SCCA Solo C Street Discussion

[dvalue]

Originally Posted by doctor_driver

Push was worst during mid turn and exit. It might be a while til I can get the front camper maxed out (in medical school and am about to go in lock down modes prepping for boards on June 10th). But I'll try that out as soon as I can.

I was having similar issues until I got the car aligned.

Hop in with me and I'll hop in with you at the next event. We can try some different things.

[CCJ]

Originally Posted by TMF

I actually have the opposite issue with my FRS...understeer on entry (but mainly only when I come in too fast), and oversteer on corner exit, sometimes mid-turn. Granted that is with the TRD springs, koni's, and TRD sway bars, so my setup is very different.

I'd check:
1. Alignment, specifically getting as much negative camber in front by using the OEM crash bolts (you can search for the part number and find it easily). If you still don't get enough rotation, then you can start experimenting with some toe-out. I personally always run 0 toe, but a small bit of toe-out (I believe in the rear) can help quite a bit.
2. Hot tire pressure (not cold). The 225 RE71's seem to like low 30's psi in the front, high 20's PSI in the rear. Might be different for the Rival's, esp in the 245. You generally want to set the tire pressure to maximize grip and not change tire pressure up to alter handling. Using chalk on the sidewalls can help to see how far you are rolling onto the sidewalls. Once you get the fronts and rears to roll just to the edge of the sidewall, that should be the right tire pressure. However, since you're limited on adjustments in a stock car, tire pressures can be used to alter handling. Understeer on exit can be helped with higher rear tire pressures.
3. (this should almost be #1) Check the nut behind the wheel. Sometimes it is your driving "style" (or bad habits) that are causing the car to understeer. Asking for advice from a competent local instructor at an event is invaluable. Even the best drivers still take instructors sometimes...you can always learn something from another driver.
4. Consider getting adjustable struts. Adjustable struts give you another dial to adjust how the car is handling. Koni offers a direct replacement (not sure if they have them for the 2017's yet. It's possible they are the same as the 13-16 struts) and they are relatively (to other other aftermarket struts) inexpensive.
5. If the above don't help enough, you could consider swapping out the rear sway bar for a larger one. In general, autox'ers want a bigger front bar to help in quick transitions (at the expense of grip during sweepers), but if you're running a lot of courses with a lot of big sweepers, you might consider a bigger rear bar.

I'd focus on 1, 2, and 3 before dropping money on parts. You will become a better driver if you learn to hone your skills first before trying to learn on a modified car with more knobs to turn.

Others, please feel free to chime in as well!

Both bars? That might be your problem. I tried one event last year, same setup as you (springs, both bars, konis) and it was a mess. Codriver and I couldn't keep the back end behind us. Went back to stock rear bar and was much better. That or an even bigger front bar might do it.

[TMF]

Originally Posted by CCJ

Both bars? That might be your problem. I tried one event last year, same setup as you (springs, both bars, konis) and it was a mess. Codriver and I couldn't keep the back end behind us. Went back to stock rear bar and was much better. That or an even bigger front bar might do it.

I didn't find my setup problematic, but you definitely have to ease into the throttle on corner exit. I had my Koni's nearly full stiff up front and nearly full soft in the rear to help compensate.

My setup will be changing this year though, since I'm moving down to DS. Should be an interesting transition.

On a random side note, on my TRD spring/bar setup, I run a different set of wheels and tires for track days (17x9 rpf1's and 225 Federal 595 rsrr's). It becomes an entirely different car, and 100% planted. Using those wheels and tires is the only time I've ever felt like the FRS needed more power and more rotation!

[Biggins]

What car were you driving before the BRZ? What is your experience level? Was the car not turning at all or were the 245s just making a lot of noise you had to add more steering input?

Shocks will give you some adjustability, but unless this event was a test-n-tune event where you had 15+ runs in the car, I'd chalk it up to learning the car.

I'm still convinced that nearly any "street" setup on this car can be very competitive on 90% of all courses no matter what front bar you have, stock vs. aftermarket shocks, or tire size 215-245. I've driven on all of these combinations (ironically except one with all TRD bars yet), and have found the car so similar in all forms that I could make it work. I'm still on TRD springs with only the 19mm Perrin front bar on soft and Konis at 1/2 turn from stiff up front and 1/2 turn from soft out back and 225 Bridgestone/Kumho/Yokohama. I've run this set-up for three years with good results, but I've been told by everyone who's co-driven that mine was always more oversteer-y than other CS/DS versions they've tried. I plan to switch to the TRD bars and fresh 225 tires later this year.

[doctor_driver]

Originally Posted by Biggins

What car were you driving before the BRZ? What is your experience level? Was the car not turning at all or were the 245s just making a lot of noise you had to add more steering input?

Shocks will give you some adjustability, but unless this event was a test-n-tune event where you had 15+ runs in the car, I'd chalk it up to learning the car.

I'm still convinced that nearly any "street" setup on this car can be very competitive on 90% of all courses no matter what front bar you have, stock vs. aftermarket shocks, or tire size 215-245. I've driven on all of these combinations (ironically except one with all TRD bars yet), and have found the car so similar in all forms that I could make it work. I'm still on TRD springs with only the 19mm Perrin front bar on soft and Konis at 1/2 turn from stiff up front and 1/2 turn from soft out back and 225 Bridgestone/Kumho/Yokohama. I've run this set-up for three years with good results, but I've been told by everyone who's co-driven that mine was always more oversteer-y than other CS/DS versions they've tried. I plan to switch to the TRD bars and fresh 225 tires later this year.

I came from a full year of autocross in a 2014 Focus ST - prepped for GS (sans Koni yellows) ran probably 15 events in the ST and by the time I got on some RE-71s I was running top 3 in PAX. So wherever that puts my experience.

I had done 2 events already on the BRZ (about 30 runs in total, lots of fun runs were had) so I am definitely getting a good feeling for the car and how to finesse it with a lot of speed through the turns. And in the turns there was no noise, I had the wheel at full lock and still had crazy understeer.

But still lots of learning to be had. Gonna play around with tire pressure at an event tomorrow and see what I come up with. Gonna do double entry to get extra runs in as well and then report back.

[imnotsureaboutbrz]

I too am moving from a Fwd to rwd. Found these around..




While those might not help in a street class there's this...

[Anthonyc77]

Originally Posted by Twinz

I drove a well-prepped DS FR-S on our local test and tune track and paxed my TRD car with a single run. Not by much, but I did 6 runs in my car before the DS run. Me vs Me, I can't cover the DS pax with my CS twin.

It seems like they kept the 17's in C stock (with or without the TRD modifications). I guess its hard to say whether or not the new 17 revamped shocks/springs would be sufficient for this class or if it worthy to upgrade to the TRD stuff. Any thoughts?

[Twinz]

Originally Posted by Anthonyc77

It seems like they kept the 17's in C stock (with or without the TRD modifications). I guess its hard to say whether or not the new 17 revamped shocks/springs would be sufficient for this class or if it worthy to upgrade to the TRD stuff. Any thoughts?

My FRS with the TRD springs is faster than the DS FRS I drove without the TRD springs. It's just not fast enough to cover the pax. (At least not on our test and tune course)

If all 2017's are in CS, then a 2017 with TRD springs will *probably* be faster than a 2017 without the TRD springs.

I just got to drive a new 2017 on the track for the first time this past weekend. It was bone stock -down to the Prius tires- so I couldn't do a useful A/B comparison with my CS-prepped 2016. However I did notice the improved acceleration from the new gearing and I learned that the "Track" mode still intervenes. (I thought I read somewhere that it turned off the nannies and the diff assist) IMO Track mode is what previous generations' "sport" mode should have been. I was driving at the limit and it only intervened twice on the run I took....and the intervention was both subtle and brief. (I would not recommend using it when competing because it still slows you down a little)

[justinco]

Yep, the 2017 is noticeably quicker. The downside is 2nd gear goes to just 56mph stock, at least mine did.

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[1slowbrz]

Originally Posted by justinco

Yep, the 2017 is noticeably quicker. The downside is 2nd gear goes to just 56mph stock, at least mine did.

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If my research is accurate, this is a difference of about 2mph vs the previous year cars correct?

How much of an impact is it going to have, and does it outweigh the benefits of the new performance upgrades, purely from an autocross standpoint?

[strat61caster]

Originally Posted by 1slowbrz

If my research is accurate, this is a difference of about 2mph vs the previous year cars correct?

How much of an impact is it going to have, and does it outweigh the benefits of the new performance upgrades, purely from an autocross standpoint?

SCCA doesn't think it outweighs the benefits, that's why stock '17+ are placed in CS for the time being and the '13-'16 got bumped to DS.

My '13 redlines at ~58 mph stock so you are correct. The gearing will be course dependent, if there's a slalom where the car can cruise through at 56-60 mph a '17 will have to shift to keep up with a '13-'16 or risk losing noticeable time while a 1st gen can ride the rev limiter. Outside of this scenario I think the '17+ has the advantage, a slower course the gearing works in your favor, and a faster course will make the 3rd gear shift moot and the '17 has the advantage again. But there could be that tiny window where a '13-'16 has an edge to fight back against a car that will pull harder out of every corner.

Gearing wise I think that's about all you'd have to worry about, being short 1-2 mph at the end of a straight won't be worth much and can be obliterated in a blink of an eye by a mistake or a great choice/bit of bravery by either car. Odds are if one car has to shift, they both will, it will be rare to be caught in the middle.

Those minor differences are what makes non-spec racing interesting.

[justinco]

Originally Posted by 1slowbrz

If my research is accurate, this is a difference of about 2mph vs the previous year cars correct?

How much of an impact is it going to have, and does it outweigh the benefits of the new performance upgrades, purely from an autocross standpoint?

Like strat61 said, I think it will be course dependent.

At the College Station tour, there was 2 of us with 2017 cars in STX, and a few pre-2017 cars. We all shifted to 3rd in the same areas, and these were long and fast courses. I have been worried about 2nd gear since switching to this car, but after a number of events and these big/fast TX courses, I am not really concerned anymore.

Obviously for street classes things are going to be different, since you can't bump the rev limiter like in ST (my car now goes 61mph w/ 7850 limiter, my 2013 went 61mph with 7550 limiter).

[1slowbrz]

Originally Posted by justinco

Like strat61 said, I think it will be course dependent.

At the College Station tour, there was 2 of us with 2017 cars in STX, and a few pre-2017 cars. We all shifted to 3rd in the same areas, and these were long and fast courses. I have been worried about 2nd gear since switching to this car, but after a number of events and these big/fast TX courses, I am not really concerned anymore.

Obviously for street classes things are going to be different, since you can't bump the rev limiter like in ST (my car now goes 61mph w/ 7850 limiter, my 2013 went 61mph with 7550 limiter).

Are the newer cars capable of a higher rev limiter or was that just a choice you made between the two cars?


If that were the case, once I decided to jump to STX the 2017 would seem to have the advantage all around.

[justinco]

Originally Posted by 1slowbrz

Are the newer cars capable of a higher rev limiter or was that just a choice you made between the two cars?

If that were the case, once I decided to jump to STX the 2017 would seem to have the advantage all around.

They should theoretically be able to run higher limiters because of the improved valvetrain. I may bump mine up some more for national events just in case.

I do think the 2017 cars have a small advantage, but the driver will make the difference.