline and then stays there - Subaru guy on site said it was pretty typical behavior for them.

My measured tire temps (cheapo non-contact gage) were pretty reasonable with the alignment above - max difference across any tire was about 10 deg F

The AD08's held up really well and actually took about 3 runs to get to what seemed like a normal operating temperature of ~130F

We started at about 1/4 tank and by the time my better half was done running, the low fuel light was on - no issues with fuel starvation under these conditions.

Owning a RWD car you don't have to worry about putting on 2 wheels is fun

Some clickable thumbnails:
quick snap of the car in paddock


my wheel tire combo - Traklites are functionally better, but I just couldn't put flat black wheels on a black car. These are Velox VX6R cast, ET42, claimed at 14.5 lb but weighed 15.4-15.6 on my scale.


the obligatory tire comparo shot - I went with AD08's thinking their reported driving characteristics would best match my driving style/experience. I went with 225's for just a bit more width and to not loose any max 2nd gear speed vs stock


Two videos:
my best run from Sunday
https://vimeo.com/43794066

my last run from Sunday - complete with spin
https://vimeo.com/43794067

[EMguy]

Originally Posted by jdrxb9

Some random observations:

VSC off is really all the way off, even with the TPMS light on - witness my spin on the last run.

As reported elsewhere, the rev limiter is very 'soft' - just kind of backs you off a bit from redline and then stays there - Subaru guy on site said it was pretty typical behavior for them.

We started at about 1/4 tank and by the time my better half was done running, the low fuel light was on - no issues with fuel starvation under these conditions.

Thanks for posting! The VSC/TPMS, rev limiter, and fuel level info is all reassuring.

[des]

I'll offer what I can, though what RWD experience I have has been in STR rather than stock, and I'm not exactly a tuning expert.

Only change to my FRS so far is the 235/45/17 Direzzas.

The good: the car was fast right out of the box. C-Stock winner in an RX8 on Hoosiers was at 43.2; my fastest run was 44.2. (I was doing fun runs but that would have paxed 40th or so of 170, better if you adjust for street tires).

The car is much less tail happy on the Dunlops than it was stock -- even on the super-slick lot we use here in the Bay Area. I'm going to slap a rear bar on as soon as possible. And I've never driven a stock car that felt better in slaloms. On Hoosiers it would be a revelation.

I'm not sure I chose the right tire size; it's taller, which may help on faster courses but probably hurt here. There were three places I would have shifted to first in an S2000, and I was surprised at how little grunt there actually was in the FRS. A shorter tire would have made a difference.

I don't think the 235 is too wide -- especially given the car's weight. But I will definitely look at a 40 series next set.

I'm not loving the brake feel: there's no bite at all, and they took a lot of pressure to hook up well.

The car takes a beautiful set into sweepers, but just as the car begins to slide the way you'd like it to, the car abruptly changes position, as if the tires were rolling over (they weren't). A buddy who runs a motorsports shop suggested a bump stop issue ...

Next up, then: camber bolts, alignment, a more aggressive rear pad, a 16mm rear bar and bump stop cups.