SCCA Solo C Street Discussion

[FRed-S]

Thanks for the information. I'm doing this more to learn right now than compete.

Sent from my XT1254 using Tapatalk

[jdp530]

Originally Posted by strat61caster

@jdp530

Tire pressures are tough, people don't like sharing those as it can make a large difference and suggestions have a lot of variables to consider so kind-hearted folks are wary of leading others astray.

No direct help but I like running the ZII SS at about 26 psi 'cold' (that is I set them in the morning when I arrive before the sun has the chance to skew temps and pressures). I haven't chalked the tires recently but I did not see anything alarming last time I did and have actually put nearly 100 miles of street driving on them when I was too lazy to bump them up.

If you have a local event that gets you more runs in (place I run at gets me ~6), maybe a test n' tune, start 'em up at where you did before and after the first two runs (for a baseline, the cold run doesn't really count imo) drop a couple psi between each run, that's how I got down to as low as I did, actually dropped 1 psi lower than where I felt the car was the best and the car definitely got worse. If you've got an air tank you can go the opposite way, a ~10 gallon should be enough to bump all tires 5 psi if memory serves correct.

Thanks for the suggestion. We usually get five runs but club does allow about twenty double entries if you get there early enough. So more run time would definitely help determine best psi after learning course.

A couple of guys running the re71-r's on other cars did suggest lowering the pressures but I didnt have time before making my last run. I usually try to avoid too much rollover to reduce wear on the shoulders but i may be giving up some traction.

I was definitely impressed with the tires tho, grip was great. Reminded me of the 'r' compound tires I have run on other cars in the past.

[Locust]

Originally Posted by FRed-S

Thanks for the information. I'm doing this more to learn right now than compete.

Sent from my XT1254 using Tapatalk

Tell them STX. Your tune likely makes a world of difference over a C-Street car because of that mid-range torque.

[TrqlessWonder]

Originally Posted by Locust

Tell them STX. Your tune likely makes a world of difference over a C-Street car because of that mid-range torque.

Email the organizers, and tell them what you have done to the car. Run the class they tell you. SCCA classing really isn't a haggling/bargaining thing. If you want it to be, NASA does it on modification points.

[Biggins]

Has anyone else run against some ND Miatas yet (not counting the one in Lincoln)?

I think we have a tough match-up on many smaller, local courses. They seem to have a bit more torque in all the right places. It was too cold to get a real comparison, but they're definitely on par with us and the RX-8s. I'm not writing a letter (yet), but I'm a little worried about them.

[edj]

Originally Posted by Biggins

Has anyone else run against some ND Miatas yet (not counting the one in Lincoln)?

i have. i'm not worried about them. it will take a couple of years of development before
one will be Nationally competitive. until then they will help keep the class counts up.
ymmv.

[renfield90]

Originally Posted by Biggins

Has anyone else run against some ND Miatas yet (not counting the one in Lincoln)?

I think we have a tough match-up on many smaller, local courses. They seem to have a bit more torque in all the right places. It was too cold to get a real comparison, but they're definitely on par with us and the RX-8s. I'm not writing a letter (yet), but I'm a little worried about them.

Yes and I've driven one. With full CS prep it will be a very serious threat. I only had one run in the car and kinda hooned it. But it's ridiculous at how forgiving the car is if you keep your foot in the throttle when you shouldn't. It's also ridiculous how many spots I could stay flat out where in my car I'd have to breathe. Maybe that's the horsepower difference but it seriously made me question my setup and choice of front bar.

Hell, with the right driver and course, bone stock + good tires is enough to turn it into a serious threat. Saturday in fun runs the local ND beat my competition time by 3 tenths after some coaching from me. It has Bridgestones and a disconnected rear sway.

[TMF]

Originally Posted by strat61caster

Noise is the enemy for what I'm looking for, if I could live with it I'd just run the XP10's all the time, maybe the first stop is a little weak but I've never explicitly noticed, they've been great for track and autocross, just tired of swapping so I don't embarrass any potential passengers with brakes that sound like a bus/shitty train.

Carbotech dust has been pretty easy to cope with, wipes away easily with some water without any effort even after sitting for weeks and getting wet (which is supposed to make brake dust impenetrable? idk), I've heard other compounds may be more difficult to remove if left on wheels/paint, and I've heard extremely mixed things on Hawk across the board in every category of performance (noise, dust, lifespan, ability to take punishment etc.)





Feel dumb for not coming up with that shortlist, going through threads now and those seem like great choices, my only problem is the price point. Those all end up around $300 for a set, do you have any experience with how long they last with street/autox usage?

Ideally at that price point I'd love for them to last 2 years of gentle street driving (>20k miles, no reason to risk anything on the street) and 2 seasons of monthly autocrosses (~100-150 runs at current rates), think I'm being overly optimistic? Again, no track time with these pads, just street and autox but autox is getting faster and faster as they try to attract speed junkies, I think the big local venue does try to throw in at least 1 70+ to <40 braking zone on their courses...

The alternative is stepping down to 'sporty street' compounds and sliding in around or less than $200, but that may be an expensive experiment if they don't hold up to a full day of autocross without fade or don't make it through a season+ (Pmu NS400, Winmax W1/2, maybe stoptech or TRD can cut it)

Many thanks for the quick responses! Hopefully others chime in, brake pads aren't a huge gain these days but an economical option means we can spend more time and money on the good stuff.

Please do share what route you end up going and your experience. I have similar goals to you (less noisy on the street), so I'll be curious to hear.

Originally Posted by jdp530

I ran a new set of 235/45/17 RE-71R's yesterday on my '14 BRZ at our local autocross. I had a set of 225/45/17 Dunlop SSII tires on the car most of the year. The Dunlops worked great on tracks for lapping days but they were lacking grip for autocrosses. I thought I would try a larger size so I bought the Bridgestones. Grip was fantastic and car felt neutral to slightly loose but I do the 'pedal dance' and prefer a 'loose' set up for autocrossing.

I know I gave up some gearing with the taller tires, and there is some weight increase as well, along with a higher center-of-gravity. I thought I might offset the disadvantages with a larger footprint and grippier tires.

I don't think I was even close to the limits of adhesion in the sweepers but I did notice the tires rolling over onto sidewalls. I started out with 32 psi in the rear and 35 in the front. I decided to bump up the air pressure about two pounds in the back and four in the front. But I didnt really notice any improvement in handling. I am now wondering if I was going backwards with tire pressures trying to improve the handling? I have always tried to reduce amount of rollover with higher pressures but now I am wondering if I am actually decreasing the amount of grip since a higher pressure reduces size of 'footprint'.

Great blog posts on tire pressures from our local alien:
Part 1: http://www.conecoach.com/2015/03/11/...he-sweet-spot/

Part 2: http://www.conecoach.com/2015/03/24/...ire-pressures/

For me, I use the chalk method and get the "hot" pressures to allow the tires to roll right to the top of the triangle. Then I tune the car balance with the Koni's, and my driving. In cooler temps, I've learned dropping 1-2 psi all around can make a huge difference.

I don't mind sharing my pressures/setup:
-225/45-17 RE-71R's, 33 front (hot), 30 rear (cold). Sometimes 34/31 on warmer days.
-TRD sways, springs
-OTS Koni's, half turn from full stiff front, half turn from full soft rear. Sometimes full soft in the rear if it's cooler or I'm trying to calm down the rear end or if I'm still getting a lot of oversteer on corner exit.
-this is on asphalt, but I used the same settings down at Lincoln.
-FWIW, I usually win my class locally and am better than top 20 overall out of ~140. Not to brag, but I got my first top 10 finish locally at the last event Can't wait for next season!

[vroom4]

Originally Posted by renfield90

Yes and I've driven one. With full CS prep it will be a very serious threat. I only had one run in the car and kinda hooned it. But it's ridiculous at how forgiving the car is if you keep your foot in the throttle when you shouldn't. It's also ridiculous how many spots I could stay flat out where in my car I'd have to breathe. Maybe that's the horsepower difference but it seriously made me question my setup and choice of front bar.

Hell, with the right driver and course, bone stock + good tires is enough to turn it into a serious threat. Saturday in fun runs the local ND beat my competition time by 3 tenths after some coaching from me. It has Bridgestones and a disconnected rear sway.

Those characteristics sound like every decent setup street class miata I've ever driven. They are just incredibly forgiving everywhere.

[Locust]

Originally Posted by TMF

Great blog posts on tire pressures from our local alien:
Part 1: http://www.conecoach.com/2015/03/11/...he-sweet-spot/

Part 2: http://www.conecoach.com/2015/03/24/...ire-pressures/

For me, I use the chalk method and get the "hot" pressures to allow the tires to roll right to the top of the triangle. Then I tune the car balance with the Koni's, and my driving. In cooler temps, I've learned dropping 1-2 psi all around can make a huge difference.

I don't mind sharing my pressures/setup:
-225/45-17 RE-71R's, 33 front (hot), 30 rear (cold). Sometimes 34/31 on warmer days.
-TRD sways, springs
-OTS Koni's, half turn from full stiff front, half turn from full soft rear. Sometimes full soft in the rear if it's cooler or I'm trying to calm down the rear end or if I'm still getting a lot of oversteer on corner exit.
-this is on asphalt, but I used the same settings down at Lincoln.
-FWIW, I usually win my class locally and am better than top 20 overall out of ~140. Not to brag, but I got my first top 10 finish locally at the last event Can't wait for next season!

Interesting links. Thanks for sharing. Personally I run 225/45ZR17 RE-71R's at 29 front/27 rear. OEM sways & TRD lowering springs.

One thing that those links don't mention that I've found is really helpful is tracking your tire pressure/temperature increase per wheel each run and then modifying your pressure to get the ideal contact patch at the point in the course where you most need it. If I'm on a course where the last two critical turns are hard rights then I'll drop my pressure lower on the front left tire before the run so that I'm closer to ideal pressure when I reach that point of the course.

I've actually never used chalk. Next year I may give it a try but the triangles have been sufficient enough and with the Bridgestones it's been fairly easy to tell where the new tire wear is vs. the old. I do track my temps with a pyrometer on outside, center, and inside tread though.

[SVLTE]

Looks like there will be a 235/40/17 RE71R available next year.

[TMF]

Originally Posted by SVLTE

Looks like there will be a 235/40/17 RE71R available next year.

Thanks for the info. At first I thought, darn, I just bought another set of 225's, should have gotten these!

However, I think these may be a too short...they are quite a bit smaller than the 225's, and the 225's are already geared fairly short. For reference:

[SeanRTR]

Dave proved at nationals you can up shift 3-4 times on course and still be fastest. I'll be trying the 235/40''s most likely.

[SVLTE]

Seems like it would only make a difference on courses where you're right on the edge of 3rd gear (which is probably the majority of locals), slower ones and ones where you're gonna hit 3rd regardless it could prove to be an option worth considering. I'm making the jump to STX next year anyway, so 245's for me. Anyone want a set of 30 run 225s?